Mark_A_W's DH Team/MAC Shanghai/64v Headway build

[Hyena]

Mine was just under 1.6kW (26.4Amax @ 59.8Vmin)

That's a bit more than 48v nominal but its good to know the exact voltages. With all the different chemistries, full pack voltages, sag etc I prefer to know the actual voltage rather than the nominal.

 

[full-throttle]

oops 49.8Vmin

 

[Mark_A_W]

I've seen 1700w on the CA.

I didn't look that closely after our little spin, but Vmin on my way home was 54v and max amps was 35 (I've seen 40, but that's a spike) = 1890w.

Your Vmin is VERY GOOD for for a 48v pack under load, that's 3.1v per cell. That's barely below charged. In fact, um, that's a bit suspicious, I can sag my Headway lower than that almost straight off the charger (need to check).


54v /20 cells = 2.7v per cell. Which is pretty good after 6Ah used, good enough I'm thinking 40A current limit. I won't go below 50v (2.5v per cell), but the cell is "ok" if you stay above 2.1v (42v for me).

 

[Mark_A_W]

Some Youtube vids.



[youtube]26tC5IkhPz0[/youtube]

[youtube]9k2bNc05NoI[/youtube]

[youtube]4SVojEhTi3w[/youtube]

[youtube]zyL-vhPu_Us[/youtube]


I'm behind the camera, not on the bike.



I've been running 40 amps/64v (2000w+) and the acceleration is great.

But, the motor is dying.

I pulled it apart last night, as I am going to fill it with oil.

The posts on the freewheel that carry the gears are working loose.

The bearings in the plastic gears have play - the gears wobble (the metal gear bearing seems fine - it is a different brand).

The metal gear is getting noisier and noiser, and that gear is showing wear (the planet and ring seem fine).

The freewheel is playing up, it doesn't freewheel that freely anymore, but at least it doesn't slip.


I'm going to replace the bearings, and fill the hub 1/3rd full with Mobil 1 0w-40 oil. I've added silicone to the side covers to create a seal. I've punched the ends of the gear posts to tighten them up.

But the freewheel design, with the cantilevered gear posts is flawed. The gears need to be supported on both sides. And the gears need to be helical, not spur.

In case you didn't notice, the noise is unbearable with a metal gear. I think I will end up going back to plastic gears and 20amps.

 

[AussieJester]

Mark you need to delete every thing after and including the '=' sign in
the youtube url so it embeds in the thread. If your unsure
hover your cursor over the youtub button in the text editor and it tells you how to do it..

Now..this is the BMC frock motor correct? your friend has a different model?
reason I ask my mate Matt.P has decided he will be buying a geared frock
intially he was going to get the BMC but now (i forget the name of it)
Hyena you know your supplying it? Is the internal gearing the same
as your BMC Mark? Seems the gears in these are the 'fragile'
element in the motor..? I think it would be worth getting
some gears cut from some better quality material (non metal)
im sure alot of the other ES BMC frock owners would put their hands up for some stronger
better lasting gears?

KiM

 

[Mark_A_W]

Thanks Kim

This is a MAC Shanghai frock motor.

The internals are basically identical to the BMC motor, incestuously so.


But the stock gears are nylon, while BMC have some sort of "composite" gear which is green (glass reinforced maybe).


However, under the load I'm putting through it, the posts the gears mount on are vulnerable. I may get them welded, if it is suitable.

I'm pushing a 500w motor to 2000w.

 

[Mark_A_W]

Mark you need to delete every thing after and including the '=' sign in
the youtube url so it embeds in the thread. If your unsure
hover your cursor over the youtub button in the text editor and it tells you how to do it..

Now..this is the BMC frock motor correct? your friend has a different model?
reason I ask my mate Matt.P has decided he will be buying a geared frock
intially he was going to get the BMC but now (i forget the name of it)
Hyena you know your supplying it? Is the internal gearing the same
as your BMC Mark? Seems the gears in these are the 'fragile'
element in the motor..? I think it would be worth getting
some gears cut from some better quality material (non metal)
im sure alot of the other ES BMC frock owners would put their hands up for some stronger
better lasting gears?

KiM

And yep, I am going to reverse engineer the gear and see if I can get some made. I know a gear manufacturer, and can sort the gear design out.

But I'm afraid it will be expensive, more so that the motor, which cell_man sells for $160 (we got them cheaper in a bulk buy).

I've punched the back of the pins which the gears mount on, and they are solid again...for now. I'd like to get them tig welded, but I'm unsure - the carrier is hardened.

