High power RC motor and drive unit production

[northernmike]

Gary, would it fit down low?

Behold the Moby "X" =

 

[GGoodrum]

Okay, I'm getting closer. I've come up with a way to at least provide a solid mount, using a thick aluminum bar attached between the steel rack that I put back on my Mariner, and the seat post. The rack is made from some very strong steel, as it doesn't budge. Anyway, Although not as "pretty" as it could be, it is at least functional, and will let me get closer to getting this thing on the road.

Here's a few shots:

The motor assembly is not mounted to the bar yet, it is just zip-tied on there, at the moment, while I figure out how to mount it permamently. I'm thinking about drilling and tapping some 1/4-20 holes in the bottom of the "foot", as I can find no easy way to do much else.

Anyway, some progress, but still a ways to go.

-- Gary

 

[Miles]

Gary,

Can't you bolt it through the seatstays, directly - above the brake?

 

[MitchJi]

Hi Gary,

I like behind the seat better.

Would it fit upside down underneath the seat-stays and fastened to the seat-stays?

If not if you can figure out a way to mount it on top of the seat-stays, mounted directly to the steat-stays rather than above them on the bar I think that would look better. Maybe you can figure out a way to tie them into the rack mounts.

 

[etard]

Gary it looks great back there with all the shiny aluminum bits. Are you running 1 chain? It looks like you could weld or bolt an idler to the rack. You have got to bring this thing out to the E-ride on Saturday, I would love to see it. How come you can't put the foot on the seatpost? maybe you could use an aluminum tube like a sleeve over the seatpost, get sleeve welded to foot and then drill and tap holes for proper tension and alignment. Then run a flat bar from those rack eyelet mounts on the frame to the holes on the side of the foot. Might cost $20 to weld the sleeve to the foot.

 

[GGoodrum]

There's no real way to bolt this to anything, including the seat stays. Like I said, I have zero access/experience to welding, and don't have any sort of local "shop" that does that kind of work, so from the beginning, any sort of solution that involves welding is a non-starter. I tried a couple of different ideas on attaching a plat to the top of the triangular frame section, but two problems, one it is curved, and two, there are two threaded pieces welded to the top that are used for the front rack supports. The other problem is that the brake sort of "floats", and it interferes with the big pulley. I also tried the area under the chain stays, but there's not enough room. The motor is too big in diameter.

I also really wanted to make use of this rack, as it is more stable for holding the battey pack. The seatpost-mounted racks just won't keep from moving around, if the bike is leaned over, no matter how tight the clamps are. This would probably be an issue with the assembly mounted to the seatpost, but you could probably add some sort of setscrew to stop any rotation. The biggest problem for me with a seatpost mount is that I'd have to go back to the "winged foot" approach, which looks too ghetto to me, and not in a "good" way. Anyway, using the rack adds additional clearance issues with having the pulley lower, but depending on how much adjustment is needed for chain tensioning, it could work with the assembly back a bit more, towards the rack. For now, I want as much flexibility and adjustability as possible.

This will definitely be a two-chain setup, with the drive's output shaft driving the large of two front chainrings. I'm going to remove the current Cyclone crank, and replace it with my IPS crankset that has a 53T chainring for the motor/drive, and a 40T chainring to drive the rear Nexus-3 hub. I replaced the stock, "el cheapo" freewheel inside the IPS crank with a 16T ENO. I'm also going to re-use the chain guide/tensioner form the Cyclone setup. I can add it to the area on top of the seatstays somewhere.

Initially, at least, I plan on using this with my 63V/200A PowerJazz ESC, simply because I know it can handle a 16s a123 pack, fresh off the charger. I still need to test whether or not the CC HV series will blow with this pack. One nice thing about the big bar I'm using is that the underside will make a good location to mount the controller, the throttle board and an EagleTree eLogger.

Tonight I'm going to try and figure out how to "adapt" the foot so that it can be secured to the bar. Like I said, I think the easiest way, at this point, is to drill and tap four 1/4-20 or M6 holes on the bottom of the foot, and then add four matching slots in the bar. That will allow the whole assembly to slide front-to-back enough to tighten the chain.

-- Gary

 

[liveforphysics]

Looking good Gary, your projects always look great!

If you get a cheapy harbor freight hand grinder, and a bench vise, hacksaw, and a good smithing hammer, you can fashion pretty much whatever pieces you may need. Not quickly, but none the less you can have great pieces.
I would like to offer you free welding up of any parts you mail me, and I will mail it back free too! So, if you happen to see some part in a project where you fashion a couple pieces of steel, aluminum, bronze, copper or even titanium, and mail them with an explicit diagram with good measurement points and things, I will happily weld them for you and send it back to you.

