Loses shape

[darreng]

Attached is a photo of a circle cut into 316 Stainless. I have marked the beginning and end of the cut. What causes this mishape? The tip was blown out, so is it just the bad tip? With power to my motors the gantry does not move when pushed, so the gears are tight. Is there a second factor to this, cus I get cuts like this every once in a while.

[MQYJ]

It isn't a matter of the material moving during the cut is it?

[Torchmate]

It is mechanical. Something is slipping or binding. I would bet money on it. The only other explanation would be that the machine is binding. Run it with the plasma cutter turned off. You will hear it if a motor loses position due to binding. Which model do you have?

[Torchmate]

Hey, I just thought of something else. Maybe you have a lead-in or lead-out that looks like it is not there unless you zoom way in. I just noticed that you don't have it starting and ending at the same point.

[darreng]

Originally Posted by Torchmate

Hey, I just thought of something else. Maybe you have a lead-in or lead-out that looks like it is not there unless you zoom way in. I just noticed that you don't have it starting and ending at the same point.

The start and stop in the photo was referring to where it no longer is cutting along the circle. The material shouldn't have moved - the circles were cut out before the outside shape and it was a 48" x 60" sheet. It only happens sporadically. I will run the table with the plasma off and listen. I keep the rails clean, the gear mesh tight. I will check the spur gears again.

It's a Torchmate 3.

[Torchmate]

I think that the best thing is to have the guys in tech work with you to solve it over the phone. We can go back and forth in here, but it is a lot easier to walk you through some tests to nail down the problem. Check both sides of the gantry to make sure that both motors have power to them. If one of the x axis drives is dead then you would most likely not be able to push the gantry, but the one motor would be having to drag the other. It does look like only one axis by the way that circle cut great 3/4 of the way around.

[darreng]

I'll give the motors a check and see how it goes from there. Thanks for the support, your customer service is incredible!

[HardcorewannabeXJ]

Whatever axis is moving left to right in that photo is slipping on either the large pulley, small pulley, or the belt is loose. This is if the gear is fully engaged in the gear rack on both sides of the table all the way across the length of travel.

[darreng]

gear is fully engaged, no pullies. Like I said, happens once in awhile.

[desertfabmotorsports]

Originally Posted by darreng

gear is fully engaged, no pullies. Like I said, happens once in awhile.

Mine did this also, what i found is I had the gear mess to tight. I reset the backlash and have not had any problems

[darreng]

what method do you use to set the backlash? I was told not to insert a piece of paper between the gear and rail by their tech support.

I'm still blowing through tips way too fast. The AHVC will occassionally just start pulling the torch away while it's firing and the software will continue to move, thinking it's cutting. I read on hear to check both the torque (mine is set at 15 or 17) and make sure the gear is clean.

[desertfabmotorsports]

Originally Posted by darreng

what method do you use to set the backlash? I was told not to insert a piece of paper between the gear and rail by their tech support.

I'm still blowing through tips way too fast. The AHVC will occassionally just start pulling the torch away while it's firing and the software will continue to move, thinking it's cutting. I read on hear to check both the torque (mine is set at 15 or 17) and make sure the gear is clean.

I just set the mess where I barely feel backlash, I then checked at 4 different spots along the rail on both sides.

[HardcorewannabeXJ]

The only problem resulting from too tight of gear rack would be rapid travel position loss. This would generally be cutting the correct size pieces in the wrong area on the table.

Flat spots on circles that is Not program caused, would be related to the motor motions not making it from the spindle of the motor, to the gear rack on the table. This is where you should be looking. If the motor is making flat spots in the same spot on the same program in different areas in the table, my assumption would be it's the program itself. To test that theory, you could change the axis on the table, or switch the motor cables to make the X become the Y and vice versa.

If the problem stays in the same spot on the program, then it's a program fault. If the problem moves to a different spot on the program, but is still in the same axis that the problem was previously, it's a physical problem on the table.

-Mike

[YuNiT]

Also, check your steel rails on the X-axis, my rails were not perfectly flat and causing the gear mesh to be too tight or too loose, causing oblong holes in some cuts. I had to drill additional mounting holes in between the factory mounting holes to get the rails to flatten out. Check you gear track with a micrometer at each mounting point; this was another item that was not flat either.