Mid-mount monster motor???

[Hugh-Jassman]

Thinking about how to make a good hill climbing motor for at least 450lbs (total combined weight) on a 9% grade at about 13 to 15 mph, with a long-tail cargo bike, got me to thinking about trying an axial flux motor as a mid mount motor mod, with a large reduction to the drive wheel.

I can't get the people at the BionX to even admit that the D500 is an axial flux motor. Does anyone know if it is?? They don't make this in 750 watts do they?

Maybe I should be looking for an asymmetrically wound motor, not that any of this exists except as an experimental over priced machine. Maybe there is a DIY motor kit?

Well a simple brushless 750watt motor is not the worst thing to use. If it were not controlled to our states limit of 900-1000w. 1200 to 1500watts maximum for a few minutes, would be ideal.

But what direct drive hub motors would be slow enough to work with a doable reduction for a 24”-26” diameter tire, and still be powerful enough?

Low rpm winding motor, like a mac 12t, but with out the planetary gears?
http://em3ev.com/store/index.php?route=product/product&product_id=107

12 turn low speed extra torque motor - 200rpm loaded at 36V ??
or should I be looking for a differnet kind of motor altogether?





http://www.appliancedesign.com/articles/89485-motors-motor-control-asymmetric-lamination

 

[silence]

I can't get the people at the BionX to even admit that the D500 is an axial flux motor. Does anyone know if it is??

I don't know, but from the images I've found it looks more like the motor on your avatar - radial flux with high pole/teeth count.
https://ohmcycles.com/wp-content/uploads/2016/06/D-series-motor-1.jpg

 

[nutnspecial]

Well a simple brushless 750watt motor is not the worst thing to use. If it were not controlled to our states limit of 900-1000w. 1200 to 1500watts maximum for a few minutes, would be ideal.

But what direct drive hub motors would be slow enough to work with a doable reduction for a 24”-26” diameter tire, and still be powerful enough?

If buying a motor, I wouldn't buy a hub for mid mount due to cooling/size/mounting limitations.

Hugh, have you looked into the gng, bigblock, or bht motors? While I think the heaviest small ev's of the east use a transmission on them like the cyclone kit does for bikes, the dd ~10lb motor that is typical can be used with a single chain reduction and can handle alot of wattage. Geared down appropriately they are a great workhorse in a small formfactor that's more friendly to mount on/in the frame.

 

[Hugh-Jassman]

is this the one? https://endless-sphere.com/forums/viewtopic.php?f=2&t=51104

The image doesn't quite do it justice-- I remember hearing that the design has magnets on the outer edge as well. FWIW, out of dozens of commercially available ebikes the Ohm is my favorite. I want to see more about that motor though... hope you guys dig something up because they wouldn't let me crack one open

 

[Hugh-Jassman]

I like the astro flight motors the best with a Davinci drive, but that will run up to $1000 just for the motor and gear reduction.

Even the Lighning rods kit can be more expinsive. And I would need to do some custom gear reductions.

Actualy the only resaon I can think of for doing a large hub motor is it maybe a bit cheaper. although it may need vintilation, as you said. But are there any 12 turn motors (or slow windings) in a motor that would be better for the situaltion that is not a fast high price machine?

I was thinking about the GNG motor and custom redution but it would be nice to not have to deal with much reduction. A slow winding wiht lots of copper would help with slow speed hill climbing, but what other options are there? Ultimatley it boils down to the money factor.

looks like the BHT bikes use hub motors...

Well a simple brushless 750watt motor is not the worst thing to use. If it were not controlled to our states limit of 900-1000w. 1200 to 1500watts maximum for a few minutes, would be ideal.

But what direct drive hub motors would be slow enough to work with a doable reduction for a 24”-26” diameter tire, and still be powerful enough?

If buying a motor, I wouldn't buy a hub for mid mount due to cooling/size/mounting limitations.

Hugh, have you looked into the gng, bigblock, or bht motors? While I think the heaviest small ev's of the east use a transmission on them like the cyclone kit does for bikes, the dd ~10lb motor that is typical can be used with a single chain reduction and can handle alot of wattage. Geared down appropriately they are a great workhorse in a small formfactor that's more friendly to mount on/in the frame.

 

[nutnspecial]

The 'bht' I'm referring to is the one I use on my build. ~30kv

Skeetab and also evolutiongts and LMX also have or are using alternatives.

Skeetab build https://endless-sphere.com/forums/viewtopic.php?f=28&t=59122&hilit=+skeetab&start=100
Big block alt motor https://endless-sphere.com/forums/viewtopic.php?f=28&t=57483&hilit=+skeetab

These are good for single reduction, unlike cyclone or the aeroplane motors. Inexpensive and simple, and better suited for mid than a hubmotor, imo.

 

[Hugh-Jassman]

A cycloidal transmission is what I need. A large reduction in a small space.
So where can I get one for an ebike high speed motor? I suppose they would be difficult to make in the reduction I need (like around 40 to 1 for 13mph with a 19 inch moped tire).

