# Debugging my lantern pinion



## dewbane (Aug 15, 2022)

My second attempt at making a lantern pinion was almost a success. The part was guaranteed to be bad, because the parting tool grabbed, and snapped it off prematurely, but I continued anyway as a practice run. I moved the Y axis out 0.129" with my DRO to drill a 0.258" bolt circle with a #60 drill, before installing 0.040" music wire for the lantern doodads. I forgot what the lantern doodads are called. It's not bad for a second try, but I have the following problems:

The #60 holes seem to be slanted. Not shocking that such a tiny bit deflected, but what to do about it? I ran the mill in low gear at about 100 rpm, and fed very slowly with the fine feed knob.

I probably had a work holding problem. I ran a DTI over the top of the part while it was in the chuck on the rotary table, and it was about 0.030" high on one side. Not sure how I can solve that, but as I write this, it seems obvious that this is probably causing the slant I detected. The only surface I can grip is only 0.080" wide. Maybe I need to sacrifice concentricity, drill this on the lathe, and make some kind of arbor that I can grip more positively in the chuck. (Or swap to the collet chuck or the 4-jaw so I don't have to sacrifice concentricity.) It could just be a crappy scroll chuck. I don't even remember where I bought a rotary table with a weird 4-jaw scroll chuck. I took the chuck apart and went through it, and it's as good as it can be, but it's not a good chuck. It's an okay chuck at best.

The #43 hole in the center is off-center. Made two of these, and had that problem both times. My 0 setting has to be damn close, because my pin holes are coming out the same distance from the edge all the way around. I don't see any way I could drill a perfect circle relative to the part, and wind up with the center hole dramatically far off twice in a row. Bit deflecting again? A #43 drill is not very stiff.

Anyway, here's the picture. I think it's kind of cool how you can see the witness marks of the parting tool chattering and catching. That little high spot there is what snapped the part right off before I had hit the target diameter:


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## BGHansen (Aug 15, 2022)

Success!  I bet you learned a lot!  Tom Griffin (www.tomstechniques.com) has some nice info on it regarding speeds for drilling, milling and lathe work.  The formula for RPM's is:

RPM = (Material factor) / (cutter/work diameter)

I don't recall the material factor for brass, but for steel Tom recommends 400 (brass is probably 800 - 1000).  If drilling a 1/2" hole in steel, the math works out to:

RPM = 400 / (0.5) = 800

For a #60 drill bit, you'll want to crank up the speed to the max.  It'll still be slower than the formula would recommend unless you are using a router or really high-speed spindle.

One thing you learned is that there's a work-holding challenge.  I'd chuck up the brass in the lathe and face it.  Center drill and drill the #43 axle hole.  Then give yourself at least 3/4" length to chuck on the mill.  I'd use a spotting drill to start the holes, just a peck.  You could use a center drill also, the lead end is usually 120 deg.; works well as a spotting drill.  Then drill the #60's.  The spotting holes with give you a countersink at the holes.  Pull the brass from the mill after the holes are drilled and face the surface again to remove the countersinks.  Then part on the lathe.  

It'll be tough to keep those tiny #60's on center when starting to drill the holes.  The spotting/center drill I mentioned above might leave you a "nib" in the bottom center of the hole which would take the #60 off center.  You may also try spotting with the #60 with just 0.030" sticking out of the chuck.  As you noted, the drills are pretty flexible, but a lot of that flex comes from the amount protruding from the chuck.  Another potential issue is the runout in your drill chuck, a #60 at 0.040" is really tiny!  

From your description you've got a good handle on what's going on!  It may take a few tries but you'll get there.  I can't tell you how many times I'm made 5 of something to get 1. . .

Bruce


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## dewbane (Aug 15, 2022)

I was afraid running the spindle anywhere close to the theoretical ideal speed would increase the tendency of the drill to whip. I have to have pretty big stick out, because these holes are relatively deep. I didn't spot the holes out of laziness, but it would really be worth it. I was already planning to leave extra meat on the top flange, so I can machine off the stubs from the wires. This would plow over any spotting marks too.

The big thing is I've been trying to use scroll chucks, and you're right, I just need to leave more meat on the part while I'm doing the delicate stuff, and finish it up and part it off after that's done. I need to move from the lathe to the rotary table back to the lathe, and I should be using 4-jaw chucks or some collet system.

I have a plan for all of this, and it's reasonable to assume I'm going to make a good part one of these times. I'm not that far away.

Then I just have to make two more just like it. Whee! The last one will be a lot better than the first one, so I will make a fourth, and so it will go.

And then I move on to the next hardest part to make, which is probably the cutters for the wheels.

It's kind of a cool feeling. I'm like Mark Watney. Work the problem. Solve enough problems, you get to have a clock.

But today, I get to go shopping for collet systems. No use continuing with a setup that just isn't adequate.


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## Mitch Alsup (Aug 15, 2022)

I have seen this problem when I needed a hole through 0.5" thick 6061T6, where one side would be off by 0.002" or more. No alteration of drilling speed or drilling pressure helped. Nor did traming the mill under 0.000,1" nod and pitch. Drills drill neither straight nor round holes.


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## tq60 (Aug 15, 2022)

You can fit the bit deep in the chuck with only 1/16 or so sticking out to start the holes.

Get work close to chuck so it is not extended far.

Place so you start the hole, shift drill in chuck for more stickout and repeat.

This takes longer but drill bit is so short it cannot wonder as easily.

Speed varies but pressure should be minimal to not stress the bit.

Peck to keep chips out and oil well.

If you needed to do many you could make a drill bushing from steel that just fits on the part and is thick enough to insure drill bit stays straight. 

Sent from my SM-G781V using Tapatalk


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## dewbane (Aug 16, 2022)

I spent hours weighing the pros and cons of ER32 vs. ER40, and I talked myself out of buying anything at all. It's just too big of an investment to make right now. I'm stuck with all these scroll chucks, and I'm going to try using an indicator to help get better concentricity out of them. It isn't ideal, but neither is dropping a bunch of money on a new setup. This is not a good time for a big investment.

One thing I can't get beyond in my thinking is leaving this stub on the bottom. Yes, I need something to grip, but brass is like $600 a pound right now. The only way to not waste the material is to leave a big enough stub that it could be a new part. The problem there is vertical clearance. With a Jacobs chuck in the spindle and a three-jaw chuck on a base plate on a rotary table, I don't have much vertical clearance. I'm bumping up against the top of the column's travel as it is.

Ironically, switching to collets would address that problem too. Maybe if I make it through December without going broke. Taxes to pay, car insurance, settling up the electric bill for the year. Lots of big ticket expenses coming up.

Adulting sucks.


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## mattthemuppet2 (Aug 16, 2022)

if you want to hold a small round part in a chuck without leaving a stub, make a temporary pot chuck. Grab a piece of alu round a bit bigger than the part you want to hold, stick the scrap in your chuck and drill/ bore to a bit under the diameter of the part and a little bit less deep. Drill a smaller hole through. Take it out and cut it length ways with a hacksaw, then put it back in the chuck. Stick a bit of material in the hacksaw slot so it doesn't close up completely, then finish the bore to the size of your part (maybe a bit over). Loosen the chuck enough to remove the material in the slot, stick the part in and tighten chuck.

