High power RC motor and drive unit production

[recumpence]

That's cool.

If you want to shoot me some of your design specs, I can get them to Dave. He is short of work right now. I am not sure if the price will be the same. But, if it is, he can whip stuff out quickly assuming his work load is still low.

Matt

[johnrobholmes]

As long as he can cut modulus 1 gears it is all good. I have diagrams but no cad files right now.

[CNCAddict]

As long as he can cut modulus 1 gears it is all good.

Haha, you wish. Sadly my gear making abilities suck. It takes some major fancy equipment to do custom gears. HTD pulleys I can probably pull off, but anything with a sharp inside corner is a bit impossible with my current set of machinery

[etard]

I think alot of us are going to put this system on DH bikes, so my concern is what to do about a rear brake. Looking at my bike, if the drive unit where to feed from the top of the rear tire to a gear on the rear disk mount, it could be possible to have a disc caliper between the chain, inside the drive. What I am proposing is that the gear and the braking could be done on the same piece of metal. However, oil and brakes do not seem to be an ideal combination, if you used a belt and made a custom brake caliper that left room for a fairly wide belt on the inside, this could be done and still be bolt on to original brake mount without frame modification. (breath in)
Matt,
Is it possible to use belt drive for final drive? Or could I use a chain wax instead of grease and just add teeth to my disk brake caliper?

CNCAddict,
Do you think you could machine a custom brake caliper that fits around a belt drive sprocket?

The way I see it, is if everybody contributes something, the end product could be available sooner. Oh by the way, I have access to a waterjet (is that what its called?) if that would help to make custom sprockets, gears, calipers, etc...

[recumpence]

Too funny!

The Dave is was referring to is Dave Monsen the owner of the machineshop my shop is located in.

The project I was talking about is the box itself, not the gears.

Man, that is a good example of talking right past each other!

I'm at the shop working on the CNC programming for my drive unit tomorrow afternoon!

Matt

[recumpence]

I think alot of us are going to put this system on DH bikes, so my concern is what to do about a rear brake. Looking at my bike, if the drive unit where to feed from the top of the rear tire to a gear on the rear disk mount, it could be possible to have a disc caliper between the chain, inside the drive. What I am proposing is that the gear and the braking could be done on the same piece of metal. However, oil and brakes do not seem to be an ideal combination, if you used a belt and made a custom brake caliper that left room for a fairly wide belt on the inside, this could be done and still be bolt on to original brake mount without frame modification. (breath in)
Matt,
Is it possible to use belt drive for final drive? Or could I use a chain wax instead of grease and just add teeth to my disk brake caliper?

CNCAddict,
Do you think you could machine a custom brake caliper that fits around a belt drive sprocket?

The way I see it, is if everybody contributes something, the end product could be available sooner. Oh by the way, I have access to a waterjet (is that what its called?) if that would help to make custom sprockets, gears, calipers, etc...

One of the best solutions would, indeed, be a Sproder (sprocket/rotor). The chain lube is not a huge concern for them. There are non-greasy lubes out there. Also, it is possible to get a sprocket and a rotor side-by-side in that area.

I am going with chain final drive. I may move to belt on my recumbent at some point. But, for width concerns with a rear brake, chain is best.

Of course, there is also the option of a small disc on the output shaft of the reduction unit. I just want to get the reduction done first.

Matt

E-tard, I live the avatar pic. I am watching the Aptera with great interest. Heck, I am looking at building a "Neighborhood Electric" slightly oversized tadpole trike. It would basically be a full suspension version of a typical pedalled trike with double wishbone front suspension and a much wider front end for stability, no pedals, and a steering "Wheel" like a Cessna yoke that uses mostly (or all) hand controls. I am looking into the laws regarding this right now.

[CNCAddict]

Haha, yeah I guess I'll officially be CNCaddict here and not Dave, lol. Anywho, I personally am going to stick a gates carbon 12mm on my bike to see how it goes. These belts are ridiculously strong, but I only have a reinforced plastic pulley right now borrowed from the ixi bike. It is designed for the poly chain belt, but I worry it will explode when I put over 100ftlbs of torque on it. Anyway, I got 3 8mm polychain pulleys for $125 with some haggling which isn't too bad. You can check them out here. http://www.ixibike.com/

More belt fun http://www.youtube.com/watch?v=FHMChA0M ... re=related

[deecanio]

I'll be going with belt drive too, it may need a little more space to run alongside a disk but i think fitting won't be a problem especially if you can gear so that the pulley is smaller than the rotor.
Good to hear your on the case guys - realistically when do you think we will see the motor CNCaddict?
I'm basically hanging on to see what you guys come up with but if its a way off i may try off the shelf first.

