Stitching Up Custom Belts

If you’ve got a 3D printer, you’re probably familiar with the reinforced belts that are commonly used on the X and Y axis. These belts either come as long lengths that you attach to the machine on either end, or as a pre-sized loop. Traditional wisdom says you can’t just take a long length of belt and make your own custom loops out of it, but [Marcel Varallo] had his doubts about that.

This is a simple tip, but one that could get you out of a bind one day. Through experimentation, [Marcel] has found that you can use a length of so-called GT2 belt and make your own bespoke loop. The trick is, you need to attach the ends with something very strong that won’t hinder the normal operation of the belt. Anything hard or inflexible is right out the window, since the belt would bind up as soon as it had to go around a pulley.

It seems the key is to cut both ends of the belt very flat, making sure the belt pattern matches perfectly. Once they’ve been trimmed and aligned properly, you stitch them together with nylon thread. You want the stitches to be as tight as possible, and the more you do, the stronger the end result will be.

[Marcel] likes to follow this up with a bit of hot glue, being careful to make sure the hardened glue takes the shape of the belt’s teeth. The back side won’t be as important, but a thin layer is still best. The end result is a belt strong enough for most applications in just a few minutes.

Would we build a 3D printer using hand-stitched GT2 belts? Probably not. But during a global pandemic, when shipments of non-essential components are often being delayed, we could certainly see ourselves running some stitched together belts while we wait for the proper replacement to come in. Gotta keep those face shields printing.

GT2 Belt Drive Conversion Of Printrbot Simple

The early versions of the Printrbot Simple at about $300 were cheap enough for even the most cash-strapped hackers to put on their desks. Obviously, for that cost, a lot of design compromises were needed to keep it cheap. Sometimes, changes carry forward to the next iteration at no cost increase. One such improvement in the current version of the Printrbot is the belt drive. Unfortunately, if you have one of the late 2013 – early 2014 wood models, it is most likely being driven by a fishing line that loops over a rubber hose attached to the stepper motor. [jason] describes the process of upgrading the Printrbot Simple to a GT2 belt drive , using the designs posted by Thingiverse contributor [iamjonlawrence].

The trouble with the fishing line drive was that it would tend to get loose over time and needed to be pulled taut. Also, it affected precision when the line tended to wander over the drive shaft. The good thing with having rapid prototyping tools is you can make bootstrap improvements using them. Once the parts for the upgrade were printed, [jason] only needed some bearings, GT2 belts and pulleys to complete the upgrade. For those wanting to upgrade their old Printrbot Simple machines, [jason] guides you through the whole process via some detailed photographs and listing out the gotcha’s that you need to be careful about.