High power RC motor and drive unit production

[mud2005]

Hi, I just had to chime in as someone who is working on a similar such drive system, that looks freakin AWESOME 8)
very nice work Matt, almost feel like I should give up after seeing that hehe, just kidding I'll never quit building stuff it's too fun

 

[recumpence]

John,

Well, I will PM you. Normally, Castle just replaces controllers. I am sending my two blown controllers in soon to be "Repaired" (New controller thrown in a bag for me). :wink:

I will be focussing on CNC Adict's motors soon. So, I do not need this AXI anymore.

D,

No name as of yet. I have just been calling it the E-Drive to those who ask about it. :?

The drive is not really going to be a standard ratio, per-se. The pulleys in the pic are just a couple I grabbed for the picture. The motor pulley can be as small as 11 tooth. The drive pulley can be almost anything. I have 50, 60, and 70 tooth pulleys here. The secondary chain drive can be various ratios as well.

I figure the best way to do this is to get each customer's requirements and setup their drive accordingly.

Are you just looking for a constom ratio for my production drive, or a complete custom drive system?

Matt

 

[recumpence]

Hi, I just had to chime in as someone who is working on a similar such drive system, that looks freakin AWESOME 8)
very nice work Matt, almost feel like I should give up after seeing that hehe, just kidding I'll never quit building stuff it's too fun

:wink: Thanks, Mud. I love R&D. I am somewhat electronically inept, but I am gifted at mechanical design and problem solving.

Matt

 

[oofnik]

but I am gifted at mechanical design and problem solving.

Matt

I would have to agree.

You know, I'm kind of the opposite, I've realized. I've done more electronics projects than mechanical fabrication. Circuits are somewhat intuitive to me whereas mechanical design requires a good amount of thought on my part. And here I am in my second year of undergrad mechanical engineering. What the hell.

On the other hand, maybe it's just because it's a lot easier and cheaper to purchase electronic components or rip things apart and desolder all their capacitors and resistors than it is to buy machines to cut metal. I don't know. I keep thinking maybe I'll switch to electrical engineering one day, but... to be honest mechanical just interests me more, and if that requires more work for me then I'm willing to do it.

That said, depending on who I talk to here at my university, I'm still debating whether to go with Matt's drive or fabricate my own. I'm planning on spending my winter break on Inventor drawing stuff up to see what I can come up with.
It really depends on how much the final drive will end up costing... I know Matt's not doing this to make a profit, but he's putting an awful lot of time and work into this, undoubtedly resulting in cost that might not fit my needs. Unfortunately I have a very restrictive budget, so the more I can do myself, the better. I'm holding on patiently to see how this project unfolds like the rest of us!

 

[John in CR]

...I will be focussing on CNC Adict's motors soon. So, I do not need this AXI anymore...

Oh, I'll be wanting one of those too. After my GPS trek yesterday, I'm realizing I almost definitely need a 2 motor rig. I need to run efficient for long distance at around 400W, then the first big hill is a 1400M ascent over 20km with 2 long 10% grades. I still need to map the 2nd mountain, but I know it has far steeper climbs, though only 3-5km ea. Hauling close to 400lb of bike, batts, and me up a 20-25% grade is going to take significant power. I'm not sure one can also be highly efficient at 400w.

John

 

[recumpence]

For absolute efficiency in your situation, two motors may be best. One motor that is very efficient at 400 watts, will not pull that much weight up such a grade. On the other hand, a 2kw motor needed for hill climbing, will not run at 400 watts very efficiently.

Matt

 

[deecanio]

D,

No name as of yet. I have just been calling it the E-Drive to those who ask about it. :?

The drive is not really going to be a standard ratio, per-se. The pulleys in the pic are just a couple I grabbed for the picture. The motor pulley can be as small as 11 tooth. The drive pulley can be almost anything. I have 50, 60, and 70 tooth pulleys here. The secondary chain drive can be various ratios as well.

I figure the best way to do this is to get each customer's requirements and setup their drive accordingly.

