Converting my Engine Lathe to an 8-Station Turret Lathe!

[widgitmaster]

Hi Bob,
Prior to this phase of the project, my lathe was propped up on stacks of metal on four corners, not so good when the base has six points to level it from! I will sneak a few pictures of the Gap for you before I'm done. The reason I removed it was the swelling of rust was raising it up, causing an uneven condition in my turned surfaces. I had not noticed it till I put the DRO on the carriage!

Yes, before I'm done, I plan on leveling the lathe, and adjusting the headstock till it produces minimal taper over 3 or 5 inches!

The other problem I have encountered, is the positive stop I made in another post, only had 5 positions, and I now have 8 stations on the turret! I have totally remade the stop, so it lands on a different location on the side of the carriage. That was a big project, but when I'm done the lathe will be really sweet to run!

[widgitmaster]

Another BIG project finished!
Today I finished making the sub plates for my lathe, and placed them under the lathe. Then I spent an hour adjusting the feet until the lathe was level on both ends and in the middle. I used a couple sets of 123 blocks, to raise my Starret level above the ways, and that helped speed things up!

After the lathe was level, I placed a 2" dia x 6" long piece of steel in the 3-jaw chuck, taking a light cut and measured the diameter for taper. After bouncing the lathe around the shop floor, the taper was .0017 over 4 inches!

So I lostened two of the four bolts that fasten the headstock to the ways, and located the adjuster nut on the back of the headstock. After a little trial and error, I have successfully eliminated the taper!

The splash guard went back on easy, along with the chuck guard, then I spent the rest of the afternoon mounting a 2x4 to the back wall, and drilling big holes in it to store all my drill chucks and centers! Then I put the coolant tank and pump assembly under the lathe, so now it's ready to do some serious work!


VIDEO

[widgitmaster]

Well, it took me a little time to get used to using the DRO with the 8-station turret, as the DRO's manual is so poorly written! After I figured out how to set the coordinates for each tool, and set the carriage stop accordingly, I ran off 20 leadscrews for the new Midi-Routers! The DRO allows me to set a ZERO for for each axis with each tool!

So while turning the leadscrews, Tool #1 was a facing tool. Tool #2 was a center drill. Tool #3 ruff-turn small diameter. Tool #4 ruff-turned large diameter. Tool #5 finish turned large diameter. Tool #6 finish turned small diameter. The trick is getting into the rythim of indexing the turret, indexing the stop turret, and switching the DRO to the next tool! And yes, I did scrap a couple of parts by missing a step in procedure, but that's what red dykem is for!

I have been making tool holders as I see need for them, the next one will be for a cut-off blade!

This Chineese lathe is running really nice and tight, and the new DRO actually allows me to turn off one tenth from the diameter (.0001").
I would have taken some video's, but I have been preocupied with getting it all to work!

While making the leadscrews, I noticed the turret was repeating within .0003", I wonder if an increase in air pressure would lock it down better?

Widgit

[BobWarfield]

Fun stuff!

I woulda thought one of those springey coiley air hoses would be good for this application, perhaps with a quick connect mounted to the backsplash.

Now just imagine a CNC gang lathe doing your bidding!

Best,

BW

[widgitmaster]

Hi Bob,
The coiled air lines take up more space, and in my little shop that is a valuable commodity! The lathe is near the front of the garage, so when the door is open it covers the lathe. This eliminates access to the celing as a place to hang an air line, coiled or straight!

But you are correct, it is FUN

Widgit!

[widgitmaster]

OK,
Here is a little video of the turret in action, making delrin nut blanks.

VIDEO

Widgit

[widgitmaster]

Another video of the turret making aluminum spacers!

VIDEO (this is a long winded movie, be patient)

Station #1 is a push bar, which puts the stock at the starting position.
Station #2 is a facing tool, removing .005" material.
Station #3 is a 1/2" stub drill, set for .4" depth.
Station #4 is a 5/8" shank boring bar, finishing bore to .525" ID.
Station #5 is a turning tool, set to turn .87" OD x .39" long.
Station #6 is a parting tool, set to cut of the part at .37" long.

