Intro & Gorton I-22 CNC Conversion

**EmeraldIsleforg** · 06-29-2010, 12:51 PM

I found this site recently while researching converting my Gorton I-22 MasterMill to CNC. I got this machine a few years ago from where I used to work & it runs pretty well. I mainly tinker with stuff right now & have been a hobbyist blacksmith & bronze caster for 15 years or so now. I'd like to use it to make patterns for casting & probably engraving and knife parts. I also plan to do some fabricating for custom external engine parts for my VW TDI.
Anyhow, I'm stuck on what size of steppers to use on it. I'm finding conflicting information. Some places/people say 300 oz/in or so will work & others say 1200 oz/in or higher are needed. I'm going to have a 2:1 reduction on the X & Y axis & 2.4:1 on the Z. Any suggestions on sizing?
This mill has the housings & cogs from a Tru-Trace system already on it, so all I need to do is mount the steppers to the housings & put a belt on them. I need to fab up the mount for the Z axis, but that shouldn't be too bad.
I was looking at hobbycnc for their kits, but it seems that they will be too small, I need a NEMA 34 size stepper for it to mount the the existing housings. Right now, I'm looking at Kelling's site for it, but I'm open to others that might be better and/or cheaper.
I've never done any CNC before. I started playing with CamBam & I like it so far. I'm planning on using EMC2 for that part of it.

Thanks for any help &/or feedback!

Mike

**EmeraldIsleforg** · 07-07-2010, 02:47 PM

Anyone have any suggestions/answers to my questions? I'm most interested in finding out what size stepper would work the best for this.

Thanks!

**MrWild** · 07-07-2010, 02:58 PM

Not many have converted a Gorton Mastermill. Keiling is a good place for drives and motors. My first mill was Gorton Mastermill. I still have a bunch of collets for one. Also have some of the electronics for the DC drives along with the motors. Not servos, just powered X and Z, axis. If you live close to southeastern Wisconsin, you could have it for the hauling. Way to much $$$ to ship though.

**EmeraldIsleforg** · 07-07-2010, 04:18 PM

Hi MrWild,

Thanks for the response! Glad to see someone who knows Gortons! I would like to take you up on your offer, but I'm in Ohio, just west of Cleveland, so that would be a goodly drive for me. If I get out that way sometime, I'll get ahold of you about that stuff.
I'm sure another mill of similar size would be close to the same size of stepper, if someone has done that before. I didn't find much info on a quick search, unfortunately.

Mike

**will gilmore** · 07-07-2010, 08:38 PM

Besides the belt reduction the other gearing to keep in mind is the pitch of the leadscrew. Put a beam type torque wrench on the axis and see how much torque it takes to move it, then figure for the reduction. You want to have a solid margin of safety for steppers so as not to lose steps.
--Will

**EmeraldIsleforg** · 07-21-2010, 09:42 PM

Well, I bit the bullet & got the steppers(906 oz/in), drives, PS, pendant, etc... from Kelling! Should be here tomorrow! I started messing around with EMC2 & found that I need to know my leadscrew pitch. Anyone happen to know what that would be on a Gorton I-22? Does it help to know that one revolution of the hand wheel =.200" on X & Y & .100" on Z? I'm sure I'll have other questions later on, but this would help a lot right now.

Thanks!

Mike

**CNCISME** · 07-21-2010, 09:51 PM

Hello Mike

Pitch is number of threads per inch. (tpi) One turn equals one thread. So 1. inch divided by .200 (one turn) is 5. So pitch for x and y axis is 5 tpi and 1 inch divided by .100 (one turn) is 10 So pitch is 10 for z axis

Good luck with project

.... and please have someone else check my work LOLOL

**EmeraldIsleforg** · 07-21-2010, 10:12 PM

That makes perfect sense now that you wrote it out for me! I should have thought of that myself, DOH!

Thanks!!!

**CNCISME** · 07-21-2010, 10:18 PM

Hey Mike I am about 2 1/2 hours east of you .... when it is done I would like to see it. I have 2 bridgeport cnc's I am retrofitting. Casting bronze in your own molds sounds so cool !!!!

**CNCISME** · 07-21-2010, 10:28 PM

another way to determine tpi is to lay a tape across the threads and count the number of threads per inch !!!

.....LOLOLOL

**bonestock** · 11-12-2010, 03:52 PM

EmeraldIsleforg any updates on your conversion. I have a Gorton 2-30 Tracemaster I am converting. I would be interested in how you fabricated your brackets for the knee. Since it is so freakin' heavy, I have considered keeping some of the hydraulics intact just to control the knee.

**EmeraldIsleforg** · 11-20-2010, 09:25 PM

I haven't done too much yet, unfortunately. I did get the steppers mounted in the last couple of days though, attached are pictures of how/where they are mounted on X, Y & Z. Now I just need to wire everything up & get EMC2 working on it. I had to put the steppers on the Tru-Trace covers of X & Y, the back side was too thick for the short shafts on them.
I haven't done anything with the knee yet. I doubt I'm going to put a stepper on it since it is so heavy, although I do have a strong gear motor that I'm thinking about mounting to it for power up & down. If/when I do that I'll post some more pictures of it.

Mike