Prazi BFE65-Littlemachineshop Big Mill table Frankenbuild, spin off thread.

[RaisedByWolves]

This thread is a spin off of the following to keep things from becoming cluttered. Lathe Mill score thread.

I got this mill head in a package deal as posted in the above thread but the milling table/base was not included. Having read everything I could find about this combo and working as a toolmaker I knew I would not be happy using the Milling head attached to the lathe and was searching for a solution. I was only able to find the complete package used for $2K+ or a sold listing for the base for $1200 and I wasn't going there.

With my experience in this type of thing I knew I could not only find a good quality milling table and base, but I could also come up with a better than factory solution for the stand alone mill and do much better than mounting it to the lathe.


I had looked at a dozen different offerings and the only thing that really looked high quality out of the box was from RC machines in Germany. They have some beautiful stuff and I fell in love with this one. Its perfect! The only problem being it was going to be nearly $1100 shipped ($850 US just for the table) and they couldn't guarantee there wouldn't be import duties, so that was out.

The Base I chose was from Littlemachineshop, and it is the 5013 Mini Mill Large Table Assembly, Solid Column Base. It came well packaged in a large box containing a small wooden crate. It was securely mounted to the crate with the bolts necessary to mount it to the column for this base.




After unbolting it I got it together with the mill head to begin drawing up a plan to mate them together. You can see my blue pencil blueprint in the lower portion of this pic.






Knowing I needed to find an appropriate size chunk of steel (4"x6"x3" thick) to make this out of would take a bit of time I began working on what I felt needed attention. First up was the cleaning and adjusting of the ways and the lead screw tomb stones. These are actually the nits, but they look like littel tomb stones and are cleverly affixed by jamb screws to the base. I knew the one for the Y travel was loose from the get go as it was smooth in one direction and erratic in the other. After opening this up my thoughts were confirmed and a simple process of centering the nut with the screw and tightneing it down fixed that issue.

Heres the capturing method of these nuts, Y travel:

You can only see the flat end of the Y nut here, but the fixing screw head is near the bottom of the casting.





And X travel.

This one came canted a bit, but it was simple to straighten out with this setup.





I do recommend disassembling and cleaning anything like this when you first get it as there is a lot of grinding dust in the works.

After disassembly and cleaning I got a good look at the fit and finish and was pleasantly surprised with the quality. Only one of each way is actually ground, but the other side is milled very finely and will act to hold oil in lieu of scraping or flaking.


There was only one small blemish in one way and overall it is really nicely made.

Here you can see the grinding dust that was still coming out after the third wipe down, there was a lot of it needing to be cleaned out.




I was thrilled to find out this actually had a reasonable facsimile of an acme thread lead screw!






Once I found my giant hunk of steel I squared it and ground it to clean it up and hogged out as much material as I could before boring the hole for the column.





Then I bored it to just .002 over the column diameter. This was necessary so the head can rotate for milling/drilling tall objects off of the side of the table like you would do on a B-port mill with an angle plate tied down on the table. The original base had this feature so you could swing the head out of the way when attached to the lathe, but I like the extra flexibility this offers, so I added the feature in.




I don't like having the mill table that cluttered and disorganized, but I had to fit this in with other work so I was running two machines at the same time and generally making a huge mess.


Bored and relieved on the top edge.





I milled a 1/8" cosmetic relief slot to hide the saw cut I needed to make so it would clamp to the column. This way the rough saw cut is hidden to all but the most discerning eyes.

 

[RaisedByWolves]

Between days doing the larger work in the shop I found a couple of things on the table/base that I thought needed addressed.

First up was the table lock screws. These were nice indexing handle type units, but they were hideously long and looked like they could get in the way or broken so I shortened them on the lathe.


As delivered:





And drastically shortened.







Much better. I did this to both the X and Y locks and decided the X needed a second lock on the opposite side so the table will not twist when the single lock was tightened, so I ordered one from LMS to be installed. The Y lock was centered in the gib so I figured that one was fine.



Back in the shop I finished the cosmetic slot going across the top and down the edge where the saw cut was to go, and began drilling the holes to mount it to the mill table. I had to leave the saw cut for last to ensure everything stayed square and rigid for the rest of the steps to be performed.




