Glowforge on Speed Bumps

So I did something silly today… I bought some trotec wood because it’s great quality, it’s 600x300 and the plan was to cut it with the pass through slot but being slack I put it in longways across the crumb tray to see if it would fit. Looking at it, it sat above the bed but fit in the machine so I thought great, just like a thicker piece of wood…

I hit print, the arm moves down and gets stuck on the wood on the right. The machine proceeds and the left keeps moving down while the right is stuck at the top. I stop the print and the arm is at about a 25 degree angle with the left being down and the right being up. It thankfully stayed on the tracks

But now, every time it moves down it sounds like it’s going over bumps. I have checked all the wheels for cracks, I’ve checked the tension and it all is ok, I can’t work out what on earth it could be…. If I move the arm manually on a slight angle again left further down than right, there is no bumping. If the machine moves really quickly to focus on the wood at the bottom there is no bumping but if I manually move the arm up and down or the machines moves slowly to the bottom right to start a print, its like it goes over three speed bumps. Anyone had this?

Thank you!

Did the gear belt get stripped?

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That would be my first thought. How thick was the wood? I buy 12x24 wood frequently and even 18x24 to feed through but you will still need bed pins to keep it from flying up. I currently have three pieces hanging out the passthrough slots as I am testing designs in 4 different materials.

You might want to get on the list to be notified when these become available

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It wasn’t the thickness of the wood it was the width, 600 x 300, but only 3 mm thick. I had a pushed to the right and so when the arm came down, it got caught on the right, but the left kept moving. It doesn’t look like the bands are stripped, it was actually moving quite slowly

One of the three pieces I have in my machine at the moment is the 20x48 inch sheet of this …

At regular price it is more expensive than the smaller stuff, but it was on sale at half price and the rest were not, but I do support it at the back and use bed pins in the machine.
If not having the material pinnned down caused damage it would be near where the drive was spinning on the belt only so nowhere on the belt but there .

I guess my question would be - is it cutting straight? It’s possible it’s just a sound, and not actually a mechanical issue…

Personally I’d ask it to cut a large square (that fills most of the bed), and a) see if it cuts without issue, and then b) see if the cut is actually square.

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For those playing at home, today I took a really close look at everything and discovered what the problem was. It seems that the wheels are actually very soft, despite looking like they’re made of metal which I’m not sure they are?

But there is the tiniest little bend on one of the wheels, which is causing the sound, however luckily does not change the performance in anyway. Hopefully this can help someone in the future. Had a curiosity. Is it even possible to replace these wheels ourselves?

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The wheels are made of some kind of plastic, so they can deform or crack under enough stress. Those rails are aluminum so a metal wheel would probably be too hard on the rail itself.

I don’t think Glowforge will sell you these wheels since replacing them means more disassembly of the machine than they’re comfortable telling a customer to do.

But, there are some options on Etsy. This guy sells used parts he’s taken out of broken Glowforges and has a gantry wheel available:

And this seller has manufactured new replacement wheels himself:

I don’t know if either offers any guidance for actually installing the replacements. You might try searching the “Friendliest Glowforge Group on Facebook” for any previous discussions about replacing these wheels.

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