X axis missing steps after long run

Discussion of tinyG control platform
Post Reply
Posts: 48
Joined: Mon Mar 03, 2014 12:46 am
Location: Leicester MA USA

X axis missing steps after long run

Post by sportrider12584 » Tue Nov 07, 2017 11:41 pm

Hey guys, I'm working on some number signs for my house. I just finished one side that took about 45 minutes. I flipped it and started the other side. It got about 20 mins into it and started missing steps on the X axis and unfortunately ruined the part (apparently when you hit stop on Chilipeppr tinyg continues to run for like 5 minutes -_-

I thought I setup my machine (Shapeoko 2) correctly as far as motor current goes. I even have a fan and stick-on heat sinks on teh driver chips to try to prevent this kind of thing. When it started missing neither the motor or the heat sink were even warm to the touch.

Any ideas? Thanks in advance!
IMG_20171107_183139619.jpg (711.48 KiB) Viewed 1019 times
ShapeOko 2 #4477. 1/4-20 threaded inserts * shaved belt straps * 48" Y-axis * tinyg * ACME Z-axis Upgrade * 400W spindle * belt drive Z axis upgrade

Posts: 8604
Joined: Mon Apr 09, 2012 6:11 pm
Location: Pennsylvania --- south of the Turnpike, East of US-15

Re: X axis missing steps after long run

Post by WillAdams » Wed Nov 08, 2017 1:13 pm

The other things which can result in missed steps:

- insufficient belt tension
- loose pulley set screw (though this seems to cause more backlash)
- uneven belt tension between two Y-axis belts
- too fast rapids or cutting forces which are too great
Shapeoko 3XL #0006 w/ Carbide Compact Router w/0.125″ and ¼″ Carbide 3D precision collets

Posts: 587
Joined: Wed Jan 08, 2014 11:33 am
Location: Birmingham, UK

Re: X axis missing steps after long run

Post by RobCee » Wed Nov 08, 2017 2:22 pm

I second the suggestions that Will lists.

In reference to your 'stop' command in Chilipeppr; that command stops sending any more commands to your system, but your system may have buffered a large amount of commands. If you need an emergency stop, then you have to also cut power to the Arduino controller in a graceful way.

If you can give us an indication of your speeds and feeds on the job, we can probably see if you are pushing things a bit too hard or not.

For reference, I have run 4-5 hour jobs on my SO2 without problems, but that took some dialling in to get working correctly. The Z-Axis was the trickiest to sort out, but now it works a treat.

Here is the most detailed job I have attempted:
93 3D Carving.jpg
Cutting time approx 3 hours - lion is just over 3 inches tall
93 3D Carving.jpg (169.87 KiB) Viewed 1001 times
ShapeOko2 #3400 - Chinese 800W AC Spindle - Stiffened X-Axis - TR10 Z-Axis - Inverted Z Motor - Hall Effect Limits - Drag Chains & Custom Brackets

Post Reply