Projects / RadMini4 /

Second Battery Mount

May. 24 2023

One of the aspects of the RadMini4 that I really like is the dual tube design. For starters, it just just neat, but for me it’s also a great shape to build on.

The project here is to mount a second battery on the mid-tube of the bike. I modeled up the two bar frame in Fusion, measuring the tubes and spacing with some calipers.

I love having the dual tube setup as it allows me to model around both to create bracing that will stop the battery from rotating side-to-side – a real problem when you only have a single tube to work with.

As there are three pieces per battery support, they need to bolt together. To do this I decided to use heat inserts, and the way this is modeled, the inserts are melted into the plastic from the opposite side of where the bolt will “pull” on them, giving them a TON of resistive strength when 3d printed.

Finally, you add lots of chamfers and fillets to make the piece easier to print and nicer to hold.

And the final piece works great. It’s printed int PETG which can survive outdoors no problem and VERY thick walls/infill to give it some heft. Overall these work out great. I also really appreciate that these are non-destructive to the frame – no drilling, no riv-nuts, etc.

If you’re interested in making your own, I’ve included the Fusion and STEP files here:

• Fusion 360 (f3d)
• STEP file model

Also available on Printables.

Enjoy!

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