Cheers,

D

[recumpence]

The only reason I am not running a belt final drive right now is drag. Under power, a toothed belt is very low drag. But, when a large pulley spins a small pulley in a freewheeling condition, there is a bit of drag present. I like to pedal without any discernable drag. Also, a chain final drive is basically silent as long as the small sprocket is not spinning to fast.

I am at the shop tomorrow afternoon CNC programming for the reduction drive. However, I am stuck waiting on some mechanical tubing to arrive before I can start machining.

Matt

[deecanio]

Hi Matt,

thanks for the info, maybe i should reconsider chain drive, i had ruled it out due to noise, mmmmmm.
looking forward to seeing what you come up with and more so what your going to do with that mean dh

Cheers<

D

[recumpence]

I am not trying to sway you on your final drive choice. However, again, if sprocket RPM is kept low enough, noise is not an issue.

I cannot hear the chain on my recumbent at all.

Matt

[CNCAddict]

Yeah, the belt vs. chain decision is really preference. For a high powered setup where no pedaling is done, I would take the belt because there is no maintenance, belts are cleaner, and the slight decrease in efficiency shouldn't really matter.

The motor will be done at earliest in a month. I have to order all the parts first (not quite done with the design). Then it takes a while for the magnets and stator to be made up and sent to me. The other parts I can make really quick since I've got the CNC lathe and milling machine here at the house. If you know a fast/affordable way to have custom magnets made up..please let me know

[deecanio]

Hi Guys,


i wish i did know a fast way for custom parts CNC, i might be a bit closer to finished than "just needs a drive"
belt vs chain is tricky (don't worry matt, no swaying felt), chain is much easier to mount but imo belt is a slicker look,but i dont want any drag (with all belt drives?) , anyway i guess it doesn't really matter as long as it hauls ass whilst not blowing my stealth, something i had no problem keeping with my hub.
i think i might try something in the interim as long as its not too expensive, did either of you look at the magmotor and box i posted? Miles mentioned that it wasnt very good for efficiency but other than that no one commented? i would like to know what you think of that in particular matt and eplain its shortcomings.
i Think my problem is i need to bone up a bit on motors and gearing, i could look at 100 motors online but not understanding their specs how would i choose one?
Anyway enough of my bleating, crack on gents, you guys rock


Cheers

D

[MitchJi]

Hi Guys,

i think i might try something in the interim as long as its not too expensive, did either of you look at the magmotor and box i posted? Miles mentioned that it wasnt very good for efficiency but other than that no one commented? i would like to know what you think of that in particular matt and explain its shortcomings.

Cheers

D

Hi D,

It sounds like one of Matt's 2 stage might be ready fairly soon.

You might want to consider using that drive with an interim motor. That might be easier than building your own gear box and when you build your more permanent system you would only need to mount a new motor on your existing box plus maybe change a sprocket or two to tweak the drive ratios.

[etard]

Sproder, huh... Now your making things up Matt. Haha

The cessna yoke sounds like something I was contemplating. So what, you pull back to go faster and push foward to brake. That would add a whole new experience to those trikes. What if you rigged the seat to sit up a lil when you push foward, and swing back (better aerodynamics) when you pull back on the stick.

I was joking with one of my friends as I was explaining the RC application on bikes, I told him I'm going full fly-by-wire. I'm just gonna get the rc car wheel controller to steer, gas, and brake. But, it got me thinking, and I think on a tadpole, or trike you could actually do that, if you had the right servos.

CNC,
There are alot of guys that build thier own motors on the forum : http://www.rcgroup.com. Those guys special order magnets and windings, etc... all the time. I would be willing to pay more for better magnets though.

[CNCAddict]

CNC,There are alot of guys that build thier own motors on the forum : http://www.rcgroup.com.

Haha, yeah I'm one of them! I started off in RC and moved into electric vehicles about 3yrs ago with a brushless powered outback mountainboard. I was more or less kidding about the magnets. I'm getting them custom made, but nothing ever happens fast enough

[deecanio]

Hi Guys,

i think i might try something in the interim as long as its not too expensive, did either of you look at the magmotor and box i posted? Miles mentioned that it wasnt very good for efficiency but other than that no one commented? i would like to know what you think of that in particular matt and explain its shortcomings.

Cheers

D

Hi D,

It sounds like one of Matt's 2 stage might be ready fairly soon.

You might want to consider using that drive with an interim motor. That might be easier than building your own gear box and when you build your more permanent system you would only need to mount a new motor on your existing box plus maybe change a sprocket or two to tweak the drive ratios.