I think the way you are doing this project might work out just fine, or it may have a little too much flex that could cause the chain to hop. It's really something you just need to try out and see. But if you happen to find yourself ever thinking it would be slick to have some pieces of metal joined together, I will happily help out however I can.

Best Wishes,
-Luke

 

[Ypedal]

Looks great G !

The more i stare at this thing.. the more i think my 2 stage will make life easier on the mounting front.. having the pivot point for the 2nd stage adjustable ... i could also be wrong and end up in the same boat but that's part of the fun.. :lol:

My IPS cransk are somewhere between Japan and here.. my rims arrived a few days ago for the NuVinci.. i am ordering spokes from ebikes.ca this week and the motor from Astro is built and paid for.. it's +6 celcius outside and snow is melting.. i have the fever... Hepititis-E or somethin serious...

 

[recumpence]

Y,

I got some joy today! I pretty little box arrived from Astro Flight.

Not only that, I got a UPS notification that my custom motors are on their way.

On top of that, it looks like Fetcher is having success on his throttle/current limiter.

Life is goooood!

Matt

 

[sockman]

hi matt, is there any way to check my shipment? eg tracking number or ETA singapore?
i'll be leaving for melbourne F1 (working there...will get to "touch" KERS)
need to get someone to take note of my parcel when i'm not around..

cheers,
russ

 

[MitchJi]

Hi Gary,

Would something similar to this work?:

One set of cross-bars bolted to the bottom of a plate mounted above your seat-stays with another pair beneath the seat-stays? The cross-bars fastened to the bottom of the plate could be very thick or even doubled or tripled in back to raise the rear of the plate.

Groves in the cross-bars where they contact the seat-stays would be a big improvement. Clamping two together and drilling at the joint might be a good way to make the groves.



I wanted to find a way to purchase a drive set up like D's, with a FW in the large pulley, without inconveniencing Matt. I also thought more than 90t might be useful for some installations.

I contacted Pfeifer Industries in Naperville and asked about boring out pulleys for FW's and pulleys larger than 90T and, in case anyone else is interested in either of these topics, this is what I found out.

He said they would bore out an existing pulley for a White FW:

Our hourly rate is $67.17/hr. Figure it will take us about 2 hours to do the job. We would also charge for material used....

Remember, the cost in the set-up of the machines, every time you add quantity, you are dropping your unit cost price.

I asked about pulleys larger than 90T set up for a FW (price is less than boring out an existing pulley):

100 tooth pulley would cost you $114.87, or you could try adapting one of our existing 102 tooth pulleys (closest that we have to 100) to fit your needs

Do you have any other existing pulleys that are larger than 102t?

Yes

How much would your 102T pulley cost bored out to roughly 2.125"?

After seeing the pictures, I wouldn’t do that, we would make you one from scratch. The problem you will run into is keeping everything concentric to the original bore. The only true way to do it is to make soft jaws (for a lathe chuck) and rebore the pulley. It would be cheaper for us to build you a new pulley to exactly the number of teeth you are looking for.

I didn't get a price on a gt than 90T pulley set up for a 1/2" shaft but its bound to be less than a single custom 100t pulley ($114.87) bored out for a White FW.

 

[GGoodrum]

Looking good Gary, your projects always look great!

If you get a cheapy harbor freight hand grinder, and a bench vise, hacksaw, and a good smithing hammer, you can fashion pretty much whatever pieces you may need. Not quickly, but none the less you can have great pieces.
I would like to offer you free welding up of any parts you mail me, and I will mail it back free too! So, if you happen to see some part in a project where you fashion a couple pieces of steel, aluminum, bronze, copper or even titanium, and mail them with an explicit diagram with good measurement points and things, I will happily weld them for you and send it back to you.

I think the way you are doing this project might work out just fine, or it may have a little too much flex that could cause the chain to hop. It's really something you just need to try out and see. But if you happen to find yourself ever thinking it would be slick to have some pieces of metal joined together, I will happily help out however I can.

Best Wishes,
-Luke

Well, I have the bench vise, hacksaw and a dremmel with a cutting wheel, but I'm not sure what a "smithing hammer" is, maybe something they use to use to fashion foot wear for horses? Anyway, thanks for the offer, but what would need welding would be tabs to the frame tube somwhere, to bolt to the sides of the "foot".

I hear you about the possibility of flex, but frankly, I'm not too worried. The rack doesn't look it but it is extremely strong. I tried straightening the curved up pieces on this same rack on my other folding bike, and had no luck. I tried locking it in a vice and trying to use leverage, but nada. I also tried hammering it with a sledge hammer, but not even a dent. Anyway this setup is a lot more rigid than it looks.

