Just finished my Lathe Conversion Harbor Freight to CNC

[seanreit]

took about a week to do, pretty simple system. Pictures show the story.

YouTube - My lathe vid 2

YouTube - My lathe vid 2

[PEU]

very nice!

you attached the rails directly to the carriage? was it difficult?

[dareposte]

Is that a LM rail on the bottom there? Whats the purpose of it?

You saw my conversion-in-progress, I was attempting to keep the ballscrew as close to the ways as possible.

Very impressive for a week's worth of work, mine has dragged out a month so far and only the Z axis is done.

What size motors are you using?

[dareposte]

Have you figured out a way to do a spindle index pulse for threading yet?

I've got a few ideas but haven't attempted anything yet.

[seanreit]

I have not even tried spindle control RPM wise, I bought the CNC4PC on/off control, and the motor in this unit basically blew that box up, it didn't have a chance. At start up, the stock motor I think is over 15 to 20 amps.

Feel free to call me at 512-656-2357 to discuss what I did. I am not a "machinest" per say, just a hobby guy looking to make parts. I know how to work this, but I do not know a lot of the vocabulary. Some of you guys will cringe to know that I'm driving this as a Mill, with x being left right, and z being depth of cut. I could not figure out how to do it any other way. I do not know what "LM" is, I can tell you I used 640 OZ steppers. Connected to Gecko drives through a cnc4pc breakout board.

[dareposte]

Those steppers are massive!

I did manage to put a Hitachi frequency drive on mine (X200-007-NFU), and with a cheap 3 phase motor it makes a 1 hp spindle useful from about 30 rpm-2500 rpm. It has an analog input for speed control that takes 0-10 volts, which I plan on integrating into EMC2 some how.

I absolutely need to be able to do threading on my converted lathe, so I definitely need a spindle index pulse at a minimum, and would prefer getting 1/4 rev resolution or better.

The LM guide I was asking about looks like it's attached down behind the ballscrew, the long linear guide. I was just planning on using the lathe's ways as my linear motion control so I haven't made any accomodations for other linear motions.

[dareposte]

If you want to do an On/Off control it is a fairly simple matter to wire up a contactor and a control relay. Well maybe not so simple, but definitely not extremely hard either.

You have a 5v signal turn on a low current solid state MOSFET control relay, which switches 24vdc or 110-220vac to pull in a 50 amp rated motor contactor. For the stock lathe it can replace the forward/reverse switch if you don't ever need to run it in reverse.

With the VFD I put on mine it just takes a simple buffered input to turn it on / off from EMC2, and appears to work pretty well. I am very excited to get mine running.

[jhowelb]

Originally Posted by seanreit I have not even tried spindle control RPM wise, I bought the CNC4PC on/off control, and the motor in this unit basically blew that box up, it didn't have a chance. At start up, the stock motor I think is over 15 to 20 amps. Feel free to call me at 512-656-2357 to discuss what I did. I am not a "machinest" per say, just a hobby guy looking to make parts. I know how to work this, but I do not know a lot of the vocabulary. Some of you guys will cringe to know that I'm driving this as a Mill, with x being left right, and z being depth of cut. I could not figure out how to do it any other way. I do not know what "LM" is, I can tell you I used 640 OZ steppers. Connected to Gecko drives through a cnc4pc breakout board.

That appears to be Mach 3 that your running on your computer. In that same package of software is Mach 3 Turn, specifically intended for lathes. There is a pdf on their site that explains everything you need to know about it.

Included in that software are wizards to do inside and outside turning, tapers (in and out) balls and cavities and threading. A spindle pulse will give you the ability to use the threading.

GOOD JOB!!

[antichip]

Very nice work. Clean.

I will be using an optical interrupter with like 100 count wheel. parallel port may read it or I may need some I/O interface. we will see. I am not looking for x control at the moment just some automated turn down and easy threading. I will be using emc2. There is a pwm to 10v+- but I can't recall it