Ogberi's Taig lathe

ogberi

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Oct 20, 2014
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Hi All,

Well, as I wanted to, I was able to get out in the shop a little bit this weekend. Gimpy knee was a hindrance, but the urge to make chips was stronger.

First thing I did was clean up my lathe and accessories. Despite being wrapped in oiled paper, and being wiped down with oil before being boxed up, there was surface rust here and there. A quick once-over with a brass wheel took care of that, and everything got a nice clean wipedown with clean oil on a clean rag.

The work surface is a 1" thick piece of MDF I cut from an old computer desk. It's topped with a 12ga sheet metal shelf I scrounged from an old equipment rack.

The motor is a DC treadmill motor. Definitely overkill as far as power goes, but if you work within the limits of the machine, it's nice to have a motor that doesn't struggle or bog down when cutting. You don't hog off insane amounts of metal, but a normal cut for the machine with a sharp tool goes like a dream. Normally there's a cover over the open end of the motor, but it went missing. I'll need to make another. My temporary fix is the cut-off bottom of a pop bottle zip-tied in place. Ugly as sin, but it keeps the chips out. One thing I really like about that motor, is that I can have lots of grunt at low RPM, or spin the lathe up to ~6K. All without changing the belt. The sharp-eyed among you will no doubt howl about the spindle pulley. Yes, it's not the correct one for that belt. The one I was making got lost, so I'll have to make another proper pulley. It's on the to-do list.

The motor controller is mounted in a plain electrical box. It has a breaker, an On-Off switch, and a speed control knob. I also use a DC motor on my Atlas horizontal mill, and use locking plugs to swap the controller between the two. Convenient. :)

I added inexpensive (Harbor Freight) digital calipers for my "poor man's DRO", and they work simply awesome They're accurate enough for the work I do, and when more accuracy is needed, I get out the micrometers. They make it easy to zero in on a dimension, then sneak up on it. I haven't had any battery issues, other than not having any on-hand at the moment. Need to get some. When I use the milling attachment, I generally have a 1" DI in place on it to provide me with a readout for the Y axis. Since I have a horizontal mill, I don't use the milling attachment on the Taig as much as I used to. I haven't seen a need to fit a caliper on the milling attachment yet.

So that's my little Taig. I need to finish cleaning up my accessories, and get it's workspace tidied up, then I'll post more pictures. As-is, my Taig workspace is the only organized area in my shop at the moment.

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More pics to come as I pimp out my lathe.

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I've been easing back into machining with little stuff. My QCTP, dedicated indicator for dialing in stock in the 4 jaw, etc.

So, while buying grub screws for the QCTP toolholders, I saw some shoulder bolts. Snagged some, and used some ground and polished 303 stainless I had in the scrap bin to make spinny handles for my lathe. Simple, easy, quick project, with very, very gratifying results.

Now, it's time to step up a little. Despite the fact that I'm purchasing a SB9A next month, I've decided to resurrect my project of adding a leadscrew to my Taig.

I already have some 1/4x20 left hand threaded rod ready to go, a matching tap, and plenty of scrap. And if I don't have scrap to fit, I have plenty of wood for patterns and a foundry capable of casting aluminum (and brass.) ;)

And, because I'm a lazy cuss, (hey, I work in IT for a living!), I want to add power feed to the leadscrew. It won't be spindle-driven, probably a gear-reduction DC motor with a speed control and a reversing switch. I have another idea for cutting threads on the Taig.

I plan to have a handwheel on the right end of the screw, and the DC gearmotor on the left end. A dog clutch will disengage the DC motor, so I'm not turning all that over when manually feeding.

The "half nut" will be a piece of brass, drilled and tapped, then cut in half. A push-pull rod will engage it to the leadscrew, and I'll use another piece of brass behind it to prevent the threaded rod from bowing away from the half nut.

I'll build the speed control myself. A 556 timer, a TC4420 mosfet driver, and an IRF810 mosfet. Add a potentiometer to set the duty cycle (speed), and a DPDT switch to reverse the motor and I'm all set. If I find the speed control heats up too much, I'll redesign it. It'll provide good PWM at piddly power levels, and I can beef it up if necessary. Dang it, if I can design and build an 8kW induction heater, I can drive a dinky little gearhead DC motor! :)

I have another idea kicking around my head, but I need to let it ferment a bit. I am one of those people that will sit back with a couple of beers, a cigar, and stare off into space for a bit while my mind wanders free for awhile. I've had some really good ideas that way. And.....some really bad ones.