Or maybe I need a variable magnetic gear reducer. That sound like the best if any one could make such a thing.

http://lcamtuf.coredump.cx/cycloid/

[youtube]eX0IpXYDyRU[/youtube]

 

[robocam]

What about the Cyclone 3000? How long do you need it to climb continuously? If the Cyclone 3000 isn't enough, a Cyclone 7500 might work.

Thinking about how to make a good hill climbing motor for at least 450lbs (total combined weight) on a 9% grade at about 13 to 15 mph, with a long-tail cargo bike

 

[Hugh-Jassman]

this motor is now out of production and no stock available

https://endless-sphere.com/forums/viewtopic.php?f=28&t=57483&hilit=+skeetab

are these calulations correct? a 9to 1 reduction would give me room for error....

 

[Hugh-Jassman]

Well I asked about the BHT motor that ran at such a reasonable speed. But they said it is not in-production any longer and no stock available. So now I am back to the hub motor idea. Is there a hub motor that runs about 1500rpm at the 1000watts?

 

[Hillhater]

A cycloidal transmission is what I need. A large reduction in a small space.
So where can I get one for an ebike high speed motor? I suppose they would be difficult to make in the reduction I need (like around 40 to 1 for 13mph with a 19 inch moped tire).
]

Check out Bobc's thread..
https://endless-sphere.com/forums/viewtopic.php?f=2&t=75357

 

[macribs]

A cycloidal transmission is what I need. A large reduction in a small space.
So where can I get one for an ebike high speed motor? I suppose they would be difficult to make in the reduction I need (like around 40 to 1 for 13mph with a 19 inch moped tire).

Why don't you have a look a Tangent Drive. It got everything you need, including gearbox and it is small, uses the well proven Astro 32xx motors and is designed and manufactured by ES member Dave. https://endless-sphere.com/forums/viewtopic.php?f=31&t=70098&hilit=+tangent+drive.

You should be able to climb all day long with his setup. Look here at a build thread. https://endless-sphere.com/forums/viewtopic.php?f=28&t=70099&hilit=+tangent+drive

Here is the most high powered build using Tangent Drive cycloidal transmission https://endless-sphere.com/forums/viewtopic.php?f=28&t=76078&hilit=+tangent+drive

 

[Hugh-Jassman]

That looks like what I need. But is it noisy?

 

[macribs]

Well it ain't quiet as a hub motor powered by a sine wave controller if thats what you target.
But according to those who run the tangentdrive noise is not a problem, the sound level is well within acceptable range. On the plus side there is the added safety of sound too. You will be less likely to have pedestrians suddenly roaming out in in front of you.

The best thing is that many ES members has already done tangentdrive testing with various Astro 32xx motors. The motors them selves are well known for their longevity and build quality. All internals can take at least 200 C of heat without demagnetization due to samarium cobolt magnets and hi spec wires. Designed and assembles in the US rather then the typical China motor. The cycloidal drive seems to take a lot of abuse and have even been used even with the most powerful Astro 3220 which for short bursts will do 10+ kw for a few seconds. That few seconds burst of power will take you close to full speed.

I think for your specific build and needs it would be a very nice combination. You can pack whatever weight you need to load and go where ever. If others can ride there you can too even with your heavy load, and you will find that you can ride places others can not because of steepness and low speed which can be traumatic experience for hub motors. Your astro/tangentdrive will purr happily even on steep hills at low speed.

And you can run a 45 v batterypack without sacrificing anything. Which means you get even more range for you money as you can add more parallels.

Btw just after I posted in this thread there was a new post worth reading in the tangent motor thread:

I've just got off a stealth b52 bomber to see if enjoyed the hub drive set up...my full thoughts are here:

https://endless-sphere.com/forums/viewtopic.php?f=3&t=84430&p=1235786#p1235786

But the cliff notes are:

Brilliantly built and solid. Lovely to ride. Suntour gearbox was hard to shift but nice once engaged.

A quiet ride that felt no match for the 3220 powered Tangent. Perhaps it is due to the weight...who knows.

It felt like a very light motorbike with less power. Overall very nice but i feel this mid drive kit is superior in nearly every way and once i figure out a stronger drive chain set up in the higher gears it'll be even further ahead in all possible ways.

Hard to say how good Daves kit is until you've compared it to something of equal power...but at 5 times cheaper and more power/stealth/off road ability...Tangent motors is well ahead of the most expensive "heavyweights".

If you're thinking about buying a Tangent Ascent set up...do it and enjoy the smiles for miles.

 

[Hugh-Jassman]

But what is the reduction percentage?? from 7500rpm to what?

is there only one fixed reduction??

 

[robocam]

https://www.youtube.com/watch?v=j3QewyTer6U

That looks like what I need. But is it noisy?

 

[Ham]

But what is the reduction percentage?? from 7500rpm to what?

is there only one fixed reduction??

The 3210 kit provides a 40:1 reduction at the box plus a 2:1 from motor output to crank (variable by user sprocket choice) for a total of roughly 80:1 reduction to match pedal cadence.

The 3220 kit provides 20:1 reduction at the box plus the same choices from motor output to crank so roughly 40:1 total for Tazmanian Devil pedal cadence....about 200 ish give or take...