X2 CNC Conversion: Max speed and acceleration settings

[Dr. DRE]

I just converted my X2 mill to CNC using the CNC Fusion kit with ballscrews, Keling 282 oz in steppers, a 48 V power supply and the Gecko G540 controller and EMC2.

I've test cut a bunch of parts out of wood but it looks like I'm getting errors due to missed steps.

If anybody has a similar setup, what are you using for maximum acceleration and velocity setting on each axis.

Thanks!

[Clot]

Velocity = 2000
Acceleration 400 (I think)
Metric units, Kelling motors and drivers

Saying that I'm still trying to fine tune my set up and am having quality issues of my own so I'm also interested in what others are using.

[SpeedsCustom]

Dr Dre- For the 540 and EMC2 did you set the drivers spec to EMC2 Stock Gecko settings in Stepconf? I have not cut anything cause i'm waiting for resistors, but it's fast. Just let me know.


-Jason

[Dr. DRE]

My current settings are

X-Axis -> 0.5 in/s, 0.125 in/s^2
Y-Axis -> 0.5 in/s, 0.125 in/s^2
Z-Axis -> 0.25 in/s, 0.0625 in/s^2

I've been using a maximum cut speed of 5 in/min.

I can go to much higher velocities and accelerations but I turned everything down until I stopped seeing errors that might be due to missed steps.

[SpeedsCustom]

See, I wonder if that common than.



Before you did velocity on ea' axis in Stepconf. On the first page where it asks you the name of your mill, how many axis and then it asks you what drivers you are using. I'm assuming you said Gecko. You may need to adjust that.



-Jason

[Regnar]

This is what I have.

x2 with Cncfusion kit, Xylotex 269oz 3 axis kit with 24V Power supply

All my axis have the same settings

Velocity @ .75 in/s
Max Acceleration @ 30.0 in/sec

These settings are lower than what the machine is capable of. I find it a little scary when the little mill is doing rapids over 45 ipm.

I rough cut at 15ipm and bit size determines the amount of depth but anywhere from .1 to .2

Finish cut at 15ipm and usually do it at .015 for pretty much all the cutters.

And a photo of today's experiment for my DIY Router Build that is going to have a pulley system. I wanted to get a tight loose fit and achieved it.

Also what kind of couplers are you using and if they are the lovejoys you might want to make sure they dont have any slop in them. When I first set up my mill it would miss things at weird spots for either loose set screws or the rubber starting to goto mush.

Also make sure the setscrews holding the ball nuts are tight aswell. These sometimes need to be tightened and depending on the load can make the stepper stall for short periods or loose steps but when checking with no load will not show any backlash. Hope it helps

[Jay C]

Guys. Don't forget the 540 is 1/10th microstepping drive. That means if you have a 5tpi leadscrew then you'll need 10*200*5 = 10,000 steps per inch. What is your base period? Did you run the latency check? (check here). I know on my HobbyCNC at 1/4th stepping I have 2000 steps per inch. Going to 10000 is going to have an affect on my top speed due to latency and the fact that it's a P3 733Mhz laptop. If the 251's don't work out, then I'll sell them to someone that can use them.

Jay

[acondit]

Originally Posted by Jay C Guys. Don't forget the 540 is 1/10th microstepping drive. That means if you have a 5tpi leadscrew then you'll need 10*200*5 = 10,000 steps per inch. What is your base period? Did you run the latency check? (check here). I know on my HobbyCNC at 1/4th stepping I have 2000 steps per inch. Going to 10000 is going to have an affect on my top speed due to latency and the fact that it's a P3 733Mhz laptop. If the 251's don't work out, then I'll sell them to someone that can use them. Jay

In my book the timing specs on the G540 is marvelous. I would think you could still get way more steps per second than you can use. Just don't forget to adjust the timing for the G540 rather than using the timing for the hobbyCNC.

While you are correct that for 5tpi direct drive the G540 is 10000 steps per inch, 10000 steps per second would produce 60ipm. I would be real surprised if your machine would not produce at least 10000 steps per second with the G540 timing.

Alan

[Jay C]

Point taken Alan, but the real test I was planning to use the Geckos on my new Widgitmaster Wide router ... uses ACME leadscrews (need to figure out the TPI on these).

Also, I'm using Mach3, these guys are using EMC2 which is a bit different in how it manages the pulses.

[acondit]

Originally Posted by Jay C Point taken Alan, but the real test I was planning to use the Geckos on my new Widgitmaster Wide router ... uses ACME leadscrews (need to figure out the TPI on these). Also, I'm using Mach3, these guys are using EMC2 which is a bit different in how it manages the pulses.

Jay,

I am using EMC2 on my CNCRouter and my CNCLathe.

Alan