High power RC motor and drive unit production

[recumpence]

You guys are hillarious!

Hmm, the double adaptor sounds interesting. My only concern is minimal sales of that part versus just the normal FW adaptor. I will have to consider that.

I also decided to have Jason quote me on adaptors for different secondary stage sprockets. Currently I have been designing this drive to use a standard steel 1/4 inch chain sprocket. That sprocket has a large (steel) set screw hub. This sprocket is heavy and not cheap! So, I am having Jason quote me on aluminum sprocket hubs to use aluminum scooter and robotics hubless sprockets. I can ship the first drives with the steel sprocket, then upgrade to aluminum later, or ship with the aluminum sprocket setup from the beginning.

I am expecting Dave to start on the CNC mounts within the next couple days. :wink:

Safe, yup, moving right along!

Matt

 

[swade]

My current 408 hub motor settup has me running 11.5ah of a123's right now at 66 volts (20s5p). Would going to a 12 or a 24 volt rc system mounted on one of these allow me to reduce my total pack weight for roughly the same speed and distance? I guess I'm asking if the general consensus is that these will be more efficient and by how much. Of course there are lots of factors, I'm just after a general ball park guess from those with a bit of experience already.

Great work! I have thoroughly enjoyed lurking on this thread and watching it all play out.

 

[GGoodrum]

Hi,
Gary: Please let us know what you think about different FW adaptors to accommodate both FW's and Cogs.

I tend to agree that for use on the "series drive" option, a FW adapter that was just wide enough to fit a track cog and a FW, would be desirable, with the setscrews underneath. That would minimise the "overhang" problem of having both of these on the same side of the output shaft. Maybe this could simply be the same one, but then the shoulder part can be cut off for the series version?

For me, my most immediate need is for the regular adapter, with the shoulder. The first bike I'm going to do is a 16" Dahon Curve folding bike, which has an SRAM 3-speed hub. For this I plan to use a single-stage version, using the 6:1 belt drive, with my Hacker A60-18L. This will have a 12T track cog (on the FW adapter...), and will drive a 53T crank chainwheel. Because of the relatively low kV of this motor (149...), and the small wheel size, I can get away with only needing a single stage for this setup.

In a somewhat parallel effort, I will be doing the Neu 2215/P62 setup for my wife's Townie, which has an 8-speed Nexus hub. Again, I need only a single stage version of the "eDrive" (the best name, in my opinion... ), but since the P62 is acting as the 1st stage, this one will need a 6:1 chain drive. The torque output of the P62, which provides a 6.75:1 reduction, would shred even a 15mm HTD belt.

-- Gary

 

[GGoodrum]

My current 408 hub motor settup has me running 11.5ah of a123's right now at 66 volts (20s5p). Would going to a 12 or a 24 volt rc system mounted on one of these allow me to reduce my total pack weight for roughly the same speed and distance? I guess I'm asking if the general consensus is that these will be more efficient and by how much. Of course there are lots of factors, I'm just after a general ball park guess from those with a bit of experience already.

Great work! I have thoroughly enjoyed lurking on this thread and watching it all play out.

The simple answer is no, I don't think you can go down to a 12V or 24V system and get equal performance. Less weight, for sure, but not that much of drop in voltage. With a bit more info about your current setup, a more educated guess could be made. What is the current top speed of your existing 408-based setup? What kind of range are you getting with your 20s5p a123 setup?

I don't have any direct data yet, for an RC-based system, vs a hubmotor setup, but I do have experience with my Cyclone 1000W setup on a 20" folding bike. This bike originally had a front-mounted 5303, a 4110-modded controller with a 65A limit and 24s4p a123 pack. Tons of torque, and a higher top-end than I ever would use on a bike this size. The problem is that is an extremely heavy setup, and most of the weight is in the front-end, which complicates folding/handling. The Cyclone 1000W setup has a 55A controller that is limeted to 48V, so I reconfigured my 24s4p pack into a 16s6p configuration. Where the 72V/5303 setup hit 4500-5000W peaks, the Cyclone tops out at about 2600W. Because the Cyclone gets the advantage of using the rear gearing (Nexus 3-speed hub...), however, it turns out that the total torque available in 1st gear is way more than what the 5303 had, even though it is running on 48V/55A vs 72V/65A. The top speed is still higher than I would ever want to go on a folder. The weight reduction was also very dramatic. Now, without the battery pack, I can easily fold the bike and pick it up with one hand. No way I could do this with the 5303 up front. Granted, the 408 weighs a lot less than a 5303, but an RC-based setup will weigh quite a bit less than my Cyclone 1000W setup.