-- Gary

 

[GGoodrum]

Mitch, those parts look just like the Cyclone bits I just took off. None would do anything for this setup. How would you bolt the "foot" to these?

I'm actually pretty happy with the current setup, at least until I've had a chance to finally do some testing. I didn't get time to work on this tonight, but I will get back at it tomorrow.

-- Gary

 

[liveforphysics]

This is a Cross-peen hammer, AKA smithing-hammer, AKA smithy, AKA cross-club, AKA blacksmith hammer.

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200375227_200375227

A strong well mounted vise and a hammer like this make a perfect pair for bending and folding metals to make brackets and things. With some patients and elbow grease, you can make a huge range of metal parts with these tools. I'm not saying that you will need to do anything more than what you have planned, and if that rack is super strong, it should work fine. Just incase sometime in the future you happen to need some brackets at a funny angle with some twists and bends and folded tabs and things, the vise and smithy hammer can make you pretty much anything if you are willing to sweat a bit for it.

Best Wishes, and good luck with your great project!

-Luke

 

[MitchJi]

Hi Gary,

Mitch, those parts look just like the Cyclone bits I just took off. None would do anything for this setup. How would you bolt the "foot" to these?

My suggestion was to use cross-bars, above and below the seat-stays to mount a plate on top of the seat-stays. Something similar to the upper Cyclone bars, but with grooves to fit the seat-stays. The plate would be on top, next the top cross-bars, next the seat-stays, and finally the bottom cross-bars. You would bolt the plate to the cross-bars clamping the groves to seat-stays. You would fasten the "foot" to the plate exactly the same way you would fasten it to your existing plate.

The only difference in mounting the foot, or the end result, is the plate would be lower (mounted on the seat-stays instead of the rack).

If its necessary to raise the plate for pulley clearance or could clear the rack mounts you could use more than one cross-bar between the plate and the seat-stays to increase the height of the plate.

I'm actually pretty happy with the current setup, at least until I've had a chance to finally do some testing. I didn't get time to work on this tonight, but I will get back at it tomorrow.

-- Gary

I'm sure its going to be excellent. But if you prefer a lower mount I think its possible to make a very solid mount to the seat-stays without any welding or complex fabrication. If you are interested in how I think you could do that, and still don't follow my poor job of communicating, let me know.

Tonight I'm going to try and figure out how to "adapt" the foot so that it can be secured to the bar. Like I said, I think the easiest way, at this point, is to drill and tap four 1/4-20 or M6 holes on the bottom of the foot, and then add four matching slots in the bar. That will allow the whole assembly to slide front-to-back enough to tighten the chain.

The L-shaped stock you called wings might look OK if you used the holes originally intended for U-bolts to bolt to the flat-plate. Bolted to a plate they wouldn't look like wings hanging out from the top-tube.

 

[GGoodrum]

Yes, I see what you are talking about, re: the Cyclone bits. I can get a plate in there, but the front-to-back movement is somewhat limited in that case, mainly due to interference between the pulley and the rack. I need to see how much play I really need in order to tension the chain, which I can do with the current bar approach. If it is not much, I can move the permanent installation lower.

Yes, the "wings" look less odd when on a plate.

-- Gary

 

[Miles]

Yes, the "wings" look less odd when on a plate.

Yes, that has to be the punchline of a joke about turkeys, but I haven't found the rest, yet...

 

[oofnik]

So...
Any updates on those clamps? This is pretty much the last major mechanical bit left for me and I'd really like to have something functional in the near future.

 

[recumpence]

I have a finalized design. But, they are still going to cost me $90 per set ($10 materials and $80 machining) because there are 4 parts for two complete clamps with mumtiple operations each..........

I can have them manufactured, but I need to know there is a market for these and there are a number of different frame tubes to contend with.

I need to have a minimum numbe of them made to get them in production (probably about $800 worth).

I would hate to make them and be stuck with many of them, etierh because the drives are already mounted, or because the bore is wrong.

