Bruiser! Have I chosen.... poorly?

[Psylence]

Just finished putting together the re-re Bruiser's transmission. Installed the hop-up slipper clutch while I was in there because why cheap out now, right? With that in mind, is it considered a bad idea to use something like this instead of the crusty old silvercan?

[TA-Mark]

Most people would go for a crawler tuned motor like the Tamiya CR35T (or higher turn) in this type of model. Sport Tuned is going to give you more speed, and less climbing power, sort of the opposite of what the model was designed for.

[waterbok]

yep, CR35T or the torque tuned, but nothing faster.

she does look nice though the sportstuned.

[Psylence]

Had this one laying around but no CR tuned. Just this sports tuned and a Dynatech 01R

More concerned with mulching the gearbox at this point than having it be a bit too quick. I figured on mostly running it around in first anyway, 2wd doesn't work so well in the grass around here!

[matman]

I have put in a torque tuned motor in mine & they are cheap ..

[Psylence]

I gotta say the transmission was pretty intimidating to build. I'm half expecting my first attempts at forward motion to result in massive ginding noises!

[Champ85]

As long as you are gentle on the throttle (ie. almost coasting during the shift change) when shifting gears, the motor choice should not be much of a problem (within reason).

According to the almighty Tamiya Motor page: http://www.zaonce.com/stuff/motors/motors.htm

The stock RS540S is around 15K rpm and 194 g/cm torque at peak efficiency.

The Sport Tuned is around 18K rpm and 350 g/cm torque at peak efficiency.

The Torque Tuned is around 16K rpm and 305 g/cm torque at peak efficiency.

The extra 3K rpm from the Sport Tuned you picked will make the truck go up to 20% faster and the extra 77% torque will certainly give it more grunt.

I plan on using a Tamiya GT Tuned in my Bruiser once I get around to building it.

Specs for the GT Tuned are 19K rpm unloaded, and 500 g/cm maximum torque (according to the Tamiya GT Tuned box specs).

The 500 g/cm maximum torque as labeled on the Tamiya GT Tuned box is, I think, incorrect.

At stall, these types of motors produce greater than 2000 g/cm of torque (source: BZ/TZ/RZ motor boxes), so I'm taking the 500 g/cm "maximum" on the GT Tuned box as "peak efficiency" torque, which is in line with the torque ratings of the higher speed TZ/BZ/RZ series of motors. The magnets are the same in these motors, only the rotor windings are different (23T vs 25T), which accounts for the rpm differences.

Therefore I think the GT Tuned is going to give a peak efficiency speed of around 15K to 16K rpm and 500 g/cm of torque, which is right around the RS540S in terms of speed, but 157% more torque. While this may seem ridiculous for the torque, keep in mind that the original Bruiser and Mountaineer came with the RS750S which was around 11K rpm and 500 g/cm of torque at peak efficiency (if my source is correct). The re-re Bruiser transmission is a stronger design in my opinion, so should be able to take the extra torque without grenading.

The weakest part of the driveline in both the original and re-re Bruiser is the universal drivershafts (mostly the rear one). Just watch for wear on the universal joints and replace them when they get too sloppy or upgrade to aftermarket ones.

[taliesin]

I wouldn't do it, but that's just me. Torque tuned or a 35t lathe motor is what I'd choose just to maximize the climbing and 4wd performance. Frankly, the Bruiser is fast enough with the silvercan, so slower is better IMHO.

[Psylence]

Well, we shall see if this thing can move under its own power later this evening. Who knows if this will end up being a runner or a shelfer at this point... I've got a High Lift kit still to build to see the evolution of the 3 speed. High lift kit looks a whole lot less inspiring though with all that plastic... probably more durable and precise though.

What's the general consensus so far on high lift vs. bruiser re-re for a runner/basher?

[mongoose1983]

[...] What's the general consensus so far on high lift vs. bruiser re-re for a runner/basher?

Well, I know the Toyota High-Lift is a much better runner than the original Bruiser, but the 2012 Bruiser is a completely different truck.

I presume the differentials really make a difference. One thing I'm not a fan of the new ones is how noisy they are. Anyway, only TCers who have run one of the new ones might be able to tell you about how better (or worse) runners are those compared to the High-Lift.

[B.M.T.]

The Bruiser's suspension actually tried to do something to absorb bumps, something that a High Lift doesn't

I've left my diffs unlocked (but with a healthy squirt of AW grease in the centers to slow them down) and the silver can in because the Bruiser to me is a big jacked up truck that is only 4WD some of the time, not a rock crawler so I want to be able to put some boogie on but not have the thing trip over it's self like crazy, a thing that locked diffs do at speed.

Just try it with the Black motor, but I think you might find a poo in your pants when you snag 3rd and give it a boot full They are the rhinoceros of the rc world, big, heavy and dumb but can crank up to a deadly pace really quick... and don't stop in a real hurry for anything.

[Percymon]

You could always set the throttle end point on your transmitter at 80% to roughly cap the sport tuned motor revs at max silver can levels

[Psylence]

The Bruiser's suspension actually tried to do something to absorb bumps, something that a High Lift doesn't

I've left my diffs unlocked (but with a healthy squirt of AW grease in the centers to slow them down) and the silver can in because the Bruiser to me is a big jacked up truck that is only 4WD some of the time, not a rock crawler so I want to be able to put some boogie on but not have the thing trip over it's self like crazy, a thing that locked diffs do at speed.

Just try it with the Black motor, but I think you might find a poo in your pants when you snag 3rd and give it a boot full They are the rhinoceros of the rc world, big, heavy and dumb but can crank up to a deadly pace really quick... and don't stop in a real hurry for anything.

