Thingiverse
Remix of Tevo Tarantula's Belt Tensioner Design by kyledavis
by Thingiverse
Last crawled date: 4 years, 8 months ago
I love the design of this original belt tensioner. Unfortunately, (and maybe this is a difference in the Select Mini V1 versus the V2), there are several issues with the original design that make it difficult to use with the V2, so I have tweaked this design ad nauseam until I think I finally have it perfected.
First, the original is too wide and collides with the servo motor under the heater bed when the Y axis attempts to move to its zero position. I've narrowed the total width enough for the Y axis to zero properly without the tensioner colliding with the servo motor, which included narrowing the holder for the M3 screw hole without compromising the strength required to tighten the belt sufficiently. I also increased the width of the legs on the outer part because I had one of them break on me, and I narrowed the width of the inner part to accommodate the change. I also increased the depth of the smaller adjoining part slightly to allow a better "click" with the M3 screw required to join them, and I added a protrusion on one side to give you something to grab with a pair of needle-nose pliers while you insert it. I also had the portion between the screw hole and the legs split on me, so I've increased the width there to increase strength. I think I have all the weak points reinforced enough to hold at this point, but I will continue to update this design as I find new areas of improvement.
To use this mod, I recommend printing it with 100% infill to maximize strength and with no brim or raft, which hopefully shouldn't be necessary for this small of a part. You may need supports under the screw hole depending on your particular setup. I get a great print on my Monoprice Select Mini V2 with 30% supports with a zig-zag pattern. Don't reorient the print so that the legs and screw hole are facing vertically, because the anisotropic nature of 3D printing makes the legs too weak when printed in that direction.
After printing, remove the original factory-installed spring tensioner on the front of the Y axis belt under the heated bed and replace it with this. I recommend using a 10mm M3 screw to give yourself a bit of tightening leeway in the future. First, insert the screw into the larger part and screw it down until it is flat with the bottom of the screw hole. Then when you install it onto the belt, the screw head should be facing to the left to ensure that the servo motor will not collide with the backside of the tensioner, the legs should be on the right side and pointing down, and keep it as close as possible to the front of the bed nearest the zip-tie that's holding the two ends of the belt together. If there is excess belt clamped off after the zip-tie, just bundle it together into this clamp. Then use a pair of needle-nose pliers to grab the smaller part by the aforementioned protrusion and insert it between the belt and the end of the screw. Then tighten the M3 screw until the belt starts to "twang" when you pluck it.
In addition to the STL files, I included the SketchUp files that I derived from the original STLs. Enjoy.
First, the original is too wide and collides with the servo motor under the heater bed when the Y axis attempts to move to its zero position. I've narrowed the total width enough for the Y axis to zero properly without the tensioner colliding with the servo motor, which included narrowing the holder for the M3 screw hole without compromising the strength required to tighten the belt sufficiently. I also increased the width of the legs on the outer part because I had one of them break on me, and I narrowed the width of the inner part to accommodate the change. I also increased the depth of the smaller adjoining part slightly to allow a better "click" with the M3 screw required to join them, and I added a protrusion on one side to give you something to grab with a pair of needle-nose pliers while you insert it. I also had the portion between the screw hole and the legs split on me, so I've increased the width there to increase strength. I think I have all the weak points reinforced enough to hold at this point, but I will continue to update this design as I find new areas of improvement.
To use this mod, I recommend printing it with 100% infill to maximize strength and with no brim or raft, which hopefully shouldn't be necessary for this small of a part. You may need supports under the screw hole depending on your particular setup. I get a great print on my Monoprice Select Mini V2 with 30% supports with a zig-zag pattern. Don't reorient the print so that the legs and screw hole are facing vertically, because the anisotropic nature of 3D printing makes the legs too weak when printed in that direction.
After printing, remove the original factory-installed spring tensioner on the front of the Y axis belt under the heated bed and replace it with this. I recommend using a 10mm M3 screw to give yourself a bit of tightening leeway in the future. First, insert the screw into the larger part and screw it down until it is flat with the bottom of the screw hole. Then when you install it onto the belt, the screw head should be facing to the left to ensure that the servo motor will not collide with the backside of the tensioner, the legs should be on the right side and pointing down, and keep it as close as possible to the front of the bed nearest the zip-tie that's holding the two ends of the belt together. If there is excess belt clamped off after the zip-tie, just bundle it together into this clamp. Then use a pair of needle-nose pliers to grab the smaller part by the aforementioned protrusion and insert it between the belt and the end of the screw. Then tighten the M3 screw until the belt starts to "twang" when you pluck it.
In addition to the STL files, I included the SketchUp files that I derived from the original STLs. Enjoy.