[gt40]

I wanted to start a new thread to document conversion of my Jet 13x40 lathe. Most of this should translate to similar size lathes like the PM lathes etc. and I hope it will be of help to anyone considering it. I am basically building off of the lessons learned from successfully converting my PM45M mill to CNC.

http://www.cnczone.com/forums/vertic...g-factory.html


My Jet mill suffered another crash last year and completely lost threading capabilities on what was a decent machine. Instead, I am converting it to a gang or turret style cnc lathe with vfd and controlled by Mach 3.

I started by taking off the lead screws, x axis compound etc off. All of this goes away with a cnc conversion and I will use a pendant to control it. There is no reason to have cranks and they just get in the way.
Initial mockup. Note the compound goes away:
Attachment 237564

The servo will go underneath with timing gears to run it.

I was able to pick up a 2.5"x 10" x 13" piece of 7075 tooling plate from the scrap pile at industrial metal supply. It will replace the compound and shelter the ballscrew from shards etc and be a rigid platform for a turret or gang setup.

Next I had to machine the saddle to make where I would mount the ballscrew perfectly parallel to the surface on the dovetail. This setup took several hours to get it aligned but I was able to use it to flatten the saddle and also drill the holes to mount the ballscrew:

Attachment 237566

I made ballnut mount via cnc on the mill:

Attachment 237568

I was a little concerned whether having the ballscrew mounted offset would cause binding but after everything was mounted, a small cordless drill easily moves the x axis really well. I can't even begin to describe how much more rigid everything is with no compound and a giant piece of 7075 on the x axis.

Pic of the ballscrew mounted:
Attachment 237570

Next up, I have timing pulleys coming and a 3 hp extreme duty motor already to go:





My jet used to look pretty much the same as the PM lathes. Now it is definitely on a "diet":

Attachment 237576

left overs:
Attachment 237578

I took some time today to prep the lathe now that it is all stripped to go ahead and paint it.

2 coats of primer:

Attachment 237580

I ended up having some fun with the paint:

Attachment 237582

Attachment 237584

Attachment 237586

For reference, this is what the lathe looked like when I started with it:



thanks for looking,

Gt40

[gt40]

Update:

I made some progress with the x axis. I mounted and aligned the ballscrew and the new riser plate. I was concerned whether there would be any binding. After aligning with my test indicator, I tightened up my dovetail, then torqued all of the screws holding he riser plate to the x axis, the ballscrew and mounts. I hooked up my test indicator and couldn't get it to move, everything is extremely solid. Next I hooked up my drill to check movement. Here is a short video moving the x axis over its full range:





Finally, I drilled and tapped the timing pulley and mounted it. The axis moves smoothly and without binding using the drill and by hand.

I am using a 15 and 25 tooth "L" timing gear setup.



I will probably get a shorter belt to keep the axis more compact. The belt was a left over from the mill conversion.

Thanks for looking

[charlieslasher]

Update:

I made some progress with the x axis. I mounted and aligned the ballscrew and the new riser plate. I was concerned whether there would be any binding. After aligning with my test indicator, I tightened up my dovetail, then torqued all of the screws holding he riser plate to the x axis, the ballscrew and mounts. I hooked up my test indicator and couldn't get it to move, everything is extremely solid. Next I hooked up my drill to check movement. Here is a short video moving the x axis over its full range:





Finally, I drilled and tapped the timing pulley and mounted it. The axis moves smoothly and without binding using the drill and by hand.

I am using a 15 and 25 tooth "L" timing gear setup.



I will probably get a shorter belt to keep the axis more compact. The belt was a left over from the mill conversion.

Thanks for looking

Looking good.will you have css? Are you using modbus? What sotware are you using?

[bill south]

Nice Job!
Love that chuck!
Bill

[gt40]

Looking good.will you have css? Are you using modbus? What sotware are you using?

I am going to use Mach3 with DMM Tech servos. I used these with an Ethernet smooth stepper on the PM45 conversion. This has proven to be reliable on the mill and I will have one less thing to learn: P

I would like to do constant surface speed- any suggestions on running it on Mach 3 would be appreciated, as well as affordable cam if it exists. I haven't used Modbus yet but am looking into it for when I get a turret setup.

[gt40]

Update:

I made some real progress and got the z axis largely done. I made a monolithic ballnut block that is 1.8" thick and mounts to the saddle. I also made the two bearing blocks that support each end of the ballscrew. The trick was getting everything square and aligned. I was rewarded by a z axis that moves very smooth without any binding on the full range. The ballnut block has a "L" shaped cutout for my skarf guard I am making to protect the ballscrew. I have to finish the other 2 sides of the "box" I am building under the saddle that will protect and house the x axis servo and pulleys still but I can't wait to get this thing running. It is so stiff and solid compared with the way the lathe was stock and there is absolutely no perceptible backlash.