After the mounting holes were finished I cut the front corner on a 45* angle to give it a nicer and more factory look. I hesitated on this as I wanted as much rigidity and especially mass in the machine as possible, but in the end this piece came out to 20lbs of solid steel VS 3lbs of cast aluminum on the factory part its replacing.


Should be more than good enough.










In the above pic it was setup to be milled flat, then was later ground to match the rest of the surfaces.

At this point I brought it home and mated it up with the base. Any miscalculations would be discovered at this stage before going any further and possibly needing to scrap the whole works, but everything fit perfectly. That was a nice surprise as I only had .004 clearance on the bolt holes.






Next up was the threaded and bored clamping bolt holes. I drilled and tapped for M8-1 bolts using fine threads to increase the clamping forces.





I counter bored these holes so the head of the cap screws would stand slightly proud of the surface so they would be easy to feel from the front of the machine to loosen/tighten with a wrench until I can make some factory style locking levers similar to what's on the vertical clamping lock for the head.

Here I have it in position to tap the holes. I made the counter bores large enough to accept the tap handle jaws as to allow the maximum thread depth for increased longevity of the threads.




Then the final step was the saw cut.





After the saw cut was done I sandblasted the whole thing to hide my sins give it a good surface for paint to adhere to.

And with that finished I put it together and everything looked fine and worked well, then the doorbell rang.

My vise was here just at the perfect moment.

All together and (Mostly) ready to go.







Cute, isn't it?







I ordered a 3" vise as I wasn't sure how much it would stick off the back of the table or the quality of the brand, but there's more than enough room and the vise is nice enough, so Ill probably order the same vise in 4" as the 3" seems just a tad small. The 4" is also almost twice the weight so it will help with the mass equation.

Just need my clamping bolts and the ER-20 collet chuck and collets to show up and I can start to use it.

 

[RaisedByWolves]

Next step was to tram the head. Frankensteining these two machines together poses some challenges, but its really nothing much different than setting up the factory column and base. Break out the indicator and tram the X axis which is simple and standard, then for the Y you need to shim the base.

I broke out my shim block to help with this.

You can see the .0015 shim I cut out with scissors, but that was no where near enough so the shim block was used.



I cut the shim (.004) down to size and put it in the block.





Man, I need to clean that block.

After putting the feeler gauge in and smacking it with a hammer I had this.




I slipped these in and re trammed the head finding that it was still off, so I repeated the process with .010 shim and tried that.




That got me within .001, but the accuracy of this was all over the place every time I moved the head up or down. This is a known issue on round column machines rotationally, but this was front to back in the "Nod" direction which should not be an issue.


After fiddling around a bit I discovered what the issue was. The clamping system for the head on my milling head is different that others I've seen and now I understand why they made the change. In this pic you can see the two clamping levers oriented in a vertical row. These levers impinge on a large key that clamps it firmly to the column.





I'm hoping I can split this either in line with the clamping levers or slightly to the left and add in clamping bolts similar to what I used on the column mount. If it comes right down to it I may remake the whole thing in a later style.

This looks promising, Note that this example is made out of aluminum.

In any case the Collet chuck and collets showed up yesterday but not the threaded rod I need for the drawbar. I threw caution straight out the window last night and decided to try out the mill without the drawbar. The spindle has am MT1 taper (Lol, yeah, I know) and being a locking taper and having experience with this type of taper on my Steinel mill I felt it would work fine without a draw bar and it did. I just chucked the collet chuck home on the taper after cleaning everything with acetone and it worked fine.

The tooling system I'm using for the lathe also has a small fly cutter that uses the same tool bits. This tooling system was designed by Edelstall back in the late 60s and works well for these little machines. It has all of the basic angles built right into the tool bit so you need only to grind the tip on a simple angle and everything else is done for you.

Can you imagine trying to grind proper relief and rake angles on something this small?





They measure 1/8" tall by 3/16" wide and fit into holders with a matching profile.

This is the fly cutter with a very long bit installed. This is one of the M42 cobalt bits you can get and I didn't want to cut it down and waste a dozen or more sharpening's so I just ran with it.






It worked OK, but I need to work on the proper angles for the fly cutter. I have the grind worked out for the lathe tooling, but the fly cutter is going to be a bit different.