It's a fair bit of work for just one part, but you can use it again for the same size of part or bigger (by boring it out). You can also do the same with alu soft jaws on your mill vise - #JimDawson is a pro at that.


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## homebrewed (Aug 16, 2022)

dewbane said:


> I probably had a work holding problem. I ran a DTI over the top of the part while it was in the chuck on the rotary table, and it was about 0.030" high on one side.


You probably had the part installed in the chuck jaws so its backside wasn't in contact with anything flat (like the chuck face).  In this situation it can be difficult to properly install the work . The way to get around that problem is to use a chuck spider, a thing that fits between the jaws.  It basically translates the flat surface up to the base of your part.

If you have a 3D printer you can print one.  I've used a small piece of (flat) scrap that was the right thickiness and used it to do much the same thing.  If you're doing that on a lathe chuck be sure to remove the alignment piece before turning your lathe on!

Regarding your drill bit drift problem, the best solution would be to use a new, high-quality tungsten carbide drill bit; but lacking a high-speed spindle your odds of breaking it on a manual machine are pretty high.  The TIR of your drill chuck could be a limiting factor, too.  The next-best would be to use a new, high-quality HSS or cobalt drill and crank your spindle up to its maximum RPMs.  A good drill will be very straight so you shouldn't have any kind of drill whipping problem.  Especially if you start with the drill protruding just a little ways out of the drill chuck.


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## dewbane (Aug 16, 2022)

A carbide bit would definitely either make a straight hole or explode. I didn't even think about carbide drills existing at sizes this small, but they do. It's not the worst idea, and carbide bits this size have larger shanks that would be better to grip in a chuck. Or probably large enough to grip in an ER32 collet for that matter. That's not a crazy idea, although the chances of the bit exploding are very high.

The work was just floating in the air, up above an empty chasm. I tried throwing a parallel under it, but I didn't have a parallel remotely small enough. Chuck spider. I need to think about that. Or a pot chuck could work. More to look at there.

Or I could just throw away a few inches of brass. I'm only making three of these, or whatever number I end up having to make to get three usable ones.

Good food for thought.


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## mattthemuppet2 (Aug 16, 2022)

The pot chuck or soft jaw approach is also really handy if you need to turn the part around for another op, like facing and chamfering.


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## homebrewed (Aug 17, 2022)

dewbane said:


> A carbide bit would definitely either make a straight hole or explode. I didn't even think about carbide drills existing at sizes this small, but they do. It's not the worst idea, and carbide bits this size have larger shanks that would be better to grip in a chuck. Or probably large enough to grip in an ER32 collet for that matter. That's not a crazy idea, although the chances of the bit exploding are very high.
> 
> The work was just floating in the air, up above an empty chasm. I tried throwing a parallel under it, but I didn't have a parallel remotely small enough. Chuck spider. I need to think about that. Or a pot chuck could work. More to look at there.
> 
> ...


I too dislike wasting material when I don't have to, but sometimes you don't have much of a choice.

I've found that I sometimes can use smaller pieces by gripping them from the inside with an expanding mandrel.  I have a mandrel set, and also have made a few.  They're not too hard to make if you've got a lathe.


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## ub27Rocks (Aug 17, 2022)

A couple of things to try:
- Use a stub drill, shorter and less flex, preferably 135dg tip, these don't wander as much
- Use a 90dg spotting drill to make a pip before drilling, centre drills don't work for spotting, esp. tiny holes
- Make a spade drill, possibly from the spring wire. I don't have a referecne handy but these are typical clock and watch makers tools.

gerrit


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## homebrewed (Aug 17, 2022)

ub27Rocks said:


> A couple of things to try:
> - Use a stub drill, shorter and less flex, preferably 135dg tip, these don't wander as much
> - Use a 90dg spotting drill to make a pip before drilling, centre drills don't work for spotting, esp. tiny holes
> - Make a spade drill, possibly from the spring wire. I don't have a referecne handy but these are typical clock and watch makers tools.
> ...


I had thought about suggesting a spade drill but sort of dropped that idea after seeing that the holes are just .040" in diameter.  Not easy to make or harden.


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## ub27Rocks (Aug 18, 2022)

A diamond stone or equivalent should take care of sharpening the wire, and a small blow torch and some veg oil takes care of hardening. Although it is likely the wire is hard enough already, he is 'only' cutting in brass.
You could hold the wire/drill in a pin vise in a chuck to save the trouble of more elaborate bushings, etc. Peck drilling, lots of retrations to clear chips. But basically a free drill as short as you want it to be.

gerrit


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## homebrewed (Aug 18, 2022)

An unevenly-sharpened dril, no matter what its style, won't drill straight.  Hand-sharpening is pretty unlikely to produce a drill that will work well, especially considering that the spade portion will be half the width of the wire -- .020".  Sounds pretty challenging to me but I'd love to be proved wrong!


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## ub27Rocks (Aug 19, 2022)

If someone is working with sizes that small they would generally have an eye loupe to see the work. A few light strokes, look at result, a few more and you are done. Not an uncommon task for clock and watch makers, even in the 1700 and 1800's and earlier.

George Daniels in Watchmaking pg 34 describes sharpening as a light stroke on one side, a light stroke on the other side and then check. This is e.g. for drills from 0.1mm to 2mm. Use a pin vise to hold the drill. Spade/flat drills don't grab the matersial, a big problem with brass.
As for cutting speeds, 500 rpm in brass is a starting point, 300 rpm in steel. High rpm translates to heat, the skill comes from applying just the right amount of pressure to drill.

An example of purchased one: https://perrinwatchparts.com/collec...ories/products/mascot-flat-pivot-drills-28364, starting at 0.008"

An example of making one: 




Gerrit


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## dewbane (Aug 19, 2022)

ub27Rocks said:


> An example of making one:


Clickspring is my inspiration, and hero. Looking at his setup is what inspired me to venture down this road. He has some equipment I lack, but nothing outrageously exotic. I tracked down a copy of that John Wilding book, and I have the plans for that clock. I'm starting with something much, much less ambitious though. "Building an American Clock Movement" by Conover. He cuts a lot of corners in his design, so you can just build something and enjoy a success. It uses commercial pallets, and I bought a commercial escape wheel to mate to the pallets, so I have a fighting chance that my escapement will actually work. (I've built three laser-cut wooden kit clocks, and the escapements never work well.)

If I want to go all Clickspring and make every single part myself (I actually don't, and I'm totally fine with using commercial screws and pins) I can always use the commercial escape wheel as a template to clone with my own part. I may do that much. Using the commercial one seems too much like cheating, but anyway, the point of the design is to keep it relatively simple. I think it will be a good first project. I'm encouraged by what I've been able to produce so far. It ain't there yet, but it's not too far off.

Anyway, your idea of sharpening a bit of the music wire is totally sound. I'm already doing that to make reamers elsewhere, and one of those would probably cut its own hole. I don't feel like it's overly difficult to get them sharpened evenly.

