Replacement unit Y-axis belt is misaligned - not cutting square


#1

GF replaced my Basic unit due to a loud vibration that it developed. Other than that vibration, it was perfect. I am now concerned that maybe I should have just sucked it up and lived with the noise, as I see some concerning things in the replacement unit.

Last night I was experimenting with the correct kerf for a box design, and I noticed that the box tabs fit together differently depending on whether the tab was cut on the X or on the Y axis. I saw this thread describing a similar problem caused by the frame not being square.

One of the troubleshooting steps in that thread involved checking how the belt was riding in the pulley. Well, I went looking, and I noticed that the rear right pulley, on the Y axis, looks totally different than that in the rear left. It sticks much farther out away and looks like it’s about to come loose, although I don’t think that’s the case. Could someone take a look at the photos and let me know if this is normal? I am 100% positive that my previous GF was not this way.

Also, what is the expected range of variation in cutting dimension? I cut some squares in different corners of a sheet of acrylic, and I notice there is about a 0.007" variation in size from one corner to the other. Since this is more than the kerf is typically in this material, and the GF specs page says 0.001", this seems wrong. But it would be good to get some confirmation.

Rear Right Pulley:

Rear Left Pulley:


#2

The main thing you are looking for is to make sure the belt is running strictly parallel to the rails that the carriage rides on. It does look like it is farther away from the rail on the pulley than it is at the carriage, but it’s hard to be definitive from the angle of the image.

Do your cut squares have all four precise right angles? The thing that varies is the Y (or front to back) distance?


#3

On the right hand side, the belt does not appear to be parallel. It is about 3-4mm away from the rail in the back than it is in the front. And no, the angles do not appear to be exactly square to me - there is about a 0.005" difference in the X and Y axis measurements of a 1-inch square.


#4

All of the angles could be 90 degrees even if you’re getting rectangles right? Are you saying the X and Y are different and the diagonals are also different?


#5

Actually, the diagonals are the same - at least within my ability to measure it. Or course, this is on a one inch square. Should I cut something larger and measure that?


#6

Actually - I retract that statement. The diaganols of the square cut in the upper right corner are the same, but for the one cut in the lower left corner they are off about 0.005".


#7

Hmmm… Weird. Perhaps there are two things happening simultaneously. It’ll be interesting to see what support wants to know on top of what you’ve posted. I’m guessing that for the tolerances you’re talking about it isn’t immediately obvious from pictures of the cuts.


#8

Yep. I wonder if an6py of this is user serviceable. It’s tempting to just let it go, but it makes tabbed boxes not really work anymore. I never had this issue with my previous unit.


#9

Thanks for writing in - I’m researching!


#11

I cut a tabbed box out of some :proofgrade: draft board yesterday. Depending on the orientation of the tabs when they were cut, some sides were very snug, snd others were so loose that they just fall apart. This is definitely a problem, and one that I didn’t have with my previous GF.

@Rita do you have any updates? I am not a very happy customer right now…


#12

I followed up with support via email. I just want some sort of resolution quickly. You can give me my old unit - the one with the loud vibration noise back, or send another replacement, or provide instructions for me to fix this one, or just give me my money back. Something, anything, but let’s make it happen soon.

And anyone think I am being unreasonable in asking this get resolved quickly: I am, in effect, awaiting successful resolution of a problem first reported on December 8.

You can close this thread.


#13

@mhumphrey, I apologize profusely for the long wait you’ve had, and for the trouble with your unit. I’ve finished my investigation and, unfortunately, you are correct that it needs to be replaced. I’ll email in a moment to make arrangements.


#14