Coming to a touch.






Video of this taking a .030 cut in aluminum for an Allen wrench handle. The head is not as noisy in person, I had the phone right next to it trying to stabilize my hand. The cut was fairly smooth for a fine point on a fly cutter. Yes I'm being rather cautious with the feed, but as mentioned, the collet chuck is only held by the locking taper, no draw bar yet.

Well that video looked like hell. Maybe trying to stabilize my hand on the mill head did just the opposite.

After that I milled a slot for the Allen wrench short end to slide into.

 

[matthewsx]

Great to see this working out for you....

John

 

[RaisedByWolves]

Great to see this working out for you....

John

Thanks John, this is really fun.

Im trying for what may be the first time in my life to set this all up properly from the beginning. I'm setting this up in our generator room that has acted as a make shift work shop/hobby room for years, and had become somewhat of an underutilized cluttered mess. I had a compressor, bandsaw, belt sander and small drill press down there for years, but honestly much of that was bought to fill a niche or were cast offs from the neighbors.

Putting stuff in a room for occasional use is one thing, building that all into a well thought shop is a bit different.

Example, I spent an hour last night getting my blow guns throttled down to a reasonable level for this small space. Blasting chips over my head and down my pants was sub optimal and kicked up too much residual dust.

This is the space I'm working with. I'm still trying to get rid of some of the "Legacy" stuff (Read mess) and free up space, but that needs to go somewhere and will take time. There are probably 10RC boats and 3-4 RC Helicopters in this room along gunsmithing supplies and other ephemera.






I want to get both machines (Mill and Lathe) on one side at one end of the room to try and keep all of the chips away from the entry/exit to lessen migration into the living space, so everything is constantly getting moved as time and supplies permit. As to supplies, I installed a dehumidifier (White thing behind the bandsaw) which needs a constant on plug on the power strip. Thanks to an A-Zon supplier who couldn't get their **** together it took me 4 weeks to get this. The power strip is perfect, but the time to acquire it.....

Moving on, I completed my first project on the mill.






Nothing much, but I'm still getting used to not having a DRO on this and the overall response of the machine to inputs. Plus Im still waiting on the threaded rod to make a drawbar.

This is a T handle for the lathe tool holders with a replaceable Allen key. I made one for the lathe at work and everyone loved it and it does make tool changes much easier than a plain Allen wrench or a plastic handled T wrench. The plastic handle wrenches are nice, but they seem to fail too often under shop conditions and are costly to replace.

It goes here.





Since I'm waiting on parts I decided to work on taming the way covers. The amount of way cover material they give you with these seems excessive and I hadn't had this table for one day until I started bending the thin metal bars that attached them with from the factory. I made new bars out of 5/32 O-1 and shortened the covers by a few inches.


Looks and works much better.







And now it doesn't balloon all over when fully compressed.





In that pic you can see the poorly fitted clamping screws. I intended these to be temporary until I can make proper handles, but the bolt length needed and the amount of thread on those didn't line up with my plans, so they stick out.

 

[matthewsx]

Looking good, nice to have a fire hydrant right there just in case

John

 

[RaisedByWolves]

Looking good, nice to have a fire hydrant right there just in case

John

A friend showed up one day with a caved in front bumper and that in the bed of his truck. I claim ignorance to the back story and he died years back without ever retrieving it.

That's my story and I'm sticking to it.

I shortened the front way cover and ran into a slight snag. The mounting holes in the front are close together, something like 1.250" where as the rest of them are 4" or so apart. This lead the bellows shaped way covers to want to pull around the ends of the hold down bar.





I didn't care for that is it looked unsightly and was going to lead these covers to fail eventually so I added keeper plates to the ends of the hold down bar to keep this in check.





This worked out really well and overall it looks much better.







There's still a lot of excess material in the front when the table is fully forward, but its better than it was having removed a full 2.5" of excess. This will make clean up and general use much neater.


I also got the parts for the drawbar and finished that up and also got some adjustable threaded handles for the quill lock. It only had an M6 bolt for the lock which puzzled me at first, then I realized these things weren't 2 for $6 delivered when this machine was made, so cost was most likely the driving factor.







These are also much nicer than the ones that came standard on this table for the X Y locks, having 10 detent points VS 6 and are of overall better quality, so Ill probably change those all out too.