Also, after mulling it over for a few days, I did pull the trigger on an ER32 collet setup across the board, and an additional ER16 setup for the mill. I think I'm going to be glad I did. No, this isn't a good time for a major investment, but I slept on it for a few nights.


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## ub27Rocks (Aug 19, 2022)

The main thing is to start building something. Looks like a decent clock.
 I am presently building a Synchronome electric clock. Someone gave me the cast iron casting of the frame. Everything else is from scratch including the screws. Making tools as I go along to provide a good mix of challenges.

John Wilding's books are great, he also doesn't use esoteric machines and tools. And illustrates making tools as needed. Pricey books but worth it.

gerrit


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## dewbane (Aug 19, 2022)

ub27Rocks said:


> The main thing is to start building something. Looks like a decent clock.
> I am presently building a Synchronome electric clock. Someone gave me the cast iron casting of the frame. Everything else is from scratch including the screws. Making tools as I go along to provide a good mix of challenges.
> 
> John Wilding's books are great, he also doesn't use esoteric machines and tools. And illustrates making tools as needed. Pricey books but worth it.
> ...


I'm debating whether to go to the extreme of making B&S style cutters with the correct profile, or just using fly cutters. If I use fly cutters, I need to make a straight holder. I'm probably going that route. I also need to make a new gear cutting arbor. What I came up with last time (learning to use a dividing head making test gears) was a split and threaded rod with a machined section to hold the blank that slipped tightly into a threaded section to clamp everything together. I think the concept is sound, but I need to do a more accurate job of making the next one, and I need to size it to the wheels this project calls for.

I need to make one of those depthing gauges, and I need to finish my bluing tray. I'm sure this is just the tip of the iceberg making tools for this project.

Come to think of it, I have a very crappy wood-cutting bandsaw that's basically worthless. I can't keep a blade on it for two minutes. It's junk. But if I put my thinking cap on, I bet it could be the foundation of a filing machine.


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## ub27Rocks (Aug 19, 2022)

I Ibuilt a Eureka relieving device to make cutters for T2.5 timing pulleys. 12 tooth cutters. A good inbetween that and fly cutters might be Deans Photographica description of an earlier method: http://www.deansphotographica.com/machining/projects/multipoint/multipoint.html . He credits this article by David Creed who credits others  https://vdocuments.net/cutter-making-david-creed.html?page=11 Clickspring eventuallly also did a vid but I didn't see any credits from him (one of the reasons I stopped watching his stuff)

If you want even more, Malcolm Wild's book is excellent.

Sorry for adding to the potential decision paralysis, there are so many ways to make gears 
Gerrit


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## dewbane (Aug 20, 2022)

ub27Rocks said:


> If you want even more, Malcolm Wild's book is excellent.
> 
> Sorry for adding to the potential decision paralysis, there are so many ways to make gears


I find it oddly fun that there are so many ways to get to the same result. If I end up making parts that work, nobody can fault me for how I arrived there. Thanks for reminding me that I have Wild's book. I haven't looked through there in a very long time.

It also just flashed into my head that I'm not going to be able to drill the #43 center hole on the lathe unless I invest in some type of bit with a huge shank. I have a big Jacobs chuck on my tailstock. I sized it to hold 9/16" shanks for human sized projects. I should flip through the plans and think about any other times I might want to drill an accurate, wire gauge sized hole in something on the lathe, and I should probably just acquire some of those big shank drills in these sizes. Cheaper than the alternative solutions. New tapers, new chucks, new collet holders, new drills. I think the drills have it.

I also kind of like the challenge of using a benchtop engine lathe to do this work. It's on the big side and the sloppy side for trying to do work like this, but I've been making improvements to the lathe over the years, and I feel like I'm getting the most that can be gotten out of it. I think it's going to be fine. I do have enough experience building clocks that run to know that clocks don't have to be perfect to the nearest tenth to run. I think the Wild book is where I saw clock parts that had been hand-filed to an approximation of the right tooth profile, sold commercially, and having run for years. Amazing what you could do with Victorian era sweat labor.

Speaking of which, I'm going to take a moment to appreciate that I don't have to make chronometer chains to avoid starving to death in the street. Fusee chains. I can't find the video, but Tony Robinson tried his hand at the task in one of his Worst Jobs in History shows. Or I guess programmes since he's British. Yeah, okay, enough stalling, I must surrender the keyboard, turn out the lights, and go earn my daily bread at my dismal and unrewarding job.


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## ub27Rocks (Aug 20, 2022)

I use pin vises to hold small drills in larger chucks. Outside of 8mm WW collets none of the usual ER11/16 etc. ones will do it well enough. I plan to make more WW collets this winter, finally have a working tol post grinder. A recent article in Model Enigneer's Workshop (Mar 2022) showed a workable method of producing them.
I have a Taig lathe, on which I bored out the spindle to an MT0 taper, to fit the Sherline WW adapter. You could accomplish similar using the mandrel described in the MEW article in a collet chuck on your lathe.

Gerrit


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## dewbane (Sep 5, 2022)

Update: I got ER32 for the lathe headstock, the mill, the rotary table, and the dividing head. I got #60 carbide bits with 1/8" shanks that would fit in an ER32 collet.




The part ended up being a fail. Whoops. I was stupid enough to try to clean up the music wire stubs on the lathe, with a parting tool. Dumb, dumb, dumb, dumb, dumb! It was actually going quite well, until it exploded. Oh well, it was probably going to be too far off to be useful anyway. It was a practice run. A practice run while I waited for Morgan Fairchild to get out of the swimming pool _en deshabillé_ and come cook me a bacon egg and cheese sandwich. Yeah, that's the ticket! Morgan Fairchild! (If you don't get this joke, just shut up. I'm not old. I'm chronologically enhanced!)




Problem 1: I'm getting crappy run-out on the lathe with my horrible ER32 setup that involves an MT3 fixture, a MT3 to MT4 adapter, and the headstock of a Chinese lathe. The TIR is 0.003" and the only reason I persisted with this was because I was getting 0.016" TIR with my 5C collet chuck. Crap!

At intervals, the run-out gets extremely bad, and I have to knock this out and slam it back in to return to the 0.003" that is my optimal achievement. Pretty much if a butterfly breaks wind anywhere within 15 square miles of this setup, it goes all wonky, and needs the knock and slam treatment in order to become somewhat less wonky.

I guess I never noticed before, because none of the stuff I ever made was that critical. Putting ER32 on the lathe headstock could be accomplished with either an 80mm or 100mm ER32 fixture available commercially, but these all advertise 0.016" TIR, which is insanely bad.




The best alternative is to learn how to thread and cut very accurate tapers, so I can make my own 1-3/4"-8 to ER32 fixture out of a big slug of steel. For now, that project is beyond my skills. I tried a commercial MT4 ER32 that was a complete piece of Chinese garbage. The nut wouldn't even thread on without binding. I could fix it if I knew how to thread, but wait, I don't understand gibberish (apologies to the member whose photo I just ripped off).




I think that says, "If you put a chicken sandwich in a hurricane, your typhoid will forty twenty." It might also say, "If you hello girl say to goat, then rotted spline."

