Idler Pulley for 625 Bearing
by lincomatic, published
This creates a belt pulley out of a 625 bearing.
This is a plastic wrapper which lets you make an idler pulley out of 625 bearing. The 625 bearing is a smaller, more compatible size than the 608 bearing that's usually used in Repraps, because the diameter is closer to that of the drive pulley.
This bearing guide has an inner lip on the bottom, which holds the bearing so that it's centered under the belt.
I printed it with 25% fill and 2 perimeters. If your printer has problems with printing the upper lip, you can decrease the topangle variable. The file is set for a 6mm belt... increase the beltwidth variable if your belt is wider.
Also, since it is small, you might have problems with ABS if you print too fast. I printed it at 15mm/s. Try to set your extruder temp as low as possible. If the upper lip starts to curl upwards, you need to add some cooling while it's printing the first few layers. I used a fan set at a very low speed to blow on it. If your printer vibrates a lot, you should also slow down the speed, because the accuracy has to be pretty good for it to turn out nicely.
The bearing is a tight fit, so any blobbing and other imperfections may make it hard to insert. Clean up the inside carefully with an x-acto knife if you're having trouble inserting the bearing.