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lar45
04-19-2005, 12:38 AM
Hi all, been busy with school and haven't been around much.
I'm working on converting my lathe/mill to CNC. I bought some stepper motors and have been working on getting them mounted. I picked up some stepper driver kits to put together. I'll get them soldered tomorrow. A friend gave me an old PC to run it with, but it's not working and I have to go through it. I got the demo version of Mach2 CNC, limited to 1000 lines of code. It looks like it will have lots of cool features to learn about. It will take a DFX file from AutoCad or a scanned in jpg or bmp and generate G-code. It has a setting for backlash to help deal with the slop of the machine also.
should be fun. I'll post pics as it progresses.
This will be the final for my Mechatronics class.
http://www.lsstuff.com/pics/projects/stepmotor-01.jpg
The lead screw ended inside of the bearing block, so I had to bore it out and braze an insert in to lengthen it.
http://www.lsstuff.com/pics/projects/stepmotor-02.jpg
Here it is with the stepper motor hanging in the air. I have it bolted down now and I'm working on the cross table next.

Buckshot
04-20-2005, 12:09 AM
............CNC, COOL! Now you can go into production.[smilie=w:. I know zip point nada about setting up the mechanis or the code. I've just seen some nifty repetative work done on them.

BTW, you need some way felts on that tailstock dude! You have them on the carriage, right?

..............Buckshot

TCLouis
04-20-2005, 10:03 PM
Way Felts . . . OH no my old South Bend does not have them either.

I'm guessing felt wipers to remove grit, grime and chips . . . .
Sounds like a good idea to me. Do you have any pictures?

Buckshot
04-21-2005, 12:32 AM
...........No photos on hand. My lathe had them on the carriage but they were dead. I bought some hard wool felt from McMaster-Carr and used a razor blade to cut it to fit the housings. I got to looking at the tailstock, which didn't have them, yet it too was slid back and forth regularly. I made my own wiper holders out of 1/4" thick alum milling the backside out. The tailstock also had to be D&T'd to accept them.

Besides excluding abrasives, the wipers also lay down a layer of way lube for the carriage to slide over. This summer I want to remove the saddle and apron and go through them. I saw a neat alteration a guy made on his saddle. He drilled through them and then added Gitts drive in springtop oilers, one on each arm of the saddle. This makes sure that oil gets to where it's needed most, as you have cast iron sliding on cast iron.

Logan Actuator sells the way wiper holders but they charge like $40 for 4 of'em:shock:! I appreciate the fact that they still make parts available, but holy cats! At least I can make those simple enough.

TCLouis, what size South Bend are you running?

You also might go to the Home Shop Machinist BB and type in 'Way Felts' in thier search engine.

.................Buckshot

lar45
04-22-2005, 12:57 AM
Yes the carriage has them. I never thought about putting some on the tail stock, but it's a good idea.
http://www.lsstuff.com/pics/projects/boards-01.jpg
Step Motor Driver boards.
http://www.lsstuff.com/pics/projects/boards-03.jpg

http://www.lsstuff.com/pics/projects/pc-02.jpg
Why doesn't it blink???
http://www.lsstuff.com/pics/projects/shaftmod-02.jpg
Working on the cross table.

lar45
05-07-2005, 02:24 PM
It works finally.
http://www.lsstuff.com/pics/projects/pawn-01.jpg
This was my test piece. I tried takeing too large of steps with the first one.
The second one went much smoother.
I only have the 2 lathe axis' hooked up, but after finals, I'll get the mill axis going also. I mounted the stepper drivers in a $4.99 plastic tool box. I used an old PC power supply for the boards and motors.
I still need to plumb in some chill water for the heat sinks.
http://www.lsstuff.com/pics/projects/box-01.jpg

http://www.lsstuff.com/pics/projects/heatsink-01.jpg

http://www.lsstuff.com/pics/projects/screenshot-01.jpg
This is the Mach2 control program.

Buckshot
05-14-2005, 03:55 AM
.............It looks to be coming along. What's the latest update?

.............Buckshot

lar45
05-14-2005, 02:13 PM
I was useing the 12vdc lead from the PC power supply to run the motors. The power supply is now only putting out 10.3v and the z axis motor is starting to stall on movements. I'm building a bigger PS from scratch and will try it inplace of the PC one. I called clickautomation.com and asked about the motors, they said to run it at 70-80vdc and maybe go to a bipolar drive if I don't get the kind of performance I need. I think I will try those options first. If not, I'll get bigger motors. I have the 640 oz/in ones now, but they have one that goes up to 1200oz/in in the same frame size.

I've been checking the accuracy and repeatability of the axis to try and fine tune it. The repeatability of going out and comeing back to the same point is really close. I have a dial indicator that goes to .001". It definatly stay's withing 1 mark and looks to be +- .0002". It does seem to have a problem on indexing a specified distance though. I can't seem to get it less than 1 mark or +- .001". The drives do have a 1/2 step funtion with full torque, so I may play with that and see if it gets any better.

I put on the cap and gown today for graduation and got my stainless stell pinky ring for order of the Engineer last night, so I guess that makes me official now.

We're having a big BBQ at Mom's after graduation(read big pile of Elk steaks that have been marinating since yesterday).

Willbird
05-16-2005, 12:57 PM
I'm wondering how hard it would be to gin this kind of setup to do engraving ?? a Hermes is a good engraving machine and they are not cheap, and they just trace a template and drag a diamond, there is a rotary engraving add on avail for them.

with a small stageing table (like they use for a microscope) and spring loading it to remove backlash this type of setup would work great for engraving like 07/02 mfg. do on their products.

Bill

Rrusse11
05-26-2005, 01:45 AM
WOWOWOWOWOW!

You're building a what????????

Magna cum Laude in my book man.

You go mister! / {:o)

Richard