525 MPCNC (IE/US/1") - Belt Tensioner + Corner Block

thingiverse

Now compatible with 525 version (june 2017 stock files check). For a perfect roller/corner belt allignment, you should add 2 speed washers per roller. They need to be placed between the bearings and the roller body. It was first intended to be tightened by four M4x80 screws, but I couldn't find them here. You can still do it, just don't insert the M4 nuts in the blocks, only in the corner foot. I didn't actually use plastic inserts. It's a very hard item to find here. They are blind rivet nuts, but they work very well. I thinks this ones are the same: http://www.ebay.com/itm/100x-Flat-Head-Metric-Blind-Rivet-Nut-Insert-Rivnut-Nutsert-Assortment-Kit-Screw-/281802239497 Timing belt tensioner system for the Mostly Printed CNC by Allted Original design: http://www.thingiverse.com/thing:724999 I’ve been cracking my head to design a belt tension system that can work with the default corner blocks, but it was too hard. So I approached the issue the other way. First, design the belt tensioner and then adapt the corner block to it. The corner block ended up being a part stiff and easy to print, with a bulky look that I like, but the parts of the tensioner are more tricky to print. The teethes of the clip should match perfectly the timing belt. Also, the belt should be held tight between the walls even without tension applied from the screw. As it was very confusing to put all the files here, the corner blocks were moved to: IE (F-25mm OD) Corner Block: http://www.thingiverse.com/thing:1459025 US (C-23.5mm OD) Corner Block: http://www.thingiverse.com/thing:1459158 1" (J-25.4mm OD) Corner Block: https://www.thingiverse.com/thing:2385574 .STP files uploaded =) Enjoy! Bill of Materials Corner Block (x8) M4x40 Socket Head Cap Screws (x16) M4x30 Socket Head Cap Screws (x16) M4x20 Socket Head Cap Screws (x40) M4 Nylon-Insert Locknuts (x16) M3 Blind Rivet Nuts (optional) Timing Belt Tensioner (x8) M3x20 Socket Head Cap Screws (x16) M3x10 Socket Head Cap Screws (x16) M3x6 Socket Head Cap Screws (x8) M3 Hex Nuts