Motor/Mechanical Brakes? - RC-Monster Forums

Shark413 · **Motor/Mechanical Brakes? -** 01.16.2009, 05:50 PM

Ok so here we go, first let me state I do not advocate one system over another, and in fact I use both motor brake only, mechanical brake only and a hybrid system that uses both on my 1/8 scale buggies/truggy. I am not here to start a debate on what's better, I just want to point out something I noticed that I believe explains some of the difference in "feel" between mechanical and motor only braking. With mechanical braking there are calipers/disc that stop the front and rear driveshaft’s, basically providing even braking power to the front and rear regardless of the amount of grip/traction each tire has. Now here is something I noticed with my motor brake only setup, this system works by the motor (pinion) stopping the spur, the spur being connected to the center diff then stops the front/rear driveshafts. But, the braking power is not even, but dependant on the center diff action and available tire traction. Do this test, take your motor only brake buggy and place your finger on the spur to simulate braking, now place the buggy on the ground and while holding the spur push the buggy forward, it doesn't move right? All the wheels are braking, right? Now, while still holding the spur, pick the rear tires up off the ground and push the front wheels forward, what happens? The tires will now rotate, because of the diff action of the center diff. The rear wheels will also rotate, so now the braking power has changed (diminished) because of the diff action and rear traction changes. This unloading of the rear happens almost everytime the brakes are applied (weight transfer), which will make the rear end lighter and could potentially cause the rear to lose traction momentarily and in turn impact the front braking power. To be honest, both braking methods seem to work perfectly well to me. With motor brake, you also have a lighter system, with less moving parts and it's cheaper as well. The only advantage I see with mechanical brakes is bias and the fact there is consistent braking power and it is not affected by diff action. Does this make sense? Am I missing something?

jhautz · 05:59 PM

Yep. About sums it up.....

Edit... the only thing I would like to add is it seems to me that the diff almost acts a an antilock brake mechanism for the front tires. When you hit the brakes the weight transfers to the front wheels and unloads the rear wheels usually making them be the first ones to unload and lock up letting the front wheels continute to roll thru the diff action. At least if you never lock up your front wheels you can always steer. Once the front wheels start skidding you have no steering at all.

Matthew_Armeni · 01.16.2009, 07:40 PM

Quote:

Originally Posted by Shark413

The only advantage I see with mechanical brakes is bias and the fact there is consistent braking power and it is not affected by diff action. Does this make sense? Am I missing something?

As far as braking characteristics, yes you're right, but mechanical braking also alleviates stress off the motor during breaking action, helping to lower motor temps. Another benefit.

bdebde · 01.16.2009, 10:05 PM

I have never driven anything nitro so I don't even know what the mechanical brakes feel like. Been running electric for over 20 yrs and never had a problem with motor brakes. Of course the larger scale with the center diff does act quite a bit different than anything with a transmission in the center (or direct spur drive).

01.17.2009, 01:38 AM

I found that with the motor braking, it didn't feel as precise when slowing down. I figured it was because of the center diff, as Shark was saying.

The other thing I was concerned about was the extra wear and tear on the pinion/spur. With motor braking, the entire force of slowing the vehicle would be generated from those tiny teeth.

Ryu James · 01.17.2009, 04:25 AM

interesting point Shark. i had never even taken the time to think of this but i am sure that is why i like the mech. brakes better. something about them just "felt" better to me but i think you just explained why.

funny, there has been alot of talk on motor vs. mech brakes lately, huh? i think this is like the 4th thread in a week. its a good thing. i have learned a lot. many interesting points have been put forth.

jayjay283 · 01.17.2009, 04:44 AM

IMO which isnt worth 2 grains of salt.... Mechanical brakes were for nitro, had to have them, you cant hit reverse and it stops, just like a 1.1 car just rip up the tranny and flip. We all had the old.. (old us old folks) the 3 speed mechanical ESC tamiya things with brakes, you slamed that into brake you flipped and scuffed up that scale Tamiya lid (worth $300 unscathed on ebay now) Now a days escs have nice firmware and are pretty close to mech. brakes, no bias but maybe you need to relearn your sucky driving.. JMO kick me when needed

starscream · 01.17.2009, 05:13 AM

Quote:

Originally Posted by jayjay283

IMO which isnt worth 2 grains of salt.... Mechanical brakes were for nitro, had to have them, you cant hit reverse and it stops, just like a 1.1 car just rip up the tranny and flip. We all had the old.. (old us old folks) the 3 speed mechanical ESC tamiya things with brakes, you slamed that into brake you flipped and scuffed up that scale Tamiya lid (worth $300 unscathed on ebay now) Now a days escs have nice firmware and are pretty close to mech. brakes, no bias but maybe you need to relearn your sucky driving.. JMO kick me when needed

You are probably right about my sucky driving but you can't teach an old dog new tricks (or can you?) Anyway, I've tried many esc and other settings and have not been able to get motor brakes only to feel right. Motor brakes just don't allow the truggy or buggy enough steering around tight corners and turns. The motor brake ends up locking up the front wheels making it virtually impossible to power slide around a turn like you can a 1/10th 4wd buggy with a front oneway. Maybe there is a trick with using the right center diff weight oil but to this day I haven't found one. Unless I have a rear mech brake, I can't power through corners to save my life...

