Messages

41

General Mach Discussion / shuttle pro

« on: January 19, 2009, 02:18:59 PM »

while at the computer might as well wright 2 topics!

i own a shuttle pro to run my lathe and find it is the best addition i made to it. it has every function that i need for efficient control and positioning but it is not made for the toolroom where coolant and hot chips is the norm.

do you know of a pendant that would be available with similar fonctionality to the shuttle pro, especialy the dual wheel action, but with a more rugged housing suitable for a machine shop?

42

General Mach Discussion / thread info

« on: January 19, 2009, 01:56:53 PM »

hi all

i recently ran into a thread problem and finaly have it runnign. this issue had me wondering if there is any reason to use g76 over g32 beside the fact that the code is shorter. if it is generated by a whizzard or a cam software the lenght of the code doesn't really matter?

43

General Mach Discussion / Re: thread problem

« on: January 16, 2009, 08:27:08 PM »

the final chapter

i think i get it working for good now. from wath i can see the problem was a timing problem. i dont know how mach3 manage the threading sequence but from wath i can see, if the spindle slows down a little bit while threading because of a change in load, probably mach3 expected an index pulse that is comming a little too late, it then assume that it missed it and realign the z speed accordingly. so i end up with a z axis that is one turn of the spindle too late and eat the thread on the shaft.

i had to cut this thread the same day i upgraded from a previous version of mach3 and assume the upgrade was the problem. so if cutting acme thread use the low gear on the lathe and light cuts because it takes more power then the v thread of the same pitch.

thank you for your help

and by the way, where did you get the info about that g32 thing? is there a secret mach3 bible!

44

General Mach Discussion / Re: thread problem

« on: January 16, 2009, 10:44:55 AM »

yes a ran the turn diagnostic, dont see anything wrong there.

now to thread with G32, do i have to write manualy the code or is there another whizard to do it? if i have to do it manualy, how do i tell the program to wait for the index pulse to start the cut?

45

General Mach Discussion / Re: thread problem

« on: January 15, 2009, 10:50:46 PM »

ok still have this problem , here is wath i did today

- remove mach3 with all related files, folder and driver from pc
- download and install a fresh copy of ver 3.042.020 plus config
- ran driver test at 35 kHz, everything fine here
- removed the ball screw from the lathe and clean. i tough a chip in the ball nut might give an intermitent slow down on the z axis and damage the thread
- change the electronic gearing on the z axis drive from 10 to 4. this gives me 10 000 ppr, this limits the rapids to 210 ipm but thats fine for wath i do
- ran turn diag. cut a thread in the air, everything fine.
- when everything done, i cut a thread on a piece of scrap, and got a perfect thread

I then loaded a good shaft in the lathe... guess wath same problem!!
after cuting a few more on scrap shaft, i found that the x axis moving problem dissapear. from wath i can see when the thread is cutting, the first 4 or 5 cuts are ok, then on the next one it starts fine then somewhere along the cut, it looks like mach3 stop sending the pulse to the z axis for a breif moment, the axis gets behind a few thousand for the rest of the cut, then the process repeats over the 16 toal cuts!!
i've tried suggestion posted here and still at the same spot!!!

46

General Mach Discussion / Re: CAN SOMEBODY HELP ME ?

« on: January 15, 2009, 10:22:25 PM »

i had a similar problem once. i dont know if the kit you bought has a charge pump security, but if it has one it might be just the active high/low that needs to be change. when you hit reset you motor are active, and when you remove reset they stop.

47

General Mach Discussion / Re: thread problem

« on: January 15, 2009, 11:01:05 AM »

here is a picture of the finish acme thread. it is not very clear but you can see the tickness of the thread decreasing as the z axis gets further from z zero. in the mean time, i tried with an older version of mach 3 that used to work with no better success. for the x axis this is very strange, on the first pass the x axis is moving out about .03" over the six inch lenght, i can see the motor turning and the x dro moving on the screen. this proble realy sucks, hope someone is going to come up with a good idea

48

SmoothStepper USB / compatibility questions

« on: January 14, 2009, 10:29:27 PM »

hi all

i've seen that SS can output to 4MHz! how does this relate to the kernel speed setting in mach 3? if i go beyond 45 kHz on my pc, the driver becomes unreliable. I use ac servo on the x and z axis with 10 000 pulse/rev, right now i have to use electronic gearing with a ratio of 10 to 1 so i can get decent speed on the axes. how does SS handles that? my lathe has a 6 ppr sensor can it be hooked on the SS? i also have a campbell design breakout board with spindle speed control, any compatibility issues?

that makes for a lot of questions!!

49

General Mach Discussion / Re: thread problem

« on: January 14, 2009, 10:00:51 PM »

this threads sure looks better than mine. what spindle speed and first cut depth do you use? my threads cut in about 20 pass.

50

General Mach Discussion / Re: thread problem

« on: January 14, 2009, 07:19:16 PM »

thanks i will try this tomorow, but did you actually cut any long thread? because i would not have noticed this problem if the lenght of my thread had been shorter then 2 inches.