The importance of good quality torque plates

[NeilP]

U am not sure what the axle size is...or the size of the torque arm..I never measured either, but I did have to file out the hole to make it fit, and it was a tight fit, so this was not a case of different size torque plate to axle, if I did not have one that fitted, i would have mad a clamp type

 

[Alan B]

It might be good to note here that Justin's measurements didn't show much difference in torque needed to spin a 12mm vs a 14mm axle. There was a difference but it was not enough for safety.

Making the torque arm harder doesn't help much either as it just cuts the axle. If the axle is hard and the torque arm is hard then that would be an improvement.

Making it thicker is key. Increasing the surface area spreads out the forces and changes everything for the better.

It is not clear that making the torque arms clamp matters much either, if the material has enough area and is strong enough the clamping doesn't really change that. What it does do is reduce the minor rocking between acceleration and regen. If the locknuts work properly and the nuts maintain the correct pressure (such as NordLocks) then the rocking doesn't matter.

DoctorBass has shown that, with non clamping torque arms he can twist axles. No clamping required.

 

[LI-ghtcycle]

I have made a mistake, the NuVinci small axle (left side) is actually considerable smaller, it's a 10mm axle with 8mm flats, so an even greater risk for spinning out.

I have found that thickness makes a difference, but until I hardened the steel I was using, the axle was slowly digging through the soft 1/4 inch wide torque plate I had made. Now that I have hardened it, even though it is most likely just "case hardening" (I have no idea of the carbon content of this trailer hitch mount has) it has stopped the deformation.

In the case of the 12mm+ sized axles, it would appear it's more forgiving.

I believe the same 1/4 inch thick metal used to make Neptronix's torque plates in my shop are still holding up fine, even though they are not hardened so it's different for different sizes.

I am considering having Doc do a run of NuVinci sized torque plates, but for the minimum production run of 12 sets, I will see if I can get a group together so I won't have more than I can use.

 

[dogman dan]

Well, not knocking the Docs design at all. It's nice and thick. I like the clamp for it's absolute zero free play, even though I don't regen at present. And my pinchers are 1 inch wide. Hope it's wide enough. :wink:

 

[Rassy]

LIght-cycle said:

I have made a mistake, the NuVinci small axle (left side) is actually considerable smaller, it's a 10mm axle with 8mm flats, so an even greater risk for spinning out.

I have found that thickness makes a difference, but until I hardened the steel I was using, the axle was slowly digging through the soft 1/4 inch wide torque plate I had made. Now that I have hardened it, even though it is most likely just "case hardening" (I have no idea of the carbon content of this trailer hitch mount has) it has stopped the deformation.

As you know I purchased my "standard" NuVinci from Staton-Inc. There were two of those tabbed washers, one sized for each side, plus, for vertical dropouts a regular torque plate for the large side, which attaches to the deraileur mount, and an insert for the small side that fills up the extra space in the dropout and also includes a tab so the small axle seats in line with the large axle side.

 

[LI-ghtcycle]

Nothing wrong about the clamp design, however, if a more elegant lower parts count design will suffice for the average person, I'd personally go with the Doc's.

I think the punishment Doc has put his bikes' drop-outs through pulling a bus among other things speak for themselves. :wink:

 

[LI-ghtcycle]

LIght-cycle said:

I have made a mistake, the NuVinci small axle (left side) is actually considerable smaller, it's a 10mm axle with 8mm flats, so an even greater risk for spinning out.

I have found that thickness makes a difference, but until I hardened the steel I was using, the axle was slowly digging through the soft 1/4 inch wide torque plate I had made. Now that I have hardened it, even though it is most likely just "case hardening" (I have no idea of the carbon content of this trailer hitch mount has) it has stopped the deformation.

As you know I purchased my "standard" NuVinci from Staton-Inc. There were two of those tabbed washers, one sized for each side, plus, for vertical dropouts a regular torque plate for the large side, which attaches to the deraileur mount, and an insert for the small side that fills up the extra space in the dropout and also includes a tab so the small axle seats in line with the large axle side.

Yeah, those are good things too, but probably best used under pedal power alone. I haven't had trouble using them for the larger 12mm axle, but the smaller 10mm is the one that needed more, and even the 1/4 inch plate wasn't enough until I hardened it.

