Dear Readers!

Today I’m going to share how I managed to salvage a bike accessory of mine, namely a Velotech 2x0.5W USB rechargeable lamp, which after a semi-prolonged usage became almost unusable due to the clamp’s rubber band giving in. Unfortunately, this isn’t the first time it happened, as quite a few bike lamps in the past ended up in my drawer because of the very same problem: the clamp becoming trash filler. To try to avoid the problem, I bought a lamp with a different clamp design each time, but it seems it is impossible to break out of this cycle, so this time around I decided to cheat the system by trying something different. I decided to copy the original clamp as much as possible while eliminating the weak point, which as mentioned before, was the rubber band with the latest lamp. The following image shows what I mean:

nameOriginal clamp with torn apart band

As you can see, the rubber band tore apart at the very last hole on each side, despite me trying to be extra careful with it, by which I mean putting the whole thing on only when I needed it to save the rubber from stretching too much over time. Unfortunately it broke anyway, altough the cold weather didn’t help either I guess. Anyway, after some careful measurements, a bit of drawing in CAD software and a walk to a local photocopy shop equipped with a 3D printer, my efforts “fruited” the following item:

nameOriginal clamp with 3D printed replacement Ver.1

nameOriginal clamp with 3D printed replacement Ver.1

nameOriginal clamp with 3D printed replacement Ver.1

name3D printed replacement Ver.1

The first design came pretty close to what I wanted, but the little pin that keeps the lamp in place was just a bit too ahead, so it couldn’t snap in as I slided the lamp in place. An obvious mitigation was to move the pin back by 0.8 mm, and since I was already editing, the knurled surface of the release and the side mounts for the cable ties were also adjusted to mitigate some of the minor inaccuracies of the printer. The second version is as seen below (right hand side):

name3D printed replacement Ver.1 (left) and Ver.2 (right)

name3D printed replacement Ver.1 (left) and Ver.2 (right)

name3D printed replacement Ver.1 (left) and Ver.2 (right)

nameLamp in place inside 3D printed replacement clamp Ver.2

The result is quite good, from a functional perspective anyaway, as the finish is not pretty, especially at the release, where I needed to remove the support material manually with a hot knife. Some melt marks are still visible (on both versions actually), but I don’t think I will sweat over it for now, as I first want to see how durable this thing will be. My primary concern is hot summers as the mechanical properties of the material changes quite drastically, especially above 50°C, so for hot summer times it seems to be a good idea to take it off. See following publication for more info.

Until that time, as always, thanks for reading.


I decided to make the STL file available, which you can download here.

Also, here are some images of the clamp now mounted onto the bike, which works more than satisfacorily so far. Interestingly enough, the parallel lines originating from the print process are actually not as visible in real life as it is on the photos. Also, to avoid slippage, I applied a bit of silicone rubber glue to the bottom cylindrical part of the clamp before mounting it, which after drying provides a permanent rubber-like surface. Just to be clear here, I didn’t glue the clamp to the bike. I let the glue completely dry on the clamp first, and only after that was it mounted. Here are the images:

nameClamp Ver.2 mounted onto the bike with cable ties.

nameClamp Ver.2 plus lamp in place. It looks gorgeous.