TorqueMaster Pro 540 or 550?

[fyrstormer]

I just got a TRX-4 and I'm planning what electronics upgrades to install. The TRX-4 is approximately the same size as my SCX10 II and my Ascender, which use Holmes TorqueMaster Pro 540 27t motors. However, the TRX-4 is absurdly heavy, only 100g lighter than my heavily-modded Axial Wraith, which uses a Holmes TorqueMaster Pro 550 21t motor. As a result, I'm unsure which size motor would be better-suited for this truck. On the one hand, the scale nature of the TRX-4 means it will never tackle the kinds of obstacles my Wraith does, like climbing over vertical ledges, because the bumpers get in the way. On the other hand, the TRX-4 will only get heavier as I upgrade it, and driving in high gear may overheat a 540-size motor.

Thoughts? Personal experiences? Etc?

[Mountainsofbeer]

I'm using a Trqmaster Pro 550 30T with the stock XL-5HV esc also on 3s and its working well. The 27T version would be closer to stock top speeds I would imagine and just better everywhere else since its a handwound.

Mine feels smooth, great initial start for slow crawling and has a strong drag brake, only the esc gets hot not the motor.

But ya 550 for sure.

[fyrstormer]

Okay, I kinda figured that's the answer I'd get. I fried several 540 motors (not TorqueMaster Pro's, though) in my Wraith before I wised-up and put a 550 motor in it.

I mean, the TRX-4 doesn't *look* like it should need a larger motor than my SCX10 II or my Ascender, both of which are perfectly happy with 540 motors with endbell cooling fans, but damn the TRX-4 is heavy.

I wish I could figure out how to keep the spare tire without the weight penalty. It accounts for about 100g all by itself, and having it hang off the back is the second-worst place on the vehicle to have dead weight. (the worst place would be the roof rack, which I already removed.) I don't like the idea of completely removing the "scale accessories" on the back because it will leave bare holes in the body, but I may do it anyway.

[HumboldtEF]

I tried the HH 550 sealed can 21T and its a good inexpensive motor, just a touch faster than stock.

I also tried out the HH Crawlmaster pro 550 12T which i needed a new ESC for. That motor is quite nice and even at 12T its not much faster than stock, very good slow speed control.
Honestly the only reason I tried the sealed can was to avoid replacing the ESC and to stay within its 21T limit.

As for removing the spare tire I came up with an alternative that I liked, it can be found in the TRX-4 mods thread bottom of the post.
I eventually added a 3D printed first aid kit as well

[fyrstormer]

Cool, I have a couple of those HH TrailMaster Sport 21t motors already. I run them in my Tellurides. I can put one in my TRX-4 pretty easily to determine if I'm content with it. It's also nice that the timing is adjustable on the TrailMaster Sport motors, if you're willing to put some oomph into it. I'm surprised it's faster than the stock motor, though; I figured they'd be comparable with each other.

I decided to remove the entire rear-gate assembly after all. I reinstalled the bolts to secure the body to the inner frame in that area. Dropped the weight of the truck by 164g/5.8oz, all of which came off the back of the truck, and fairly high-up too. That will help. I'll worry about how to make it look pretty later.

- - -

I was just looking at the stock motor, and I realized if I go with a 550 motor I won't be able to install an endbell cooling fan to keep the comm from overheating during (relatively) high-speed driving. I think I'm going to try a 540 motor after all, at least to get some baseline temperature readings.

[slickwill16]

I had been running a Tekin Pro 30t 540 motor in mine for a while. At first I just ran it off the stock esc. I did notice quit a bit if heat in both the motor and esc, so u added a heat sink to the motor which helped. Eventually the esc started to give out, so I installed a Castle Manna X, and kept the same motor. After that, I had no issues with heat building up in the motor. It ran a whole lot cooler. Seemed to run a lot better too. Smoother startup with better top end. Since then, I yanked out the Tekin and threw in a Castle Slate 1406 (2850kv). In low gear, I still have the great low speed control as I had with the Tekin, but in high gear, she is a screamin demon. Moral of the story is, with a good quality esc, I wouldn't hesitate to use a 540 motor.

Sent from my SAMSUNG-SM-G935A using Tapatalk

[AGHolman]

Hey SlickWill,
What pinion are you running in your 2280kv Slate?
I just got mine in and not sure where to start.
I assume you run 3s lipo?

Thanks!

Originally Posted by slickwill16

I had been running a Tekin Pro 30t 540 motor in mine for a while. At first I just ran it off the stock esc. I did notice quit a bit if heat in both the motor and esc, so u added a heat sink to the motor which helped. Eventually the esc started to give out, so I installed a Castle Manna X, and kept the same motor. After that, I had no issues with heat building up in the motor. It ran a whole lot cooler. Seemed to run a lot better too. Smoother startup with better top end. Since then, I yanked out the Tekin and threw in a Castle Slate 1406 (2850kv). In low gear, I still have the great low speed control as I had with the Tekin, but in high gear, she is a screamin demon. Moral of the story is, with a good quality esc, I wouldn't hesitate to use a 540 motor.

Sent from my SAMSUNG-SM-G935A using Tapatalk

[slickwill16]

AGHolman,
I started with a 13t pinion, but moved it back to the stock 11t. With the 13, it was just a little too fast for my liking. The 11 made everything just right. Startup and low speed crawling was perfect, and the top speed came back down just enough to make it controllable (for me, ha ha). And oh yeah, 3s all the way. Hope this helps.
P.S. I have the 2850kv, not the 2280kv.

Sent from my SAMSUNG-SM-G935A using Tapatalk

[AGHolman]

Thanks! I guess I should try a 13t then with the 2280. I appreciate the response!

[Inspector86]

I guess I'm the odd man, I changed to a 9t pinion and run 2s batteries. The rig is still way faster than I can run let alone walking but the slow crawling is much improved. I have a 3s battery but I don't like the touchy throttle feel.

[fyrstormer]

I decided to try a 30-turn 540 motor just to see if it could handle the workload, because using a shorter motor means I could fit a cooling fan on the endbell. (why? because the massive amperage from LiPo batteries makes brushes get incredibly hot, and I want some airflow to cool them off.)

So far the motor is doing well. I wouldn't complain if it had a little more torque, as it can't quite make the truck pop a wheelie on a hard takeoff, but that's not really what this truck is for anyway. Thus far I haven't seen temperatures above about 130F, which I'm satisfied with. We'll see if it starts running significantly hotter when I get to drive it on rougher terrain.