3-gear gearbox conversion - gearing question

[Sjonnie82]

Morning,

I know I have read it somewhere in a thread, but I cannot find this anymore... So really sorry if this is discussed before.

At this moment I am building a SCX-10-3 kit, and want to use an Element Stealth gearbox. But i know but this one is geared lower then stock.

So I am lookking for some help:
- Which pinion / spur is best to avoid a really slow car ;-)
- What motor is used best? I was thinking a Holmes 27t on 3s for good Torque and decent trailing speed

Thanks in advance!"thumbsup"

 

[svt923]

I was running 56/13 on my 3 gear converted SCXIII with a Castle 3800kv motor on 3S. It had wheel speed in the range I usually prefer but the Castle motor wasn’t as smooth as I liked so I swapped it for a Holmes Puller Pro 2700kv. The 80:1 gear ratio was great for running high RPM brushless motors but not great if you want to run brushed with any sense of wheel speed. If you want to stay brushed, I would recommend pinion/spur gearing in the 3:1 range with a 27T brushed motor.

 

[Sjonnie82]

I was running 56/13 on my 3 gear converted SCXIII with a Castle 3800kv motor on 3S. It had wheel speed in the range I usually prefer but the Castle motor wasn’t as smooth as I liked so I swapped it for a Holmes Puller Pro 2700kv. The 80:1 gear ratio was great for running high RPM brushless motors but not great if you want to run brushed with any sense of wheel speed. If you want to stay brushed, I would recommend pinion/spur gearing in the 3:1 range with a 27T brushed motor.

Thnks for your reply! Do you still use this setup?
With 3:1 you mean 54 spur and 18 pinion? thanks!

 

[svt923]

Thnks for your reply! Do you still use this setup?
With 3:1 you mean 54 spur and 18 pinion? thanks!

I stole the electronics out of the SCXIII to put in my VS4-10 Phoenix so I don’t have the truck setup with any electronics at the moment. The Puller Pros already have great low speed control but it was next level smooth when combined with that much gear reduction.

On the pinion and spur, yes 54/18 would be a 3:1 ratio. Since you mentioned the Element transmission, I didn’t know if you were going to be running 32P or 48P gears so I didn’t want to give specific tooth counts. That gearing would get the total ratio in the 56:1 range which would allow some decent wheel speed with the RPMs you can get out of a brushed motor on 3S.

 

[Sjonnie82]

I stole the electronics out of the SCXIII to put in my VS4-10 Phoenix so I don’t have the truck setup with any electronics at the moment. The Puller Pros already have great low speed control but it was next level smooth when combined with that much gear reduction.

On the pinion and spur, yes 54/18 would be a 3:1 ratio. Since you mentioned the Element transmission, I didn’t know if you were going to be running 32P or 48P gears so I didn’t want to give specific tooth counts. That gearing would get the total ratio in the 56:1 range which would allow some decent wheel speed with the RPMs you can get out of a brushed motor on 3S.

Thanks for you input! i will make a topic when the build is more interesting to look at "thumbsup"