Next operation will be to hold the new parts in a collet, and face them to the final thickness.

These little spacers are used between the ball bushings and snap rings on the x-axis slide of the Mini & Midi-Routers. Two required for each router.

Widgit

[ozzie34231]

Hi Eric,
Are you getting that finish on the ends without polishing? (On the screws)
If you are maybe you can spell out the details of speed, feed, and maybe a closeup picture of the finishing tool; ,,,,,,,,in your spare time :-)
Ozzie

[widgitmaster]

Hi Eric,
Are you getting that finish on the ends without polishing? (On the screws)
If you are maybe you can spell out the details of speed, feed, and maybe a closeup picture of the finishing tool; ,,,,,,,,in your spare time :-)
Ozzie

Hello Ozzie!
No, making the ends is tricky!
I have found that by the time the tool bit cuts off the thread, the intermittant cut has killed the cutting edge! This is the advantage of having a turret lathe, as one tool rough turns the bulk material off. Then a finish tool removes the last .010" in light cuts.

Lastly, I file off a little taper from the 1/4" diameter, and polish the finish diameters with a Cratex stick (rubber impregnated with abrasives)

The tool bits are 3/8" AR brazed C6 carbide, sharpened on a diamond wheel. I have purchaces tool bits from Enco, and was not happy with them, so now I buy them from McMaster Carr. Enco's Chinese bits are not as tough as a C6 grade bit should be, and the steel that they are brazed to is bent or twisted!
This is a big problem for me, as the rigid tool holders on my lathe's turret require the tool to be exactly .375 from spindle center line!

The finish tool has a sharp point.

Widgit

[ozzie34231]

Thanks Eric,
I'll have to try the Cratex.
Why the sharp point?
Ozzie

[BobWarfield]

The videos are very enjoyable, Widgit!

Oh, but you are so close to nirvana. That lathe would be so easy to CNC!

Probably less trouble than building the turret and stops for it. Imagine it singing along with a pneumatic collet closer and bar puller.

If you leave off the spindle speed control, you would just need a few relays to turn spindle on and off, reverse (if desired), coolant relay, and a couple of Geckos for the two axes.

What a machine it would be for turn out router parts!

Best,

BW

[widgitmaster]

Pics.
After cleaning up a bit and re-looking at Erics pics, I see there are not many differences.
The piston is held on by a nut and there are some parts in Eric's pics I don't recognize.
I now see that the top screw broke while extracting it, I don't know why as the set screw was totally out.
I could make another but creating the hex hole would be a project for me. I think I'll just use a bit of loctite blue on the threads.

Jerry

Hey Jerry,
Did you ever get that 8-station turret hooked up and running?
Eric

[ozzie34231]

Hi Eric,
After looking at the thing for a long time I decided to work on setting it up. I took a lot of pics. and wrote an article which I've submitted to Home Shop Machinist.
Most of the article is on making and setting up the tool holders for CNC use along with Mach3.

It seems to work well in early tests, but shortly after completing it I decided to paint my '94 Infinity. Re-learning to paint with today's materials has proven a long experience. I painted and re sanded the hood four times.

Next week I'll get back to using the turret and giving it some real tests of repeatability and stiffness. I used a commercial angle plate to mount the turret and it was just big enough; so if stiffness proves a problem I'll go to a larger one or consider a huge chunk of cast iron. The weight of that would be more than I want to deal with at my age. It will be interesting to see if it's stiff enough for a parting tool. Of course I can still use my old post for heavy work; I've set the turret up as a back tool post. Using both back and front makes CNC coding a bit tricky with Mach3, avoiding collision and such. It's not a huge problem, just have to keep one's wine consumption under control.

Assuming I'm happy, I'll consider designing a new back end so I can rotate the turret with CNC. That shouldn't be too tough. The real beauty of the Mag is the indexing system; lots of surface, lots of surfaces.