Are you just looking for a constom ratio for my production drive, or a complete custom drive system?

Matt

Hi Matt,

complete custom drive system im afraid
im still working on what i want but it will only be a re-arrangement of what you have already with much more emphasis on compact and a more box like consrtuction.
also is it ok to have dual belt at 5kw? im planning to try a cyclone like setup but use a pletty and reduction GB for the power?
cheers Matt, and again very very nice job


D

 

[The Stig]

..."if there was some sort of super high torque RC transmission It could be good"...

Close but not RC...Dewalt, and I'm sure others, multi-speed hammer drill transmissions. They can definitely handle the rpms and torque. The only questions are durability under continuous use and their efficiency. Actually the real question is who will be the first to try other than the company selling the silly priced gearboxes you just plug your hammer drill directly into. It's on my list with lots of other stuff to try. Here's info from the robot war guys. http://www.robotmarketplace.com/products/dewalt_gearboxes.html

John

The first question that comes to my mind is what sort of gearing ratio do these transmissions have. Would it really get the RPMs don to where we want them?

Stig,

I'd be more concerned about possible efficiency loss in too much step down in the gearing. Looking at the specs on the 2 speed transmission for the 24v motor (which both have the most shared data for alternative uses) it seems the high speed gearing is a step down of about 10:1, and 45:1 in low gear. Like RC motors those small power tool motors are very high rpm to develop the kind of power they do in such a small size. Given how cheap the hammerdrills can be from those who bought package deals just to obtain the Dewalt batteries.

If I swing the Bosch sponsor deal I'm working on then I should be able to get full specs on the motors and transmissions in their cordless power tool line. I'm primarily after their batteries, but I'll include the possibility of using their motors too for my Caribbean to Pacific on a single charge ride, but I'd need data that has been elusive about power tool motors especially with regard to efficiency and durability testing they've already done. I'll be sure to share anything I can.

John

Those transmissions could have potential. The more options the better

 

[etard]

Great work Matt!
I was wondering if you could take some more pics of the other side layed out, and maybe even throw a tape measure (with inches, HAHA) in there so I can get a better idea dimensionally. I am trying to figure out where to mount your drive on my rig, I would like to keep it high and out of harm's way. It would be ideal to mount it inside the triple triangle, because it can be folded into a triangle. Also, I am not seeing how the motor is mounted, can you please elaborate? How much does it weigh with that AXI on it? Thanks for all your hard work.

 

[recumpence]

I can take a few more pictures in various positions if you would like. I can also weigh each part of the drive individually. The drive is not complete, so a total weight number is not available.

The motor mounts to the front by two 4mm screws through the face of the motor plate, threaded into the motor face.

The drive system face plate that the motor mounts to is currently machined with no motor mounting holes. Those will be machined on an individual basis per order. I will probably setup a couple "Generic" drives with CNC's motor and a "Standard" reduction ratio. Those drives will be prebuilt and ready to ship. However, I have a feeling most drives ordered will require some individual setup and/or minor additional machining to make it ideal for that particular customer.

This is not a bolt on affair. There are too many different bikes out there to make this a simple turn-key kit (I know most of you understand that already). So, I am ready to do some additional setup to make the drive ratio, motor style, and mounting style as close to perfect for the individual application as possible.

It may be that I will take an order for a drive, evaluate it to see if I have the pulleys and sprockets to meet their requirements (if not, the proper ratio pullies will be ordered while the motor mount plate is being machined for their particular motor). Once the correct pulleys are ordered and modified for E-Drive use and the face plate is machined to mate with the motor, the drive will be assembled.

I can also offer a "Blank" kit that is unassembled (with included instructions), and no motor slots machined. That would be for those who have access to very basic machine tools and want to do some finishing on their own. This would be the least expensive option because I would not be doing so much labor to prep the drive.

Lastly, I do not mind selling any individual part to those who want to do something custom on their own and want to start with my foundation. For instance, I could sell the drive framework with no shafts, sprockets, or pulleys to anyone who wants to setup all those parts on their own, but do not have the ability (or desire) to make the drive unit pieces themselves.