Relax, I don't go putter around in the workshop while I'm plying my imagination with ethanol. I might wield an import digital caliper, a pencil, and most assuredly an eraser. But not a machine. Beer is for thinking of a project, and for enjoying when the day's work is done. Not for when running machines. I have no doubt that Taig lathe is just *waiting* to use the 4 jaw chuck to remove one of my fingers, and I have no plans on letting it do so. The SB9A will want several fingers, and I intend to keep it disappointed as well. The Atlas horizontal mill? I watch it like a hawk, and sometimes give it a smack with a wooden ruler just to keep it in line. The table saw? Me and it have an understanding. It doesn't try to eat my fingers or hands, and I don't melt it down in my furnace. It's an uneasy truce, but it works.

And now, it's time to sit down and stare at the carriage off my Taig lathe, apply some ethanol, and remember to write down my thoughts.

Stay tuned, it should be at least vaguely amusing!
 
Rummaged through my 'totes, and found an old drill I bought at a yardsale for a dollar.

One whole dollar.

Here's the pre-carnage pic. It's nasty, sticky, and cheap.
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A few minutes with a screwdriver yields this:
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D'oh! Forgot to remove the chuck while there was enough to grip! Note to others (and self), remove the left hand threaded screw, grab an allen key in the chuck, grab the drill solid, and flail the poo out out of the key with a chunk of steel or lead.

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Chuck separated. :) It joins it's siblings on the pegboard of moderate embarassment.

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More disassembly. Don't need a clutch, don't need half that crap.

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So, I figure I can cut down the output shaft to drive the leadscrew. I'll need to make a housing to hold all that assorted junk. One of these pieces of aluminum holds a planetary gear reduction leadscrew drive assembly. Which one is it?
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But my burning question to those who know more than I do -

I want to cut this down. How the heck do I grab this? The flange with the pins precludes grabbing it in a chuck, but I need to cut it shorter, face it off, and drill it to accept the end of the leadscrew. The easiest way I see to do it is to make some jaws for the 3 jaw chuck that let the big part sit next to the chuck, and clamp on the shaft beyond that. It'd be an afternoon project, but very doable. I need the flange & pins to engage the planetary gear. I need to drill it, so working between centers is out.
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This promises to be an interesting project. to me, anyway.

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I like your idea of making some extended jaws for your chuck. You might also make a split collar that would just fit on the shaft, with the same OD as the flange, that would give you a bit more to grab onto and make it more stable. You could also punch the pins out and put them back in when you're done machining, would get the work closer to the chuck.
 
Got some work done on Saturday.

I decided to use the middle chunk 'o scrap for the planetary gear housing. I'm not quite sure how I'll wrangle it, got a few doodles. So I cleaned it up a little and called it good. This is about the biggest part I'll turn in the 4 jaw, and the DC speed control and treadmill motor let me turn it just fast enough to do the job. Forgot to get a picture of it cleaned up.
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And yes, I'm combating rust. It seems the rust in my workshop literally scoffs at a well-oiled rag wiping things down. I've never had stuff rust so dang fast! I'll need to get a gun bluing kit or figure something out. :/

So with that piece cleaned up and the gears in my head turning, I set about making some other bits and bobs. I'm making this very similar to the one seen on John Bentley's site. However, I'll be using a plunger type half nut, much like Dean did on his site. I don't have the links handy, and my tablet isn't the best for multi-tasking.

I used the horizontal mill and the Taig's milling attachment to do the work, simply because the mill is handy, it's there, and I haven't used it in awhile.
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Mmmm...chips...

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Here's the two little pieces that fit into the extruded base of the Taig. I removed the thin aluminum plugs that are pressed into the ends, exposing the concrete-type material it's filled with. No complaints about the construction of the lathe, and I'm sure it reduces chatter by a lot!

