Brushless thoughts?

[sbednara]

Im going to be installing a brushless motor/esc combo in my rc10 ce. I had just about decided on the trackstar 17.5 from hobbyking.com well, wondering eyes have me looking at cheaper options on ebay. especially after my experience with the goolrc tx/rx. I've been pleasantly surprised with it. In addition, I also picked up a cheap Chinese esc from amazon for the raider pro and it has also performed better than expected. anyway this has me considering less expensive options for a motor/esc combo to use in my rc10. some of the ones ive seen are in the $30-40 range for the combo. anyone have first hand experience purchasing these or seeing them run in cars? goolrc seems to be a brand i see a lot of but there are several options, some noname stuff etc. most seem to be around 60a or less. not really sure what this means in terms of performance but the 17.5t trackstar is rated at 80a.

anyway just curious if anyone has any experiece with these or maybe for an inexperience rc hobbyist like myself what red flags should i be looking for to steer clear of that might indicate potential poor performance or setup for failure?

[YakkityYak]

I installed a 4370kv GoolRc brushless system in a Stampede 4WD for a friend. He runs it on a 3s lipo. No complaints whatsoever. Motor never gets above normal temps. ESC has no issues. Very powerful for the price. Excellent buy. They also offer sensored versions.

[sbednara]

Great to hear. Thanks for sharing Yak! I’ll prob go this route, goolrc.

[sbednara]

What does 3650 mean when it’s liated next to brushless motors? It doesn’t appear to be a kv rating as that is usually listed separately. Size? Surely this has to be diameter x length, right?

[jwscab]

Yes, it's motor size. Not exactly sure how they get those dimensions but they are in mm

[sbednara]

Thanks. I believe first 2 digits are diameter, second 2 are length. But as you said I’m not sure where measurements are taken.

After further review it looks like there are a variety of sizes. I’d guess a 35xx is what I need, but what length, idk.

Also, if I wanted something equivalent to a 17.5t motor, what kv rating should I be looking for? 2200? I see a lot of high 3xxxkv and 4xxxkv, but fewer lower than 3000.

[jwscab]

its just kind of a rule of thumb. they don't really end up being the same, but essentially something around 3000-3500kV is around 17.5/13.5

[Basher67]

You are correct. A 3650 is 36mm dia. x 50 mm length, which makes it aproximately the size of a 540 motor. A 3660 is a little longer and about the same size as a traxxas velineon motor. When I got back into racing last winter, I started out with a 5200kv ebay el cheapo that cost me around $18 to my door IIRC. Unlike my goolrc motor, it did not cog whatsoever. It was smooth and powerful, especially for a sensorless motor. After crashing every other lap for a couple months, I finally crashed so hard that the endbell came off the motor on the track. I popped it back on, tightened the screws back up and kept racing. I still have that motor running strong in a short course truck. It was such a great value that I ordered another one and had the same good experience with it. They do not have the power when compared to higher end sensored motors when compared turn for turn. My 5200 kv motor should be roughly the equivalent of an 8.5 turn but actually has less power than my Trinity 10.5 turn. For bashing or any situation where the latest high end spec motor isn't required. The cheap no name brushless stuff will bring alot of smiles for very little money.
Here's a link to the one I used. https://www.ebay.com/itm/3650-4Poles-5200KV-Brushless-Motor-for-1-10-RC-Car-Boat-Parts-/172950258605?hash=item2844a383ad

[sbednara]

Thanks guys! Appreciate the info.

Any thoughts as to whether a 45a vs a 60a rating would make a big difference? Would one run hotter than the other?

What about a 3800kv on my 6gear transmission? Is that too much?

[Basher67]

I wouldn't think it would be too much. With brushless, alot of the transmission damage is from the initial strong torgue or "punch" of the motor. This can be turned down with most brushless esc's. If your planning on running any kind of brushless setup on a six gear, I would recommend the outdrive bearing mod.

[sbednara]

Glad you mentioned the outdrive mod. I have already purchased the outdrives, just haven’t installed. I was contemplating just using the #6614 gears instead. This settles it, outdrives it is.

[NomadRacer]

You might have to open up the top motor screw slot when using a brushless motor. I used a diamond coated (because I have them) file and took about .5mm off.

[sbednara]

So reading this again, I realize the outdrive bearing mod is different from what I was referring. I meant swapping the 6614 idler gears for the mod’d outdrive, going to an all metal gear transmission. However you meant swapping bearings for the felt washers. This makes sense for a smoother running transmission esp at higher rpm’s and more torque.

Nomad, not sure I know what motor holes your referring to. I’ll take a look and see if I can figure it out, may post up a pic to be sure.

[NomadRacer]

Sorry, I should have provided more detail...

The motor mounts to the motor plate with two 3mm screws. The bottom hole is just that, a single hole... think of it as the pivot point. The top is in the form of a slot. When you bolt the motor to the plate, with the only the bottom screw, look at the slot. your threaded hole in the motor most likely is not centered in the slot, not letting you install the 2nd screw. It's really best to file the slot, not the bottom hole.

I have three Reedy Mach 3 17.5's and one Motiv MC2 13.5. All of them would not line up until I filled the top of the slot a bit. If you need a picture, let me know and I'll try to get one for you.

[sbednara]

okay, thats makes more sense. so are you filing in such a way that your lengthening the grove on one end? surely your not filing a spot where your opening up a hole in the middle of the grove, right?