Tenshock RC906: yes or no ?

[Shawns303]

This is with the update. I don't think it can get smoother with a non-sensored motor than this! Good lookin out for the scale guys!

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[Shawns303]

I have been wondering if anyone has tried a heli motor for crawling. I have seen some 10 pole heli motors that run a 36mm can but have just started researching them. In theory, with the 200,000 rpm limit on the Mamba X, you should be able to run a 3100kv 10 pole motor. Would be waterproof and should not have any cogging with ridiculous torque. Any thoughts?

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[GTSLOW]

Curious if anyone else has ran the 1250Kv motor?

[Shawns303]

Just ordered the 2400kv for my Bomber. I will let you know how it goes once it is installed and driven a bit.

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[Shawns303]

So I tried running the 2400kv in my Bomber with a MMM, cogged like crazy. I was wondering if Castles new update for the X series escs made that big of difference with a non-sensored motor and put the 2400 in my SCX10 II. Smooth as butter!

https://youtu.be/opXwPw01lyw
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[Motorider]

Originally Posted by Shawns303

So I tried running the 2400kv in my Bomber with a MMM, cogged like crazy. I was wondering if Castles new update for the X series escs made that big of difference with a non-sensored motor and put the 2400 in my SCX10 II. Smooth as butter!
https://youtu.be/aHVyWyFtPSw

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You were running the 2400kv tenshock motor on the castle manba x?

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[Shawns303]

Yes, I fixed the link to the video also.

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[MattySlimz1987]

Tenshock makes some really good batteries, I have a 3 cell from him thats been used a lot, works great still. Haven't tried out or seen the bl crawler motors. I'd like to see more of his stuff make it over here to the U.S. for faster shipping or even in some lhs's.

[Schs2013]

Curious to know if anyone has tried a 1750kv or 2400kv in there TRX4 with 3s how where the results? with what ESC gearing ill say Stock. mostly trailing Canadian Snow banks not much of a crawler but when it happens ill crawl.

[Hardcoretam]

This is a recent, really good comparison video of the 3 of the Tenshock RC906 motors vs a Castle sensored motor in a variety of situations.

For the price, they seem to perform great.

[Schs2013]

is there a youtube link Hardcoretan?

[JatoTheRipper]

Yeah I'd like to see video of crawling with this motor.

[Hardcoretam]

Whoops! I forgot to post the link in my previous comment.

Sorry to keep you waiting. Not my video but a really good comparison

https://www.youtube.com/watch?v=OV3VY0vicm8

[Schs2013]

Originally Posted by Hardcoretam

Whoops! I forgot to post the link in my previous comment.

Sorry to keep you waiting. Not my video but a really good comparison

https://www.youtube.com/watch?v=OV3VY0vicm8

No worries. It will be worth watching for the wait. Since I mainly trail I don't need sensored motors but they have their advantage to

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[Ninomaniac]

Interesting motor for sure. But it looks like 4s at least for creep AND wheel speed.

[Hydrocarbon92]

Just like I'd expect, if you want both creeping speed and high speed - get sensored! Otherwise the low KV with low gearing still makes for a good crawling motor at a relatively low price. The old thing to be wary of is the ESC you use. IMO the key is gearing and the ESC. Cheap ESC's can cog worse, and high (more mph) gearing can result in the same.

[robert@castle]

Originally Posted by Hardcoretam

Whoops! I forgot to post the link in my previous comment.

Sorry to keep you waiting. Not my video but a really good comparison

https://www.youtube.com/watch?v=OV3VY0vicm8

Good comparison despite the high KV on the Castle motor.

On the Tenshock motors, it really shows how torque goes down as KV goes up. The higher KV motors don't have the torque to get the motor spinning when loaded down on the slopes. This causes it to cog because it's rocking between phases trying to get the motor to spin. You can see this on the Castle motor as well. It looks like you needed to use more throttle to get the truck moving. You can see the tires load with torque but not start the truck moving, but with the sensors it doesn't cog and keeps applying power to the correct coil. A 2850 or 2280kv motor would give you more torque and allow for a lower minimum speed on a slope because it wouldn't take as high of throttle percentage to get and keep the motor moving.

[Hardcoretam]

Originally Posted by robert@castle

Good comparison despite the high KV on the Castle motor.

On the Tenshock motors, it really shows how torque goes down as KV goes up. The higher KV motors don't have the torque to get the motor spinning when loaded down on the slopes. This causes it to cog because it's rocking between phases trying to get the motor to spin. You can see this on the Castle motor as well. It looks like you needed to use more throttle to get the truck moving. You can see the tires load with torque but not start the truck moving, but with the sensors it doesn't cog and keeps applying power to the correct coil. A 2850 or 2280kv motor would give you more torque and allow for a lower minimum speed on a slope because it wouldn't take as high of throttle percentage to get and keep the motor moving.

Thanks Robert, but that's not my truck sadly, but i'm subscribed to this channel on Youtube and thought it would be a good one to show here.

1750kv seems the best of the trio of Tenshocks overall. They look pretty good for the price. I think the video creator said he was purposely driving to try and get all the motors to cog, including the castle but it only became more noticeable in the longer gearing.

I'd go for around 2280kv if i picking a Castle motor but that dude likes his wheel speed> Few videos of him crawling / speed running with the 7700kv.

[Schs2013]

Think I've seen what I needed and have all the information. Thanks guys I'll look for the Castle system for 3s trail runs I think the lower kV will work best. And I probably won't need anything else for along time.

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[JohnRobHolmes]

Originally Posted by robert@castle

Good comparison despite the high KV on the Castle motor.

On the Tenshock motors, it really shows how torque goes down as KV goes up. The higher KV motors don't have the torque to get the motor spinning when loaded down on the slopes. This causes it to cog because it's rocking between phases trying to get the motor to spin. You can see this on the Castle motor as well. It looks like you needed to use more throttle to get the truck moving. You can see the tires load with torque but not start the truck moving, but with the sensors it doesn't cog and keeps applying power to the correct coil. A 2850 or 2280kv motor would give you more torque and allow for a lower minimum speed on a slope because it wouldn't take as high of throttle percentage to get and keep the motor moving.

Sooooo, you do know that motor torque is based on the motor size/design and not the Kv, right? This is an old saying from brushed motors that does not translate to brushless. While higher Kv will have more copper losses in the ESC phase side and wires between esc and motor, this only causes a bit more motor rpm increase when unloading occurs. Torque loss is only an after effect of decreased ESC efficiency, and we should actually see an increase in torque if the motor is not saturated and phase amps not limited.
If he had simply regeared the motors as should be done, the higher Kv motors would have started up BETTER and produced MORE torque at the wheel and the shaft. Volt up, gear down. Or Kv up, gear down. It works the same.

More direct to the point of high Kv motors sensorless having startup problems. The problem with high Kv motors running sensorless is not the lack of torque, it is the low inductance and low bEMF making sensorless feedback difficult if regearing is not done to increase commutation rate accordingly. The obvious culprit of his setup (besides not regearing) was the async rectification causing the diode drop to mask part of the bEMF. On a sidewinder 4 the performance differences would be more difficult to see. If he had properly regeared the higher Kv motors would have been hands down winner.


Because of gearing limitations in our rigs, there will be a threshold where Kv does impact sensorless startup because further geardown is not possible. Every setup is different, but there is absolutely no reason that a modern truck running 4.75" tires can't run a sensorless 2800kv motor on 3s effectively.