Circles not coming out round

This has probably been visited several times but I need help.

I can not get circles to come out round. I have had my XCarves for about 6 months have have been pretty happy with it. I had a few problems getting started but was able to iron those out. This one is has me stumped.

I recently broke the X-axis belt on the maker slide while cutting 28 in diameter circle. I have cut several of these as I have been selling a number of monograms. All have turned out perfect. Anyway, when the belt broke the spindle only moved in the y direction and caused quite a crash. it actually pulled the Z-axis wheels off the Z-axis slide. I could not figure what caused the belt to break. I had to order parts and got everything put back together. Now i can not get it to cut a round circle of any size. I have tightened the belt, adjusted the v wheels, etc. I can not get to cut a round circle.

I need help as I have a few orders that are waiting on me to get this fixed.

Thanks in advance to anyone who can help.

Check your pulleys and set screws. They may be loose or missing. (a common problem)

Breaking a belt is often because the pulley is misaligned (sticking out too far or too little) so the belt’s edge wear against something.

Check your belts. If the circles are kind of “slanted” it often means that one of the belts it too tight or too lose. Brand new bets stretch just a bit after initial use and usually need to be re adjusted.

Broken belts can also be caused by debris being pushed into them and wearing them out. If you don’t have dust guards (or if you don’t regularly inspect the top AND bottom of your belts), that’s one potential fix.

Broken belts can also be caused by excessive tension, do you have a quantitative method to measure the tension in them? I have mine set on my XC1000 to take ~3.1 pounds to pull the center up by 1 inch. Some people have more tension on theirs, some less. Each machine is different.

I ended up having to loosen my V-wheels and bump up my pots more than I thought I should in order to get small round circles instead of ovals. If you know the direction of travel and the largest/smallest points on the oval in relation to your workpiece, you can determine which axis is failing to move until it’s too late.