29a
100 W
Hi guys
anyone got any info/advice/links on front torque arm design.
48v/408/35amp/MTB
anyone got any info/advice/links on front torque arm design.
48v/408/35amp/MTB
torque arm
- Thread starter 29a
- Start date
Lessss
1 MW
When all else failstake it to a highschool metal working shop.
29a
100 W
Its the front torque arm and any sort of heavy duty axle retainer im interested in,
anyone got any pics/links/schematics
All i could find was this http://www.users.bigpond.com/solarbbq/torquearmsandwashers.htm
but it doesn't look strong enougth
Knoxie plz post link to team hybrib (or other) torque arms i couldn't find em.
anyone got any pics/links/schematics
All i could find was this http://www.users.bigpond.com/solarbbq/torquearmsandwashers.htm
but it doesn't look strong enougth
Knoxie plz post link to team hybrib (or other) torque arms i couldn't find em.
knightmb
100 kW
Yeah, a website to torque arms would be great. I've already gone through about 3 forks on my e-bike. Mainly just because I was experimenting with too much power and bent the steel forks I was using, destroyed one motor that way 
I've been tempted to visit a few machine shops here in town to see how much it would cost to fabricate one of these, can't imagine it being too expensive if they make it from steel. Heck Knoxie, you could prefab some of these and sell them in an online store :wink:
I've been tempted to visit a few machine shops here in town to see how much it would cost to fabricate one of these, can't imagine it being too expensive if they make it from steel. Heck Knoxie, you could prefab some of these and sell them in an online store :wink:
Lessss
1 MW
Cost me 91.20 CDN to have one made see My XPe Chinese Sailing ship thread.
knightmb
100 kW
Lessss said:
**Breaks out currency calculator** Yeah, maybe cheap is not the right word then at $77.54.
Seems like I could just take some torque arms they use for children's pedal brakes on bicycles to save some $$$. Hmm, I think I need to make a quick trip to Wal-mart
knightmb
100 kW
Cheap tools to the rescue. Here we go, 1/2 inch wrench, solid steel, can take about 200 lbs (how much torque do you think a high power motor will put on the front?)
Plus, it's easy to strap it to the front frame now and you can even screw back over top of it with a washer behind it for a perfect fit.
It may not be pretty, but if you put one on each side, I bet this will go a long way to keeping your motor from spinning out of the front fork if it has a lot of power going to it?
What do you think?
Plus, it's easy to strap it to the front frame now and you can even screw back over top of it with a washer behind it for a perfect fit.
It may not be pretty, but if you put one on each side, I bet this will go a long way to keeping your motor from spinning out of the front fork if it has a lot of power going to it?
What do you think?
Attachments
TylerDurden
100 GW
Lifetime supply of torque arms?
Maybe use Sears Craftsman wrenches... if they crack or round-out, you can get free replacements.
:wink:
Maybe use Sears Craftsman wrenches... if they crack or round-out, you can get free replacements.
:wink:
Rustler
1 µW
ElectricRider is selling replacement torque arms for the Phoenix (X-5). Bottom of the page, $14.95
http://www.electricrider.com/crystalyte/parts.htm
http://www.electricrider.com/crystalyte/parts.htm
knightmb
100 kW
Rustler said:
Awesome, just wish they had a picture of it. Anyone have a picture one they can post up?
29a
100 W
thanks guys
I really like the wrench idea (TY knightmb)
I was thinking of using the ring side of the wrench as this would allso retain the axle incase of drop out failure and prevent easy theft (if i use torque screws 4 fixing).I see u used the original threaded screw holes, would it weaken the forks too much to drill holes through them 4 fixing wrench along its full length.
It would be nice if they showed a pic + it doesn't say front or rear, or give axle size.
I really like the wrench idea (TY knightmb)
I was thinking of using the ring side of the wrench as this would allso retain the axle incase of drop out failure and prevent easy theft (if i use torque screws 4 fixing).I see u used the original threaded screw holes, would it weaken the forks too much to drill holes through them 4 fixing wrench along its full length.
If you put the wrench in a vise and heat it red hot with a propane torch, you could bend it so the box end is parallel to the fork. If you look hard, you can find wrenches that are extra thin.
knightmb
100 kW
I tried ring side, it wouldn't fit around it29a said:I really like the wrench idea (TY knightmb)
I was thinking of using the ring side of the wrench as this would allso retain the axle incase of drop out failure and prevent easy theft (if i use torque screws 4 fixing).I see u used the original threaded screw holes, would it weaken the forks too much to drill holes through them 4 fixing wrench along its full length.
I have other sizes I can try, but that's a good point. That way the wheel won't going flying off somewhere should something bad happen.knightmb
100 kW
You have a lot more wisdom than I, would a wrench that size even be useful in your opinion? I know it's just steel and not very long, but surely the motor would break the frame before it would break the wrench? It's easy to get steel a wrench like that for cheap at the hardware store, maybe a $1.00 USD tops.fechter said:
Cheap & effective DIY torque arm in pitures:
http://www.velectris.com/forum/topic213.html?highlight=torque+arms
Or the classic option, if you can find a suitable fatburger shovel:
Torque arm wiki (in french, maybe use altavista to translate?)
http://www.velectris.com/forum/topic249.html?highlight=torque+arm
http://www.velectris.com/forum/topic213.html?highlight=torque+arms
Or the classic option, if you can find a suitable fatburger shovel:
Torque arm wiki (in french, maybe use altavista to translate?)
http://www.velectris.com/forum/topic249.html?highlight=torque+arm
patrick_mahoney
100 W
Thanks for the eletricrider link, rustler.