Of to A-Zon to order two more.

 

[RaisedByWolves]

Got a package from Micro Mark today, brandy new power feed unit.






Aaaand, it doesn't fit.

I knew this would probably be the case though, I basically wanted it for the guts. I could have bought the LMS unit that would bolt right on, but it was $75 more and was out of stock. Its basically the same unit, but the lead screw is longer on my machine, hence the not fitting part. Everything else would bolt right up, but I am going to go for a "Bridgeport like" operation with this, so its all coming apart anyway.

Ill have the drive motor on the side as pictured, but on the right side Ill have the varispeed knob and a handle like on a full-size Bridgeport. Ive been running B-ports for so long even the servo units feel alien to me and I'm constantly reaching for something that is not there.

Making half of this from scratch will let me add features the standard power feed setups do not have. I want to make a splined clutch dog that is sprung in conjunction with having the BP style lever both actuate the clutch and move the direction switch simultaneously. I would also like to implement a fast traverse button in the mix somehow.

In stock form you have to rotate the handwheel and manipulate the clutch, or have the drive going while turning the clutch dial to get the drive engaged, neither of which is ideal IMO.

I looked at buying all of the parts separate only to find out it would cost more for the parts than to just buy the cheapest "Same" unit and cannibalize it.

By "Same" unit I mean that I found the majority of these units to have the same gear motor, control board and controls, with only the clutch housing and the corresponding bolt locations being either narrower or wider depending on the size of the machine their meant for.

The Grizzly unit already had the fast traverse baked in, but the gear motor is huge as it is meant for the larger round column "Wrong Foo" type machines.

Now all I need is to do is build it all.

 

[RaisedByWolves]

So, I have a lot of irons in the fire right now but today I found myself with some spare time and a lack of components to make any big steps, so I took a small one. I decided to tackle the overly tight quill spring I have been dealing with. This quill spring is set so tight everytime I let go of the quill handle it tries to launch its self into the sun.

This is not only annoying it is also problematic as it takes all sense of touch away when drilling a hole or coming to a touch with a tool.


To give you an idea just how tightly wound it is, here is a 2.5lb weight hanging off of the quill handle. The handle is 10" long which seems excessively long, and it is holding the weight perfectly balanced without the quill lock on.

Yeah, I think that's a bit much.




The manual says not to go in through the quill rack side and I'm thinking this has to do with the quill spring being anchored there, so I took the left side of the machine off to gain access to the guts and see what's what.

It looked like this.




I had been in here before so I kinda knew what to expect, and I was after that little gear way in the back.

Its only held in with one slotted screw, but it is crowded on all sides and I couldn't remove it this way to reset the spring.

Not coming out this way.






I did notice the rack gear cut into the quill had the teeth going all the way to the top. Sometimes the stop is effected by the last bit of the quill not having teeth fully cut in them, but I got lucky and these did go all the way to the top.






So all I had to do was loosen three screws that hold the quill guide/boss/sleeve whatever you want to call it and let the quill gear ride up and over the end of the quill teeth and I would have full control of the spring to reset it.



Loosened up, but not enough travel.




So I installed the longest screw I had that would fit and this let it drop down enough.








That let the quill drop down and I simply rotated the gear backwards until I was happy with the feel. You can see just how much more relaxed the clock spring is in this pic vs the previous shot of this area where its nearly hidden by the gear.







MMMmmmn, forbidden butterscotch.....


I buttoned everything up at this point and plugged it back in to test only to find out it would only run if I held the start button in. This had me a bit concerned as the big soviet made cap these units use can be problematic, and I did whack it just a bit trying to get the taper in the quill to release the tooling I had in there, so I took the electronics panel off to see if I could visually identify a problem.


Ah HA! A wire terminal came off!






Checked it over and it seemed pretty loose on the terminal, Ill just unplug the unit from the wall, just crimp this a bi......




Suddenly it felt like I was hit by lightning. The bones in my hand ached and my hair stood on end.......... Smoke was coming out of my orifices' and my wife said she didn't know if I was cursing in some foreign dialect or talking in tongues.