Next, I used a home-made transfer punch (read, turned a point onto a scrap piece of mild steel I had on-hand) to transfer the existing holes I made long ago in the lathe (for CNC operation) to the new end plugs. Drill, tap, and clean up.
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Headstock end in place and secured. I made two short pieces that stick out towards the carriage (photos were blurry as heck), and got them installed.
I turned down the leadscrew, 1/4x20 left handed threaded rod - then marked and drilled the mounting arms. I still need to drill for brass bushings, but I did throw some clearance holes for the threaded rod, just for giggles. :)
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The half nut, I thoroughly messed up. I'll have to make another one, because while I was de-burring this one, the fibre wheel snatched it right out of the vice grips I was holding it with and shot it somewhere in the shop. (and yes, I had on my safety glasses!) It's *somewhere* in there, but good luck finding it. :/ I heard it bounce off the weed-eater's shaft, and a sharp metallic rattle after that. I'm writing that little piece of brass off, and will make it anew. But at least I have pictures of making the one that got away.
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I should be using a zero rake tool for brass. Another item for the to-do list.
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Drilling. I always make positive I won't hit the edges of the T slots. Though why I didn't rotate the workpiece so it would center on the T slot, I don't know. This is *after* I removed the clamp. Drilling brass without clamping it down? That's asking for get hurt.
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A 1/4 x 20 left handed tap. I've had that for about 3 years now, waiting on a Round Tuit. Found the Round Tuit!
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Milling off the end. I used a 1-2-3 block and a short scrap of threaded rod to align the hole vertically.

Unfortunately, my camera batteries died at this point. Working in the garage on these little machines gives me a good chance to use the macro function on my Nikon D3100. Nice camera, but I end up wrapping it in a rubber glove so I don't get it all manky.

So I milled the end off of the rod to expose a little more than 1/2 the thread diameter, and drilled an axial, just-under 1/4" hole to press fit onto a piece of scrap 3/8" SS rod that I had turned a 1/4" spigot onto. Like an idiot, I didn't press fit it *before* I de-burred it. I instead grabbed it with vice grips, thinking that I would de-bur it first, press fit it, then hit it on the fibre wheel to remove any vice grip marks.

*ZIP!* *PING!* *clatter-clatter-clatter*

"uh.... one two three four five six seven eight nine ten, one two, one two, one...no everything vital seems to be there...."

I'll omit the expletives, but I'm sure you have heard 'em before. :lmao:

I doubt I'll get any shop time this week. Work is absolutely insane from this Monday (today!), until about 2 weeks after new years. What with family, work, and the Honey-Do list, I expect to see all my tools corroded into shapeless chunks by the time I wander back out to the shop.

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To my surprise, I got some shop time in today.

The leadscrew is in place, and works. Still some stuff to finish up on it, but it's functional, and it produces a much superior surface finish vs using the gear & rack handwheel.
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The ugly 4-40 slot head screw will be replaced with a grub screw, as soon as I can find the pill bottle that contains them.
There's still plenty of shaft left on the left hand side for adding power feed.
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The half nut is simple as heck, but it works great. I've noticed no tendency for it to pop out while using it. I will be adding a friction lock to it as well. And a knob on the back to let me get a better grip. Just have to track down the chunk of brass I had earmarked for that part.
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I've been using the heck out of my QCTP, and it won't be too awful long before I buy another stick of 1.25" square to make more of them.

Here's an example of how I use my dedicated QCTP indicator holder for centering in the 4 jaw. Quick, handy, and always on center. :)
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I'm slowly getting tooled back up and organized. I ordered some more blank 1/4" toolbits, and 10 blank spindle arbors so I can begin re-making a bunch of stuff. Soon I'll order that stick of aluminum and start making more toolholders.

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So let's see...

Variable speed DC spindle motor - Check.
Digital calipers on the carriage and cross slide for better accuracy - Check.
Leadscrew to drive the carriage - Check.
Spinny handles on all handwheels - Check. (and they work *nice!*)

Getting the leadscrew powered is next on the to-do list. Gotta spend some more brain sweat on that, as well as doing some work on my horizontal mill. It needs some attention too.

So stay tuned for the next installment of "Pimp My Lathe." :lmao:

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Over the weekend I made some replacement jaw adjusting screws for the 4 jaw chuck. The originals look to be 12L14, and the hex holes were getting nasty. The head of one was starting to crack, despite that I don't gorilla tighten them. Four 1/2 13 set screws at Ace set me back only $5, the rest was just a lot of parting to groove the screws for the jaws to ride in.20150214_133311.jpg 20150214_133311.jpg 20150214_210750-1.jpg
 
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