I ordered an ISCAR MT4 ER32 collet fixture from MSC that will be here Tuesday. That set me back. Ouch. In the meantime, I thought I would try making a part anyway. The only dimension that's actually critical is getting the bolt circle right, and centering it on the center bore.




Problem 2: I broke all my carbide drill bits. Crap! I was pretty stoked by this and thought I was going to make it through, but everything went sideways after about the fourth hole. That was when I remembered to lock the rotary table. When I left the rotary table unlocked, the bits didn't break. After locking the rotary table, the bits tended to break when hitting the lower flange. Even though I was feeding slowly with the quill knob on my benchtop mill. I blew through $21 in bits, and finally had to swap back to the mini Jacobs chuck and the conventional HSS #60 drill. This probably means all the holes I drilled with an unlocked table are wonky anyway.

Problem 3: I drilled down too far in several places. I kept losing track of things after all the tool swaps. This is easily fixable next time with more care.

Problem 4: After getting all 8 pins tapped in, I went to clean up the stub ends, and WHAMMO! I busted the part.

Crap.

On the bright side, I think the center hole is centered this time. Maybe.




So now I'm off to McMaster-Carr to buy another bunch of #60 carbide drills. I will try rotating the quill feed much more slowly.


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## WobblyHand (Sep 5, 2022)

Not sure where you are buying your supplies, but I bought a 100mm ER-32 chuck from Little Machine Shop, and Orange A collets from Amazon and have less than 0.0005" TIR on my mini-lathe.  

Are you sure that your spindle is running true?  Use a DTI on the spindle taper and measure it.  Are the surfaces clean and chip free?  All of this matters.  On my Grizzly G0752Z I turned my own back plate for an ER-40 set true chuck.  I have a threaded spindle so I had to single point the back plate.  Very low runout, under 0.0002".  First time I have ever attempted something like that.

One thing I know for sure is the smaller the diameter the more critical run out is.  I have far more trouble machining small stuff than bigger items.


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## homebrewed (Sep 5, 2022)

Based on how your drill bits are breaking, it's possible that your mill is out of tram, so they're shifting sideways as they go down.  It wouldn't take much of that to break #60 carbide bits.

An out-of-tram condition can be caused by two separate issues.  The column can be misaligned with respect to the table; or the head can be misaligned relative to the column.  If your head is misaligned and you adjust-out the observed tram by rotating the column, you still will get sideways shift of cutters and drills when you raise and lower the head.  This could be on either axis, or could even be a combination of both.

One way to test for this situation is to install a test rod in your collet or drill chuck and use a dial indicator against the side of the rod as you raise/lower the head.  You will want to do this on both axes.  Mount the DI base on the side of the column and perform RDM to compensate for a test rod that isn't perfectly straight.  Using RDM in this fashion keeps column-to-table tram problems from clouding the measurements.

If you do find head-to-column misalignment, how you fix it depends on what kind of mill you've got.  Adjusting the Sieg mini mills requires a combination of shims (for the Y axis) and for the X axis, rotation of the head by loosening the mounting bolts.  For the latter case, it may be necessary to scrape some paint off the spindle housing block so the head can be rotated.  Here is a more detailed description of the procedure.


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## dewbane (Sep 5, 2022)

homebrewed said:


> If you do find head-to-column misalignment, how you fix it depends on what kind of mill you've got.  Adjusting the Sieg mini mills requires a combination of shims (for the Y axis) and for the X axis, rotation of the head by loosening the mounting bolts.  For the latter case, it may be necessary to scrape some paint off the spindle housing block so the head can be rotated.  Here is a more detailed description of the procedure.


I confess, I did NOT check the tram. I took for granted that it wouldn't have moved since I dialed it in last time. The g0704 is a dovetail column mill, and adjusting the Y axis tram is a beeeatch.

Measure error
Unscrew four hex head cap screws
Install shim(s)
Tighten four hex head cap screws
The problem is that last quarter turn. You can do one, ten, twenty, fifty turns and everything looks perfect, but when you finally get the screw fully tight, the needle moves. A lot. It's necessary to fully tighten all four screws just to see what you got.

I ended up with 0.0015" shims, and I had it dead nuts.

The X axis is evil too.

Measure error
Loosen three clamping bolts
Loosen pivot bolt
Adjust
Tighten three clamping bolts
Here too, the needle moves a lot in that last quarter turn. In both cases, you kind of just have to guess. It says I need 0.003" but when I get this tight it will move 0.007" so I should adjust -0.004. -0.004 + 0.007 = 0.003"

All of that whining notwithstanding, you're absolutely on target that I need to strap on my big boy panties and check the tram again. The other problem with my mill is that I put it up on leveling feet that aren't bolted to the floor, and if I sneeze hard, it's depressingly easy to move the entire mill. I checked the level just the other day, and had it dead nuts, but I shifted the mill imperceptibly just cranking some part. This is probably my cosmic reminder that I need to drill some holes in the feet, and Tapcon those suckers to the floor.


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## dewbane (Sep 5, 2022)

WobblyHand said:


> Not sure where you are buying your supplies, but I bought a 100mm ER-32 chuck from Little Machine Shop, and Orange A collets from Amazon and have less than 0.0005" TIR on my mini-lathe.
> 
> One thing I know for sure is the smaller the diameter the more critical run out is.  I have far more trouble machining small stuff than bigger items.


Ain't that the truth! I've done plenty of useful real world work with my lathe and mill, like fabricating a new oil drain plug, and some centering sleeves for the wheels on an old pickup truck. I've made lots of parts for my lathe and mill to improve them. Now that I'm trying to make an itty bitty part, errors I never would have noticed are punching me right in the nose, and I have developed an appreciation for why the guys who wrote books on building these things were all using a Sherline, Taig, or Unimat. I am determined to push forward anyway.

LMS is a good suggestion as a source for those chucks. At least according to their catalog anyway. They list less run-out than everybody else. Still, if I go that route, I have to buy a back-plate, and fit it. When I did that for my 5C collet chuck, I don't think I did so well, and that's probably why the 5C has heinous levels of run-out. I'm surprised my DTI hasn't filed a restraining order against me, considering what I did to that poor, innocent needle when I checked this. It's posit-nega-pos-ne-po-n-p-n-p-n/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/ive.

Water under the bridge at this point, I guess. I forgot about LMS in my search, wasn't happy with any of the chucks I could source, so I paid real machine shop prices for the MT4 ER32 made in Israel. For an MT4 ER32 the price points are pretty much $30 and $200, with nothing in the middle whatsoever. My $30 one was junk. I got an MT3 for like $60 that seems well made, but the adapter seems to be ruining the show. I fooled around rotating the adapter different ways, and the best run-out I got out of it was awful. Luckily, my tailstock is MT3 so I don't feel like the part was a waste. I will have ER32 in the lathe headstock, lathe tailstock, mill column, rotary table, dividing head, and collet blocks. One collet to rule them all.

I got Accusize collets. They seem to be adequate. I'm not going to spring for a set of Rego-Fix or Techniks collets until I've ruled everything else out.