Matt

 

[revkev6]

recumpance,

first post here, I read about your electric recombant on recombants.com and followed the link here. I was looking at a larger, cheaper RC motor to use in this application. it lists for 149.95 USD.
I originally started looking to do a velomobile-esque 3 wheel trike for registered daily type use. I was trying to look for an ESC that had reverse as well. after thinking things through for a while, and driving on the New England roads we have this spring I decided that it probably wasn't a smart idea! I figured I would post up the info I did find so it may help others. this site also has some ESC's that might work as well, but from what I've read they generally are not as reliable as the castle creations units

HXT 80-100-B 130Kv Brushless Outrunner
Model: HXT80-100-B
Wire Turns: 8
Resistance: 32ohm
Idle Current: 2A
ESC Required: 130A
Input Voltage : max. 48V
Kv : 130 rpm/V
Weight: 1570g
Shaft: 12mm
Voltage Range: 20-48v
Non Load Current: 2.0A
Maximum Power: 6500W
Equivalent: 60-80cc Gas Engine

 

[oofnik]

Revkev,
Welcome to E-S. If you do a quick search you'll see that several people have expressed interest in the HXT motors, including the 80-100.
I can't speak for their quality myself but it seems that people are generally satisfied with them.

As for the ESCs, I too debated whether to go with the cheaper Turnigy/ Hextronik ESCs or the more expensive Castle Creations ones. I decided to go for the latter option because of the extensive programmability the CC controllers offer. I've never compared ESCs in person but I can say that the Castle controller is very high quality - you get what you pay for.

 

[oofnik]

I would hate to make them and be stuck with many of them, etierh because the drives are already mounted, or because the bore is wrong.

Matt

I hear you. $90? Really?

Maybe I'm just blind/deaf to cheaper and simpler mounting options but the idea of these clamps really interest me.

Perhaps when I come visit you next time I'll bring my frame with me and we'll figure something out together.

 

[recumpence]

I would hate to make them and be stuck with many of them, etierh because the drives are already mounted, or because the bore is wrong.

Matt

I hear you. $90? Really?

Maybe I'm just blind/deaf to cheaper and simpler mounting options but the idea of these clamps really interest me.

Perhaps when I come visit you next time I'll bring my frame with me and we'll figure something out together.

If you catch me at the right time, I would be fine with that.

We could also catch some lunch. I know this great sub place.............. :wink:

Matt

 

[MitchJi]

Hi Rev,

recumpance,

first post here, I read about your electric recombant on recombants.com and followed the link here. I was looking at a larger, cheaper RC motor to use in this application. it lists for 149.95 USD.

Quality leaves something to be desired. Probably excellent if you replace the bearings, snap-ring and shaft and rewind the motor.
http://endless-sphere.com/forums/viewtopic.php?f=28&t=9279


http://endless-sphere.com/forums/viewtopic.php?f=28&t=8347#p126155

This is to swap out the cheapy bearings, and swap in the class 7 bearings I ordered today. They were $55/bearing for the class 7 precision bearings! Each motor uses 3.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=8347&start=15#p126433

So, working with the motors today, I decided that the metal used for the shafts is not really as strong as I would like. It seems to be mild-steel.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=8347&start=195#p138606

All ready re-epoxied the magnets long ago. I also put a drop of high-temp epoxy in the center of each set of the copper fill to ensure the windings don't decide to wiggle out into the rotor magnets.

In this motor, each magnet sits in a neat little machined recess, so it's nice that they have more mechanical support than many of the china motors.

So far, in these motors, the bearings are crap, the shaft is crap steel, and the snap-ring is fashioned from modeling clay. By the time you spend $200 to upgrade these pieces on the $130 motor, you are double wishing that CNCguy would hurry up and release his uber-motors that are all high quality with massively oversize bearings.

 

[MitchJi]

Hi,

I have a finalized design. But, they are still going to cost me $90 per set ($10 materials and $80 machining) because there are 4 parts for two complete clamps with mumtiple operations each..........

I can have them manufactured, but I need to know there is a market for these and there are a number of different frame tubes to contend with.

I need to have a minimum number of them made to get them in production (probably about $800 worth).

I would hate to make them and be stuck with many of them, etierh because the drives are already mounted, or because the bore is wrong.

Matt

Could you make very simple solid clamps and bore the holes to order? Maybe just some flat bar stock for each half of the clamp. Bolt them together and bore the hole.

Instead of using clamps with round holes, if each half of the clamp had a V-shaped groove they would have less purchase on the tube but would fit a wider range of tube sizes. If the bottom of the foot had a V-shaped groove it would serve as half of the mount (reducing the parts count and complexity).


Are band clamps (which would work with frame tubes of any shape or size) strong enough to fasten a mount to a frame?

Something like the Wraplock products:
http://www.wraplockclamps.com/

Or the Band-it products:
http://www.band-it-idex.com/products/products_bandit.html

The Flair Leg BRACK-IT design provides a secure fit that locks each leg in
place on round poles or mast arms of almost every diameter.

If they are strong enough one possibility would be for Gary's Dahons. A flat plate with slots for the band clamps, which would clamp the plate to the non-round tubes. I'd use two bands on each side.