RC10Talk - The Net's Largest Vintage R/C Community

After destroying several UM-1, I searched for a substitute and (hopefully) found it in parts from a 3D plotter store (for just a few cents)... pictures:

Works smooth and quiet:

Very cool! Are you going to use a reverse rotation motor?

Thanks! The motor direction remains "counter clock" due to the obsolete middle gear..
testchassis:

Oh yes, the Kyosho gearboxes have that extra outboard gear.

Tidy !

Any more information on the parts used?

Belt module is GT2 (or 2GT, means 2mm per tooth). Calculated length 142mm (71tooth). Pinion
16tooth and maingear 50tooth (better take 48: only very small gap to the outdrives left). Smaller
pinion should be no problem, respectively with a slightly shorter belt.

SPA240WS wrote: ↑Tue Dec 10, 2024 6:05 am Belt modul is GT2 (or 2GT, means 2mm per tooth). Calculated length 142mm (71tooth). Pinion
16tooth and maingear 50tooth (better take 48: only very small gap to the outdrives left). Smaller
pinion should be no problem, respectively with a slightly shorter belt..

From experience with the Zerda I'd stick with a higher tooth pinion and increase the "spur" tooth count to lower the ratio, with smaller pinions they are more likely to slip and then they wear exponentially.
Oh very cool project !

Nice project...

Dadio wrote: ↑Tue Dec 10, 2024 2:45 pm From experience with the Zerda I'd stick with a higher tooth pinion and increase the "spur" tooth count to lower the ratio, with smaller pinions they are more likely to slip and then they wear exponentially.

GT2/2GT is usually less prone to slip than MXL with a better match between belt and tooth profiles... And increasing the number of the tooth on the spur gear proportionally to the number of increased tooth on the pinion might not be possible (there might be constraints around)... On my Zerda the target is to work with the exact same ratios as the original Zerda...

Built the Saurus chassis from (almost) new parts. Some Platinum's for the rear fit perfect, for the
front even the short ones seem too long for reduced ground clearance. Took some alloy dampers
with modified pistons / Tamiya red silicon o rings and placed it in a position I found on the Kyosho
boxart to decrease some more height:

Perfect weather for finishing the car.., green or black?
Running ultrasilent, hope to test it outdoor the next weeks.

Car got a brushless update (11,5T), beltdrive takes it well, not the tires..

Frankentruck wrote: ↑Mon Dec 09, 2024 2:48 pm Oh yes, the Kyosho gearboxes have that extra outboard gear.

I've stayed up late at night and thought is it extra or simply a relocation of one from the inside, deep things to ponder