That is the beauty of machining "Beautique" products.............. Anything can be altered one at a time. It is all about the time and additional cost involved.

Matt

 

[GGoodrum]

Okay, for my first order, I need a single-stage version, with a 6:1 reduction using the #25 chain setup you are using for the secondary in the two-stage version. If possible, I'd like the larger sprocket, on the output shaft, to have a oneway or freewheel installed, but this is not a showstopper for me, as I am not so worried about extra drag while pedaling, mainly because pedaling alone will only be done when all else fails and besides, the Neu 2215/P62 setup doesn't have a lot of cogging/drag.

On the output shaft, I need two of the custom 1/2"-1.375" freewheel adapters you have mentioned trying to fabricate, one FW that will be driven by the crank, and then one fixed cog that will drive the rear hub. For the motor sprocket, the output shaft from the P62 is 12mm. I think I told you before it was 14mm, but it is actually 12mm. The mounting bolt pattern on the P62 is a 60mm circle.

Now that you have posted pictures, I get how the finished product will look. What I'm having trouble visualizing, however, is how I will mount this setup. Where it will mount is somewhere in the vicinity of the seatpost downtube, so using a couple of U-bolts that bolt to some sort of plate that then attaches to the drive is I'm guessing the easiest way. Any ideas about how this plate might mount to the motor plate? Also, have you thought about maybe providing some of mounting tab on the motor plate for an HV110 controller? That would make for a nice and tidy package.

After I get this first bike finished, with the Neu 2215-3Y/P62/single-stage eDrive setup, I'm going to do a second bike using a Hacker A60-18L and the full two-stage version of the eDrive. This will be used to replace another 5303 setup on one of my folding bikes.

-- Gary

 

[deecanio]

Hi Gary,

i hope you dont mind but i was wondering if you'd jot a few lines in my thread (as not to clog) about your cyclone setup - i plan to use it too more or less exactly how you had it but with a plettenberg and Matts gearing, i'd like to know how the cyclone performed and where it was weak - judging by your planning to change out a second 5xxx im guessing/hoping that you weren't totally unhappy with it?
Also can i ask why you want a chain reduction and not belt?
im working on mounting to the seatpost as thats where my drive is going whether it likes it or not so it'll interesting to hear your thoughts on all fronts, i'm hoping Matt can box mine giving me protection from belts/chains but also to provide a nice flat back which i plan to use mount to the seatpost.

Cheers,


D

 

[recumpence]

I got my 40 series X-Era outrunner from CNCAdict today! Woo-Hoo!

This thing is absolutely beautiful! Very good work, Man. I will post some pics of the motor (on and off my drive) tonight or tomorrow.

I can honestly say, other than my Plettenberg motors, this is the highest quality outrunner I have ever had and I have had ALOT of different motors.

For the money, this thing is beautiful. I cannot wait to run it.

Weather is cold right now. I may setup a test stand with a prop, tach, and full data logger and get to some testing.

I am getting excited to get my projects all done this winter and get to some R&D going for next summer!

Matt

 

[GGoodrum]

Hi Gary,

i hope you dont mind but i was wondering if you'd jot a few lines in my thread (as not to clog) about your cyclone setup - i plan to use it too more or less exactly how you had it but with a plettenberg and Matts gearing, i'd like to know how the cyclone performed and where it was weak - judging by your planning to change out a second 5xxx im guessing/hoping that you weren't totally unhappy with it?
Also can i ask why you want a chain reduction and not belt?
im working on mounting to the seatpost as thats where my drive is going whether it likes it or not so it'll interesting to hear your thoughts on all fronts, i'm hoping Matt can box mine giving me protection from belts/chains but also to provide a nice flat back which i plan to use mount to the seatpost.