Or ever, because I just checked my balance, and saw that I've already spent double my budget. More than ever, now is the time to hunker down and make do.


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## dewbane (Sep 6, 2022)

I don't have access to the pictures from this computer, but I drilled holes in the leveling feet and installed Tapcons.

The first chapter of "Events from My Amazing Life" happened when the Tapcons ripped out of the concrete. Crap. Off to the store to buy bigger Tapcons. The next chapter happened when one of the Tapcons snapped off, with about 1/4" sticking proud of the concrete. Awesome.

I tried to drive the broken Tapcon deeper with a punch, and I mangled the punch. Dang!

So I gotta hand it to my Chief mini air die grinder and Chief carbide burrs. I am not generally a fan of Harbor Freight, and that is one of the only powered tools I ever bought there that I genuinely like. That thing ate steel that was harder than a punch, and it digested a little concrete too. The cutter still looks fine. Wow!

I mean, I've shattered at least a dozen carbide end mills and a couple dozen carbide drill bits. I was using the analogy earlier that carbide tools are like ceramic tile. If you put tile on a rigid cement backer, it's pretty much going to survive Armageddon, but if you put tile on drywall, the way my shower was originally built, sooner or later the tile is going to crack. Carbide requires totally rigid setups. (Which is why it's weird that the drill bits broke AFTER I remembered to lock the rotary table.) There is nothing rigid about using a burr in a die grinder, so I wonder how this tool was able to chew through so much without breaking. It's genuinely amazing.

So anyway, now I level the mill again, and it should stay level this time. I don't think it actually matters all that much. You can't level a mill on a ship, and that doesn't stop navy machinists. Still, it will be less dangerous to use now that it can no longer shift around randomly, just from cranking the handles, or torquing a collet with a wrench. It really isn't heavy enough to be stable just relying on its own weight to hold it to the floor. (The lathe is fine though. I built these leveling outrigger feet out of ridiculously sturdy C-channel, and it has a wide base and almost a ton weighing down on the feet with all my chucks and centers and tool holders and other hefty stuff inside a ridiculously strong cabinet.)

Okay. Now to get leveling, and then check the tram. I'm going to bet $5.00 right now that the tram is actually fine. It may have been two years, but it hasn't been that long in operating hours since I last went through and dialed this thing in with a ridiculous degree of obsessiveness.


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## homebrewed (Sep 6, 2022)

dewbane said:


> I'm going to bet $5.00 right now that the tram is actually fine.


Maybe so, but if the bit is shifting due to the kind of tram problem I described, locking the RT would be a quicker path to failure.  If the part isn't free to move so it can follow that shift the drill wil eventually snap.  Eventually the backlash in the RT will be removed and the drill would break anyway, so if that's what is going on there's a limit to how deep a hole you can drill with carbide bits with your current setup.

Now, this theory all depends on a particular situation where the shift occurs in a direction that coincides with the backlash in the RT.  That may not be the case, so I could be totally wrong about what is going on.

Something to look into is how much flex a small carbide bit can accommodate before breaking.  That would tell you how good your tram really needs to be.


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## dewbane (Sep 6, 2022)

homebrewed said:


> Something to look into is how much flex a small carbide bit can accommodate before breaking.  That would tell you how good your tram really needs to be.


Yeah, it's probably like picometers or whatever is smaller than picometers. I have snapped carbide stuff that was like 1/2" in diameter, and this is about 0.040". However, I drilled four holes uneventfully. Every time the bit snapped, it always did so upon entering the lower flange. Maybe I just got over-confident after four holes, and turned the fine quill feed knob faster. Also, I used high gear and the highest speed possible, which was something like 1800 RPM. That's probably half what it should be.

Yeah. I poinked some numbers into a speed and feed calculator, and this drill should be running at 19,000 RPM. Okay, that's not happening today.

I still haven't checked the tram. Got side tracked making a fancy holder for my ridiculously fancy center bashing rod. I painted it to match the lathe, which prompted me to realize my paint can is almost empty, and go looking for another one. Hammerite Deep Green used to be $80 a gallon, and now it's over $300 a gallon. *OUCH!*


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## dewbane (Sep 6, 2022)

It's amazing how far out in the weeds I got on this. I'm still messing around with getting the mill leveled. Adjust. Settle. Get bored. Get distracted. Go back an hour later. Adjust. Settle.

When I eventually get it level in some number of hours, then I will whip out the goodies to check the tram, and I'm still betting $5.00 it will be fine.


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## johnnielsen (Sep 6, 2022)

dewbane said:


> Yeah, it's probably like picometers or whatever is smaller than picometers. I have snapped carbide stuff that was like 1/2" in diameter, and this is about 0.040". However, I drilled four holes uneventfully. Every time the bit snapped, it always did so upon entering the lower flange. Maybe I just got over-confident after four holes, and turned the fine quill feed knob faster. Also, I used high gear and the highest speed possible, which was something like 1800 RPM. That's probably half what it should be.
> 
> Yeah. I poinked some numbers into a speed and feed calculator, and this drill should be running at 19,000 RPM. Okay, that's not happening today.
> 
> I still haven't checked the tram. Got side tracked making a fancy holder for my ridiculously fancy center bashing rod. I painted it to match the lathe, which prompted me to realize my paint can is almost empty, and go looking for another one. Hammerite Deep Green used to be $80 a gallon, and now it's over $300 a gallon. *OUCH!*


This statement could be telling (Every time the bit snapped, it always did so upon entering the lower flange.)
Perhaps you have a miniscule amount of vertical end play in your spindle so the spindle drops a couple few thou when you drill though the first piece and start to drill the second. The drill would buckle a bit before starting to cut causing breakage.


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## dewbane (Sep 7, 2022)

johnnielsen said:


> This statement could be telling (Every time the bit snapped, it always did so upon entering the lower flange.)


You could be right. The farther the bit extends, the worse the play gets. It's traveling pretty far to reach the lower flange. It's 0.200" top to bottom, after going through 0.060" + 0.080" + air gap. It's close to 3/8". I should check the quill for slop, and see if there is any adjustment I can make to tighten things up. I do have a suspicion that something could be off.

At least things should be better on the lathe side of this operation. I got the ISCAR MT4 ER32 and had to face my first problem. It was set up for through coolant, and while it would be useful to be able to extend a small diameter part all the way through, it would be hard to knock out without a beater backer. I ordered an off-the-shelf beater backer from McMaster-Carr, and when it came in, I got an M6 instead of an M16, because I'm stupid.

So I makeded one.







I cheated and just smoothed the end on a belt grinder. Then I whacked it in, and set up the tenths indicator. This is WAY better than the Chinese one I had before. It's still a lot of TIR compared to what I could achieve in theory, but I went from 0.0160" to something like 0.0004". Sometimes, spending money on good stuff actually rewards you.


I did enhance that image a little in the GIMP, but I actually recorded several Super Slo-Mo videos with my phone, and the worst I saw was 0.0008" TIR, and it was only that bad because the needle reached that far once in 18 seconds.

