Bri

I am looking at a brushless motor for a light weight 4wd SCT, have the choice of 1/8" and 5mm shaft size and was wondering if it makes that much of a difference. The 1/8" size is cheaper so may get that one if either size works just as good.

Best regards,
Brian

EbbTide

iTrader: (39)

For a 4x4 sct definitely go for the 5mm shaft. It does make a difference when using mod1 gears and a heavy drivetrain.

tvih

As EbbTide said, definitely better get 5mm. I was hesitant on the same matter, but in the end I'm glad I went with the 5mm recommendation. There are affordable yet good 5mm shaft motors too, like the TrackStar 540 4-poles.

ddd228

iTrader: (24)

Lots of choices when going to MOD 1 pinion and spur gears!
Have you see the adapters that allow you to run a 5mm pinion on a 1/8' motor shaft? THAT is a joke.
Robinson makes OK pinion gears.
Use a spur gear cover to keep rocks out of there!
Also cut a hole in the bottom of the chassis to let the rocks out,if you have that kind of set up.
One rock and both pinion and spur will be almost toast. Well,very noisy,at best.

SouthFloridaApp

iTrader: (6)

I spoke to my girlfriend and she said shaft size does not matter.

tsair

iTrader: (3)

That's not what she told me!

ddd228

iTrader: (24)

OK,that was fun but maybe we can back on topic.
We have had sausage-fest here B-4.
Brush less motor MOTOR SHAFT SIZE.

billdelong

iTrader: (33)

sausage-fest aside, I'm with EbbTide on this one... I've seen many cases of 1/8" shafts snapping on 4WD SCT's both locally and on the forums. You might save some cash up front, but what good will it do you if you have to buy twice and end up buying the 5mm shaft later anyway?

If you're a super clean driver, then it's possible you may never snap a 1/8" shaft, so I guess the real question is what level of risk are you willing to take?

GLWD

tvih

Heh, yes, as for buying many times, a local guy with his SC10 4WD SCT said he burned up 3 thin-shafted Speed Passion motors in a very short time before buying a "proper" one (a bit of a slow learner I guess!). Now, these were motors that work very well and reliably in lighter cars, I have one in my B5M and another in my SC10 2WD. But a 4WD SCT is so much more demanding, thin-shafted motors aren't built for that kind of thing. It's not just the dimensions of the external shaft itself, it's the underlying differences within the motor that usually go with it. A 4-pole, whether 540 or bigger in size will have more power, less heat and all that jazz compared to a regular 2-pole 540, and a 550 2-pole will have those advantages over a 540 2-pole as well while usually not as good as a 540 4-pole.

But as I mentioned, on a budget the TrackStar 4-poles as an example should provide what the OP's looking for.

Bri

Thanks for the info. Anyone know of any other budget friendly 540 4 pole sensored brushless motors? I looked at the TrackStar and the 4250 kv one is out of stock. It seems 540 4 pole motor aren't as popular as they once were.

Best regards,
Brian

Badsn95

https://www.rcjuice.com/root-catalog...sct-motor.html

I don't have a 4wd SCT so I haven't actually used one of these but I use the regular 540's in my 2wd SCT and 2wd buggy and they run well with lots of torque.

It looks like they are out of stock on the 4300KV though.

Oh and I developed a saying in my younger years building loud car stereo's, "buy cheap, buy twice".

ddd228

iTrader: (24)

Hobby King MAY have one.
https://hobbyking.com/en_us/tracksta...red-motor.html

Tower is mostle out of Castle motors.
Search Results | TowerHobbies.com BUT most are 1/8" shafts.
Why a sensored motor? Just a few extra wires to fall out or get damaged.
My sensorless Castle 1406 works fine.(1/8" shaft) Stadium truck.

billdelong

iTrader: (33)

if it were me, I'd target a 550-4 pole in the 3800kV range for a lightweight SCT, something like this motor here:
https://www.amainhobbies.com/hobbywi...401058/p580785

If you need to find a "ROAR Approved" motor, then consider more options listed here under the "4x4 SC" section:
http://www.roarracing.com/approvals/...lessmotors.php

note that the motor I just linked is on the ROAR Approved list

billdelong

iTrader: (33)

I've had pretty good luck with HobbyStar motors in the past as well, though I haven't ran this particular motor, I noticed that they are out of stock for the 4300kV motor but would definitely consider the 3500kV, especially if running on 3S.

I used to run 3S for a while when most tracks in my area didn't care, it was far more efficient with longer run times and my batteries saw far less stress without any pack swelling and they would go at least 1-2 years before they needed to be replaced... I currently run a Tekin Pro4HD-4300kV and that motor kills most of my packs in about 6 months, I also typically run that motor between 65% EPA for the 1/10 turf track and 90% EPA for large 1/8 tracks.

Bri

I was getting a lot of cogging with a sensorless motor the last time I tried one in 4wd SCT. The motor doesn't have to be on the ROAR list. I would prefer a 540 4 pole due to it's smaller size and most likely a little less in weight in comparison to a 550. I was looking at the HobbyWing XERUN G2 motor but have read a few recent reviews of the motor case coming apart. I like the Castle 1410 1Y and was thinking about going with the cheaper sensorless SCT combo (thought I would give sensorless one more try since it is a lot cheaper) but the BEC is only listed at 5 volts.

Brian