Cheers,


D

Do you have a link to your thread? I will be happy to post over there about the Cyclone setup. I have that on a 20" Dahon Mariner folding bike (the one in my avatar...). The Neu 2215/P62 with Matt's single stage eDrive will go on my wife's Townie, which has a Nexus 8-speed hub. The second eDrive will replace the 5303 on a West Marine 20" Port Runner. I don't plan on doing anything to the Cyclone setup, at least until the freewheel wears out. At that time, I'll probably look to at least replace the motor-crank chain drive with a #25 chain setup, along with replacing the freewheel with one of the ENO units, if I can figure out how to do that. The finer pitch chain drive should help reduce the noise.

The reason I'm using the chain drive versus a belt is because this is really the secondary drive. The P62 is the primary stage, and it has a 6.75:1 reduction. I just don't trust the belts with this much torque. I used to shred belt drives on big RC electric helicopters, pushing 5kW+ peaks. Never could find one that could handle the power.

-- Gary

 

[deecanio]

Hi Gary,

thanks for getting back to me.
Thread is here ..... http://endless-sphere.com/forums/viewtopic.php?f=6&t=267&st=0&sk=t&sd=a&start=660
i am planning on using the plettenberg and one of matts dual stage reductions, i was torn between using belts or chains but both you and mitch have said that nois won't be too bad using chains so i may go that way, if your planning to swap out the normal chain to your crank for a #25 i may look into doing the same, again for noise issues.
if you could post the good and bad of your cyclone kit that would be great - i think the cyclone is a good system poorly executed and could be amazing with the right kit, the fact you've dropped the x5's for a geared solution tells me im headed in the right direction especially as your x5 setups had more grunt than my puma setup.
the main reason for me to move away from hubs is to mount the drive on the frame so that the suspension is free to do it's thing and allow me to ride a lot harder than i could get away with with a heavy hub in the rear, plus the performance should be better to boot
i'll take a look at the neu motor today, intersting that its internally geared - i did look before but i dismissed it for some reason (certainly not quality).

Thanks Gary.

Cheers,


D

 

[recumpence]

D,

One thing to remember is that torque is not equally distributed through a drivetrain. This can be tough to understand, but think of it this way;

Take a 3 stage drive, for example (my recumbent is a good example of this). At 5kw, the primary drive is taking 5kw, as are the second and third stages. However, wattage is not the same as torque. wattage (or horsepower) is the maximum work available from a given power source. Torque is static pressure applied, totally unrelated to, or unreliant on RPM. The primary stage runs at higher RPM, but less torque (static pressure) than the second stage. The second stage, likewise, runs at higher RPM, but less torque than the third stage.

The first stage is fine up to 5kw with as much as 13,000 RPM for a 5mm pitch, 15mm wide belt. However, the second stage will be running roughly 4 or 5 times lower RPM. Though the kw remains the same (relatively the same other than efficiency losses), the torque is quadrupled because you are trading RPM for torque by gearing down in that stage. So, for the second stage, the belt is overwhealmed and will shred. Therefore, a small pitch chain is required.

A belt is more efficient and much quieter than a chain at high RPM, but lower torque handling. This makes a belt a perfect primary reduction for this application. The chain handles torque MUCH better, but is very innefficient at high RPM as well as being noisy, making it perfect for the secondary stage. At lower RPM, the chain runs nice and quiet and efficient. See what I mean?

Gary's Neu motor with planetary reduction is a good setup mainly because he already owns it. It will be high power and light weight. However, that motor is a very high RPM inrunner that will whine at high RPM along with planetary gear whine. It is not a bad setup at all. In fact, it will be quieter than his Cyclone drive. But, a belt driven outrunner will be quieter, though a touch heavier.

So, type of power plant depends on what you are looking for. If you want absolutely lightest motor with highest power and do not care about sound, his setup would be a very good choice. Outrunners are torquey and quiet, but a touch heavier and a bit fatter than his setup (though shorter motor length).

