CNC'ing a Hardinge 2nd OP DV-59 Lathe

[Ken_Shea]

Started collecting parts for a CNC lathe some time back, in trying to figure out what to use for a spindle and bed this was seen on Ebay.
Well you can see the winning bidder
I know of at least one other on the CNCzone (NEATman) that is doing much the same thing so perhaps he will join in along with any others for ideas that may help any considering a building or converting a CNC lathe, particularly the Hardinge DV-59 type.
Text and pictures will be posted as this project progresses.

[Ken_Shea]

First step was my favorite, ripping something apart
The entire unit was dissembled to see what made it tick, and then to get serious about the conversion.

This picture is surfacing the bottom of the lathe to make things parallel with the top for some subsequent top side machining and be assured that we are on the same plane. As it turned out this step was unnecessary as it was almost perfectly parallel with the top side.

Wms, if you see this, I'm making use of that 1" cutter that you gave me, thanks

[ViperTX]

How much was the shipping on that little jewel...where in the US are you?

[Ken_Shea]

ViperTX,
My location is north central Ohio about 50 miles due north of the capitol (Columbus).
Shipping to my door was $258

Ken

[nervis1]

You need a longer coolant hose Ken. No doubt.



I'm real keen to watch you build this thing. It looks like the start of a great project and I'm looking forward to lots of pics and "how I did it's"

Can't believe you got that little jem for 300 bones. Nice find.

Dave

[Ken_Shea]

You need a longer coolant hose Ken. No doubt

LOL, yeah, I have not a clue why I have put up with that short hose for so long, I think I just got so used to it that it wasn't thought about, but now that I am, it is dang annoying. Think I will do something about that tonight.

I thought it was a good deal as well, my favorite part is the stand, I just love that stand, the doors are 3/16" thick

I intend to post lots of pics.


Ken

[NEATman]

Ken-
I was under the impression that Pstockley had also planned on doing a hardinge conversion.

Post #16 from his thread reads:
"After much thought, I have decided to go the retrofit route. The numbers just weren't adding up with the approach I planned.

So I have bought a Hardinge TFB lathe from eBay that isn't in great shape but will be perfect for my needs. I will create a new thread to cover the conversion.

This thread is now closed."

It's a good point anyway, to start a new thread. Now we can all use it.

Thanks for getting it under way.

Anyway, with that said, this is the thought that I had for locating the THK rails to help keep them clean, and protected. Also keep the maximum swing possible. (see jpg)

For the cross axis, the rails move and the modules are stationary.

I have some real wild ideas on how to use ballscrews and make it both manual and CNC. I'm thinking of making both the ball screw, and the ball nut rotate on thier own bearings. So, on the Cross axis (short travel) there would be a handle on the end of the ballscrew. With the stepper motors engaged, and holding position, they would hold the ball nut stationary. So you can use the lathe manually by cranking the handle and rotating the ballscrew without backdriving the motor. Conversely, when using the lathe as a CNC, there will be a clamp on the manual handle to lock it in place so the ballscrew cannot rotate, and the stepper motor can control the machine.
Again, this I need to add to the model.

Attached is a picture of the THK rail placement that I am considering, and a picture of the old hardinge. I still want to find some way to use the old turret tailstock... Maybe a stepper motor linear actuator to cycle the handle to preprogramed depth's...

Keith

[NEATman]

A few more things...

Great deal on the lathe, :-) However, I got paid $250 for removing this lathe, a bridgeport, and a 36" sheet metal shear. ;-))))

I have an extra collet closer. I'm not sure what model Hardinge it fits, but it'll be for sale soon.

Keith

[Ken_Shea]

Keith,
I read and then forgot about Pstockley decision.

I like your setup, I did not get a cross slide or Tail stock, not likely to be used but they should sell well. I see you also got a Chuck, those little buggers go for $150-$250.

Early in my thoughts on how best to mount the THK rails I considered your approach but decide for top mount for sake of being easier and then just forgot about the underside mount. Your idea has now renewed my interest to where I think I will opt for that route as well. Unfortunately the original plate was ordered last week and cut for pickup today. So that is about $80 gone. I don't suppose you would reimburse me since if you had mentioned it earlier I would not have ordered it.

The new plate should be available next week.
The mock-up shows that it will need be about 11" wide, 12" was all that was available but I will machine it down as needed.

The Rails I am using are THK HSR25LA x 820mm
These use the longer trucks, I will be using only one per side for the cross slide.
For those interested in a link to THK Specs and what all those letters and numbers mean, here is a good one.
http://www.arsales.com/pages/thk/products/hsr.htm

[RotarySMP]

Keith, why do you want to add manual control? It is really unnecessary on a CNC, and compromises the design and enclosure greatly, but the need to put your hands to the machine when running.

The idea of separating the screw and nut drives is novel, but ensures you lose your zero every time you touch the manual portion. A better solution is servos and a servo to go or Pico systems driver with real closed loop feed back, so you are using the encoders as DRO's while manual driving, and never lose position.

The other issue is that ball nuts back drive, so you would need to add some sort of friction brake or partially powered motor to prevent the tool loads jerking the axis out of your hands.

Those machines look like great basis for a fantastic small CNC.

[Ken_Shea]

However, I got paid $250 for removing this lathe, a bridgeport, and a 36" sheet metal shear

I have no comment

[NEATman]

RotarySMP-
Thank you for pointing out the tooling loads. I was planning on leaving the steppers powered, to hold the nut in position, but I have several 24volt power off brakes that would be a perfect saftey measure.

Concerning loosing the zero point, there are several things I did not mention. One, I would have the reference switch (Zero point) mounted between the moving carriages, so that it's easy to pick up zero again. Second, I have a couple DRO's and I was thinking of mounting a rotary or linear encoder on each axis to allow me to easily repeat back to the same position. Also, it's nice to have a DRO on a hardinge.

As to why I would want manual control, I'm not making this for production. This is a "toy". I already have an old 9" south bend, but there is no way the old 9" can match the accuracy of the spindle on a Hardinge. (Sorry if I offended any SB lathe lovers) Also, the majority of the work that I do is manual, but I literally have all the parts needed, I just have to make the time to design it and put it together.

Also, this lathe never had a dovetail way. It only has a T-slot. It does have a manual cross slide and compound, but they are pretty beat up, and there is no carriage. So, Converting this machine is not destroying a toolroom lathe, I'm not that crazy!

Keith