Hah! Good comparison. I'll definitely keep that in mind as I'm testing it out this week; as heavy as this thing is it's got definite ankle snapping potential

You could always set the throttle end point on your transmitter at 80% to roughly cap the sport tuned motor revs at max silver can levels

This is also a very good idea...

So I'm gonna be disappointed in the high-lift suspension compared to the Bruiser? That's somewhat frustrating, I'd definitely expect that later "evolution" of the Bruiser to be superior in most aspects. Guess I'll have to look into "fixing" it before it's built

[Psylence]

Well, put her down on the floor in the house to take it for a test run since it's pouring rain outside

First, wow... can't believe I got that tranny put together right and everything seems to shift PERFECT.

Second, good lord thats a noisy drivetrain!

Third, the Tamiya 302 ESC might not have been the best option. Too much braking; letting off the throttle abruptly makes me wince as I can envision gears slamming into each other. Doesn't appear to be adjustable, so a better, more adjustable unit might be happening sooner rather than later!

[Psylence]

Aaaand she's already broken. Pin holding the rear driveshaft lost an e-clip and dropped the shaft onto my floor. Awesome.

Guess they weren't kidding about putting rubber cement on those eclips eh? Ah well, at least it's not serious!

[mongoose1983]

Yeah, for some reason the new ones are so noisy. Not that the originals are that silent either.

[Psylence]

Sadly won't be making much noise for a while though.. Whatever size e-clip they use on the propshafts isn't contained in anything else I have. Not sure how it dropped off so quickly; I guess I sorely misjudged the use of rubber cement. At a loss for the moment.

Seriously though? Rubber cement to secure e-clips? Is there a better solution, perhaps not involving e-clips at all?

[Champ85]

I assume you mean the e-clip depicted on the lower-left of page 15 in the manual used to hold the cross pin in the universal joint.

The original driveshafts didn't use e-clips, instead it was a type of aluminum rivet. I don't know why Tamiya uses them in the re-re.

I agree it's a stupid design. It's not like you'll ever want to pop it off to gain access to the universal joint pieces. Usually the joint wears down so much that it shears off and you throw the whole shaft in the trash and buy a new one.

Have a magnet handy? Try scanning the floor with it and you might get lucky.

[Psylence]

I assume you mean the e-clip depicted on the lower-left of page 15 in the manual used to hold the cross pin in the universal joint.

The original driveshafts didn't use e-clips, instead it was a type of aluminum rivet. I don't know why Tamiya uses them in the re-re.

I agree it's a stupid design. It's not like you'll ever want to pop it off to gain access to the universal joint pieces. Usually the joint wears down so much that it shears off and you throw the whole shaft in the trash and buy a new one.

Have a magnet handy? Try scanning the floor with it and you might get lucky.

That is absolutely the piece I'm looking for. Seriously, it must be a 1mm eclip since the 2mm size is far too large.

I've been checking all over the area where the Bruiser ran to see if I can find it. If I don't get lucky I suppose I'll head over to rc4wd and see what sort of upgrades they have for the driveshafts. Even if I find the e-clip I'm not exactly confident in its ability to do its job; it popped off in less than 50 feet of travel on carpet. It would never survive outdoors at this rate!

I looked at my high-lift manual while I was at it, and learned to my dismay that it uses the same crappy eclip system to hold the u-joints.

[bromvw]

Sadly won't be making much noise for a while though.. Whatever size e-clip they use on the propshafts isn't contained in anything else I have. Not sure how it dropped off so quickly; I guess I sorely misjudged the use of rubber cement. At a loss for the moment.

Seriously though? Rubber cement to secure e-clips? Is there a better solution, perhaps not involving e-clips at all?

buy some proper engineered c-clips IMO those e clips are donkey droppings

[Psylence]

buy some proper engineered c-clips IMO those e clips are donkey droppings

You're not wrong there. Got a source for hardware? Gotta say I've never had to use outside hardware to correct a Tamiya oversight but theres a first time for everything.

[bromvw]

You're not wrong there. Got a source for hardware? Gotta say I've never had to use outside hardware to correct a Tamiya oversight but theres a first time for everything.

Sure Buddie - just google Clips n Bits . They do a decent assorted package for around £3 plus P&P . You might need the correct pliers to fit them though

[Psylence]

Well, put on a rear driveshaft from RC4WD and she's now back and running. Was very glad to see that the sport tuned isn't *too* fast flat out in 3rd, but I think a crawler motor may be in order as low speed torque in first could be a bit better.

Or I need to lock a diff or two.

Either way, best Tamiya kit I have built so far. Bad news is it may have spoiled my appetite for things that aren't tanks or 3speeds

[Champ85]

Which driveshaft did you end up getting? I totally love the look of the Ultra Scale Hardened Steel driveshafts, but not sure which length would work, if any. None of the sizes offered seemed to match up with the stock one.

[Psylence]

Which driveshaft did you end up getting? I totally love the look of the Ultra Scale Hardened Steel driveshafts, but not sure which length would work, if any. None of the sizes offered seemed to match up with the stock one.

It was an ordeal finding out what the length of the rear shaft on the Bruiser is. The front? All over the internet, simple to find.

Anyway, I went with the Mega Truck universal shaft 125-165mm. At its shortest, it is a couple mm longer than the stock bruiser shaft but can still easily be mounted without removing relocating or dismantling anything. It was about 5 minutes from "parts in mailbox" to "Bruiser tearing around the yard."

The Ultra Scale Steel in 120-160mm would work too, and I probably would have gone that route myself but I SWEAR it was out of stock in that length as of a couple days ago..