[JerseyBill]

With a Torchmate 3, ATHC and a Hypertherm 1000, I have been getting scalloped cuts especially when cutting small parts using thin metal (.125"). Jim Colt suggested that I check the machine movement. So I attached a felt tip pen to the torch and ran the cut file. The result is attached. All of the drive components are tight with no play or slop. But the pen line shows the machine is not plotting a smooth curve. This is also exactly reflected in the cut metal. How can I fix this?

[JerseyBill]

I talked to Mike at Torchmate today and he suggested that the belt drive bushings may be worn. I dismantled the motor mounts to check them and indeed they are worn. Time to replace a few parts. Just by tightening up the belt and reducing the clearance between the spur gear and rack, I was able to reduce the scallop by half. I should see additional improvement once the bushings are replaced. Unfortunately, there is some flex in the stepper motor mounts. When time permits, I'll have to make some changes to the mounts.

[jmusser15]

Here is the link to the modification I did to my x and y axis when I was having those same issues. I do not have those problems with scalloped edges anymore. Extremely happy with the upgrade. Table is 2x's as fast before it experiences any stalling of the stepper motors.


http://cnczone.com/forums/showthread.php?p=1103536

Sent from my iPad using Tapatalk HD

[JerseyBill]

Thanks for the link. You have done a fabulous job on the upgrade. You have used thicker plate, a shorter distance from belt drive bearing to the spur gear and spring loaded the spur to the rack. Nicely done. I hope that I can do as well. It looks like you have upgraded the steppers also. I don't think I can afford this right now but you have definitely shown me a better solution than I was going to use.

[jmusser15]

The steppers are still the original Torchmate 269 oz stepper motors that came with the table. Feel free to email me when you decide to upgrade, I will answer any questions you might have. I even have the cut files for the mounting brackets I fabricated to attach CNCRouterparts rack and pinion system to.

[JerseyBill]

I am very impressed that you can run speeds up to 450 IPM with the original steppers since the drive upgrade. This is some serious motivation for me to upgrade real soon. Also, thanks for the generous offer to answer questions and provide the cut files. I'll need to work out the details carefully since my Trochmate 3 seems a little different in the racks. The racks are a bit higher and they are mounted the reverse of yours. I would need to turn these around to make this work. The devil is always in the details, ya know. Thanks again for your help!!