My goal for sunday is complete!!

[willburrrr2003]

Last couple days I have not been able to get out and work on my cnc lathe , so made myself a promise I would get out there today and get the following accomplished.

1) get lathe wired into control panel

2) get computer moved out to shop and wired up & connected to control panel

3) troubleshoot the limit switch error that crept up on me before the move out to the shop

4) plan my part cuts , which is for an encoder wheel for my spindle so that I can get spindle speed indication

5) load and set my tooling (facing tool, boring bar, turning tool, and part off tool)

so after all that I chucked up a 2.5" piece of round stock and proceeded to generate and run a face off program. Then loaded tailstock with pilot drill. I drilled pilot hole, then enlarged it to 3/8". Next I generated and ran the boring program for enlarging the 3/8" hole to 1.04" and a depth of .08 . I followed up with a scribe mark for the encoder hole locations (mark located at 2.0 dia. I then generated my turning program, and turned the outside down to 2.2" for .12" . All this went smoothly, but part off wasn't a nice easy cut...having problem with worn spindle gears, so it took forever to make the parting cut. At one point I switched parting tools, and my other tool cut a bit better but not much. Pics below are my CNC converted mini lathe, the stock I made my part from, the part from right, the part from left, and the part head on showing the 0.04" thickness.

The encoder goes in between the two nuts on the spindle shaft that can be seen to the right of the encoder in the last pic. I will get it mounted and hopefully get the optical encoder wired and working too

That my friends is my first CNC machined part, using my lathe to make itself better

Regards,

Will R. Everett, WA.

 

[DICKEYBIRD]

Congrats Will...what a nice feeling eh? It's an empowering experience getting the "magic" to work and making something with it.

What software are you running? Must be EMC? TurboCNC and Mach3 both want 1 slot/hole in the encoder wheel. I recently got my spindle speed readout working with a CNC4PC C3 index pulse card/sensor kit using MACH3. It's amazing how accurate it is.

Milton

 

[willburrrr2003]

Dickeybird,

Thanks yes it was a very good feeling to actually get things working and make a useable part I am running EMC2 for my software, and when I was talking with the EMC2 group about setting up my encoder realized that I did not make it right. I do need to have a single index pulse, and the encoder pulses (32 is good) on the wheel. I do not have enough materi8al to add the index pulse mark (has to go outside the encoder pulses). I made the encoder part based on the one on littlemachineshop.com, but the encoder is made to hook to a spindle speed box that they sell as well. The part came out exactly as I wanted, but turns out I didn't know exactly what I needed .... hehe. I will be re-making it, as soon as I figure out why I am having such a problem with parting off. I can't get the lathe to cut right, either chattering badly, or stalling the spindle. and I can't get feed rates wort a dang with my other tooling and get light chatter, and stalling with them as well. It was gutting great on a practice part about a week ago, then stuttered a bit on a couple passes, then got real bad and stalled....gears made their awful noise, and hasn't cut right ( had to drop all my feed rates down or would stall from then on) since then. I was thinking that I didn't have my cross-slide adjusted right from when I did my toolpost mod last week, so I tightened up the adjustments on the cross-slide. That did not fix the problem. today I took my parting blade to work for re-grinding today. Will see if that helps it cut better tonight I am thinking that my beat up spindle gears in the head might be part of the problem too (did I just say the problems all in my head?? hehehe), but I can't order them until Friday.

Regards,

Will R. Everett, WA.

 

[DICKEYBIRD]

"Parting is such sweet sorrow."

Sounds like your blade is digging in and grabbing due to lack of rigidity of the saddle/toolholder and/or blade angles ground too aggressive. Move the toolholder to the back side and mount the blade upside down. You won't believe the difference!

I envy your ability to work with EMC. I haven't tried it but it looks too complex for this old dog. Maybe later when I get better at the CAM thing. I do OK with TurboCAD but the CAM (CAD2Lathe) is slowing me down right now.

 

[willburrrr2003]

Well I had the chance to get out in my shop and work with my lathe more last night. Turns out my spindle gears are fine, my drive belt was way way loose and that's what the slipping and noise came from. That is why my spindle was stalling and chattering with most of my tools and cuts. I now have excelent feed and speed rates for boring, turning, and facing ops again ;D Parting is still a pain, though it is better than it was. I tried to re-make my spindle encoder, took about 1/5 of the time it took me last try (last time had to figure out lots as I went, this time, knew the steps and procedures I needed to do ) so about an hours worth of work. Everything went great and I made a nice looking part. I started my part of, was going ok...making little chips instead of a nice curl but was cutting.... right up to the point to where I killed the part ??? . It cut the part off way sooner than I expected. ??? so a confused me took a look at the part and work piece, and tool....conclusion, make sure tooling is ground properly! In my case, the tip of a parting blade has to be ground perpendicular to the work...mine slight angle to it, which pushed my cutting tool to the right as it cut, causing it to break out of the stock early and kill the part. I chocked it up to a good learning lesson, and lathing practice :big: instead of getting all frustrated... I will be out in the shop again tonight to give another go at it 8)

Regards,

Will R.