Taig velocity/acceleration

[juzwuz]

Hi! What is a reasonable value of velocity and acceleration on the x,y, and z axes of a Taig mill? I have 280 oz-in stepper motors on each axis. Right now I am using the EMC2 software. I currently set the max velocity to be 30 ipm and max acceleration is 2 inch/sec^2. I was cutting a small lithophane (3 inches wide by 2.25 inches tall) with 30ipm on x,y, and z and I have a strange offset. Is this caused by missed steps or maybe my old computer (1GHZ Pentium 3) had a hiccup? I'm thinking the z-axis velocity and acceleration are probably too high. Thanks!

[metalbyter]

Hi,
I'm using Mach3 so I don't know if this will help but,
max velocity is 35-45 ipm depending on the situation faster rapids don't always save much machining time.
I have had my rapids set as high as 75 ipm for testing, I don't know how reliable it is at those speeds and it can't be good for the screws and nuts.
acceleration is set at 24 in /sec/sec.
I have 200oz/in steppers and a hobby cnc board
Mark

[wolfgang314]

I just recently purchased a CNC Taig and before my Xylotex board went out I was getting 45" IMP jog speed with my accel set at 2.5. I didn't get to make any chips but reading other post, this was about it's limit. I had 276oz motors.

[juzwuz]

I just noticed that I have my max acceleration set to 5 inch/sec/sec which could be too high. I've set it to a max accel of 2 inch/sec/sec and hopefully it will work better. After consulting with Nick Carter, he also suggested that I decrease the feed rate a little bit because the lithophane uses a lot of 3D x,y,z moves. I'll try 20ipm or maybe 25ipm.

When I first got my Taig working under computer control I was messing around with the jog speeds. The max I tried was 45ipm because it seemed "scary" fast for the Taig travel envelope. I have a feeling I could make 2D shapes pretty easily at the faster rates but not with a lot of z-axis moves.

Hey Richard, I knew I recognized your name. I bought two of your spindles off of Ebay a while ago. I was thinking of mounting one of them on the Taig headstock if I ever wanted the higher rpm's. I'm still working on a cnc router and I plan on using one of the spindles for it. Hopefully you'll get your Taig going again soon. Are you looking at getting a different driver or sticking with the Xylotex?

[wolfgang314]

1

[wolfgang314]

I went ahead and sent my Xylotex in for repairs ($60) and depending if the board is repairable or not I'll decide from there. Right now I'm running my back-up StepperWorld board. I'm only getting 10ipm with it, but at least it's something. If the Xylotex is completely toast, I may go unipolar, either upgrade my StepperWorld set-up or maybe even go with HobbyCNC. It's a tose up.

I believe the Xylotex is the best out of the three, but in my opinion it is just a bit too sensitive for beginner CNC'ers. It would be nice if it had a cover of the electronis like Gecko's to prevent "Static Discharge" and such. If the board was groundrd to the it's own case, this may provent this. What beginner CNC'er is going to be thinking about "Static Discharge"? I don't think this is what happened to my board,... to be honest I don't know what happened to it.

Originally Posted by juzwuz Hey Richard, I knew I recognized your name. I bought two of your spindles off of Ebay a while ago. I was thinking of mounting one of them on the Taig headstock if I ever wanted the higher rpm's. I'm still working on a cnc router and I plan on using one of the spindles for it. Hopefully you'll get your Taig going again soon. Are you looking at getting a different driver or sticking with the Xylotex?

I hope those work out for you. I have been gradually improving the design Of my spindles over time (.0005 T.I.R.) and now will be introducing CNC products into my line up here very shortly (reason for the CNC Taig).