Has anyone here tried to modify an EPS power unit?

Discuss light weight issues concerning road bikes & parts.
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Artisan
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by Artisan

I'm in the process of dissecting an EPS power unit in an attempt to reduce it and find a more 'stealth' position on or in a frame.

Has anyone on WW tried to use a seperate power source and/or place the 'brain' in the frame? It's not a small unit and could prove problematic trying to waterproof properly.

If I actually manage to pull this off, I will post more. Otherwise :oops:


Here is a sneak peek.

Image

Omiar
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by Omiar

Is the PCB small enough, so that after removing the battery and making a custom case for the PCB, it still fits inside a frame?
Scott Foil Ultegra Di2
Scott Scale 35 26"
Scott Spark LTD 29" M8000

maxxevv
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by maxxevv

Interesting why they need what looks like a pretty large circuit board (by relative embedded electronics standards) ? :shock:

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sugarkane
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by sugarkane

You do understand how small those surface mounted resisters are in real life?

maxxevv
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by maxxevv

If you want a relative size, the SMD marked at R20 (222 on it) is approximately 1.5~2 mm in width (measured left to right). When you scale up the board as we see here, you get the relative scale of things.

From what I've seen for embedded devices, this is quite big comparatively, especially considering we are not seeing the whole board yet.

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CharlesM
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by CharlesM

Size doesn't have to be a problem...

Image

cost and capability however...

Not everyone is a Fairwheel.

Ufgators
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by Ufgators

which groupset is in that picture?

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Werdna
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by Werdna

Those are TRP brake levers, with, I'm assuming, an integrated EPS shifter button.

Artisan
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by Artisan

The PCB or whatever it's called is almost the height (width) of the EPS power unit (40mm). The battery is rather small and I'm sure open to options in the future.

After speaking to a few people, the hard part will be to leave the PCB intact and re-house it safely and not mess with the electrical conductivity/signals (I'm obviously no electrical expert). I'm hoping to re-connect the battery seperately and allow the two seperate units to be placed inside a frame.

One thing though, I don't think anyone will be putting one inside a stem...

It (was) a very well made, water tight unit. No question about that!

mrfish
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by mrfish

I would take a look at how electric helicopter / boat / car crowd package their electronics. On helis they use heavy duty heatshrink to protect speed controller electronics and that's it. Not familiar with the others, but I'm sure a search at rcgroups.com and a couple of questions will help.

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sugarkane
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by sugarkane

you could also set the controller pcb in epoxy that will environmentalize the unit pretty well.. you wana be sure of what your up to though as once its done, its done

maxxevv
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by maxxevv

Maybe you can post some picts of the complete board next to a ruler ? (40mm width seems bigger than what I was expecting. What about length ?)

It would be useful for people to come up with suggestions of how to package it though.

Omiar
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by Omiar

I wouldn't be too worried about the re-housing.
I would suggest to have the case 3D printed. I would use a profile joint between the two sides and use some sealant when putting it togheter. For connectors, source some MIL grade connectors from local Radioshack store.
Scott Foil Ultegra Di2
Scott Scale 35 26"
Scott Spark LTD 29" M8000

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