Motor Suggestions for 6x6 build

[WesTX]

Looking for suggestions for a motor for my 6x6 build. Will be a heavy scale rig with a matching gooseneck trailer to be a crawler hauler. Running a summit 2 speed transmission, yota 2 rear axles, SCX front axle.

If the standard size HH revolver outrunner were in stock I would look at that option, but needing other suggestions since its out of stock.

Wes

[robertjpjr]

If you can fit it, and it doesnt affect your cog too badly..
Turnigy 2350kv 4 pole 1/8 scale motor. Sensored brushless.

Or the hobbywing 3400kv 4 pole 3656sd motor.
Both are $60 and 85 respectively.

Or if you need brushed, a titan 775 for larger size, or the titan 21t 550.

[Szczerba]

If you are going brushless sensored, anything over 2500kv is going to be too high of a kv, won't have the torque.

I run the Tekin ROC 412 2300kv on a 13.5lbs TTC truck on 4s and it's a perfect mix of super smooth low end and great mid-range punch. Would have went the HH sensored outrunner route as well.

I would say the ROC 412 at 2300 or 1800 on 4s. Valuehobby.com sells good 4s packs for cheap.

[WesTX]

Originally Posted by robertjpjr

If you can fit it, and it doesnt affect your cog too badly..
Turnigy 2350kv 4 pole 1/8 scale motor. Sensored brushless.

Or the hobbywing 3400kv 4 pole 3656sd motor.
Both are $60 and 85 respectively.

Or if you need brushed, a titan 775 for larger size, or the titan 21t 550.

The titan 775 may be a decent start, I hadnt thought of that. I think I even have one laying around I could start with along with the stock Summit ESC (EVX-2)

Would love sensored brushless power, thanks for the feedback Shane. Good to hear what your TTC truck is running as I know that thing RIPS. I am thinking with the trailer I may be pushing 20 lbs easy before I put a rig on the trailer.

Ill throw that Titan 775 on that I have, and when it burns up look at the options maybe. Still open to any other options people have.

Wes

[svt923]

If you have the space on your truck, go for an 1/8 scale motor. One of those should bolt right up to the summit motor plate. The Hobbywing XeRun 4274 and Tekin T8 are some good choices for big, sensored brushless motors.

[JohnRobHolmes]

I disagree that higher KV motors lack torque, they will produce plenty of it with enough battery. But, faster motors need enough geardown so the ESC isn't running half throttle under load all the time. On 3s a 3000+kv motor will actually produce more torque at the shaft than a slower motor on the same voltage, and when you adjust gearing as well it is a double whammy of additional power. If you are looking at brushless, I really can't say anything will do you wrong as long as it is sensored and you can gear it proper.


I'm working on getting Revolvers back in stock, and also have 2200kv Pullers coming with the next batch. I personally wouldn't hesitate to throw a 3500kv motor in there. Our Puller Pro 540 would be over the top power, but maybe too much isn't a bad thing in a tow rig.

[Highmark]

Originally Posted by WesTX

. Running a summit 2 speed transmission, yota 2 rear axles, SCX front axle.

Those yota axles are going to cause you problems with any real power and weight.

[WesTX]

Originally Posted by Highmark

Those yota axles are going to cause you problems with any real power and weight.

Planned for this, already working on some titanium axle shafts to replace the stock ones. That should make them serviceable.

Thanks,

Wes

[maslin]

I would recommend the new TRLILMASTER PRO from holmes. It's smooooth

[Szczerba]

Originally Posted by JohnRobHolmes

I disagree that higher KV motors lack torque, they will produce plenty of it with enough battery. But, faster motors need enough geardown so the ESC isn't running half throttle under load all the time. On 3s a 3000+kv motor will actually produce more torque at the shaft than a slower motor on the same voltage, and when you adjust gearing as well it is a double whammy of additional power. If you are looking at brushless, I really can't say anything will do you wrong as long as it is sensored and you can gear it proper.


I'm working on getting Revolvers back in stock, and also have 2200kv Pullers coming with the next batch. I personally wouldn't hesitate to throw a 3500kv motor in there. Our Puller Pro 540 would be over the top power, but maybe too much isn't a bad thing in a tow rig.

I left out the assumption that he would be on 3s-4s in my high kv comment. Also, I left out the part about gearing down to like 10:1 at the trans. I need to quit posting about motors or just have you proofread the post beforehand.

Originally Posted by maslin

I would recommend the new TRLILMASTER PRO from holmes. It's smooooth

I have the same motor, need to hook it up to a truck and get to tuning/testing.

[JohnRobHolmes]

Even though I don't say it on the website, the 3500kv and slower models of the Puller Pro are 4s capable. We recommend 3s max, but the rotors will take 50,000 rpms until the rotor gets past 180f and the epoxy starts to soften. They are carbon wrapped as an additional safeguard.



The real loss in torque with high KV motors occurs in the ESC and wiring as it warms up. It isn't exactly a torque loss, but a voltage loss. Less voltage applied = less amps induced. Amps make torque. So in a roundabout way, high KV motors can produce less torque when the rest of the system starts to heat up.

[WesTX]

Originally Posted by JohnRobHolmes

Even though I don't say it on the website, the 3500kv and slower models of the Puller Pro are 4s capable. We recommend 3s max, but the rotors will take 50,000 rpms until the rotor gets past 180f and the epoxy starts to soften. They are carbon wrapped as an additional safeguard.



The real loss in torque with high KV motors occurs in the ESC and wiring as it warms up. It isn't exactly a torque loss, but a voltage loss. Less voltage applied = less amps induced. Amps make torque. So in a roundabout way, high KV motors can produce less torque when the rest of the system starts to heat up.

And now I have learned something today. Thanks for the electrical class session JRH, you're always a great asset around here for those things!

Wes

[JohnRobHolmes]

Thanks! Any system has the same type of heat/torque issue. Since higher KV motors need higher (phase) amps to produce the same output torque, it is easier to feel the "softness" as things get warm. But with regearing and/or a larger ESC and battery to handle higher overall power, the net result is more torque until the motor reaches saturation.


I tend to build systems around specific motor speeds, based on pole count. For most applications, spinning two and four pole motors around 35,000 rpm is safe yet still powerful. For higher power to weight ratio, pushing closer to 50,000 rpm is the edge of reliable. Outrunners of 14 poles work best at 16,000 and 20,000rpm steps. and etc etc etc...

[MountainStorm]

I've been impressed with my 3500KV Puller Pro and BLE Pro combo pushing 11 pounds around on 3s and now that it's only pushing 7 pounds look out world! Geared down it seems to make "too much torque" IMO (2 axles later) so I geared up a little. I've get fans on the motor and ESC and the motor barely gets warm no matter how hard I thrash. The ESC gets hot enough to thermal without a fan...but with a fan I don't see any problem with it.