How do you fix double belts to v-slot extrusions?

How do you fix double belts to v-slot extrusions?
I decided to double belt all my axis and I can’t figure out a secure way to clamp these suckers at ends.

I’ve seen somewhere suggestions but my search came up with nothing.

I used double sided tape to hold the belt in the groove. I have not had any issues with it.

How did you fix ends of belts to maintain the tension?

What did you mean by double belts? Do you have a photo of your setup?

Ok so this link has 3 images, click on different links just above the image - http://imgur.com/YS5JXOw,X2Mn8ou,asl6suG#0

basically its following this idea here

by using dual belts with lower one being fixed to extrusion with teeth facing up. It allows the second belt on top, being placed in a normal manner to lock in with the lower one and increase accuracy by …a lot.

My problem is as it can be seen in 3rd image I am not sure how to fix the belt ends to a machine. This setup in 3rd image doesn’t really tension the cable since it just clamps it.

The lower belt isn’t tensioned though, right? So the top belt is just tension with the stepper, or at the ends, separate to the lower belt.

@Chris_Brent correct

Yes. Apparently it’s supposed to be a lot better at stopping our beloved gantry from extra travel :slight_smile:

Reviving an old thread: Instead of double-stick tape, I used IC-2000 to glue the lower belt into the extrusion. I was concerned about adhesive creep with tape.

Note that this doesn’t work with the SMW3D / Hobby-Fab plates which fix the X and Y motors; that doesn’t give you a way to tension the upper belt against the lower belt. You need a set of plates with slots for the X and Y motor mounting screws rather than tapped holes.

I’m using the Michael K Johnson / C-Beam OX · GitLab plates that @Eclsnowman and I designed based on the Big OX plates by @Metalguru that are designed for C-Beam X and Y, and either 2060 or C-Beam Z (both are supported).

To avoid racking forces, the order of operations is:

  • Install the lower belts in the extrusion
  • Install the upper belt over the pulley, but do not fix the pulley to the motor shaft; let it spin freely
  • Tension the motor by pulling up to remove belt backlash
  • Square the gantry. Shim it if needed to make sure it naturally rests square
  • With the gantry square and power off (so that each motor is at a full step) and all belts tight, tighten the pulley grub / set screws.

With this in place, on my 1 x 1.5 meter OX, belt stretch is a thing of the past, and mechanical compliance from bending C-Beam is the primary failure mode.

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