The importance of good quality torque plates

NeilP

1 GW
Joined
Nov 27, 2010
Messages
5,012
Location
49.17303, -2.05354 Jersey, Europe
This was using one of those laser cut torque plates with movable star fitting in the middle, not very thick metal

I am glad I never used it on my 5304 motor. I was about to say it is a piece of junk...but I shall hold judgement on that..I just had a thought..maybe it is OK and it is the axle that is too soft and and had its edges ripped out...will only know when I finally get it apart tomorrow. It is too thin to be of much good anyway..as you shall see

This was a single ride down the road and back..maybe 500 yards maximum.
Sensor less 12 FET Xlyte controller..on a cheap chinese generic 'Euro Tourer ' motor I had for free.
I was repairing the controller and needed a load for it..I spied this motor under my bench, took my 20s pack off by bike and built up a frame out of spare parts.
It is a sensored motor, but running it here sensorless

The motor was still running with the phase wires wrapped around the axle

Apologies for the crap photos..they were taken on the iPhone..need to get something better..over hyped rubbish these iPhones

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Note the quality home made throttle!!
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Torque plate...as much use as a chocolate fire guard...I'll continue to cut my own in future
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NO, very well tightened...I even took it off put a big flat washer against the star arrangement part of the torque plate and re tightened..It is still flush up against the torque plate..So it did not slip out.

Either the torque plate has had it edges ripped out, or the axle has had a groove cut in it from the hardness and narrowness of the torque plate
 
Yep, dropouts need to be thick and strong. Welcome in the club, many of us had to learn this the hard way.
 
Well I thought it was crap from the day it arrived ..last year from ...yep Ed Lyen...4 December lat year i ordered it with all my other stuff from him. Never used it on the 5304.

but today with that little 250W motor..OK so i was perhaps giving it a little more :twisted: I thought it would be fine...but no still too thin

This is what I used on the 5304..and even they are showing a bit of slop now after 3k mikes

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well it wont be till tomorrow morning now that I get back down there. I reckon the plate has cut through the axle rather than the other way around. I reckon to see a grove cut in the axle..
Just to be clear..it is not the big stainless steel ones above that caused the problem..but the laser cut adjustable one, this one


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Well this is kind of a no duh situation. Too bad that one had to learn the hard way.

those ampedbikes arms are great.. if you run two of them on like a maximum of 750w :lol:. Anything attached by a water hose clamp verges on decorative rather than functional.

Bolted directly to the frame is absolutely the way to go.
Running one on both sides is absolutely the way to go, as well.

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^-- the above has taken ~115ft-lbs of torque and a hair over 4kW off the line without even getting a scratch on it.
 
and to add to that...

Do it right or get another frame if you can't do it right. Usually, rear disc brake holes give you a fantastic place to bolt up a torque plate, or rear eyelet holes / dropout hanger holes work well too.
 
Yes, any bikes I build always have a clamp on both sides..this was not a bike build as such..it was just something chucked together from scrap spares to check the controller was working.

I wanted to put this controller : (http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=34123) under some load to check I had fixed it and I had that small motor that I had been given

Edit...after seeing your extra post...it was a scrap frame pulled out of the farm scrap metal trailer for the single purpose of testing the controller.

And it did not break the conductors..it is still running twisted like that.
 
There was a plan many months ago to build that wheel in to a different frame

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...but that frame got used on a E-BikeKit kit that I won

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so that motor was relegated to a pile under the bench...till today when I needed a load for the motor
 
neptronix said:
Anything attached by a water hose clamp verges on decorative rather than functional.


^-- the above has taken ~115ft-lbs of torque and a hair over 4kW off the line without even getting a scratch on it.

Not true. I have my stainless steel torque arms on my 5304 mongoose, with over 3000 miles now on it, those arms are held on by Heavy duty stainless hose clamps...ok not pretty, but they were on y temporary till i made some proper fixtures..but 3000 miles later i have still not got around to it.

I see peaks of 125 amps at 100 volts , with continuous cruising power of about 55 to 60 amps....so 5.5 to 6kW and more at 40 mph. Use decent clamps and there is nothing wrong with that method mechanically...Aesthetically it is an absolute abortion...but it works
 
I have double torque arms on my first build (9c 9x7 front). I see 5000+ watts peak all the time. Seems to hold up well, even with regen active. However, I would never build one (or recommend one) that way anymore. I went to double torque plates, rear motor for build 2 (9000watts peak).
 
those laser cut torque plates with movable star fitting in the middle, not very thick metal

Wow NeilP, Thanks for sharing I have one of those same exact torque arms. Have not used it yet and will be careful not to use it in anything more than one of small geared motors. What is your feeling, It should be safe with one of those 350w motors running 12s?
 
No, the star is fine I think... I have not taken it off yet..that is for the morning..but I reckon it is NOT the torque are that has failed. I believe it is the axle that has been chewed by the torque arm. it is just too thin.

I never used it before..i could see it was a bad design for anything high powered...and these chinese axles are made out of poor quality steel..even the threads on my 5304 are on their way out..going to have to make new proper axle for it soon.
 
Thanks for the update NeilP. I was starting to wonder why ebike kit companies would sell those torque arm in the first place if they where so weak.
Now I am starting to feel a little safer about them.
 
We really do need to cut our own. Steel can be picked up almost anywhere. Cut mild-steel fat, cut milled or stainless steel thin, and try to bolt them to the dropouts they are supposed to be strengthening.

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Racer_X. I'd wait till I get mine off before feeling to safe about them

This was not a particularly high power setup... Well I say that... To me it was not high power
It was an xlyte 40 amp sensorless controller @ about 80 volts with a puny Euro tourer motor that was only ever designed for 250 - 350 watt range. I was not giving it any abuse, slow gentle rolling on of power and only rode it for less than a mile. The torque arm did absolutely nothing
 
They're too thin. I can guarantee the dropout and torque arm hole will be deformed into something more circular, and may have deformed the axle a bit too.

Don't waste $ on good steel when it's more width that's required. Also, through hole type torque arms of any kind along with the motor axle would need custom machining for a proper fit, so clamping type torque arms are the only adequate and easy solution.
 
Offering that motor a potential 3000 w doesn't make it a "low power" motor. I bet it was pulling at least 1500w as it began to move. Maybe even more for that crucial nanosecond before the wheel starts to move.

So no suprise to me a torque arm designed for less than 1000w peak loads didn't cut it. My bet is that the soft axle has a neat little slot machined into it now. No help that it's the 12 mm axle either, pretty small flats on those. Chances are, some damage to the arm too. Too thin for the big controller.

Steel bike, so maybe you could do something like what I did for my racing bike frame?Pinch dropout, on Race bike..jpg
 
Yep, too thin..I thought so before I used it...that is why I never used it before..it just looked too thin and weedy for anything.

Seems like I am repeating myself here..ot trying to sound rude..because it is not meant that way..but read all my previous posts...a scrap frame dragged out of the scarp trailer..and that is where it is going back too, it is bent any way, it was only brought out along with that hub motor as a test bed for the controller

I actually never pulled off from a standing start with it, I always pushed off with the feet first, got coasting before tuning the 'throttle'
Even before I started I was not happy with the little torque arm.

I also left plenty of slack in the phase wires..to allow any wind up ..as seen int he first pictures. The axle did not as much spin..as chugg its way around in small steps ..

Both frame and torque served a purpose..for a moment at least..now they are destined for the scrap


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