To each their own but until someone can teach me how to consitantly power through a tight corner with only motor brakes, I'm going to hookup that rear mech brake every time I build an 8th scale.

Oh, one thing I found that actually got my lap times faster was when my brake servo failed and I had no brakes at all

Who needs brakes anyway, they just slow you down

Ryu James · 05:23 AM

to jayjay - i thought sucky driving is when you cant tell the difference from mech, motor, brakeless or other wise. good drivers are in tune with their senses enough to know the difference from what they prefer and what they dont (just as Star mentioned motor brakes not "feeling" right for him) . if its all the same to you, why do you have an opinion anyway???? oh wait, you said your opinion wasnt worth much anyway.

there, i kicked you.

(just playful banter so you know)

Ryu James · 01.17.2009, 05:18 AM

Quote:

Originally Posted by starscream

You are probably right about my sucky driving but you can't teach an old dog new tricks (or can you?) Anyway, I've tried many esc and other settings and have not been able to get motor brakes only to feel right. Motor brakes just don't allow the truggy or buggy enough steering around tight corners and turns. The motor brake ends up locking up the front wheels making it virtually impossible to power slide around a turn like you can a 1/10th 4wd buggy with a front oneway. Maybe there is a trick with using the right center diff weight oil but to this day I haven't found one. Unless I have a rear mech brake, I can't power through corners to save my life...

To each their own but until someone can teach me how to consitantly power through a tight corner with only motor brakes, I'm going to hookup that rear mech brake every time I build an 8th scale.

Oh, one thing I found that actually got my lap times faster was when my brake servo failed and I had no brakes at all

Who needs brakes anyway, they just slow you down

i am with you 100% star! maybe we should start a forum called Mechanical Brake Monster. i mean, it appears this topic runs as deep in the blood as Nitro vs Electric. so whatta ya say? anyone?

jayjay283 · 01.17.2009, 05:29 AM

ok im going to put this English style, .. with all the wanking that goes along with toying with the bolloks mechanical brakes, the only necessity is if you cant drive for a sodding wank. I have 1/5ths (gas) which need mechanical brakes, (2 front 1 rear) they are gasoline, how else would they stop? a cricket bat. With the electrics your magnets lads. Ive yet to hit a tree or need to cut a corner closer that 1.2 inches of front brake would have helped me, sounds like you're dodging the truth, you suck at driving

starscream · 01.17.2009, 05:42 AM

Quote:

Originally Posted by jayjay283

ok im going to put this English style, .. with all the wanking that goes along with toying with the bolloks mechanical brakes, the only necessity is if you cant drive for a sodding wank. I have 1/5ths (gas) which need mechanical brakes, (2 front 1 rear) they are gasoline, how else would they stop? a cricket bat. With the electrics your magnets lads. Ive yet to hit a tree or need to cut a corner closer that 1.2 inches of front brake would have helped me, sounds like you're dodging the truth, you suck at driving

I had a hard time distinguishing English style from a really bad aussie accent. I think this cold I got is making me hear posts funny.

Anyway, I wouldn't argue with anyone about my driving, somedays its on par with the best of them and others I can stop from running into the wall.

In either case, I wouldn't stand a chance of dodging the truth or anything else for that matter without some mech brakes on my car

Ryu James · 01.17.2009, 05:42 AM

Quote:

Originally Posted by jayjay283

ok im going to put this English style, .. with all the wanking that goes along with toying with the bolloks mechanical brakes, the only necessity is if you cant drive for a sodding wank. I have 1/5ths (gas) which need mechanical brakes, (2 front 1 rear) they are gasoline, how else would they stop? a cricket bat. With the electrics your magnets lads. Ive yet to hit a tree or need to cut a corner closer that 1.2 inches of front brake would have helped me, sounds like you're dodging the truth, you suck at driving

LMFAO!!!

damn, that was good. are you british? i lived in England for a while about 10 years ago. loved it there. you nailed the british sarcasm pretty good. you crack me up. thanks for a good laugh.

Ryu James · 01.17.2009, 05:45 AM

Quote:

Originally Posted by starscream

In either case, I wouldn't stand a chance of dodging the truth or anything else for that matter without some mech brakes on my car

NIIIIIIIIICE!!!! just keeps getting better. Jayjay, you better quit while your ahead. i would say the score is Mech Brakes 2, Senseless Driving 0

gramey · 01.21.2009, 08:13 PM

I've gone with the mechanical brakes on my 8T because it helps reduce the load on and therefore temperature of my esc. Having raced 1/10 touring cars and off road which only had motor braking and 1/5th off road which only had mechanical brakes but no esc to worry about I opted for mechaincal's on my BL 8T. I can adjust the bias to suit the conditions and with the neavy duty Losi discs it stops on a dime as you Americans say.