1/5th scale 6x6 flatbed, 4500 watts, 10s Lipo

[Irishchamp]

The Monster Truck is running really well; I had to unlock the read diff, it was tracking really bad coming out of turns, I had to counter steer just to get the wheels straightened out. I put silicone putty in both diffs, it's drive great now, 4 wheel steering works great! I need to fine tune the servo savers, they were too loose and then when I tightened them up I ate two servo horns in short succession just bumping into stuff. They are definitely going to be the weakest link, the big tires when jarred chew them up so easily.
Hopefully I'll have some video soon!

Anyone know where I can get some 7075 Aluminum servo horns?

[TacoCrawler]

Originally Posted by Irishchamp

The Monster Truck is running really well; I had to unlock the read diff, it was tracking really bad coming out of turns, I had to counter steer just to get the wheels straightened out. I put silicone putty in both diffs, it's drive great now, 4 wheel steering works great! I need to fine tune the servo savers, they were too loose and then when I tightened them up I ate two servo horns in short succession just bumping into stuff. They are definitely going to be the weakest link, the big tires when jarred chew them up so easily.
Hopefully I'll have some video soon!

Anyone know where I can get some 7075 Aluminum servo horns?

possibly the Axial dual clamping servo horns ?
albeit somewhat costly... but the quality is good.

well except the crappy clamp screws they include.

Change to SS... or don't use ball drivers on them.

------------

oh and if you value yer child...
have 'em wear a helmet when they're
towed around.

young children are not good at bracing themselves
if/when they tumble.
And their head hits first the majority of the time.

So protect your child's future.

But hey... it happens with some adults too.
as seemingly humans are a little top heavy.
And extending a hand/arm out in support...
is not generally enough.

[Mike Flea]

exotekracing.com or Kyosho (infernosonly.com) make 7075 aluminum clamping servo horns. Amain has them too

I resemble that last paragraph, Taco

[Irishchamp]

It's eaten 3 of the Axial dual clamping horn already! They've always been my go to servo horn.

My boys heads will stay damage free! They got their mothers intelligence and I'd like to keep it that way!

Originally Posted by TacoCrawler

possibly the Axial dual clamping servo horns ?
albeit somewhat costly... but the quality is good.

well except the crappy clamp screws they include.

Change to SS... or don't use ball drivers on them.

------------

oh and if you value yer child...
have 'em wear a helmet when they're
towed around.

young children are not good at bracing themselves
if/when they tumble.
And their head hits first the majority of the time.

So protect your child's future.

But hey... it happens with some adults too.
as seemingly humans are a little top heavy.
And extending a hand/arm out in support...
is not generally enough.

[Irishchamp]

Those are great, thanks!
I found and ordered these, I have high hopes!
7075 aircraft aluminum for maximium strength.the spline is a hardened steel insert for super long life. FYI, they are 24 spline, not 23 as shown in the picture.

Originally Posted by Mike Flea

exotekracing.com or Kyosho (infernosonly.com) make 7075 aluminum clamping servo horns. Amain has them too

I resemble that last paragraph, Taco

[TacoCrawler]

Originally Posted by Irishchamp

It's eaten 3 of the Axial dual clamping horn already! They've always been my go to servo horn.

My boys heads will stay damage free! They got their mothers intelligence and I'd like to keep it that way!

You're supposed to eat food... not servo horns

I've been running them for years
never had an issue.
As long as you have the correct tooth count
and they fit the output shaft correctly.

Another failure is if they come loose and spin on the output shaft.
That'll strip the splines on any alloy servo horn.

The simple solution is basically the same as any servo horn.

Locktite both the primary and clamping screws.

I prefer the clamp style servo horns.
Tho' they still need be the correct spline count.

Don't blame the servo horn...
Blame the installer

[Irishchamp]

This rig is 31 lbs and has 10" tall tires, I'm surprised nothing else in the steering assembly hasn't broken..... And I gotta say, I'm not sure if you're being a di@k, a smart a$$ or trying to be genuinely helpful based on the "flip off emoji.... Just wondering.....

Originally Posted by TacoCrawler

You're supposed to eat food... not servo horns

I've been running them for years
never had an issue.
As long as you have the correct tooth count
and they fit the output shaft correctly.

Another failure is if they come loose and spin on the output shaft.
That'll strip the splines on any alloy servo horn.

The simple solution is basically the same as any servo horn.

Locktite both the primary and clamping screws.

I prefer the clamp style servo horns.
Tho' they still need be the correct spline count.

Don't blame the servo horn...
Blame the installer

[OneSixthScaleRC]

Originally Posted by Mike Flea

I searched myself, and you're right, can't seem to find any. Did a search here, and found some members years ago talking about a 55t, 550 Titan motor, but I looked on Traxxas website and e-bay and couldn't find anything, lots of different 55t 540's, but not what you're looking for. Axial has a 55t for $19, and a rebuildable one for $30, but I think they're both 540's, but not sure, as they don't list what size.

I think I have exactly what you are searching for:

I have looked at every 550 motor marketed for RC and they are all high Kv. Axial are 540s. Tested 540s 35T and 55T, they are too weak. 550s can be as much as 1.5-2x more powerful than 540s.

Also don't get the Mabuchi 550. I have tested it as well! Because they use full-contact brushes instead of brushes that contact only on the edges like crawler motors use they are not smooth at all. Also, they have a very short shaft that does not hold the pinion well.

This one is very good, it's low Kv and very powerful:
R550 High Speed DC Stroller Motor 12V 10000R MIN Toy Motor | eBay
You may need to slightly shorten the shaft with a dremel tool, very easy to do.

[Irishchamp]

Thank you, I appreciate the help! Do you have any info on how much they can be over volted? I'd love to be able to give them 22 volts, that would give me about 7-8 mph of wheel speed.

Originally Posted by OneSixthScaleRC

I think I have exactly what you are searching for:

I have looked at every 550 motor marketed for RC and they are all high Kv. Axial are 540s. Tested 540s 35T and 55T, they are too weak. 550s can be as much as 1.5-2x more powerful than 540s.

Also don't get the Mabuchi 550. I have tested it as well! Because they use full-contact brushes instead of brushes that contact only on the edges like crawler motors use they are not smooth at all. Also, they have a very short shaft that does not hold the pinion well.

This one is very good, it's low Kv and very powerful:
R550 High Speed DC Stroller Motor 12V 10000R MIN Toy Motor | eBay
You may need to slightly shorten the shaft with a dremel tool, very easy to do.

[OneSixthScaleRC]

Originally Posted by Irishchamp

Thank you, I appreciate the help! Do you have any info on how much they can be over volted? I'd love to be able to give them 22 volts, that would give me about 7-8 mph of wheel speed.

I have not tried it but I don't think 22V is possible because the wiring inside looks thin for that much voltage. There is no "rule" that tells you how much you can overvolt the motor, it all depends on parts and quality.
These motors seem good quality and are low KV so maybe could handle up to 4s lipo (16.8V), although I would personally use no more than 3s lipo (12.6V). But no way 22V. If your budget allows it, since these motors are very cheap you can always try.

Or instead, since this motor has lots of torque, you can gear it higher without sacrificing low end control.

[67mustang]

Can you upgrade to a bigger servo? Or are you limited by space?

I don't know why hi torque servos use a spline that can't handle the workload.

Google 1235mg servo. That is light years better than those 10th scale servos for what you are doing.