For a Chinese lathe and Chinese collets, I'm going to call this a gigantic improvement, and a huge win. I could probably get it even better if I shelled out for Rego-Fix or Techniks collets, but I might not do any better at all. It's a piece of "tight tolerance" O1 drill rod from McMaster-Porn, and it's just a chunk lopped off the end in a bandsaw. It's obviously not perfect, because when I go near the cut end, the needle goes all to hell. My lathe may not be the most accurate, but it's not THAT bad.

Anyway, it's the lathe I own. I can't afford to shell out for a Taig or a Sherline or whatever right now. I have to do this with what I have, or I can't afford to do this at all. They used to make clocks by hand filing the teeth by eyeball, and I think it will all be totally fine in the end. I think I can, I think I can, I think I can.

No, I still don't have the damn mill leveled yet. I'm close. I'm taking a break to let the levels settle. Yeah, the levels. It has nothing to do with the scotch I'm drinking.

Public Service Announcement: DO NOT OPERATE MACHINERY WHILE UNDER THE AFFLUENCE OF INKAHOL. YOU COULD END UP CALLING AN AMBULANCE TO TAKE YOU TO THE ER TO HAVE PARTS SEWN BACK ON, BECAUSE YOU WERE TOO DRUNK TO DRIVE THERE YOURSELF, YOU ALCOHOLIC LOSER!

But tweaking some wrenches by hand, and checking some bubbles. That's fine. Enjoy your vacation!


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## dewbane (Sep 7, 2022)

Here is the video. Maybe I am telling myself what I want to see. How do you read this?


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## jwmelvin (Sep 7, 2022)

dewbane said:


> Here is the video. Maybe I am telling myself what I want to see. How do you read this?



Yes about half a thousandth. There seems to be some motion that is not once-per-rev, which is indicative of bearing runout (because the balls take more than one revolution to come around). 

To eliminate the collet and stock influence, you could indicate the taper inside the ER adapter. And compare that to the spindle taper.


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## dewbane (Sep 7, 2022)

jwmelvin said:


> To eliminate the collet and stock influence, you could indicate the taper inside the ER adapter. And compare that to the spindle taper.


Hmmm. I didn't check the spindle taper with the tenths indicator, but it was pretty obviously barely moving a thousandths needle. Seemed fine Surprisingly fine, considering its Chinese roots.

Collet and stock errors are part of making real parts in the real world. I was getting 0.016" with a similar setup, and I got that down to at worst 0.0008". Like you said, there is some feature on the part that is worse than everything else. It could be an eyebrow or nose hair, or maybe the gaseous deposition of chemicals from a strong unicorn fart. Realistically, even if it's a lousy 0.0008" TIR, that still beats the pants off of 0.016" TIR.

My dog just farted. That probably explains the discrepancy.


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## jwmelvin (Sep 7, 2022)

dewbane said:


> Realistically, even if it's a lousy 0.0008" TIR, that still beats the pants off of 0.016" TIR.



I couldn’t agree more - great improvement. It can be interesting to me to better understand where deviations come from, especially when the indicator is set up.


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## dewbane (Sep 7, 2022)

By the way, I owe someone $5.00

I finally got set up to check the tram on the mill. I assumed it had to be fine, because I was very thorough when I dialed it in, and every check I've done since then just confirmed a job well done.

Until now. Nope. This is not even close to being in tram.


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## homebrewed (Sep 8, 2022)

With all the problems you've run into, I think you could have made a conventional pinion gear by now.  Are lantern pinions (somehow) supposed to be easier to make?  Not being familair with horology I'm probably asking a dumb question but curious minds want to know .


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## dewbane (Sep 8, 2022)

homebrewed said:


> With all the problems you've run into, I think you could have made a conventional pinion gear by now.  Are lantern pinions (somehow) supposed to be easier to make?  Not being familair with horology I'm probably asking a dumb question but curious minds want to know .


I could have just bought one six hundred times over, or just bought an entire complete, working clock movement, but that's why I started with this part. I knew it would be the most challenging thing for me to make, and if I could make one, I could make all the rest of the parts.

I think the plan does use them, because they're supposed to be easier to make. Clock pinions have a weird tooth profile, and the small ones are apparently the hardest to cut. I don't know about any of that, really, I'm just trying to follow the print in the book.

It's funny how the one thing I should have checked first has turned out to bite me square in the butt. Oh, I'm SURE the tram is good. I'm so sure, I'm not even going to check that!

I was overdue to move the milling vise anyway. It left a mark on the table, although there was no serious, heart-stopping corrosion. I pulled everything off, and I stoned the table. It really needed it. Lots of little random spots were proud of the surface a little. Now I need to make a new centering setup for the rotary table, that fits into an ER32 collet, and I need to indicate the vise back on. Oh, and fix the tram before I do any of that. It never ends.

This has been more fun than my last vacation. I spent 10 days working 12 hour days to rip out and rebuild one wall of my shower.


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## dewbane (Sep 8, 2022)

Hey now, hey now, hey now, WAIT JUST A MINUTE! I said the tram was good, I was really sure the tram was good.

I use one of those Edge Technology deals with two indicators. I know you can make one, and there are other methods, and I fell for a scam product that costs more than it's worth. Heard it all before. At the end of the day, though, you can't say it doesn't give accurate readings. Here is the setup, don't bother looking at the indicators.




So after removing the fixtures and stoning the table. Oh yeah, I got it level too. Close enough.





I set the right gauge to 0 with the quill fine feed, and then I locked the quill. Both needles moved. It happens. It's a Chinese mill. Locking the quill always changes the depth by at least 0.001" and I just account for that. So with those caveats, these were the needles:





So I guess somebody owes me $5.00 after all. I said it was in tram, and that is as good as the tram is ever going to get on a Grizzly g0704. I stand by this reading.

I'm very glad I don't have to touch the tram adjustment.

So how about the shims on the column?

It would have been great if these had read the same, but 0.005" of forward nod is not enough for me to mess with the shims. This adjustment is hard to make, and I chased the best reading obsessively. I know the calibrated shim stock I used didn't squish. The only adjustment possible is to loosen the four hex head cap screws holding the column to the base, apply shims, and tighten to full torque. At anything less than full torque, you can't get a useful reading.




I mean, okay, technically this is NOT the only adjustment possible. I could do the adjustment bolt mod, where you drill and tap holes for adjustment bolts that work independently of the clamping bolts. But I only have like 0.0015" shims in here  Maybe 0.003" in one spot. Those adjustment bolts are barely going to adjust anything, and they will dent the cast iron, and...  Yeah, you get the point.

I decided to try just tightening the column bolts. Actually, I'm going to eat a pork shop first. I make the breading from scratch, and double dip them before deep frying. If I die of a heart attack because of these pork chops, it was worth it. All of this is massively off-topic, so I made the picture really small.




So yeah. Anyway. (Burp!) Let's try tightening those bolts.

Yeah, they're all super tight. I almost loosened them, and tried inserting a shim. You just have to make a wild guess and hope for the best. Then I decided that Younger Me would have done his level best, and he was really thorough and obsessive. Every measurement on this mill goes sloppy by 0.005" if you just measure it during the wrong moon phase. Since my tram was as good as I remember leaving it, the column nod is probably about as good as it can ever get. Using the machinist square method, the reading varies wildly depending on the height of the column. I'm pretty sure the moon phase, and Earth's relationship to Jupiter also affect the measurement.

