Machine will not cut a straight line…

General Discussion
1

I’m using simple trace to try and cut a point to point straight line out of a large plate and the arcdroid always produces a slightly arcing line.
I have completed several calibrations and am confident I have eliminated that variable.
I am also keeping the line segments under 24” as to stay in the accurate working area.

What else could be the problem?
Thanks!

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2

Some jobs beg for a straight edge and a hand cut……
Maybe some error indexing the material? Try 20” segments instead of 24”. The droid might have less error in that realm.

3

Could it be the weight of the Plasma cutter cable causing the arm to droop.

Try doing the same cut with the cable supported.

4

I actually considered that Chris and checked the cut with just the stylus attached to arm. It followed the exact cut line as the torch head did. The error is definitely is coming from the arcdroid itself.
This little machine has some awesome features, but I bought it for a specific job where I will be working with some very large 5/16 plate and it would be WAY easier to move the machine instead of the stock. Its for a some structural steel stair cases and I really need to cut 24" strait lines with ± 1/16" to 3/32" accuracy.
Is there any setting within the arcdroid itself that @Amp_Mechanic_JB can help me out with?
Thanks everone!

5

hmmm…First thing, welcome. Second, there was one point where my machine would cut straight lines on an arc but it seems it was firmware related from a few versions ago. I haven’t noticed it since.

Out of curiosity, I would draw a line in your CAD program of choice, and see if that has any effect. I doubt it would though. Either way, I would reload the firmaware on the Arcdroid and on the pendant. It seems like it may not be calculating correctly. The other thing that pops into mind, if you’re getting part of the line straight before it starts to arc off in a direction, be careful where you place the line so the arm isn’t getting near it’s max extension point on one end of the cut. Or try starting the cut further to the right in the arm sweep (machine would be shifted to the left if you are facing it in front) This way you would know if the arc just happens from that physical point or if does the same as before, I would think it is a calculation problem.

I should give this a try on mine just to see if it will do a 24" line with no deviations…
I recently did a light box sign and long top and bottom edges were 19inch and I didn’t notice any arc.

6

Bad geometry can be caused by a several things:

Tilted torch axis - either torch itself or the hole in the nozzle is off-axis.

  • Check consumables.
  • Check that the torch is parallel with the Z axis and square to the table.

Load on the arm

  • Support the torch cable to reduce weight and any sideways pull.

If you are getting the curve even with the stylus, it’s likely this one:

Bad calibration - try doing it again using these tips:

  • Update to the latest firmware, both on the machine and on the pendant.
  • Check that your triangle calibration fixture is straight and square, your calibration will only be as straight and square as the fixture.
  • Make sure to use a good, flat surface, and clamp the triangle fixture to the machine so that it does not move throughout the whole process.
  • Keep the stylus/torch pressed against the shuttle cone so they don’t separate as you move them.
  • Move the shuttle slower to improve accuracy, take about 10 seconds to smoothly go across each rail.
  • Try the “Use Defaults” option at the start of calibration instead of starting from your last calibration values.
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