There is a Bafang BPM motor all plastic gears, and amazing torque, which is holding up well at 1300w. One of the Aussie guys may be doing a bulk buy soon. It's axle is too short for my frame

The geared motor design concept is very good, they just need to sort out the reliability/robustness. (And have a look at the bike, where would I put a RC motor? I don't want it running through the pedal chain.)

 

[AussieJester]

Thanks Kim

This is a MAC Shanghai frock motor.

Thats the bugger i couldnt remember the damn name of it.


I shall keep and ear out on how you get on with the gears and let Matt.P know
i'm sure he will be very interested in getting a set also if possible, shall
let him know anywayz...

Cheers

KiM

 

[Hyena]

Interesting Mark, it's certainly audible in the video but you reckon it wasn't loud previously ?
That's a bugger they've worn so quickly, I was hoping they'd take more abuse with the metal gears.

I look forward to seeing how they go oil filled.

 

[Mark_A_W]

Interesting Mark, it's certainly audible in the video but you reckon it wasn't loud previously ?
That's a bugger they've worn so quickly, I was hoping they'd take more abuse with the metal gears.

I look forward to seeing how they go oil filled.

No, maybe I didn't explain well enough.

The sole metal Planet gear is starting to show some signs of wear. The metal Sun and Ring appear fine. The two plastic Planets appear fine.


Things going wrong are:

- The posts the gears mount on were a bit loose.

- The bearings in the plastic planet gears (but not the metal planet, interestingly).

- The freewheel is a bit stiff compared to new. Sometimes when the power is released the gears spin for a while.

- And I forget, the key and keyway which tie the freewheel/gear carrier to the axle was looking a little beat up (mwhahahaha).


Oil will help with the metal planet wear, bearings, and maybe the freewheel, but not the posts.

 

[Mark_A_W]

Here are some pictures of the motor, it may make more sense.

 

[Mark_A_W]

Ok, some more corrections/observations.


I've just filled the hub with 150ml of Mobil 1 0w-40 oil. I'm not sure if that's enough, it's very hard to guess as the hub is quite full of "stuff".


- I left the bearings in the plastic plant gears be. They have a bit of angular wobble, but they run smoothly. And now they have oil.

- I repunched the back of the gear pins again, now they are solid...for a while..

- The metal planet gear was quite badly worn. I turned it over, so the load will be on the other, unworn, side. It's much softer than the other metal gears, thankfully.


I'll reassemble the bike and give it a spin tomorrow. I don't think it will be much quieter.



Mark

 

[full-throttle]

Who would have thought that the metal gear would wear the most. Think Kim wrote somewhere about running steel gears for 50-100km and then get them hardened.

Well, guess this is why we review all these things on the forum - so the others can read and hopefully not make the same mistake (just beware of the sales guy BS). If there will be a ES Guinea Pig Award in the future - I'll nominate you! For now I'll try to get you another freewheel and I've got 3 more steel gears in case you want them.

 

[Mark_A_W]

I dunno if I'd want to harden the easily removable gear...

It's impossible to remove either the sun or ring gear.

But I might take you up on a new metal gear, if the oil experiment looks (well, sounds) promising.


I put my old motor and some spokes on your desk, dunno if the spokes are the right size. The motor needs heatshrink over the damaged bit at the axle.

 

[AussieJester]

Think Kim wrote somewhere about running steel gears for 50-100km and then get them hardened.

I did yes, this was a method used in 1/8th RC buggies i used to race, once the steel gears were 'worn' in nicely we had them hardened lasted the life of the box.

I had a thought about the plastic gears to Mark, i recall back when i was flying RC choppers one of the members was making heavy duty gears but i dont recal from what material, they were not metal though and were MUCH stronger than the stock gears, perhaps Mr Recumpence SiR would be the man to ask about this seeing his custom rc heli expertise. I initially thought maybe Delerin but i dunno if this is hard enough? could always go carbon fibre? Luke has offered members free cnc milling if you pay freight material cost and send him the g-code of what you wish cut...might be an option to think about anywayz...

Best of luck..

KiM

 

[Mark_A_W]

Delrin is Acetal, which is a good plastic, but not good enough on it's own.

At work we have used Cloth-reinforced Bakelite when plastic gears weren't up to the task. We never run metal-metal gears at work due to the noise (but we run all gears dry). Typically we use belts and pulleys for power transfer.



Ok, some initial results:

- Filled with ~300ml of oil (didn't think 150ml was enough).

- Motor is a touch quieter. Sounds "righter" instead of completely "wrong". But it's still very loud at speed.

