MPCNC - Belt Tensioner Parametric Remix for US or IE Version

thingiverse

Update 4/9/2016 Rev10: Belt Tensioner Plate revised to include reinforcement option at end. Previous version broke when I pulled bolt too hard to clear Conduit cap. Update 3/12/2016 After playing with design for couple of days, I came up with change that solved all my problems with it. I connected bolt above belt clamp so I could put screwdriver on bolt head while tightening nut. I also placed open part of belt clamp inside so it would be in line with belt path. Since bolt pulls top part of clamp more, I added 15 degree angle to that so bolt would be close to perpendicular with clamp. First photo shows it in place. I left other designs here in case anyone prefers using them. New files are: BeltTensionerPlate_Rev8.scad Bolt_DbleBeltClamp_15deg_Rev1.scad BeltTensionerPlate_2x_2xBoltDleBeltClamps_Rev8.stl (print 4 of these for new design) Bolt_DbleBeltClamp_2x_15deg_Rev1.stl I liked tensioning technique, but wanted to be able to adjust some dimensions, so I copied geometry into openscad and made some of the dimensions variable. This works with: http://www.thingiverse.com/thing:1401177 & probably also Totem MPCNC corner design. I made 2 versions of clamps. One uses teeth of belt to match teeth cut into plastic & other uses double up to single width for belt to clamp it. I am leaning towards double up design, since it is easier to insert belt and also. I would print BeltTensionerPlate_2x_2xGrooveBeltClamps_2xDbleBeltClamps_Rev5.stl which has both style clamps with it & see which one you like best. If you print belt clamps separately, I would print at least 2 at a time so each layer of plastic has longer time to cool before next layer. There are 3 openscad files included: BeltTensionerPlate_Rev5.scad DbleBeltClamp_Rev16.scad GrooveBeltClamp_Rev16.scad I am using #10 x 1.5" bolts, but you could also use M5x35 or 40mm bolts. Shorter bolt means less tensioning you can adjust. Each openscad file defaults to printing 2 parts. There are several variables in each file that you can adjust. You will need 2 plates & 2 belt clamps at each corner. The belt clamp openscad file has variable Qty you can set to 1, 2, 4, or 8. I am printing these parts at 40% infill. The DbleBeltClamp part I hard coded the belt way, so there is less variables you can adjust there. I used Groove part from: http://www.thingiverse.com/thing:925911 I used Bolt Clamping part and tensioning holding plates from: http://www.thingiverse.com/thing:1191395 I used smooth groove cut from: http://www.thingiverse.com/thing:824458