Matt

 

[deecanio]

Hi Matt,

yes i understand that mostly thank you.
So i would still be better off (with my pletty) with a primary belt then secondary chain dualstage GB yes?
what do you think about from the gb output Sprocket to the 1st chainring then? chain again? #25?
I'm looking at buying the echo crank arms that you linked and Miles has, onto this i will put an ENO 22t for the ease of mounting the chainring onto it's milled slots but heres where i get a little confused again.
I have the Guestimated figures of motor rpm at 7300, so i would need to bring that down considerably to drive the chainrings (what rpm is good at the chainring i have no idea) so..... if my gb brings it down by 7-1 to then from the sprocket on the output shaft (11t) to the chainring (34t) gives me total reduction of 21-1 no? roughly 350rpm
so heres where i get lost, if i'm at 350rpm at the crank (seems good?) at that stage what happens if i use another 32t chainring (maintaining the ratio) then go to the rear cluster? if im on say the 34t sprocket on the casette does that mean that my wheel will spin at 350rpm? and increase as i go smaller and smaller down to 11t?
it' s really difficult to digest as i have never dealt with sprockets/gearing etc before so i'm struggling to calculate so i can ask you whats the smallest setup Gb we can do with those ratios required

Anyway thanks again for the info, you guys have been great at holding my hand through this, i can see why now most be peeps start with a hub

i want to start compiling my shopping list now so im hoping someone will shout STOP!!! if im doing wrong?
For the last two weeks i have been going to bed with ratios and drives spinning round my head incessantly lol - what i need is you guys to look at my poor drawing and start putting numbers on it for me so i know i wont end up with a multiple chain nightmare that wont stop wheelieing or worse still wont pull me at all but it's really hard to work it all out and i hate having to hassle you guys with questions all the time




Cheers,

D

 

[Miles]

STOP!!! :lol:

350 rpm at the cranks and you'll be like a hamster on amphetamines

The Cyclone system doesn't drive the crank, it drives the chain directly. So, decide your crank rpm for your normal cadence (circa 80-90rpm) - the rpm of the sprocket which drives the chain will then in be in the ratio of its size in relation to the size of your chainring.

 

[deecanio]

LMAO :lol:

ok so maybe i meant 350rpm at the chainrings? the crank wont be moving at all
that still seems like a lot - i thought a very high pedal cadence was say 100rpm?
do i need to reduce motor speed to match pedal cadence then?
dammit how much is a rear x5??

 

[Miles]

One thing at a time... Do you want the motor to drive the chainring/cranks or the chain directly (cyclone system)?

 

[deecanio]

well i thought that in garys cyclon setup the motor drives the 1st chainring which drives the 2nd chainring by default which drives the chain itself? and i thought that the cranks wouldn't move whilst this happens but will engage to help if i peddle?

 

[Miles]

This is what I understand as the Cyclone system (turn the sound on your computer down...):
http://www.cyclone-tw.com/

 

[Miles]

Maybe you mean something like this?
http://www.elationebikes.com.au/

 

[deecanio]

ahhhhhhhhh.
ok - look at my drawing again - bear in mind that the link just posted was my impression of the cyclone too BUT........
after i spent a week playing with Matts drive design i came up with something else like this ...
http://endless-sphere.com/forums/viewtopic.php?f=6&t=267&st=0&sk=t&sd=a&start=645
if you look at the drawing on the bottom of the page i did it's "different".
Then Mitch told me that what i thought was my idea was indeed a cyclone setup just like garys (on the very next page in the link) which indeed it was (although mine would be with matts gb and a pletty.
i thought with a fw on the crank and on the output sprocket of the gb i would be able to motor only or pedal or a combo of both?
DO you not think this will work then Miles?


***edit*** i also thought looking at the drawing that if i had 2 fw's on the gb output i could setup the serial too? Mitch sais i would have chain growth issues but i cant see where? i though my deraileur would tension?

Cheers,

D

 

[Miles]

D, your drawing shows a typical crank drive set-up - not the Cyclone. Ok, that's cleared that up.

So, yes, you need to reduce the motor speed to circa 80rpm...