Hi Mitch,

yes i'll definately be looking at Matts gearbox as he is the best we have by a long shot, however Matt is making the reduction unit with Davids motor in mind and that motor wont be ready for a while yet.
I was considering the magmotor as i can get the reduction box from them too and its all plug and play, it wont be as good as matt and davids solution for sure but it may do unil next year when all the testing is done and dusted and the motor is done and available and also castele release their new monster esc.
Half my problem is im impatient, but after a two year build who can blame me?
Bottom line is i want to buy my drive from matt and david but it wont be done for a fair while, im just considering options off the shelf so i can have a blast over winter and test the robustness of the bike once the drive is seatpost mounted, trouble is to buy an interim setup will cost more than buying from our guys but being as i have to revert to a standard wheel anyway it's tempting to see if will work
R&D takes a while, as does shipping from the states for replacement parts if anything breaks, i'm trying to do the sensible thing and wait it out but the snippet of fun we had at jozzbikes meet tells me my bike is close to where i want to be and all i need to do is revise the drive system, im not even that worried if it's alike for like swap as far as power is concerned, just need to get the weight out of the wheel and regain the ability to ride the bike like its meant to be ridden


Cheers,

D

[voicecoils]

I was considering the magmotor as i can get the reduction box from them too and its all plug and play, it wont be as good as matt and davids solution for sure but it may do unil next year when all the testing is done and dusted and the motor is done and available and also castele release their new monster esc.
Half my problem is im impatient, but after a two year build who can blame me?

I say buy the magmotor and gearbox, give it a go. At ~6.4kg for 6kW, it's got decent power to weight IMHO. Figure ~8kg to get it mounted and connected to the rear wheel.

If it doesn't work for you just flog it back off to the robot crowd.

Only concern I can see is the length of the motor and possible gearbox noise. I doubt it was designed to be quiet.

I've got the C40-300 magmotor which I've never used for anything (planned to make a powered bike trailer) but the motor quality looks top notch. It is a brushed motor, so you'd need to find an appropriate controller. What would you run it at, 36v? How many paralleled A123's does that get you? ie how many amps could you pull?

[edit] two links: http://www.robotbooks.com/robot-motors.htm
http://www.ampflow.com/ampflow_motors.htm
Read about overvolting in the first link. Efficiency may be an issue for these motors overvolted or at lower RPMs...

[recumpence]

My drive is being designed with David's motor in mind. However, David is also designing his motor with my drive in mind. So, I gave him the screw spacing I would like and shaft length.

The drive will work with a number of readily available RC motors.

The only "Perfect" RC motor for this that is currently available would be the Plettenberg. But at $1,100 who really wants to buy one (other than those of us who are insane and really impatient for the best)?

I wish this stuff was easier to adapt to bike use. But, we are close, very close. The ideal setup would be an Astro Flight twist throttle, running a Castle SHV200 ESC, into a motor like David is making, with a silent reduction drive.

My recumbent is close to my ideal. Heck, if I could pull 160 to 180 amps through my HV110, I would be happy as a pig in slop! The "Perfect" system can be setup right now. The problem is price. There are a couple $1,000+ ESCs that work for this, and a couple $1,000+ motors. But, the ideal setup should be available to the average Joe. I am thinking as long as you can setup a 4,000 watt drive for $1,000 (motor, ESC, and reduction), that is ideal.

Anyway, I am doing some programming on the drive unit today.

I highly doubt there will be much R&D needed with the reduction unit. I have already learned what I need to know with my recumbent. I am, essentially, using the same rough drive setup in a very compact, variable layout structure. But, all the components have proven themselves. I have 600 miles on my recumbent so far.

Matt

Matt

[Ypedal]

Hey matt.. are you still using the original spoke adapter for the rear wheel or have you moved up to a disk hub ? ( I know it's in one of the threads somewhere.. but that's alot of reading i have not yet gotten thru.. )

[deecanio]

My drive is being designed with David's motor in mind. However, David is also designing his motor with my drive in mind. So, I gave him the screw spacing I would like and shaft length.

The drive will work with a number of readily available RC motors.

The only "Perfect" RC motor for this that is currently available would be the Plettenberg. But at $1,100 who really wants to buy one (other than those of us who are insane and really impatient for the best)?

I wish this stuff was easier to adapt to bike use. But, we are close, very close. The ideal setup would be an Astro Flight twist throttle, running a Castle SHV200 ESC, into a motor like David is making, with a silent reduction drive.

My recumbent is close to my ideal. Heck, if I could pull 160 to 180 amps through my HV110, I would be happy as a pig in slop! The "Perfect" system can be setup right now. The problem is price. There are a couple $1,000+ ESCs that work for this, and a couple $1,000+ motors. But, the ideal setup should be available to the average Joe. I am thinking as long as you can setup a 4,000 watt drive for $1,000 (motor, ESC, and reduction), that is ideal.