Now that capacitor I had mentioned? Turns out it is a run capacitor and not a start capacitor. This is crucial as me thinking it was a start cap, I knew it was no longer energized when the motor was off. But I now know it is a run cap, and having it disconnected from doing its job it was fully energized when I made contact.

So, once the smoke cleared I buttoned it back up and function checked the motor and ran it through all of the gears and everything was fine except that burning feeling in my chest.



So as it sits now its much nicer feeling and well balanced. The down stroke is actually lighter than the up stroke as I think friction is holding the quill up, not the spring. Not too lose, it easily holds an 8oz hammer neutral and I'm pretty happy with that.

If it needs adjusting in the future that is easy enough.

 

[WobblyHand]

So, I have a lot of irons in the fire right now but today I found myself with some spare time and a lack of components to make any big steps, so I took a small one. I decided to tackle the overly tight quill spring I have been dealing with. This quill spring is set so tight everytime I let go of the quill handle it tries to launch its self into low earth orbit.

This is not only annoying it is also problematic as it takes all sense of touch away when drilling a hole or coming to a touch with a tool.


To give you an idea just how tightly wound it is, here is a 2.5lb weight hanging off of the quill handle. The handle is 10" long which seems excessively long and it is holding the weight perfectly balanced without the quill lock on.

Yeah, I think that's a bit much.

View attachment 454141


The manual says not to go in through the quill rack side and I'm thinking this has to do with the quill spring being anchored there, so I took the left side of the machine off to gain access to the guts and see what's what.

It looked like this.


View attachment 454142

I had been in here before so I kinda knew what to expect, and I was after that little gear way in the back.

Its only held in with one slotted screw, but it is crowded on all sides and I couldn't remove it this way to reset the spring.

Not coming out this way.


View attachment 454143



But I did notice the rack gear cut into the quill had the teeth going all the way to the top. Sometimes the stop is effected by the last bit of the quill not having teeth fully cut in them, but I got lucky and these did go all the way to the top.


View attachment 454155



So all I had to do was loosen three screws that hold the quill guide/boss/sleeve whatever you want to call it and let the quill gear ride up and over the end of the quill teeth and I would have full control of the spring to reset it.



Loosened up, but not enough travel.

View attachment 454145


So I installed the longest screw I had that would fit and this let it drop down enough.



View attachment 454146




That let the quill drop down and I simply rotated the gear backwards until I was happy with the feel.



View attachment 454147



MMMmmmn, forbidden butterscotch.....


I buttoned everything up at this point and plugged it back in to test only to find out it would only run if I held the start button in. This had me a bit concerned as the big soviet made cap these units use can be problematic, and I did whack it just a bit trying to get the taper in the quill to release the tooling I had in there, so I took the electronics panel off to see if I could visually identify a problem.


Ah HA! A wire terminal came off!



View attachment 454148


Checked it over and it seemed pretty loose on the terminal, Ill just unplug the unit from the wall, just crimp this a bi......




Suddenly it felt like I was hit by lightning. The bones in my hand ached and my hair stood on end.......... Smoke was coming out of my orifices' and my wife said she didn't know if I was cursing in some foreign dialect or talking in tongues.

Now that capacitor I had mentioned? Turns out it is a run capacitor and not a start capacitor. This is crucial as me thinking it was a start cap, I knew it was no longer energized when the motor was off. But I now know it is a run cap, and having it disconnected from doing its job it was fully energized when I made contact.

So, once the smoke cleared I buttoned it back up and function checked the motor and ran it through all of the gears and everything was fine except that burning feeling in my chest.



So as it sits now its much nicer feeling and well balanced. The down stroke is actually lighter than the up stroke as I think friction is not holding the quill up. Not too lose, it easily holds an 8oz hammer neutral and Im pretty happy with that.

If it needs adjusting in the future that is easy enough.



View attachment 454149

You are lucky that you are still around. You might consider putting a bleed resistor across the run cap. Capacitors can store enough energy to kill and always should be considered charged unless you discharge it. All my "dangerous" caps are stored with a short between the terminals, because they can pickup charge in unexpected ways. They get placed in circuit and then are unshorted. Nearly all my designs have bleeders. Like you, I learned after getting shocked. A bleeder is a very high value resistance and will slowly discharge the cap, without affecting the circuit performance. I aim for a 10 second discharge, roughly.