Pics:

[gt40]

Update:

I was able to make some real progress and the CNC conversion is almost done mechanically. I still need to add the the limit/homing switches and run the one shot oiling system, enclosure etc(It's never really done!)

I tried to document the the build with a lot of pics so you can see was involved. The electronics are easy with the DMM servos and it is almost plug and play.

Enough yapping, here are the pics:

Attachment 241258


Attachment 241260

Attachment 241262

Attachment 241264

Attachment 241266

Attachment 241268

Attachment 241270

Attachment 241272

Attachment 241274

Attachment 241276

Attachment 241278




Final overview shot:

[LeeWay]

Very cool project. That thing will produce lots of nice swarf. Looking forward to seeing it completed and making some cool stuff.

[bill south]

GT40;
Are you using any plans or just winging it? I have a Travers tool 9X30 I'm considering for CNC and like some of the mods you've made. Looking forward to the next installment.
B

[gt40]

GT40;
Are you using any plans or just winging it? I have a Travers tool 9X30 I'm considering for CNC and like some of the mods you've made. Looking forward to the next installment.
B

Thanks for the kind words. The plans are my own and I was trying to make everything as simple as possible so no complex shapes and a design that could be completed with a manual lathe or a drill press and band saw so people without a cnc mill could hopefully use the design. I think stripping the lathe down, cleaning it and paint took more time than to make the parts to convert it to cnc.

[BloomingtonMike]

You are doing a Great job. Just wanted to say thank you. I just got a brand new 13X40 manual with DRO. This CNC conversion is sweet!

[gt40]

I finally got things working. I changed the z axis layout and converted to L timing pulleys with a 2:1 reduction for more resolution and mounted glass scales to make calibration easy. The DMM tech servos are really smooth. I am only running at 100/inch min with 20000 steps resolution. Here is a test video running gcode created from Mach3 turn wizard to check function:





I need to add my skarf shields and spindle pulse generator and coolant but at least it works.

[vertcnc]

I have my eye on an Enco 13x40, may have to pick it up and take your path. Thanks for sharing.

[gt40]

Greetings:

Here is a short video of my first test cut using a taper wizard in Mach 3, cutting a 60 degree taper, 0.95" long on a 1.5" piece of aluminum:





I am still figuring speeds and feeds so i just went with 10" minute feed and .05" doc. The lathe is much more rigid now than it used to be and I think I am just scratching the surface on the speed. What's cool is how good of finish quality I got cutting a taper without a cross slide.

Sorry about the poor quality, I was so excited just figuring out the wizard and being able to cut something I shot it handheld with the phone.

If anyone has any suggestions for cheap cam for the lathe, i would be greatly appreciated. I am using mesh cam on my mill but it doesn't work for the lathe.


Thanks for looking

[gt40]

Update:

I got Dolphin Turn and have been busy learning. I am starting to make sense of things and finally was able to thread with my lathe once more. The whole reason for me doing this conversion was I had a bad crash on the lathe a year ago and it was going to cost about the same to fix it as go cnc. I am pleased I can thread again and am starting to make some lights.

After learning how to thread on a manual lathe properly, my first experience threading via cnc was really humbling. less than 90 seconds to face, turn and thread a tube with perfect accuracy. I will post some stills of the threads but they came out beautiful. I also tested cutting various stock out in steel and aluminum and threading to fit nuts I had laying around and well, it just works:



Quick pic of part of custom light I am designing. I made these bodies setting up the tool offsets in the mach 3 software that runs the lathe. FYI, the finish is right off the lathe without polishing and with mist coolant I borrowed from my mill. It is about 3 minutes to make a part including facing, profiling, threading both sides and parting off the finished part. I had to get a left and right side threading tools.

[chevydyl]

Pretty awesome man. Good job. What kind of custom lights are you making? Auto or home?

[gt40]

Pretty awesome man. Good job. What kind of custom lights are you making? Auto or home?

The design I have been playing with is a single 18650 powered light with a task led driver and xm-l led and cerakote finish. Finishing up on the head design and it should be ready to go.

[chevydyl]

Dude that's so badass I love flashlights. Can you show a pic of the components that you mentioned

[rowbare]

Very nice. It seems to perform superbly.

I noticed you chose to mount the X ballscrew to the right of the crossslide instead of using the original screw location. Was it a space issue?

bob

[gt40]

Very nice. It seems to perform superbly.

I noticed you chose to mount the X ballscrew to the right of the crossslide instead of using the original screw location. Was it a space issue?

bob

I wanted to do as simple of a conversion as possible and also use existing parts- I had previously got the ballscrew on ebay for a really good price and wanted to use it. Mounting on the side was the easiest and with the linear scale I have mounted, there is no detectable backlash or binding. The other option would have been to just machine the dovetails on the x axis flat and mount linear rails with the ballscrew between them. Given how well it is working, I am fine for now.