Losing Home (0,0) after cutting

[Brian1]

I am having trouble with my X axis (single motor) losing home (0,0). I set the torch tip at the corner of my plate, zero the x and y and then it cuts my array of parts just fine. After the last cut it travels back to the home position (0,0) but instead of being in the same place it has now gone about 1/4" to 3/8" off the plate on the x axis only, the y axis (dual motors) is fine. The plate didnt move and the set screw on the gear is tight. It recently started happening the last 2 or 3 times I have used the machine and I havent changed anything on the computer, control box or table. I havent heard any wierd noises and the torch has not crashed anything. I have been cutting all 1/4" plate. Any ideas?

[jeepsr4ever]

How old is your gantry...meaning how is your motor tuning? What is accel and velocity

[jeepsr4ever]

The reason I ask is that you had a history of issues with that axis. I cant remember but I do believe it was PC related.

[Brian1]

You are right, I have had a problem with my X motor before and it was that it was unresponsive off and on. That was a problem with the Geko card inside the control box which CandCNC hooked me up with another one under warranty. This is a new problem that I dont remember having before. To answer your other question I would have to look it up on my garage computer but it is set to the specs provided for the first version of the Bulltear 4x4 table. I will double check this week and post them. Thanks. Table has been working awesome other than this new problem recently popping up.

I just dont understand how it can correctly cut the parts and then only be off on the travel when it returns to 0,0. The last thing I cut was an array of 28, 3.5"x3.5" gussets, 4 rows and 7 columns. Not a single gusset out of the 28 was cut wrong either and all the spacing was uniform so it must be happening on the travel back to home.

[jeepsr4ever]

Try reducing your velocity of the X axis by 200

[Brian1]

X axis is set to: Steps per are 1019.1, velocity is 1000.2, accel is 50, G's .1295, step pulse 2, dir pulse 2

I dont have any cutting on the schedule for the rest of the week. Maybe next week I will give it a try with reduced velocity.

[jeepsr4ever]

Drop your accel to 40 max

[Brian1]

Drop your accel to 40 max

In addition to reducing the velocity by 200?

[jeepsr4ever]

No accel is fine but on the 380 motors when you have too much accel you can lose position. It all depends on how much preload you added when you moved your cams on the V wheels. How easy is it to move you Y axis with the controller off? If it has a ton of preload then there is your issue.

[Brian1]

It moves pretty easy by hand. I will change the accel value next time I have some cutting to do