CoreXY design: request for comment and collaboration June 24, 2020 11:11AM |
Registered: 6 years ago Posts: 23 |
Re: CoreXY design: request for comment and collaboration June 27, 2020 06:56PM |
Registered: 8 years ago Posts: 168 |
Re: CoreXY design: request for comment and collaboration June 27, 2020 08:13PM |
Registered: 12 years ago Posts: 5,796 |
Re: CoreXY design: request for comment and collaboration June 27, 2020 09:08PM |
Registered: 8 years ago Posts: 168 |
Quote
the_digital_dentist
I used some 3D printer pulleys with 3mm bore in my corexy sand table. They wore out in less than a year of occasional use. I replaced them with stacked F625 bearings with 5 mm bore. The belts are twisted so the smooth back sides ride on the pulleys, not the teeth.
In UMMD I used F608 bearings to ensure there would be 9 teeth in contact- they are 22 mm dia, so circumference is 69 mm. Belt wrap on the pulleys is 90 degrees, so covers 17.3 mm of that circumference. 17.3/2 = 8.6 but when you bend the belt, the teeth get closer, so at least 9 teeth will contact each pulley. I get no print artifacts from the belt teeth hitting the smooth pulleys. The large diameter of the bearings means that they can have relatively large balls and that means they will last a long time.
Re: CoreXY design: request for comment and collaboration June 27, 2020 09:17PM |
Registered: 12 years ago Posts: 5,796 |
Re: CoreXY design: request for comment and collaboration June 27, 2020 09:38PM |
Registered: 8 years ago Posts: 168 |
Quote
the_digital_dentist
Those bearings are normally used in skate wheels, so they're good for pretty heavy loads and long life.
Re: CoreXY design: request for comment and collaboration June 27, 2020 10:06PM |
Registered: 12 years ago Posts: 5,796 |