Y Idler Tensioner

Intro

After battling with the tension on my Ormerod 1 y-belt I decided to make this modification. It works really well with Iamburny's Belt clamp (http://www.thingiverse.com/thing:263720).

Remember that this is for final tensioning - the belt should already be attached and fairly tight.

Instructions (refer to the pics if it doesn't make sense!)

Print the parts (Hinge + Plate) - Support might be necessary on the plate part unless your printer can do nice 10mm long bridges, so if that's the case, then use the .stl file that includes support, then break it away afterwards.

Attach the plate part on to the printer in replacement of the existing part.

Attach the bearing using an M3 screw and nut.

Depending on your print you might need to check the tolerances between the bearing and the guides to make sure the belt passes through smoothly without catching - clean them up with a screwdriver or file if necessary.

Bring the belt through the bottom hole in the acrylic and around the bearing, then back again through the top hole in the acrylic.

Attach the hinge part to the plate using an M3 + nut. I used a thin washer between the hinge and the plate to reduce friction although it's really not necessary.

Place an M3 nut in the depression provided on the hinge part and push a screw through from the other side. The screw should be able to move fairly freely in the hole - if not then widen the hole slightly.

When your belt is attached on to the bed and tensioned as best as you can get it, but still not making a low tone when plucked, turn the screw to tension the final amount. The screw should turn freely in the hinge part, but the nut pushes the part away, tightening the belt further.

Let me know how you get on!

###Note: If you have an Ormerod 2, refer to https://www.thingiverse.com/thing:529595 for an adaption for that version.