RR10 Bomber Vs. Yeti Rock Racer 1/10

[davemass]

Im curious how different these two models are. I know that one is brushed and the other is brushless (I am still not sure what exactly the difference is between the two).

I want to know if the RR10 is more comparable in performance and speed to the SCX10 or if it is faster and closer to the speed and power of a yeti rock racer.

I have and SCX10 currently and I am looking for something with more speed but is still a very capable crawler.

I started into RC about 4 months ago and have very little knowledge of the electronics involved and how to match motors with esc's and so forth, so any information will help.

Thanks.

[SCREAMER]

A Yeti is incapable of crawling unless you mount 8 inch tall tires on it. It's long, wide, low, heavy, has horrible steering, and is not very durable. I recommend a Bomber for your intended use.

[mikebecher]

In the simplest of terms, brushed motors are great for crawling and brushless is for speed. You can put together a sensored brushless rig and enjoy both to an extent but at a cost (as in $$$).

The Bomber sits between a Wraith and a Yeti, quite literally. It has a Wraith front end and trailing arms like the Yeti. If you want to crawl then the Bomber is the way to go as opposed to the Yeti. The Yeti is more akin to a short course truck and needs a lot of work to be even a modestly capable crawler. You can crawl quite well with the Bomber out of the box and on 3s it has more speed than an SCX10.

[davemass]

thanks for the info!

I know the RR10 runs a 35T motor stock. how much would putting a 12T or 15T motor increase the speed?

are the brushless motors waterproof? i like to bash a bit too.

[mikebecher]

You can use this site to calculate theoretical top speeds for comparison: R/C Calculations

I also created a Google Sheet for side-by-side comparison with the calculations built-in.

Sensored brushless motors are not waterproof due to the sensors (which is a must for crawling). You can buy them waterproofed or do it yourself with conformal coating.

[new2rocks]

Originally Posted by davemass

thanks for the info!



I know the RR10 runs a 35T motor stock. how much would putting a 12T or 15T motor increase the speed?



are the brushless motors waterproof? i like to bash a bit too.

The Bomber on 3S has decent wheel speed. If you want more than that, you're better off switching to a sensored brushless setup instead of going to a lower turn brushed motor. The lower turn brushed motors (esp 12T or 15T) will strain to drive a 2.2 rig and are likely to overheat and/or wear out faster. I have a Puller Pro 3500 kv on 3S in mine, and it's a beast.

[mikebecher]

Originally Posted by new2rocks

The Bomber on 3S has decent wheel speed. If you want more than that, you're better off switching to a sensored brushless setup instead of going to a lower turn brushed motor. The lower turn brushed motors (esp 12T or 15T) will strain to drive a 2.2 rig and are likely to overheat and/or wear out faster. I have a Puller Pro 3500 kv on 3S in mine, and it's a beast.

Oh yeah, I misunderstood that as a 12 or 15 tooth pinion. You would not want to run less than a ~27 turn brushed motor. And I concur, the Puller Pro is a beast on 3s and insane on 4s. But that combo is a lot of coin to drop when first starting out.

[davemass]

Originally Posted by mikebecher

Oh yeah, I misunderstood that as a 12 or 15 tooth pinion. You would not want to run less than a ~27 turn brushed motor. And I concur, the Puller Pro is a beast on 3s and insane on 4s. But that combo is a lot of coin to drop when first starting out.

Thanks

This helps a lot!

i think at first I might go down to a 27T motor and eventually when I have gotten bored with that move to a brushless sensored motor. I want to eventually run it like a U4 truck or something of the same sort.

if i go to a brushless with that kind of power would i need to upgrade the ESC as well? or would the axial stock ESC hold up?

[mikebecher]

When that happens and you're ready to empty your wallet, take a gander at SCREAMER's IFS Bomber "Qwiksilver". By then he'll have all the kinks worked out

[mikebecher]

Originally Posted by davemass

if i go to a brushless with that kind of power would i need to upgrade the ESC as well? or would the axial stock ESC hold up?

You'll need a new ESC.

[aver3]

Originally Posted by SCREAMER

A Yeti is incapable of crawling unless you mount 8 inch tall tires on it. It's long, wide, low, heavy, has horrible steering, and is not very durable. I recommend a Bomber for your intended use.

I wouldn't say it is incapable of crawling with 2.2s. It does need a locked front differential, and the independent front suspension gives up some ground clearance in many situations. The worst part for me, though, is the steering. The steering linkage on my Yeti kit hits on the servo. I'm not even sure that a longer servo horn would fix it, although I may try that. Why design the servo mount so it puts the servo in the way of the linkage? I think I have mine limited to about 25 or 30% of its travel to prevent it from binding.

If the Bomber had been out when I got my Yeti, I probably would have picked it instead. My Wraith has SCX10 axles, so the Bomber would have been a good compromise between a stock Wraith and a Yeti.

[SCREAMER]

C'mon Aver, you can't argue with me by agreeing with me.

[mikebecher]

Incapable of crawling might be a little extreme. It's like saying humans are incapable of flight. We CAN fly, just not out of the box!!

[SCREAMER]

That's why I threw in the caveat of 8 inch tall tires.

[davemass]

Any advice on changing the pinion and spur gears? I noticed in spread sheet that if I went to the 20 tooth pinion and a 54 tooth spur gear then the speed would increase without touching the motor. Would this damage other parts of the drive train?

[mikebecher]

Originally Posted by davemass

Any advice on changing the pinion and spur gears? I noticed in spread sheet that if I went to the 20 tooth pinion and a 54 tooth spur gear then the speed would increase without touching the motor. Would this damage other parts of the drive train?

Reducing spur size and/or increasing pinion size will increase the speed but you need to really monitor motor temps (get a cheap IR temp gun) with any ratio taller than the stock ratio of 4:1. My best advise is to keep the stock spur and buy a few different pinions, a couple teeth higher and lower. 54/20 (2.7:1) is pretty tall for the stock motor and may cause it to overheat.

I think it's unlikely that you'd damage other parts of the drivetrain with a brushed motor, as long as you don't drive it like it's on fire. My boys' stock Bomber has held up on 3s and they rarely exercise any restraint.

[davemass]

Originally Posted by mikebecher

Reducing spur size and/or increasing pinion size will increase the speed but you need to really monitor motor temps (get a cheap IR temp gun) with any ratio taller than the stock ratio of 4:1. My best advise is to keep the stock spur and buy a few different pinions, a couple teeth higher and lower. 54/20 (2.7:1) is pretty tall for the stock motor and may cause it to overheat.

I think it's unlikely that you'd damage other parts of the drivetrain with a brushed motor, as long as you don't drive it like it's on fire. My boys' stock Bomber has held up on 3s and they rarely exercise any restraint.

Thanks! You have been a ton of help!

As has everyone else who posted in this thread!