I have a weird issue with my Primo build. I’m using stainless tubing 43" long for x and y, a MiniRAMBO board, and the firmware downloaded from the link on the V1 site.
I wanted to make 4 - 100mm square coasters, but when the cutting was done, the first one was 105mm in the x direction and 100mm on the y direction, and the rest were 100mm square.
I was using Estlcam to create the code and Repetier to send the code. I checked that all my settings looked correct but found no issues, so I tried the same 100mm squares with my laser and Laserburn and got the same results. What can be adding 5mm to the first x movement?
The size is consistent even if i do nested squares, and the positioning is spot on on a complex cut.
5mm is a huge difference. Are you sure the squares are sized right in CAD? Maybe share the gcode?
The gcode from Estlcam and Lightburn produce the same +5mm. even when I send G0 X??, the first move is +5 and the rest are on the money.
It varies slightly but 50mm up to 500 mm are always off. I don’t get exactly 5mm every time but 19 times out of 20 or so.
I’m going to move my laptop from the garage to the Burly in the basement tomorrow and check what happens there. I’ve been using the Bulry for a year and never noticed a discrepancy but seldom made this type project. I did try a different miniRAMBO but the results were the same.
I can imagine getting 5mm from backlash, like a loose pulley, or the far motor being off. But you would have serious problems in the next one too
If you link your gcode we can check real quick what the first couple moves are.
Further testing: If I manually position the “core” at +400mm and step in 50mm increments in the minus direction, using the manual stepping in Repetier, I get 50mm steps until I get below -100mm, so that stepping -50mm from -100mm, I measure 45mm! The only thing to which I can attribute this kind of error is a belt issue. That doesn’t hold up however, beacause all 4 lengths of belt were cut from the same roll if wire reinforced belt. When I use the came computer to test my Burly, my errors are in the range of 1mm/100. This testing is eliminating gcode and the computer. I’m stumped.
Did you buy steel lined belts?
You should be able to see a 5mm stretched spot in your belt, or your pulley grub screws are loose and slipping.
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Yes, they are steel reinforced. Later this week I’ll try a new belt but it still makes no sense whatsoever.
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The steel breaks when moving around the little pulleys and then it is just the rubber holding it together. The fiber reinforced belts don’t break that way.
Makes perfect sense to me. Good catch Ryan.
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Yup you have to replace all of your belts.
I do have a note about this in the instructions. Steel belts are made for no bend belt paths, or very larger radius bends. Every time it moves it work hardens and eventually breaks, think about bending a paper clip 10-15 times, now imagine how many times that little pulley passes the same spot which bends the belt 3 times per pass. These never last very long, typically we are seeing failures in a couple hours use. There are fiberglass and Kevlar reinforced belts (the most common), get those.
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