Loosing intensity on far right of the bed

We tend to put as much parts in one cut to minimise the amounts of prints we have to do.
So yesterday I combine 12 parts we needed on a surface of 18x10 inch.
I centralised the material on the bed and aligned the SVG file with it.
By now we know the intensity settings for our materials.
How ever this was the first time we used a surface this big.
I know there are problems on the edges and that’s why we didn’t go for the full available size.
The problem was that at the end of the print al parts on the left side were cut completely through as supposed but the parts on the right side were cut completely through except the last 1/2 inch. There it was only cut for about 80% of the thickness.
It seems the laser looses power on the far right of the bed. This is somehow logic as when the head of the laser is at the far right the laser travels the biggest distance.
But this could be solved with some compensation algorithm that adapts the intensity based on the head location!.

grts Massimo

While your theory is not impossible, this sounds like a material issue. I am guessing it wasn’t completely flat or it wasn’t uniform (or both). What material was it? If it was a plywood you could easily have had an inconsistent middle layer. If it was a hardwood the thickness can vary especially at the end, depending on how it was planed.

It’s a hard to investigate after the fact but you can inspect plywood with a bright light, and use calipers to test thickness. As for warp that’ll be really hard to verify.

Support will have you test by thoroughly cleaning the optics (as per the instructions on the support section) and then printing a gift of good measure on draft board in the spot where you had trouble.

Plywood inspection:
https://community.glowforge.com/t/trick-for-inspecting-plywood/15168

Cleaning instructions:
https://glowforge.com/support/topic/troubleshooting/cut-didnt-go-through-material

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A bit of elaboration:

By not impossible, I mean that while distance by itself isn’t an issue (light travels quite far without degrading in most situations) it might have been if your cut was particularly smoky and/or your ventilation/air assist is working incorrectly. If the inside of the GF fills with smoke, it will degrade the laser and that effect will get worse over longer distances and time, as the smoke gets thicker. However, if your ventilation and air assist are working correctly, you should see no significant buildup of smoke in your unit – the smoke should be quickly pulled away and out.

The other possibility is that one or more of your mirrors or optics before the head is faulty and is causing the laser to diverge or be misaligned. This would be affected by distance as well, as less laser light would make it into the head to be refocused by the final lenses. I find this idea to be far less likely (why? see below), but it’s theoretically possible so it bears mentioning.

So, unless you’re not seeing an extraordinary amount of smoke, I’m still sold on material issues, especially warp. How are you holding your material flat? Try the pegs or magnet methods if you aren’t already.

[ As for the mirror/lens theory causing divergence or misalignment: it’s not very likely that there’s a physical defect in the optics themselves because GF quality tests every unit. This would probably not go unnoticed before shipping. It’s possible something could get misaligned due to rough handling in shipping, but I would expect you’d have had other problems before this. It’ll all come down to what support says, but if it were me, I’d try again and be 100% sure your material is flat. ]

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For what it’s worth, I’ve had several occasions where the right side of the bed doesn’t cut through and the left side does. And every single time, it’s been because of a dirty lens, window or mirror. Why it’s the right side, I don’t know for sure… but a quick cleaning always gets me back in business.

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Thanks for letting us know about this.

Can you try the cleaning instructions @evansd2 suggested? If they don’t help, please do the test print at the very bottom of the page and send us the results.

It’s been a little while since I’ve seen any replies on this thread so I’m going to close it. If you still need help with this please either start a new thread or email support@glowforge.com.