Rodrigo Alvarez

Tinkering as a way of life

3D Scanning BMW K75 turn signals

I’ve 3d scanned BMW K75 front turn signal bracket and 3d printed them as a method of saving money while keeping asthetics the same as the original model.

Since I restored my 1990 BMW k75, I’ve been trying to return the motorcycle to its stock configuration. One of the items I’ve been missing is the front turn signal bracket holder (BMW PNs 63131459326 & 63131459325). The reason being that it turns out it is a very complicated part to get hold of.

This part was only used in some of the base configurations of the K75, but this configuration wasn’t the most sold. Other configurations such as the K75 RT/S had the turn signals integrated into the front fairing. Not only that, but it is a part that it is very easily damaged, therefore there are not many available in scrapyards. Fortunately, the reflector is the same as the back turn signal which is a shared parts of all k75 and k100 models

The part is available from BMW for around 50€ per side, which I think is a bit steep for a plastic injection part. Fortunately I have someone from which I can borrow one, so having the tools and knowledge to perform a 3d scan I decided to reverse engineer it.

To Scan the part I used a GoScan! 20, a structured light scanner with a resolution of 0,1mm. Unfortunately as the part is black, I had to use a white spray and plenty of location markers to help the scanner keep track of the 3d object.

The result of this scan after a bit of treatment to remove measurement noise is the following surfaces. As you can see, there are parts I didn’t catch with the scanner. Some are parts that were easly recreated, other simply were impossible to pick up

I later imported this file into Solidworks and with the Scanto3D function I created a model of the part. Due to copyright issues I am hesitant of uploading the files as such. For the same reason, I changed the design to fit 3d printing, as it will be the manufacturing method I will use for the final part. I also took the chance of leaving my initials and the BMW part number

Once I designed the part, I printed an FDM prototype to verify measurements, before printing them in Multijet Fusion which is more expensive.

I will upload pictures once installed on the motorcycle