If I had to guess, I would think that a setup such as Matt is doing for his new mountain bike, would probably equal the performance you are seeing with a 20s a123/408 configuration, but his will be roughly 48V. You might get similar performance on a 36V setup, if you drive the front crank in order to take advantage of the bike's gearing.

-- Gary

 

[recumpence]

my god that thing is sexy... .. i like it !

You take paypal ?

Absolutely.

Once the first run is shipped, I will begin the second run. I am not taking deposits on the first run. However, I will take deposits for the second run of drives. Depending on the number of deposits, I will ramp up production numbers to match.

Matt

 

[MitchJi]

Hi Matt,

Hmm, the double adaptor sounds interesting. My only concern is minimal sales of that part versus just the normal FW adaptor. I will have to consider that.

Matt

I am hoping that because some of the setup is the same, that if these are part of the larger order the price might be less than ordering for a few modified adaptors by themselves.

I don't expect you to cover the cost of a custom part made for me and Gary. My intention is that I or Gary and I will cover any additional cost.

It would be great if you would help us determine the best and most cost effective design and then see if we can get a good price by combining it with your existing order.

It might make sense for Gary and I to pay for 10-30 instead of 3 or 4 (might not cost much more) if we think there is any likelihood of future demand.


Thanks!

Mitch

 

[recumpence]

I can ask Jay about it. :wink:

I got my White Industries freewheel. That thing is awesone!

I cannot wait to get my mountain bike together and test all this shiney stuff.

Matt

 

[swade]

What is the current top speed of your existing 408-based setup? What kind of range are you getting with your 20s5p a123 setup?
...
If I had to guess, I would think that a setup such as Matt is doing for his new mountain bike, would probably equal the performance you are seeing with a 20s a123/408 configuration, but his will be roughly 48V. You might get similar performance on a 36V setup, if you drive the front crank in order to take advantage of the bike's gearing.
-- Gary

Hey Gary,

Thanks for the great reply. My current 408 setup gets me 24km round trip to work and back. To work is either flat or downhill and the way back home has a 300ft elevation gain. I average about 48km/hr on the flats which is perfect to keep pace with cars on the side roads I drive. This is pretty much the speed I want to keep with an rc setup if I ever use it for commuting. There's a bit of reserver so that I can still make the whole trip if there's a strong 60km/hr head wind. This happens from time to time where I live.

Another positive could be better reliability?? I've had a lot of problems with water and 408's. Another thing I'd like to play with would be to use the rc setup on my full on downhill bike. Rather than ride a chair lift or find buddies with big trucks to shuttle up mountain roads, use the light weight rc setup to get to the top of these downhill runs. Could be a game changer for the whole scene if it was durable enough.

 

[John in CR]

Matt,

You're really teasing me now by showing everyone my Christmas present with motor attached. I can't wait to see it with belts and pulleys, but I really can't wait to have it running on a bike. I'm thinking of something along these lines due to the simplicity of the build. Please forgive my butcher job stretching it to accommodate the motor and batts using Paint.

John

 

[GGoodrum]

Hey Gary,

Thanks for the great reply. My current 408 setup gets me 24km round trip to work and back. To work is either flat or downhill and the way back home has a 300ft elevation gain. I average about 48km/hr on the flats which is perfect to keep pace with cars on the side roads I drive. This is pretty much the speed I want to keep with an rc setup if I ever use it for commuting. There's a bit of reserver so that I can still make the whole trip if there's a strong 60km/hr head wind. This happens from time to time where I live.

Another positive could be better reliability?? I've had a lot of problems with water and 408's. Another thing I'd like to play with would be to use the rc setup on my full on downhill bike. Rather than ride a chair lift or find buddies with big trucks to shuttle up mountain roads, use the light weight rc setup to get to the top of these downhill runs. Could be a game changer for the whole scene if it was durable enough.