So I fixed it a different way. Look at that! Same reading on both sides! Fixed!


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## dewbane (Sep 8, 2022)

So I switched to ER32 and had to make a new system for centering my rotary table. I turned a 3/4" diameter bushing to the tightest tolerance I could manage. I cranked up the lathe to top speed and polished with oiled sandpaper (with rags covering the ways), then I drilled 27/64" I think, and reamed to 7/16". Parting left a little burr, so I chucked (colleted?) up the part to chamfer the inside slightly. My tool wouldn't fit inside the bore, so I used a needle file. Then I faced and chamfered (file + oiled sandpaper) the ends of a piece of precision ground 7/16" O1 drill rod.

It fits tightly enough, and it's made straightly enough (the spell checker didn't underline straightly?!) to stand on its end, and the bushing doesn't drop. I don't think I could have gotten the fit any better. You don't have to press it, but it's just about as tight as you could go without having to press it. I'm going to chuck the bushing in a 3/4" ER32 collet, and chuck the pin in a 7/16" ER32 collet, then diddle the X Y cranks until the pin slips through the bushing. I think this will be good enough that I can indicate a part in the rotary table collet with a tenths indicator. Here's hoping.








I dooded some good work today. Maybe crappy by real machinist standards, but highly excellent by truck driver liberal arts major standards. Mr. Pete was the only high school shop teacher I ever had. (God bless you, Mr. Pete!)


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## dewbane (Sep 8, 2022)

I'm not going to post the video, because I just don't want to go any deeper down the shop video rabbit hole. I hate shooting shop videos.

Anyway, I think that worked out really well. I mounted the bushing in the table collet, and the pin in the mill collet, then I eyeballed the alignment until the pin dropped in.

Then I cranked the X axis to put a little pressure on it. I left the quill loose, so when the pressure came off, the return spring pulled the pin out. It was really obvious when it hit the exact moment of optimal alignment. Repeat for Y axis, set the 0 on the DRO.

Then I moved away from 0 and carefully back to 0, and ran a tenths indicator around the outside diameter of the locator bushing. I measured something like 0.0004" TIR, at which point I decided to call it a day. I've got run-out in like ten different places, including my centering bushing itself, so adding it all up to 0.0004" seems totally acceptable to me.

I'm going to go fire up the lathe and make another one of these #@!%@#% things. I guess if I start breaking bits again, it's time to put some more shims on my column, instead of just throwing them on the table.

Since that centering pin stood on end on the mill table, I know my lathe is doing  a pretty good job of facing off a square edge, and my table is pretty level. After I do the first turning, I will indicate the top of the part. On my earlier iterations of this, the top of the part wasn't even very close to level, so I expect to see a lot of improvement there.


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## dewbane (Sep 9, 2022)

Up until this point, I've known I could do better, and I wasn't taking any of this too seriously. Now I'm irritated.

For starters, here are the crappy phone videos showing my setup in action. I gently crank the axis screw, and and the instant the tension comes off, the quill pulls the pin out. Whoosh. Do the same for the other axis, and that should be close! There is a tiny amount of slop in everything, and when all that slop aligns in the most optimal way, the pin moves. That's not me forcing a pin that is misaligned with hand pressure.






Then I set up the tenths indicator on the OD of my bushing, and spun the table around by hand. I only see like 0.00035" needle movement here.

This was AFTER I set 0 on my DRO, moved away from 0, and moved back. I got under 0.0004" TIR out of this whole setup.






So my rotary table is good. Unless I'm stupid, and I'm missing something. Am I?

My lathe is good. I haven't touched anything except the ER32 nut since I got those great results.

My part was good up to this point. I was getting a great surface finish, and all my features were close enough to suit me. Maybe one feature was a little too far off, but whatever. I was willing to run with it, and proud to do so. I parted it down to this much without anything going whacky, and then I plucked it off the lathe.





I drilled the center #43 hole on the mill. I started with a 3mm spotting drill, then a carbide #43 spinning at $MAX_RPM (~2000), then I chased it with a HSS #43, because the carbide drill was too short.

I couldn't tell if the hole was centered or not. It looked like maybe not. But what else could I have done here?

I was apparently no longer in picture mode, and I didn't take pictures of moving the part back to the lathe. Chucked up a #43 in the tailstock, and it slid perfectly home. Chucked it up backwards, and it impacted on the surface slightly, but I was clamping the flutes in the chuck, so, meh, not going to worry about that.

I don't physically know of any better method for checking this than to use my finest and most accurate digital dial calipers. Clamping between the center hole and that upper flange, the distance seems to vary by 0.010" or more around the part, but when I spin up the lathe, by eyeball, that center hole looks centered.

Anyhoo, installed a broken #60 carbide drill as a scratcher, blued the top of the part, and moved the Y axis 0.129" by the DRO.  0.258" / 2 = 0.129", there isn't even a tenths rounding error to consider. Cranked the table 360 with the drill barely scratching the surface.

It don't take a rocket surgen to eyeball that the drill bit scratch circle is NOT concentric with the center bore. I'm not even totally sure the center bore is concentric with the spotting drill bore. That could just be a parallax camera angle thing.

Could a 0.005" nod over 6" really cause an error this huge? I kind of suck at geometry, but I don't think so. I don't know, maybe. I got really lost in the weeds trying to figure this out. A triangle with a side of 0.005 is so many arc micro gigapixels multiplied by the pie root of square.

Anyway, at this point I am willing to drill an oversized center bore and salvage the part, if I can somehow make a hole concentric  to a 0.258" bolt circle.

Or at this point, maybe I'm just trying to do too much with my Chinese crap. Maybe this is a lost cause. I have no idea how to fix this, and it's not really fun anymore.


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## jwmelvin (Sep 9, 2022)

When you are indicating on the rotary-table bushing, TIR looks to be ~.003” (not .0003”). 

That measurement will not reflect spindle-table alignment, which would instead want you to have the indicator measure between the rotary table and spindle (e.g. using an indicol holder). 

Sorry I haven’t been following all that closely - why not drill the center hole on the lathe?

Can you indicate the center-hole bore while mounted on the lathe?


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## Just for fun (Sep 9, 2022)

Well, by looking at it, your rotary table wasn't centered.  Check this video out he explains it well. 






Also, on the drill speed personally I would slow down.  I don't have a tach on my mill yet but I'm thinking a couple hundred RPM.  At least that is where I would start and then go from there until it sounds good, and you start getting nice chips.

I can't help you on the nod, but I wouldn't think that would be causing the problem.


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## Asm109 (Sep 9, 2022)

Take the rotary table and set it on the workbench next to the mill.
On the lathe make your part.  Leave OD oversize by maybe .050 inch. finish size other features. No center hole.
With a calculator, figure out the x,y coordinates of all the hole locations for the pins. (relative to the the part center.
Clamp the part on the mill. Vblock and mill vise would work just fine.
Use dial indicator mounted in the mill spindle to get the part centered under the spindle. (use part od).
Set DRO to zero.
Spot drill, drill, ream center hole to finish size.
Dial table to first hole, x,y location.  spot drill,
Move to second hole x,y spot drill.  Repeat for all holes.
change to drill bit and go around the wheel again.
Remove part from mill, deburr.

