So we created a 3D model of the Molex seal in Freecad and have printed it on our Prusa i3 Rework 3D printer.
The task
We are not too sure whether this is a design fault with the clients bike or just down to where an tear but they were having problems with the electrics and felt that the seal for the connector for the electrics, housed below the bike, was possibly to blame. We where given a brief that included a similar connector and used a model for that seal as the basis for this build.
The difficulty was that the seal is 2.2cm x 3.3cm x 0.4cm with a thickness of 1.5cm (approximately) so we had to print it as fine as possible. To do this we have first printed it at 0.98mm layer height with a 0.25mm Nozzle diameter. Bed adhesion was an issue due to the small surface area so, after some messing about, a Brim was the only answer so we used a 0.5cm brim on PVA on a Glass topped heated bed. This worked fine.
nGen Flex 3D printer settings for our Molex seal print
Printer: Prusa i3
Filament: ColorFabb nGen Flex
Hotend Temp:260C
Bed Temp: 100C
Cooling Fan: Auto 50%
Retraction: None
Print speed: 40mm/sec
nGen Flex results
In the end it printed very well, the problems we have encountered were really to do with the model itself. The picture below is of the seal on a standard Molex connector. We are currently confirming dimensions for the MotorGuzzi fitment and when we have this we fill print out a final version for use on the bike. However, it did serve as a very good test for nGen Flex, 3D printing it with non-standard settings. ColorFabb nGen Flex is a stiff flexible filament that is easy to print with and produced a functional part. The model hasn’t been tested in situ yet so we cannot comment on that but currently it is looking good.
When we have finished refining the model we will make it available via the usual channels.