I'm not sure about a reliability increase, unless you mount the RC-based setup in a more protected fashion. If your setup gets wet a lot, you might want to consider an "inrunner"-style RC motor, that doesn't have a rotating can.

Your idea for getting back up the hill is definitely doable, and could be done probably with a 2p, or maybe even a 1p a123 configuration. This is where the high C rating of the a123 cells would come in handy. With the right gearing, you could probably get away with something like a 16s2p setup.

-- Gary

 

[GGoodrum]

Matt --

What is the setup you are going to do on your MTB? What is the gearing on the 1st stage and the 2nd stage, and if you are still planning to drive the left-side of the hub, what is the gearing for that stage? What is the kV of the 60-series motor from cncaddict that you will use? Is this what you are planning to use, or is it the big Pletti? If the latter, do you know the kV?

Thanks -- Gary

 

[recumpence]

Hey Gary,

I will be going with right side drive so I can use the cassette. The mountain bike will use a double chain drive, freewheel crank setup very much like the bike in your Avatar. The drive will be in front of the main frame spar just in front of the cranks. I will try to get away with a single stage drive because I have essentially two additional stages in the drive to crank and crank to wheel. But, if I have to, I will go with a two stage reduction (only if I have to). I will either use the 60 series or my Pletti (not sure yet). The pletti is 200KV. The 60 series will be roughly 150kv (if I am remembering right).

The goal of the mountain bike is to be very durable, and very versatile. I want to be able to ride it like a light weight dirtbike, or cruise around town, or some "Urban Assault" curb jumping and overall juvenile fun.

Oh, great wheelies are a MUST!!

Also, I want this thing to be rolling artwork. I refuse to build something that does not look the part.

Overall, I guess you could say I am looking to upstage the Optibike by a wide margin for a LOT less money. I like the Optibike concept, (it is the ultimate production E-bike) but for that kind of money, I think we could do better on our own (power, speed, looks). :wink:

Matt

 

[etard]

Here here, 3 cheers for the poorman's freeride (as in free from petrol) dirtbike.

Matt,
Are you content with your batteries from the recumbent? What kind of voltage and C rate would you suggest for the 40 series and 60 series?

Who else wants one of these , and what bike are you going to put it on?

 

[recumpence]

I am very happy with my recumbent batteries! They are 10C continuous, 15C burst cells. Those cells weight 5 pounds total (with wiring). They are 12S (50 volts fully charged) 10Ah. I can pull 150 amps from that pack without hurting the cells. In the average ride, I rarely pull the pack down more than 4 volts under load. So, if the pack is at 48 volts at idle, I may pull it down to 44 volts under hard accelleration. But, normally not even that far. Lipos rock in that respect.

I plan to run a very similar pack in my mountain bike. That bike is a Mountain Cycle Tremor Freeride bike. It is very light, though not a true downhill bike. It is not quite as rugged as a full-on downhill bike. That makes it perfect for my needs. I will probably run the drive in front of the main frame spar driving a large chainring with FW cranks. I may even go so far as to polish the frame. We shall see.

CNC's motors are 8 pole. As such, they are not restricted to voltage nearly as much as the Plettenberg (at the cost of some very low RPM tractability and smoothness).

Honestly, for most riding, I very rarely see more than 3kw unless I am really pushing my recumbent hard. With a geared bike (using the cassette), this is far lower. If geared for 15 to 18mph top speed in first gear, the bike would instantly snap wheelie with even 1500 watts. Only if left in high gear and accellerated hard would the motor pull many kw.

My biggest worry is my rear wheel and spokes with that much pull. I may have to go with a more beefy wheel and hub. I am currently running a 24 spoke, small flange hub setup on that bike. I think a 36 spoke wheel with alrge flange hub may be in order.

Matt

 

[deecanio]

sounds about right to me on the hub matt, im having 36h dh/freeride hub, also i'll be having my torque arms on there again just to make sure the wheel stays put!!
I dont know what type of dropouts the tremor has but i've gone with a solid 10mm axel with my hub to take the pounding, witha decent hub and some arms if needed i think we'll be fine.