Put a chunk of scrap in the lathe chuck and turn a spud to a as close a fit to the ID of the center hole as you can make it. Make spud shorter than part length.
slide part onto spud. Hold it in place with live center in tailstock.
Turn OD to final size taking small cuts so part does not spin.
Remove part and celebrate with cold one.


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## jwmelvin (Sep 9, 2022)

Asm109 said:


> …turn a spud to a as close a fit to the ID of the center hole as you can make it. …slide part onto spud. Hold it in place with live center in tailstock. Turn OD to final size taking small cuts so part does not spin.



This sounds like a really good approach (hole locations in one mill setup then turn OD). Every time I’ve used a mandrel to turn an OD concentric with a bore, it’s worked very well. You may want to make a small piece to go between the live center and part, to give clearance and push axially without expanding the bore entrance.


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## dewbane (Sep 9, 2022)

I definitely needed the extra eyes, guys. Thanks.

All I was measuring was how well the table spins, and it doesn't spin very accurately. I never managed to check the center to the spindle at all. I just trusted my centering pin and bushing setup, and it obviously didn't get close enough.

So I salvaged the bad part by sanding a brass pin until I could press it into the hole with a vise. It ran okay in the lathe. I faced off the stub of the rod, and took a skim pass that only partially removed the layout dye. The dye that remains is even everywhere, so I didn't bend the part. I got the center hole re-drilled, and I drilled it on the lathe this time. This part may not end up usable, but I'm trying. This could work. I have no idea if I got the pin all the way to the back of where this part is going to be cut off, so the back bore of the finished part might be seriously janky.

Then I indicated my vise back on the table. As well as I could. It's impossible to get the needle to stop moving, as I've seen some Youtube people do. The best achievable is the needle moving predictably, and in a tight arc. Even with a tight arc of in the neighborhood of 0.0003" it still jumps an entire 0.001" whenever I reverse direction. Cranking this way, needle hovering around 0. Reverse direction, needle hovering around 1. At least it's repeatable.

I put a brand new square collet block in the vise, and I'm going to leave it there for the duration. I think holding the part in an ER32 collet is still an acceptably precise idea. So whenever I get the OD indicated to the spindle, in about 16 to 693 hours, I will set the 0 and use the DRO to drill the bolt circle coordinates. It's that iGaging stuff and my mounting system isn't the greatest, but it seems to be holding accuracy. Here's hoping.


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## dewbane (Sep 10, 2022)

I need to spend more time honing my skills at indicating the spindle, but I got close enough for this exercise. This part was trash yesterday. I just wanted to see how far I could go.

I'm not ready to put it in the finished pile just yet, but it's a lot better!



The center bore is still off slightly. It was extremely hard to center the part once I parted it off, and it was impossible to tell what the back side was going to look like until I did. I pounded another filler rod in there and re-drilled it, and it came out okay. I've built wooden clocks with lantern pinions that ran a lot worse than this, and I probably could use this in a functioning clock, if not for the major mistake I'll discuss shortly.





My big screw up was switching my Z axis DRO to metric inadvertently. Instead of 0.010" I was going 0.01mm, or about 0.004" into the lower shroud. A couple of the trundles (I just looked these terms up, and now I sound horologistical or something, _oh là là!_) just didn't seat right. It was hard getting them in there, and ain't no getting them back out. The center bore is a little wonky too.

Now I just need a coaxial indicator, a better interface for my DRO, a CNC conversion kit with balls screws to save me from backlash hell (it took forever to get the coordinates dialed in, riding the knob with one hand and dragging the table lock with the other, intentionally wearing out my gibs and ways, because it was the only way to achieve that kind of precision), or a real rotary table.

This was so much easier on a rotary table, but you can see that a couple of these pins are the slightest bit off. That was spending as long as it took to finally get the right number to hold on the DRO. I couldn't have been more accurate, and the holes were a little off here and there. My point is 0.004" slop in the table is bovine manure for a job like this, when half a thou is visibly wrong. (There are already rounding errors built right into the coordinates. That's what you get when you convert a fraction into a decimal.)

Finally, I would like to brag that I went through two bits on this, and that is only because I heard a little DINK! as I was cranking the table. Seriously?! I didn't raise the quill fine feed high enough, and I wasted a $7 bit that spent 42 seconds in the machine, and never spun once in its sad life.

The other one came through just fine though. All eight holes, and it went back into its little box.


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## jwmelvin (Sep 10, 2022)

Improvement is often all we can ask for. Making click parts seems challenging because of their small size. As you’re finding out, small things are challenging, or at least that’s been my experience. Nice work though and thanks for sharing your progress.


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## dewbane (Sep 10, 2022)

jwmelvin said:


> Improvement is often all we can ask for. Making click parts seems challenging because of their small size. As you’re finding out, small things are challenging, or at least that’s been my experience. Nice work though and thanks for sharing your progress.


It really gives me the utmost respect for watchmakers. That's a whole new league of working at a small scale, with dedicated little specialty collets, and specialty equipment. I can barely make these clock parts with the equipment I have, but if I can make these smallest, most intricate parts, I should be able to build the whole thing in time. The other parts are much bigger, and I already had some successes cutting gears.

I scored a good deal on a Blake co-ax indicator, and while I wait for that to change my life (hopefully), I'm going to change over to making some fixtures and wheel blanks and such, to round out my stay-cation.

Also: It bears special mention that I finally invested in an opti-visor. That is a real game changer. I never would have even seen the error with the lower shroud without that thing.


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## Just for fun (Sep 10, 2022)

Glad you're making progress, the photo of the part on the quarter really puts into perspective of just how small it is.  Not much room for error!


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## dewbane (Sep 10, 2022)

Just for fun said:


> Glad you're making progress, the photo of the part on the quarter really puts into perspective of just how small it is.  Not much room for error!


After I slept on it and eyeballed the thing again this morning, I decided to put that one in the finished parts pile after all. I didn't drill the lower holes deep enough to hide the cut ends of the music wire, but they *are* in there. It was hard steel, and I basically nailed it into the brass. Nobody is going to see those little shadows of cut ends that I didn't notice myself without magnification. When it spins under power, it's going to be turning very, very slowly anyway. The angles will be a little off in a way that will probably wear parts of the clock out prematurely, but I'm 50 years old. How long do I need this thing to run to be satisfied? My overall plan is to build a simpler clock first before graduating to the John Wilding skeleton anyway. I want to build mine to plan, including the bell on top, but I feel that is too advanced for a first clock.

I already rescued this part from the jaws of defeat once, and I'm going to gamble on being able to work through any problems its minor defects might cause. I think I can, I think I can, I think I can.  It's the Little Lantern Pinion that Could


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## ub27Rocks (Oct 3, 2022)

Back to an old topic in this thread, making your own pivot drills. I just found an excellent descriptive video on making the drills. These are more forgiving than carbide.


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