- 300mls is too much I think. It's coming out the wire hole, so it's above halfway. I need it below the axle to allow for expansion - the oil will expand some due to the heat. I will drain some.

- It's also weeping out the side plate join, despite me creating a silicone gasket. More silicone needed!

 

[AussieJester]

- It's also weeping out the side plate join, despite me creating a silicone gasket. More silicone needed!

Perhaps try something from SuperCheap Autos they have gasket sealants specially designed for this purpose IF the silicone doesn't do the job

KiM

 

[full-throttle]

I put my old motor and some spokes on your desk, dunno if the spokes are the right size. The motor needs heatshrink over the damaged bit at the axle.

Yeah, thanks for that, Mark. Your motor will help with all the controller fixing business.

I EVENTUALLY got the right length spokes from the LBS. Apparently they mixed two kinds in the same box.

This is off topic, but its a good example of what kind of people work there: bikeshop assistant notices my interest in new belt drive Trek, I ask him what is the ratio, he tells me "its different with belt drives". Ok, I think to myself, skip 'technical' questions: "How much are the replacement parts then?" - "200 bucks for the belt and 200 for the back cog, oh and the belt last twice as long as a chain plus we can replace the belt for 300 including labour" was his reply.

 

[Hyena]

I take it despite being very similar to the BMC their composite gears down fit the MACs ?
Take some photos of where you're siliconing it Mark, I may want to copy when I get mine
Hopefully with a bit of oil in there and backing the current off to maybe 30 amps from day 1 will keep it a bit happier ?

 

[full-throttle]

..It's coming out the wire hole.. ..It's also weeping out the side plate join..

Sorry Mark, but I find it funny to imagine - oil squirting out like in Monty Python movies when you stop at the traffic lights.

 

[Mark_A_W]

- It's also weeping out the side plate join, despite me creating a silicone gasket. More silicone needed!

Perhaps try something from SuperCheap Autos they have gasket sealants specially designed for this purpose IF the silicone doesn't do the job

KiM

It's more to do with the fact there's only 6 screws holding the side cover on. There isn't enough pressure at the midpoint between screws.

 

[Mark_A_W]

I put my old motor and some spokes on your desk, dunno if the spokes are the right size. The motor needs heatshrink over the damaged bit at the axle.

Yeah, thanks for that, Mark. Your motor will help with all the controller fixing business.

I EVENTUALLY got the right length spokes from the LBS. Apparently they mixed two kinds in the same box.

This is off topic, but its a good example of what kind of people work there: bikeshop assistant notices my interest in new belt drive Trek, I ask him what is the ratio, he tells me "its different with belt drives". Ok, I think to myself, skip 'technical' questions: "How much are the replacement parts then?" - "200 bucks for the belt and 200 for the back cog, oh and the belt last twice as long as a chain plus we can replace the belt for 300 including labour" was his reply.

$200 for a belt? My arse.

Bike shops are doomed.

 

[Mark_A_W]

I take it despite being very similar to the BMC their composite gears down fit the MACs ?
Take some photos of where you're siliconing it Mark, I may want to copy when I get mine
Hopefully with a bit of oil in there and backing the current off to maybe 30 amps from day 1 will keep it a bit happier ?

I think the BMC gears will fit fine.


The issue is the price: US$45 + $14 shipping for the V2 freewheel and gears, $105 + $14 for the V3 version, which looks identical, but is apparently stronger (I'd love some proof).


I'm going to get a price on local manufacture of a few sets. If not, I'll try BMC gears, but I got to wait a month for V2 gears.


Mark

 

[Mark_A_W]

..It's coming out the wire hole.. ..It's also weeping out the side plate join..

Sorry Mark, but I find it funny to imagine - oil squirting out like in Monty Python movies when you stop at the traffic lights.

I'll make sure I stop next to a wanker in a Maserati.

 

[Mark_A_W]

Ok, more ups and downs.

The battery box is coming along. Looks too much like a petrol tank on the bike, but in of itself it looks good. Black and shiny. Will get a pic up soon.

Haven't sorted the closing of the box yet. Maybe press stud buttons on webbing.



And the oil...

I'm going to drain most of the oil out. The motor can only get to 55kmh no load, instead of between 75 and 80kmh. The no load power is over 500w.

That's 200-300w just to wade through the oil. It's ok for a motor doing below 30kmh, but if you go faster the drag is intolerable.

And I'll fit the plastic gear. It's too noisy.


However, the freewheel is behaving properly again, just needed a little lube job.


Oh, and I think the BMC gears are the solution, or a better compromise if not "the" solution.