 

[GGoodrum]

Hey Gary,

I will be going with right side drive so I can use the cassette. The mountain bike will use a double chain drive, freewheel crank setup very much like the bike in your Avatar. The drive will be in front of the main frame spar just in front of the cranks. I will try to get away with a single stage drive because I have essentially two additional stages in the drive to crank and crank to wheel. But, if I have to, I will go with a two stage reduction (only if I have to). I will either use the 60 series or my Pletti (not sure yet). The pletti is 200KV. The 60 series will be roughly 150kv (if I am remembering right).

The goal of the mountain bike is to be very durable, and very versatile. I want to be able to ride it like a light weight dirtbike, or cruise around town, or some "Urban Assault" curb jumping and overall juvenile fun.

Oh, great wheelies are a MUST!!

Also, I want this thing to be rolling artwork. I refuse to build something that does not look the part.

Overall, I guess you could say I am looking to upstage the Optibike by a wide margin for a LOT less money. I like the Optibike concept, (it is the ultimate production E-bike) but for that kind of money, I think we could do better on our own (power, speed, looks). :wink:

Matt

I think this is a great plan, I would think you wouldn't need a 2nd stage either, especially if you go with the 60 series motor, which has a kV similar to my Hacker. With it I'm planning to use the 6:1 belt reduction, and then a 12T trials cog driving a 53T Sugino 110 BCD sprocket that will bolt to the modified "Big Cheese" adapter/ENO 22T FW combo. This is a total reduction of 26.5:1, to the crank.

The Optibike is pretty, for sure, but way too underpowered for my tastes. I agree, we can do better. More power, more speed and look great.

 

[skydog]

Matt:
I was looking specifically for a Mountain Cycle myself, first a San Andreas then a 9.5 . A friend of mine used to build them and I was very impressed but had difficulty locating the right used one. So I opted for an Intense M1 from EBay. Never having a DH bike before I was thoroughly impressed but it is as much or more motorcycle as it is a bicycle. My original design thoughts revolved around the Mountain Cycle, so now I'm kind of at ground zero.

I'm looking for suggestions. My head is swimming with variations and having trouble dialing it in.
The M1 is about 40lbs. with a very rugged 24" rear wheel. I would like to do a fair amount of high speed peddling, mostly road but not entirely. But since this is a real clunker, I think it'll be assisted through all the peddling. I'm thinking of locating the batteries in a backpack. I would like it to be both quick and fast, maybe 40 MPH. And I would like to retain both disc brakes. There is no F. Derailleur. I will be looking to put a large chainring on.

I am open to all input regarding motor location, motor size or types, Batts, gearing, and dual or single jackshafts, etc. I would prefer a single because I think size/location is going to be an issue.

Is anyone here considering a left side sprocket attached to the spokes? I'm not wild about it but it seems the gas bikes use them. Just one more variation to confuse things. And actually I would prefer to run it through the existing drive chain.

All thoughts are greatly appreciated.

Cheers,
Rob

 

[recumpence]

I agree your bike is more motorcycle than bike.

I would say 40mph will require a good 1500 watts minimum. So, you really should look for at least 2kw.

You can drive the left side if you want. But, spoke drive makes freewheeling for the motor much more difficult.

The drive unit mounts are in the CNC right now being cut and tapped. I should have them in hand to show pics of by Monday (maybe tomorrow).

All that is left is machining some pulleys and FW adaptors.

Matt

 

[johnrobholmes]

I have found a place to make 25c/50c packs in the 5ah capacity. They are cheaper than MA cells by far, but not quite as cheap as the hobbycity packs. The quality is very high though. If you still need a source for cells Matt (or anybody else for that matter), just contact me and we can see what we can do. 12s lipo would be the perfect compliment to the drive unit.

 

[recumpence]

What would a 12S 5ah pack cost?

Matt

 

[safe]

I would say 40mph will require a good 1500 watts minimum.

My old bike peaks at 1300 watts and I'm getting top speeds in the 45 mph range while in a tight tuck.

