Bit of 3D printed fun - portals with underdrive

[steve_fix_it_anyway]

Hello from a long time listner first time caller,

I picked up a new (to me) FTX Mini 3.0 / RGT Adventurer v2. I realised straight away that what I should've bought is an SCX24, as the parts / community support is massive.

Anyhoooo, as the mod potential without DIY was low, I set about designing my own parts - I'm just that kind of guy

So fully 3d printed portal axles with underdrive it is then. Underdrive (rear) ratio is about -20%

Pictured is the smallest reliable prototype of these axles.

Design considerations were:

- reliable gear mesh (so herringbone)
- fully printed (torque load is low in 1/24)
- must be essentially "bolt-on" replacements for current wheels so:
(1) gears at least 5mm thick to accomodate stock 7mm hex axles
(2) must accomodate stock steel axle length without fouling tyre
(3) no cutting etc of standard components

- must be as small as can be reliable

Here they are partly disassembled

Consequences of this mod:
- track is wider than wheelbase!
- springs are softer with more articulation due to leverage
- portals themselves are chonky, so may hang up?
- 14mm lift raises CoG
- slight cheating with "bolt-on" requirement - to use underdrive a smaller gear that fits directly to the axle has to be used, instead of the stock 7mm hex (which has to be removed)

I hope you like this little adventure in printing - happy to hear comments and questions below

 

[RudyF6]

That's awesome!
Great idea to underdrive it, beyond the size constraints, how's it crawl?