Hey Carve_one, Graham and all.....
the solsylva acme upgrade is basically done, and producing parts!! Have run for a couple of days at X=60IPM and y=65IPM to check for loose parts etc.... Finally found all my strange intermittent problems where do to a weird issue with the puter I was running Mach with. Didn't realize that was the problem til I talked to Art.. The issues almost went away with the Acme upgrade, but were still there very intermitently. No probs at all since I changed out the computer.
Now that it seems happy for a couple of days, I decided to see what it could actually do now. Just did a few air cuts of the contract job I'm doing, after bumping up the max speeds a lot. I set the Y up to ~100IPM, and the X up to 90IPM, accel at 10, and all jogs semmed happy, much to my surprise. It ran almost half way through the job before the Y coughed... WOW!!! set them both to 90 and it ran all the way through.. Gonna back off to 80 to actually run the job some more. Still a little gun shy after my weird problems...
These are the following changes from the plans after a year of use....
1) Xylotex board with 269oz steppers, 24" x 48" cutting area.
2) NEW! 1/2-10 acme lead screws from Enco on all axis, no turned ends, using all 0.5" ID hardware, including bottom Z bearing added.
3) NEW! Steppers on Y and Z coupled with short belts, not direct, with 15T pulleys.
4) NEW! DumpsterCNC AntiBacklash nuts.
5) NEW! Doubled up both of the 1x4 end plates to limit vibration, especially on stepper end.
6) 1.5" x 2.5" Steel tubing for sides and gantry. (sure glad I did that, and to think I only used those because they were free LOL)
7) Added dampers, since it really made the slower cutting speeds sound much better.
Now to slowly change the rest of the wood to metal...
Didn't go the multistart to keep upgrade price down. Didn't go ACME originally went 1/2-13 allthread, which was a disaster, since I didn't know about Enco 1/2"-10 prices, actually cheaper than allthread. LOL. I'm trying to forget the allthread trouble shooting time, cutting it out of my life.....
All that said, Does anybody out there have an extra foot of 1/2"-10 5 start, or 1/2"-8 4 start they didn't use from a longer piece? want to change the 1/2-10 on the Z axis to this to help with the moving the weight up and down issue. Some contract stuff I'm cutting has about 605 up and downs in each cut, and the Z is the weak link from a speed standpoint right now with the 1/2-10 single start.
Or else does any know anywhere on the web that will sell a 12" piece? everywhere seems to have a $50-$60 minimum order, and I only need 12", about $9 worth...
More on the upgrade and some pics maybe tomorrow, and will upload the gcode for part of the contract job, since it is a VERY good test of the machine. 55 sets of 11 holes, 605 in all, on a 2'x4' sheet of luan..
Don
www.eurekaaircraft.com