The future bikes I'm building will be closer to 1000 watts peak (in order to be federally legal) but the nice thing about this RC motor concept is that you can use a motor that is designed for 3000 watts peak and just limit it to 1000 watts. Or not, just let the motor run at full power. (60 mph with good aerodynamics?)

It would be a lot of fun to swap out my existing motor with one of these.

Be sure to post photo's of the full deal once you have it together.

 

[GGoodrum]

Personally, I think you guys are nuts for using LiCo-based RC packs, given their volativity, especially without at least using a cell-level LVC circuit, but whatever. Lighter? Yes. Weigh less and take up less space? Again, yes, but I'm sure both of you have had experiences where a pack either caught fire on a plane/heli, or during charging. I don't know anybody with a long history in RC electrics who hasn't. What we've learned from these experiences is to respect the explosive tendancies of these cells, and use/handle them accordingly. Many here, however, have no experience with these, and so they might not treat them as cautiously as we might. These are not as safe as LiFePO4-based cells, period. I think if their use is promoted here, we should also make sure people understand the very real risk these pose. I personally know three people who have had major parts of the homes burnt to the ground, due to chargers that failed in ways that allowed the cells to spontaneously combust. Ever since then, I have never charged a single LiPo pack anywhere but out in the open, even with direct supervision.

-- Gary

 

[recumpence]

Yup, that rcgroups thread about Fred's garage fire is still running.

I have had one lipo explode in my house.

The issue with Lipos is charging and over discharging. Nearly every accident I have heard of with lipos is related to the Astro 109 charger, including my explosion. The Astro is a voltage variation charger. What is needed for safe lipo charging is a current tapering charger like the Hyperion. I have never heard of any issues with those chargers. I love mine! Also, cell phones, laptops, PDAs, etc, etc, etc, use lipos successfully.

It is all about correct handling and charging. However, I am an expert with Lipo packs. I understand them. For those who don't, stick with safer chemistry.

Matt

 

[eav2k]

I've been lurking for a short while, and like what I read here.

I am thinking about getting a trike, a TerraTrike Cruiser most likely, I like the idea of adding electric boost to it, however long term what I would like to see in a trike is a normal drivetrain to the rear wheel and two motors on the front wheels, (one for each wheel).

I believe this would make for a very simple design, you mount each motor as directly as possible to each front wheel. I would like the output shaft from the electric motor connecting straight to the wheel hub. If there are torque issues then put a gearbox between the electric motors and the front wheels. (Perhaps using a rear wheel with internal hub drive would be possible?) Have both wheels running off one controller if possible.

With the motors at the wheels they won't interfere with pedaling, and if light enough the unsprung weight will not be too great an issue.

I think this actually makes for a simpler design than connecting the electric motor to the rear wheel drivetrain.

 

[GGoodrum]

Yup, that rcgroups thread about Fred's garage fire is still running.

I have had one lipo explode in my house.

The issue with Lipos is charging and over discharging. Nearly every accident I have heard of with lipos is related to the Astro 109 charger, including my explosion. The Astro is a voltage variation charger. What is needed for safe lipo charging is a current tapering charger like the Hyperion. I have never heard of any issues with those chargers. I love mine! Also, cell phones, laptops, PDAs, etc, etc, etc, use lipos successfully.

It is all about correct handling and charging. However, I am an expert with Lipo packs. I understand them. For those who don't, stick with safer chemistry.

Matt

I don't remember what Fred was using, but it wasn't a 109. I have two local friends, who each had their garages burnt to the ground and neither of them were using 109s either. One was using a Schulze and had the wrong cell count entered and the other was using something else (can't remember...), but it simply failed in a way that overcharged the cells. In bothcases, boom!

I had a pack in a Raptor conversion that apparently had some weak cells (remember the whole "gen2" fiasco that TP had? It cost Charlie over $1m to replace all those failed packs...) and when too much load was put on, the pack exploded. I still have a video of that somewhere. The point is that with ebikes, you don't need to use the higher quality, more expensive cells. It is those cheap imports, which may have been made with poor quality control procedures, that really worries me. If air gets into the pouches, they will puff. When that happens, and you put a big load on them, they can, and will explode.

-- Gary