That, and I don't stay to the rules about not using a higher than 2:1 ratio of crank ring to rear freewheel, for example, I use a 48T high gear chain ring, and 16T freewheel which is a 3:1, so I'm already outside the design limits even with pedal power, yet it hasn't failed me yet!

 

[neptronix]

Dude, your torque plates have taken 4kW/~115ft-lbs repeatedly without having a scratch on em :lol:
You cut the disc brake side out of a friggin' tow hitch.

One day those torque plates will be in an ebike museum somewhere

 

[LI-ghtcycle]

Dude, your torque plates have taken 4kW/~115ft-lbs repeatedly without having a scratch on em :lol:
You cut the disc brake side out of a friggin' tow hitch.

One day those torque plates will be in an ebike museum somewhere

Good thing you moved from the Red (Rust) Coast!

If you had stayed in Oregon, they wouldn't be recognizable by the time they made it to the museum! :lol:

Pretty crazy when you think about it though, the little 10mm axle on the NuVinci started digging into the same metal just from my leg powered trip to the coast! (270 odd miles IIRC!!)

 

[hillzofvalp]

What you are making, doc, seems respectably unnecessary. There is no way that much, if any, hardened material is needed. What matters is snug fit and sufficient contact. I am probably wrong, but those things u make might as well be a sport motorcycle part. (I wil still probably buy them from you after I realize just how naive I am).

I have not made my torque arms yet, but I will attempt to go around 5mm thick.. And be very snug. Within .001". Stainless.

S
I was wondering, for those of you with dropout slots larger than the axle flat thickness--do you fill in the gap to keep the axle from rotating? Seems like the first place to address with any motor spin out issue

Edit: uh oh. The head honchos are here. And btw, my skepticism is me pleading for help and my frustration with my project

One issue I have now is that I dont have much axle left. I cut them when I was on lower power.. I can still fit in a little

 

[Doctorbass]

What you are making, doc, seems respectably unnecessary. There is no way that much, if any, hardened material is needed. What matters is snug fit and sufficient contact. I am probably wrong, but those things u make might as well be a sport motorcycle part. (I wil still probably buy them from you after I realize just how naive I am).

I have not made my torque arms yet, but I will attempt to go around 5mm thick.. And be very snug. Within .001". Stainless.

S
I was wondering, for those of you with dropout slots larger than the axle flat thickness--do you fill in the gap to keep the axle from rotating? Seems like the first place to address with any motor spin out issue

I still have some in stock :wink: even if you want to stop to fear about something that could break :wink:

Over the 260+ torque arm set i sold from now, i never got any negative comments. After all, i designed them by reading all these post about torque arms desing and problems and to build something that i think myself would agree to use on my extreme ebikes ( 20kW+)

Doc

 

[hillzofvalp]

Will it fit? I work in a CNC lab and I'd like to make some myself. Don't know if yours would fit or be thin enough (I cut axle some).

Let's not forget that you are looking at 1/4" steel construction here.

I was thinking maybe a specialized long washer that would fit snug on that huge lip. Would be cheaper to water jet. I've had a pain adjusting the disk mounts, so I almost rather avoid making that more of a challenge to adjust

 

[LegendLength]

I think it's rude to the creator of these torque arms to keep this title of "The importance of good quality torque plates" . I feel at least a correction (if not an apology) in the first post is needed.

 

[hillzofvalp]

Was kidding, and he knows this. So many old farts on ES taking things so politely and seriously

Will .185" thick heat treated stainless 440C fit the bill for 3500W peak? .185" is the maximum I can fit on to get 100% nut engagement (cut axle). If its okay to only partially engage the nut, let me know and I may be able to do .22 or something

 

[NeilP]

I'd rather have a clamping style torque plate / arm rather than something that the axle just sits in.

I made these and they were a tight fit. They are already sloppy and the axle turns through about 5 or 6 degrees now when ever I use regen brake or accelerate.

I made up these a couple of weeks ago on to a scrap frame to use as a mobile test bed for the little 'granny bike' motor. Everyone I build now will be of that design, or maybe a double bolt type with sliding block to trap the axle.

I think it's rude to the creator of these torque arms to keep this title of "The importance of good quality torque plates" . I feel at least a correction (if not an apology) in the first post is needed.

How can the title of a thread, that starts about a different problem involving torque plates, that then branches off in to talking about someone else's nicely designed torque plates, be insulting to the builder of the nice torque plates??? I think maybe you have missed the point of why i originally started this thread

 

[NeilP]

Will .185" thick heat treated stainless 440C fit the bill for 3500W peak? .185" is the maximum I can fit on to get 100% nut engagement (cut axle). If its okay to only partially engage the nut, let me know and I may be able to do .22 or something

I'd go as thick as you can. Mine are i think at least 5mm thick of hardened stainless and I feel they are not thick enough

 

[hillzofvalp]

Problem is that I have no place to mount clamping mechanisms.. See pics.

I want to try to put jb weld/steel nibble on the threaded portion of the axle that does not actually become threaded. This way if it does rotate t isn't hammering my frame and removing material.

I figure .185" won't fail catastrophically... I'll be able to tell they're not working before long right?

440c stainless is like $40 plus shipping for .185"x2"x12".. I'm going to try this .125 shit for a test, and hopefully I will tighten down nord locks properly this time around

 

[neptronix]

hillz, i have another idea for you. Use the two bolt holes closest to the dropout to control the torque. The clamping-hose-against-the-frame method is a suboptimal design, and does allow for a little flex. Super tight fitting bolt holes, using the leverage of the disc brake area and rack mount area do not.

If you are not running a few kW, then don't worry about it. Hose clamp is fine. My style of torque plate is really more like a piece of mind thing - really over built, but it will handle anything.

 

[Hugues]

Problem is that I have no place to mount clamping mechanisms.. See pics.

I want to try to put jb weld/steel nibble on the threaded portion of the axle that does not actually become threaded. This way if it does rotate t isn't hammering my frame and removing material.

I figure .185" won't fail catastrophically... I'll be able to tell they're not working before long right?

440c stainless is like $40 plus shipping for .185"x2"x12".. I'm going to try this .125 shit for a test, and hopefully I will tighten down nord locks properly this time around

if you can cut your own torque arm, you might as well get rid of the "arm" part and just use the thickest and strongest steel you can cut, then just glue them in place. No clamp, no arm neeeded.
Check out the thread by Doctor Bass on this, he's using 3M DP-420 glue, he's done a great test on this glue on video. I've done mine that way and it just does not move. YOu have enough surface and side walls to have a strong bond in my opinion.

part 1 of his test here:
http://www.youtube.com/watch?v=3NWzODqhSbw

 

[hillzofvalp]

Problem is that my axle is so short cause I cut it too much. Could I half engage a stainless nut and put thicker stuff in?

Here's a .125" prototype of the actual arm I'm thinking... If I do an arm.

I do want to consider threading the end of the dropout slot so I can clamp it... And epoxy some machined shims to hold the axle better.

 

[Alan B]

The Cromotor axle is 16mm so much larger flats to grip on, if that helps any.

 

[hillzofvalp]

Now that you mention that, I think I should keep this future proof and not enclose the axle. What kind of steel are u using, doc? 1095?


The lip on my frame would give more epoxy bonding surface area. But, as of now, I will not Be able to install 8-10mm thick plates since I cut the axle too short. Can I half engage a standard nut? Can I use a half nut with some lock tite?

I could get away with .2" additions as is I think on each side.

 

[Alan B]

I don't understand why your axle was cut short. Can you replace the axle? It is also damaged from spinning??

 

[hillzofvalp]

When I was running 14S without torque arms I didn't see a need for excess axle. Simple as that. Regret it. I'm not putting anymore time and money into this motor.

It's not really damaged. I fixed the threads after I cut it with repair die.

Has anyone actually tried turning the dropout into a clamping one? It is much easier to do on horizontal, .25" thick dropouts. Does anyone think it's worth a try? Some special spacers tightened down? That would be so easy? It's a nice frame, and i would hate to have permanently epoxied tool steel on it... ( I still like the idea and am considering it)

 

[John in CR]

Will .185" thick heat treated stainless 440C fit the bill for 3500W peak? .185" is the maximum I can fit on to get 100% nut engagement (cut axle). If its okay to only partially engage the nut, let me know and I may be able to do .22 or something

I'd go as thick as you can. Mine are i think at least 5mm thick of hardened stainless and I feel they are not thick enough

I go with at least 1/2" of steel on each side with clamping on all my builds now. No dropout worries for me.