Rotation of the turret with the air disconnected does not seem a problem; the spring loaded ball locater holds well enough, with the tools presently installed.

Thanks for your interest,
Ozzie

[Tkamsker]

Hi
i know this is an old thread but i am thinking to build me an Turret for my CNC Lathe (a new retrofitted one )
But i don't know if vertical or horizontal turrets are better.
So my question is about the real world use ,..

i expect your version of much "stabler" when you cut steel
i am thinking of doing one with steppers and electronic driven. Which you can or can not use with cnc. (also manual)

And your experience with your types of holders would interest me as well.
And if i may ask can you give me the diameter of you plate with the t-slots in it and the width of the t slots ?
i would like to have an idea of the size of the plate.
best reg thomas K

Another video of the turret making aluminum spacers!

VIDEO (this is a long winded movie, be patient)

Station #1 is a push bar, which puts the stock at the starting position.
Station #2 is a facing tool, removing .005" material.
Station #3 is a 1/2" stub drill, set for .4" depth.
Station #4 is a 5/8" shank boring bar, finishing bore to .525" ID.
Station #5 is a turning tool, set to turn .87" OD x .39" long.
Station #6 is a parting tool, set to cut of the part at .37" long.

Next operation will be to hold the new parts in a collet, and face them to the final thickness.

These little spacers are used between the ball bushings and snap rings on the x-axis slide of the Mini & Midi-Routers. Two required for each router.

Widgit

[Uguessedit]

I’m not sure how anyone can machine without getting polished parts. I’m self taught and I’m sure it all boils down to quality of tooling. I hired some parts out once I was overloaded and ended up throwing them all away after getting stiffed with his $1200 bill and what looked like sanded finished parts off a CNC Bridgeport. Worst parts I ever seen. All my parts have always finished polished looking like they’ve come off a buffer and hold a tighter tolerance than any name branded knee mill or CNC. I also don’t buy cheap tooling. Experiment, spend money like the rest of us learning because “education isn’t cheap”, like one man once told me after I had to buy 3 vices before I gave into a $900 Kurt vice. You get what you pay for and willing to invest in. It’s not all about feeds and speeds.

Hi Eric,
Are you getting that finish on the ends without polishing? (On the screws)
If you are maybe you can spell out the details of speed, feed, and maybe a closeup picture of the finishing tool; ,,,,,,,,in your spare time :-)
Ozzie

[Uguessedit]

Wish this were the case today. Not only do they not stock cast anymore even though it’s listed on the site they charge 3x what you paid plus shipping. MSC has the best price for Gray Iron and Ductile is fairly reasonable too if you don’t mind paying high dollar for cast. $380 for a 1.5” x 7” wide by 2’ section. Their 2-1/4” thick doesn’t come in blocks wide enough to be usable or you have to use straight gray iron and a a 1’ x 8” x 2” section is around $150 plus shipping. Either way you’d want to harden it especially gray iron being so brittle and crumbly. I need an 18” long section at least 6” wide for my project and no less than 2” thick preferably 2-1/4” to get a 2” finish which isn’t available in ductile unless I want to go somewhere and special order for $500 plus shipping. Not worth it I may as well just use a block of tool steel cut the ways, harden it, finish machine it, and keep it well lubricated. Essentially it’s been holding me back from doing my project since I’m set on cast iron but I won’t pay that much for it. It starts getting the cost up enough where I’m ready to leave the lathe alone and do a build from scratch epoxy granite frame with linear ways and frame out a Swiss mark style build with multiple hydraulic spindles. More or less and all out or in scenario where the Chinese machine just isn’t worth the huge investment despite its amazing accuracy. Then again we always need a good manual lathe anyways.

This morning I called Speedy Metals 1-888-744-4140 and ordered one piece of cast iron for the adapter base plate!

A 12 1/4 x 6 1/4 x 2 1/4 piece of cast iron cost me $85.98 including UPS shipping!

That's still cheaper than buying a used Turrel Lathe!

Widgit