5304 axle snapped after 5700 miles

[NeilP]

too bad about the blue, but double check continuity too, wire may be severed or pulled out of the hall.

honeywell SS41 mouser part# 785-SS41

Thanks
for the p/n...bugger though...£12.00 delivery charge

do not think the wire has pulled out, It was all still well secured inside, it had not pulled. I have taken the wiring back to the final junction and tested from there, so it has to be the hall. Looks a right pain to get out.
Seem to remember reading about fitting the halls alternately, one way and the next the other...any info on that?

 

[NeilP]

The arm should be integral to the axle,

How do you mean?

 

[dnmun]

the hall sensors will be keyed to fit the slot in the stator. it will face the hub magnets.

they are a pain of the first order, you gotta dig it out with an older soldering iron to soften the epoxy and dig all the old epoxy out with a pick on top of it so the new one will go back in the slot all the way. i would take extraordinary measures to prove it is dead before removing it because of what a hassle it is. that's why i mentioned continuity.

 

[NeilP]

well if I do one, I'll do all three.
I have taken the wiring all the way back to the last soldered junction, so it has to be the hall


but what I mean is that the sensors can go in two ways, in the slot...writing up or writing down , if you see what i mean, does that make any difference

 

[John in CR]

Yes, but the root radius will also function to wedge the dropout slot apart. It's not just the workmanship that's wrong with flatted-axle hubmotors, it's the whole concept. Interrupted threads strip out easily, abrupt shoulders on the axle create stress risers, and at best you still get a terrible excuse for a torque-transmitting interface. The arm should be integral to the axle, inside the dropout, and anchored to the frame at a distance from the axle center. Heinzmann gets it. The Chinese manufacturers only get that it would cost them an extra buck (even though it could save the end user hundreds).

Agreed. It's so bad that there's no way hubmotors with the normal attachment to the bike could ever be manufactured in the US. It's supporting most of the weight of the vehicle and rider too, plus the torque of the motor. Regarding dropout spreading, wouldn't shaping the inside edge of the dropout to match the shape at the axle cure most of that effect? It wouldn't take much radius to pay good dividends.

All of my motors have significantly larger diameter axles, so I worry less, but I build clamping dropouts on all my bikes, so about the only purpose of the axle nuts is to protect my shins from the sharp threads of the axle. :lol:

I like Farfle's larger diameter pipe as the axle...more strength, less weight, and vastly more space for running big gauge phase wires...and coolant tubes for those who insist on driving a motor into lower overall efficiency by using too small a motor for the job and pushing it into saturation. The only extra cost to do a Farfle axle is the larger bearings required. That's definitely the route I'd go if I needed to replace an axle unless someone comes up with a better easy solution.

John

 

[dnmun]

i only have three left outa this bag of 50. i can sell you one but not all three.

maybe you can buy a bag of 50 to get the price break and supply guys over there from your stash. nonlinearguy is replacing the halls in his mac too so he may go in with you. or someone else over there.

 

[NeilP]

just bought some from Ed Lyen...6 for the cost of just the delivery charge rom Mouser.

I do see that RS Export sell them individually and I know they do not have any delivery charge, so that would have been a bit cheaper, but at least buying from Lyen I guarantee that I am getting the exact correct variant of them

 

[NeilP]

All of my motors have significantly larger diameter axles, so I worry less, but I build clamping dropouts on all my bikes, so about the only purpose of the axle nuts is to protect my shins from the sharp threads of the axle. :lol:

how do you get around the limitation on axle diameter at the freewheel side? or are you running chain free?

 

[Alan B]

The Cromotor has a 16mm threaded axle with 10mm flats. Huge improvement over the Xlyte.

The phase current multiplication at launch with your high starting power is really causing a lot of torque and waste power at launch. If you restricted phase current your new axle from Xlyte would likely last just fine. Just soften the launching a bit.

 

[NeilP]

The Cromotor has a 16mm threaded axle with 10mm flats. Huge improvement over the Xlyte.

still small though...was thinking of 20mm minimum for my new axle

Just soften the launching a bit.

..where is the fun in that ?

 

[NeilP]

You know, lying in bed at 3 in the morning, unable to sleep thinking about this bloody axle, and the thought that I have a 5405 motor on its way that I was planning on gunning at higher power levels......uuuuughhh Oh hell. This spline or not , or Keyway or weld business, plus having to cut out and rebuild the complete frame rear end, fabricate disk brake calliper and derailleur mounts, torque clamping assembly for this bike, the 5405,,,, plus the kick scooter project I started , just makes me want to get rid of the lot, including the 2 hobby king orders that I just order for more LiPo, the halls from ed Lyen, stuff from Kenny, all these parcels on their way..,
And I still have a Harley, a Landrover and a tractor as unfinished projects, that all stopped for one resonance or another, ...., anyone want to buy a complete life..... Job, house, farm, workshop. 5 or 6 unfinished projects. £ 1 million and it is yours.,. I want to go live on a beach with sun, women, beer and a fishing rod

 

[MadRhino]

Ha Ha

What about a trade
I got the beach and fishing rods, plus 3 ex wives, 7 kids, 19 horses and a dozen unfinished projects

 

[neptronix]

Neil, i have been there about 3 times with the eBike stuff. Totally normal

 

[NeilP]

That trade could work out, I got horses here too, and live 50 yards from the beach. Can you fly? As you would need to take over my Mecivac flights too. I'll send you my bank details and as soon as you wire me the money, it is all yours


I just keep starting new things while waiting for parts for other jobs. The tractor restoration is something not touched in 6 years, the Harley in bits 2 years now, Landrovers,,? 3 years. F/box just waiting to go back in. Two other new jobs appeared yesterday, weld up cracks in the tractor mounted paddock mower, and fit new roof to spit roast machine.... It just never ends

 

[SamTexas]

The tractor restoration is something not touched in 6 years, the Harley in bits 2 years now, Landrovers,,? 3 years.