I tried to buy one - I need one too - but the shipping seemed surprisingly high on this ~$15 torque arm. Shipping via UPS Ground from Kansas to Colorado came to $20... for a total of $35.
I tried to buy one - I need one too - but the shipping seemed surprisingly high on this ~$15 torque arm. Shipping via UPS Ground from Kansas to Colorado came to $20... for a total of $35.
The reason the dropouts break is the torque from the axle spreads the dropouts apart. A wrench is made of about the strongest steel in existence. As long as the axle flats can't twist, the fork will be fine.
Better than an open end wrench would be a flat piece of super strong steel with a double D shaped hole that matches the axle. Having the metal wrap around the axle would be much stronger than an open end.
But... like you say, you can go to Sears and get a wrench for a few bucks that's already made.
Better than an open end wrench would be a flat piece of super strong steel with a double D shaped hole that matches the axle. Having the metal wrap around the axle would be much stronger than an open end.
But... like you say, you can go to Sears and get a wrench for a few bucks that's already made.
Rustler
1 µW
patrick_mahoney said:
That seems a little excessive. You might want to call their toll free number instead. I think my X-5 replacement wheel only cost about $35 to ship, and it's 30lbs boxed.
Hi
Yes I thought the spanner would work as well however when testing the puma motor on the BMX i snapped one accelerating, the problem with the spanenrs is the head is cold forged and is actually quite brittle and they dont flex, a good torque arm needs to flex a little.
Also you dont want to put anything on there that will damage the axle, now I have the BMX controller back I must look in to making a better one for the BMX as my home made one is struggling, I dont want to have to put one on both sides but I may have to.
ITs not something I have ever had to think about until I started playing around with the BMC motor and those lipos!! its so important to get a good toque arm on these things, I was amazed at the torque of the BMC.
When I come up with a decent design that works I will knock them up on the CNC machine at work for who ever wants them.
Cheers
Knoxie
Yes I thought the spanner would work as well however when testing the puma motor on the BMX i snapped one accelerating, the problem with the spanenrs is the head is cold forged and is actually quite brittle and they dont flex, a good torque arm needs to flex a little.
Also you dont want to put anything on there that will damage the axle, now I have the BMX controller back I must look in to making a better one for the BMX as my home made one is struggling, I dont want to have to put one on both sides but I may have to.
ITs not something I have ever had to think about until I started playing around with the BMC motor and those lipos!! its so important to get a good toque arm on these things, I was amazed at the torque of the BMC.
When I come up with a decent design that works I will knock them up on the CNC machine at work for who ever wants them.
Cheers
Knoxie
TylerDurden
100 GW
How 'bout a new design...
Knoxie brings up an interesting issue: the torque is so great, that even cro-mo steel snaps. So, a torque-arm might be better designed if it included damped movement to get past the highest torque periods: heavy accelleration.
Keeping in mind, most vehicles and machines with large motors have flexing motor mounts to compensate for the initial startup (and vibration while running ).
Knoxie brings up an interesting issue: the torque is so great, that even cro-mo steel snaps. So, a torque-arm might be better designed if it included damped movement to get past the highest torque periods: heavy accelleration.
Keeping in mind, most vehicles and machines with large motors have flexing motor mounts to compensate for the initial startup (and vibration while running ).
Attachments
I'm not sure you would want any play in the axle, I think it would make the axle nuts tend to loosen.
They really should have the torque arm built into the motor. If you can snap a wrench, that means the torque is very high. Sort of like twisting on a wrench with a long cheater bar. Sounds like the CNC - make your own approach will be the way to go. The material needs to have a very high tensile strength, but not brittle. Something like Cr-Mo.
They really should have the torque arm built into the motor. If you can snap a wrench, that means the torque is very high. Sort of like twisting on a wrench with a long cheater bar. Sounds like the CNC - make your own approach will be the way to go. The material needs to have a very high tensile strength, but not brittle. Something like Cr-Mo.
searth
1 µW
- Joined
- Jan 6, 2007
- Messages
- 4
With this topic i wonder why no one mentions carbon fiber. My plan is to make a steel reinforcing plate that is the same as my rear dropoout and stay and then carbon fiber will be used to mount the steel to the frame and instead of using resin i will use jb weld. basically the dropout will be thicker steel with the frame that is aluminum. then the rear tube will be wound with carbon fiber and sealed with jb weld. Strong and flexible stronger than steel. total cost 10 buck for the fiber on ebay and 6 buck US for the JB Weld. I havent done it yet I just used steel wire and a special clamptool that bond the wire to the frame. clamptool.com has the tool. You all might like the tool a lot. but next tire change I will use the carbon and see how that works. its relatively cheap and supposedly super strong.
Lessss
1 MW
Carbon fibre is expensive. More expensive than most are willing to experiment with.
Generic carbon fiber is not expensive, and the loose fibers being mentioned are even cheaper. One thing though, I just mounted my X5 hub into an aluminum frame, and am just going to cut out steel plates for each side and bolt them on to the dropout. Even tiny 160,000 psi Unbrako fasteners have plenty of shear strength to handle the job.
http://www.unbrako.com/Engineer_guide.htm
http://www.unbrako.com/Engineer_guide.htm
Similar threads
