To much gear down a bad thing?

[GTSLOW]

So we've all heard that famous phrase "volt up, gear down." My question is, is it possible to gear down to much and have heat issues?

I.E., a popular gearing is 11/56 on Axial rigs. What if you ran 9/64? I suppose there's other factors but say we're talking about an otherwise stock SCX10II?

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[lonleycreeper]

Short answer in my experience, NO.


Final drive ratio, is kind of the most important part...

Spur/pinion, x axle ratio x transmission ratio.

I am currently running 87:1 low gear ratio in my big Bronco, Ultimate Adventuring Bronco. Using a revolver and sw4. Low speed control is incredible and heat is never an issue...

On the opposite spectrum my Trail King is running stock gearing (40:1ish)with a 16t Crawlmaster sport, and a fusion esc/Rx very good control and more heat.

Wheelspeed is about the same, but the lower gearing is just incredible.

[themountain]

Originally Posted by lonleycreeper

I am currently running 87:1 low gear ratio in my big Bronco,

I would like to see that

[lonleycreeper]

Originally Posted by themountain

I would like to see that

3.75:1 axle, 5.05:1 low gear in rc4wd AX2, 60/13 spur/pinion...

60/13=4.16 and change
4.16 x 5.05= 23.3 and change
23.3 x3.75 = 87.375 and change...

The revolver startup is super slow, allowing you to actually count rotations aprox 60rpm maybe 100rpm. I love it despite the noise. The gear box is super noisy too so there is that as well.

I will try to get a video in the next few days.

[Voodoobrew]

I usually run 9/92 which is roughly 100:1 reduction. I have also had rigs that are 200:1.

For the most part there are 2 downsides to gear reduction.

1 obviously reduced top speeds.
2 loud gear noise.

My 100:1 rigs running 2200kv on 4s have excellent bottom end and are only walking speed running flat out.

Going slow they aren't bad but at full throttle they sound almost like a revolver.

Not a big deal as I drive pretty slow 99.99% of the time.

This is 100:1 with a revolver if I remember correctly. https://youtu.be/0Ur5XGuuF64

I have a few older videos with a stock 35t motor at 126:1 and even they have plenty of torque. More then a torquemaster magnum at stock gearing for certain. https://youtu.be/0Ur5XGuuF64

Outrunner motors are the way to go IMO though.

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[Voodoobrew]

And I never had any heat issues running brushed.

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[Ninomaniac]

Brushless motors can overheat quickly with no load, but I think just the gearbox and diffs in a crawler provide enough resistance.

[themountain]

Originally Posted by Voodoobrew

I usually run 9/92 which is roughly 100:1 reducion...lk

Eeeemh...I am lost here...isnt that 1:9.2 reduction??? Pinion turns roughly ten times for one rotation of the spur gear??

[twade984]

Originally Posted by themountain

Eeeemh...I am lost here...isnt that 1:9.2 reduction??? Pinion turns roughly ten times for one rotation of the spur gear??

9/92 is 10.222:1 at the pinion, I’m sure he is reference final drive ratio of 100:1

Assuming common/standard ratios:
10.222 x 2.6 x 3.75=99.66

2.6=axial 3 gear internal ratio
3.75 = ar44/ar45/vp/element standard ring and pinion ratio


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[Voodoobrew]

Originally Posted by twade984

9/92 is 10.222:1 at the pinion, I’m sure he is reference final drive ratio of 100:1

Assuming common/standard ratios:
10.222 x 2.6 x 3.75=99.66

2.6=axial 3 gear internal ratio
3.75 = ar44/ar45/vp/element standard ring and pinion ratio


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Yes this, brilliant!
Bugs me when people only mention the pinion and spur reduction. Too many different drivetrains and custom options.

Also depending on the method you choose for gear reduction you might introduce "slop" into the drivetrain.

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[Yudi13]

I have one rig that geared low, and other than the gear noise, it runs cool. It uses 3 gears gearbox with 87/18 spur/pinion (still has plenty of room to bring it lower), scx10 III clone portal axles with OD portal gear (21/14). Total reduction is 70:1 at front axle and 90:1 at rear. This is the video of it running backwards against the door
https://youtu.be/ZzHFpYdqz_Y

Btw, it uses Holmes Crawlmaster Mini esc and Holmes Revolver 2040kv snubnose.

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[Ragenwraith]

I'd think spinning the motor faster even with more voltage would keep it cooler unless the rig weighs a lot. Sure wouldn't be hard to test the theory out...

Let us know.

[durok]

Originally Posted by Yudi13

I have one rig that geared low, and other than the gear noise, it runs cool. It uses 3 gears gearbox with 87/18 spur/pinion (still has plenty of room to bring it lower), scx10 III clone portal axles with OD portal gear (21/14). Total reduction is 70:1 at front axle and 90:1 at rear. This is the video of it running backwards against the door
https://youtu.be/ZzHFpYdqz_Y

Btw, it uses Holmes Crawlmaster Mini esc and Holmes Revolver 2040kv snubnose.

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Excellent display of low-speed control, you used your imagination on that clip, having it done hands-free!

I have a 1800kv v1 Revolver in a Bomber controlled by a Mamba X - so noisy, but still fun.

I'll definitely be picking up the Holmes new silent Crawlmaster ESC soon, I have a another Revolver that needs to go in a rig (v2 this time - 2200kv).

I would have commented on your vid, but you have them turned off, so I just gave it the ol' thumbs up!

(I lived in Jakarta when I was a kid for a couple years - went to the JES school in the mid-'70s)

[Yudi13]

Originally Posted by durok

Excellent display of low-speed control, you used your imagination on that clip, having it done hands-free!

I have a 1800kv v1 Revolver in a Bomber controlled by a Mamba X - so noisy, but still fun.

I'll definitely be picking up the Holmes new silent Crawlmaster ESC soon, I have a another Revolver that needs to go in a rig (v2 this time - 2200kv).

I would have commented on your vid, but you have them turned off, so I just gave it the ol' thumbs up!

(I lived in Jakarta when I was a kid for a couple years - went to the JES school in the mid-'70s)

Yes, it shows the rpm lock feature of Crawlmaster Mini. I really looking forward for the 4s capability with this gearing I have. But with the current settings it's only 3s for my motor.

I am not really familiar with the youtube settings, I upload it there just because I can not upload the video directly here

Good to hear that you were in Jakarta in the '70s, I think you meant JIS (Jakarta International School)

[durok]

Originally Posted by Yudi13

Yes, it shows the rpm lock feature of Crawlmaster Mini. I really looking forward for the 4s capability with this gearing I have. But with the current settings it's only 3s for my motor.

I am not really familiar with the youtube settings, I upload it there just because I can not upload the video directly here

Good to hear that you were in Jakarta in the '70s, I think you meant JIS (Jakarta International School)

It changed names, it used to be called Joint Embassy School until '78, in 2014 it was renamed again, to "Jakarta Intercultural School".

I even have a yearbook, somewhere!

My mother is still friends with a family we spent a lot of time with back then, the parents have visited us in Texas.