I have seen it suggested in the forums to use magnets to hold down light material in the Glowforge bed, but I wanted to be sure I wasn’t going to mess up the electronics in the machine. Can anyone tell me if it is really safe to use strong magnets in the machine? What if you make a super-stupid mistake and the laser cuts a magnet? Does time reverse or something?
I use magnets to hold down my materials, been doing for 3 years. Just make sure the magnets are not in the path of the print head. I’ve received an “air assist fan” error at one time because the magnet was holding on to the print head.
I use small magnets - about 1/4 by 1/4 inch. They work fine for thin materials. If the laser hits one directly it may reflect back and damage the lenses, or it may not. It depends on what material the magnet plating is. I have gotten close to a couple but haven’t actually gone over one. No damage so far. The project under the magnet obviously doesn’t get cut.
Some users will remove the magnets from hard drives which have a metal backing plate that prevents the magnetic field from interfering with the fan and they use those. What you will need to stay away from are large magnets that have a strong field that will affect the fans on the print head.
Great question! Unfortunately, I don’t have any specific information on magnets but can say that we have found that strong magnets may cause problems with the air assist fan (the fan that sits on the back of the carriage plate that the printer head moves on.) When the printer head passes over a magnet that is too strong, the fan may slow or stop which would cancel the print.
Another way to keep the material flat on the crumb tray is to use hold-down pins. For example, a lot of customers print these pins available in the free laser design section: Honeycomb bed holdown pins.