Anyway, I am doing some programming on the drive unit today.

I highly doubt there will be much R&D needed with the reduction unit. I have already learned what I need to know with my recumbent. I am, essentially, using the same rough drive setup in a very compact, variable layout structure. But, all the components have proven themselves. I have 600 miles on my recumbent so far.

Matt

Matt

Hi Matt,

well i am insane and really impatient for the best
i think i will take the plunge with a pletty and an svh200 (are they out yet??) with one of your new boxes.
did you have the terminator? specs? i know you have posted all this info but i'll have to wade through to find it.
will the pletty drop straight into the new box? that would be cool then i could just work out what gearing i need and go with 25chain and sprockets?
i think you run at 48v on that which i could do, if i reconfig my pack from 66v 6.6ah to 48v 8.8ah that would be fine for me.


Voicecoils,

i think (dont flame me if im wrong) that my 123's will do 80amps for 1s and then another 80 for every paralell string ?
does that sound right?
Anyway i know they kick ass and certainly my pack wont let me down for supplying power.
If i folow Matts lead i would be running 48v (or whatever the 123 equivalant is) so i guess that would make my pack 4p allowing me to draw silly amps, being as the svh200 is 200 amps? i will be fine to supply anything i put on really
mmmmmm, pletty and svh200 could be the ticket, i have the patience to wait for Matts second box but i doubt i have the patience to wait for davids motor.
damn this ebike lark, i cant think about anything but drive systems night and day !!!!!

Cheers,


D

[CNCAddict]

The SHV250 will be available soon for those who pre-ordered them. I was told they would only be making enough to fill current orders, so if you really want 85V and 250A, you might want to call them up and get on the list.

[deecanio]

Hi CNC,

Thanks for the heads up - up looking at the plettys now when i should be working lol
i guess i'll work out max power rqd and go from there.
ok time to start looking to buy i'll post in my thread proposed setup and hopefully all the guys will holla if im making a big mistake

Cheers,

D

[MitchJi]

Hi,

What's supposed to be functionally different with the new outrunner motor being designed and the existing RC motors?...

A few things;

#1 HUGE shaft. The internal shaft diameter is huge on this motor (I believe 15mm). The output portion of the shaft will probably be 12mm.

#2 Far better efficiency. RC planes and helis ahve alot of airflow available. So, effiency is not a big deal. But, we want the best efficiency possible. This new motor will have thin laminations and be taylor made for our application. That (among other factors) will give better efficiency.

#3 Super beefy bearings to handle the high shaft side loading a belt drive will have.

#4 Ability to handle FAR higher voltage than typical RC motors.

My Plettenberg maxes out at 50 volts. These new motors will handle 100 volts mor more!

Also, the can (bell) will be tapered to tolerate the shock loads imparted on it in bike use.

Matt

...the motor should work at any PWM you give it, and should produce a really clean BEMF signal unlike some of the other motors out there, so if you don't like the squealing just crank it up to 24khz.

Also, I plan on getting things as corrosion proof as possible on the motor. Electrically, brushless motors can run underwater. It's just the corrosion that's a problem.

Thats a pretty compelling list of features. Some of the features are compelling by themselves but all of them is great

I really like the 24khz PWM. Quiet is really nice/important.

Since Matt compared this motor to his Plettenberg I have a question. Three things that distinguish the Plettenberg are price, build quality and component quality. How is the X-era 60 going to compare with the Plettenberg on build and component quality?

Also any reason (doesn't require a oneway or freewheel) not to use 219 chain for the secondary reduction?

A hub motor is not in the cards right now.

When I saw the request for a hub motor drive for that motor I thought it was a bad idea.

That might have been correct but if someone could work out a high quality geared hub that used a motor similar to Davids I think the market would be huge. Why would anyone buy a Clyte 5 series if they could get a much more powerful and much lighter hub with massively better build quality?

I think in a large hub you could fit a two stage belt/chain drive similar to what Matt is building. SRAM already has a hub with dual RC (much smaller) motors:
http://endless-sphere.com/forums/viewtopic.php?f=28&t=4625&p=78344&hilit=sram#p78344

SRam Sparc

there are two version:
# the old one with gears (i have)
# and a newer version with belts (quieter)and higher voltage (i think still the same motors)

I think the sales volume would far exceed any chain drive option and I think both John and David would both like a popular product.

[johnrobholmes]

The issues with the hub motor design is space and total gear reduction available. If you want more power in a lighter package, you have to use more gear reduction. Unless somebody can come out with a rugged and small two stage planetary that fits inside a hub shell, I just don't think we will see hub motors with power to weight ratio equal to a divorced power train.