DIY Park Tool Pedal Dummy Replacement Head
As some of you might know, when I’m not studying I spend my time on the tools building, fixing and selling bikes. One common thing I have seen at all of the shops I have worked at is a bunch of Park Tool Pedal Dummy’s laying around, because their threads strip far too quickly. After destroying the threads on my own Pedal Dummy, I decided to use my newly acquired 3D printer to help me design and print replacement heads which should bring a bunch of the damaged tools back to life. The video below goes through my thought / design process, so watch that first, and then I have a few random bits and pieces that didn’t make it into the video below.
It has been brought to my attention that Park sell replacement parts for this tool in the USA, so my statement that they do not is incorrect. I should have prefaced that statement by saying that the Australian Distributor, Sheppard Cycles do not sell replacement parts.
If you want to print the replacement parts yourself, you can download the .stl file.
On the other hand, if you are in Canberra and don’t have a 3D printer, feel free to contact me and I’ll get some to you.
Below are a few other details that didn’t make into the video:
The parts take around 1:30 to print.
The cost of printing the parts are around 35 cents, with 24 cents of that being the cost of PLA, and the other 11 being electricity costs.
The settings I used to print the design are as below. I’m sure they can be improved upon, however they have worked quite well for me.
Layer Height: 0.1 mm
Wall Thickness: 1.6 mm
Top / Bottom Thickness: 1.2 mm
Infill Density: 20%
Print Speed: 80 mm / s
No supports, otherwise the threads will not work
I took the better part of four hours trying to determine the threads that were on the bolt. Half of that was spent identifying what imperial size it was, and the other half finding the correct setting in Fusion 360 to model the threads. Having a 30 minute turn between each revision didn’t help reduce the time either.
The thumbnail photo was by accident, I was going through the SD card of the camera to find a good photo, and then that one of me pulling faces as I was testing out lighting from the night before popped up. I couldn’t say no.
Things I learnt:
If you don’t include the hours mucking around finding what size the threads were, the first prototype took around an hour to design and get printing, and that was coming from someone who had never used Fusion 360 before. From there, I spent about two weeks on and off polishing off the design, which was a lot longer than I thought would be required. If it had just been for my own use, I wouldn’t have spent so much time on aesthetic details, however I’m very happy that I spent the extra time as it turned out quite well.
As I mentioned in the video, I’m very interested in finding out how these hold up with the day to day abuse of being in a busy workshop. Whilst my goals are that they far exceed the durability of the stock Park Tool head, realistically if they hold up for the same amount of time, I can just keep printing replacements. With this said, I have these parts in a few shops getting stress tested, and I’m looking forward to seeing how well these hold up.