Wait a minute. The above 3 are NOT tasks that you have to do. They are your hobbies, correct? Your ebike is also your hobby, not a necessity either, I assume. So your life can't be that bad with that many things to PLAY with, can it?

 

[NeilP]

Can't play with them if they are in bits.

 

[SamTexas]

Ah... Different states of mind. For me, restoring or fixing my toys is fun play time. In fact I think I had more fun building, fixing them than actual using them.

 

[MadRhino]

I can fly. One of the unfinished project is a Wankel motor sleeping in the barn for 5 years.
Look like we have very similar lives, and the trade would be mostly climatic.
You could have a taste of our -30

 

[NeilP]

No, not for me That sort of work for me was a job at one time, and I only do it because I have to if I want to keep them, I could not afford them if I had to pay the maintenance costs. I started on e bikes because I lost driving licence, so needed transport to get to work, and that ment fixing transport that needed driving license took a back seat. Got driving licence back last week, and this week the axle on e bike snaps. Maybe fate is telling me to give up on e bikes before I kill myself. Broken two fingers, cut head above the eye and had a few lucky escapes including this axle failure. Maybe I should go back to 4 wheels..... Or electrify the Landrovers....umm now how many pouch cells can a Landrovers rear load bed take ?

 

[NeilP]

I can fly. One of the unfinished project is a Wankel motor sleeping in the barn for 5 years.
Look like we have very similar lives, and the trade would be mostly climatic.
You could have a taste of our -30

I like the sound of a bit of real cold and snow etc. here it just seems permanently damp and raining. Rarely goes below freezing, and rarely above 22, but always damp

 

[SamTexas]

Wow. That's rough. Sorry to hear about that. I hope things will get better for you and soon.

 

[mvly]

I hope my HS3548 doesn't meet the same fate like that. It can be dangerous for the axle to break at 30mph+

How would one go about checking for such thing? I mean I can check my torque arm, wires, and other part, but the axle is hidden between the motor casing and the dropout.

Man just when I thought I had the most reliable build...

 

[Chalo]

The arm should be integral to the axle,

How do you mean?

I mean functionally the same as the proven torque arm design used on coaster brake hubs:

Heinzmann's hubs have a torque arm more or less like that, with a conduit that protects the motor leads:

My X5305 came with a torque arm that looked similar with its cable conduit, but it was so soft, crappy, and loose-fitting on the axle flats that I never bothered to try using it.

Note that both the hubs above have round axles with intact threads.

Chalo

 

[NeilP]

Ok, yes, i see what you are getting at.

I have axle design going around in my head at the moment, and just could not see how to easily create an axle that had a torque arm as part of it..a solid machined part , same piece of steel as the axle, machined from the same block of steel, without a lot of machining and wasted steel.

I was thinking the word integral as meaning 'same solid part of' . those pictures you posted have a supplied torque arm as part of the design and they come with the hubr, but in reality they are not a lot different to our own home made torque arms that slip over the flats on the axle. I bet if you take those apart somewhere in there, where the torque arm part fits to the axle, there will be a splined or flat section where the arm 'grabs' the axle.

I suppose if you were mad, you could start with a piece of 6 or 8 inch round bar. and machine most of it down to the major axle diameter.1.5 inch...leaving a 3/8 by 6 inch flange, 2 inch in from the end, with the short end threaded with the axle nut...then make it stepped on the long side of the flange..
The take off the lathe and cut and shape the flange to be torque arm shaped, designed to sit just along and under or inside the rear triangle. Assemble from disk rotor, disk cover, bearing, stator, outer magnet ring hub, second cover... Obviously need bigger bearing on disk cover side, to allow it to slip over the shoulder when the stator locates etc.

Um possible, as a one off design, but a lot of machining and wasted steel...totally and obviously an impractical solution..but still do able if you had the time

 

[Chalo]

I suppose if you were mad, you could start with a piece of 6 or 8 inch round bar. and machine most of it down to the major axle diameter.1.5 inch...leaving a 3/8 by 6 inch flange, 2 inch in from the end, with the short end threaded with the axle nut...then make it stepped on the long side of the flange..
The take off the lathe and cut and shape the flange to be torque arm shaped, designed to sit just along and under or inside the rear triangle.

You could also just weld a torque arm to the axle end, presuming a design in which the axle could be extracted from that side. That would imply a mild interference fit straight spline to the stator, like Profile cranks and their many mechanical clones: