Heinzmann disassembly

[kbarrett]

Might not wish so fast there ....

I have a very pretty, and pretty useless Heinzemann.

It looks like that loose gear I was worried about was too loose.

Power is applied, and everything spins up ... but if there is the slightest amount of torque needed, it just slips and won't go forward.

The motor spins, but the first gear in the train just slips and spins.

So ... I need to talk to heinzemann ... and maybe deardancer3?

I didn't see "as is" on that sale. I've spent a bit of change here getting this beast ready ... for nothing apparently. Any clue about how to fix this?

 

[TylerDurden]

Any clue about how to fix this?

Is it missing a key?

Bust it open again and give us some fodder for speculation.
:?

 

[recumbent]

This is probly your slipping issue.
The ramp-up bearing has a number on it, find out what it is and order one if the gear spins in both directions. It's the one in the hub in the picture I posted, easy to get to.

See the small needle bearing for the shaft? well it's the one around that one, the biggest one.

 

[TylerDurden]

What I noticed was that the small gear attached directly to the coil windings ( the very first gear in the gear train ) also had some play, and would turn with finger pressure..

@Recumbent: How is the gear Barrett is referring-to supposed to be attached... keyed, pressfit, splined... ?

 

[kbarrett]

This is probly your slipping issue.
The ramp-up bearing has a number on it, find out what it is and order one if the gear spins in both directions. It's the one in the hub in the picture I posted, easy to get to.

See the small needle bearing for the shaft? well it's the one around that one, the biggest one.

Which one in the photo is gear that is supposed to spin in one direction? If it is the big one in the picture, it was functioning like a normal freewheel ... it only spun in one direction.

 

[recumbent]

If it is the big one in the picture, it was functioning like a normal freewheel ... it only spun in one direction.

Yes the big one, and aparently it works fine, good.

Tyler Durden hit it on the nose, the gear he is speaking about is supposted to be pressed on, and not spin freely, it is directly attached to the motor spindle. :? i thought it turned the motor with difficulty using fingers. If i remember correctly, i was not able to spin it at all with finger pressure.
It's possible the gear "spun",or slipped on the shaft, It's only natural that the gear is supposed to be fixed to the drive spindle.

 

[kbarrett]

So ... the big question is how is it fixed?

Pressed, keyed, what?

If it is press fit, I have a 20 ton hydraulic press.

I emailed some folks at heinzmann. We'll see.

 

[recumbent]

question: Is this gear supposed to be kinda loose? It turns with only a bit of resistance if the coils are prevented from rotating.

This is the problem gear & spindle we speak of. Kbarrett mentioned it a couple times when he was cleaning-up the interior bits, because he felt it wasn't proper, right from the beginning.

 

[tno]

you'll probably have to source the gear yourself.
LEVT is the USA Heinzmann service center and they said they couldn't get parts for my old motor.
the freewheel bearing on the big gear attached to the hub was $142 for a German made part. The Chinese made counterpart was $10 but you have to pay high shipping cost.

 

[recumbent]

I know how to fix it, remove the offending gear, bore inside diameter, resleeve gear then press fit onto spindle.

The best way to press fit small items like this is to freeze the sleeve with Co2 fire extinguisher and it will drop right into gear bore. Similarily you then would heat the two pieces afterwards, (sleeve & gear together) and drop onto spindle, and voila, your ready to hit the road.

You might be able to find an existing bearing type sleeve, already on the market like lawn mower/chainsaw parts, then bore gear to accomodate sleeve, then bore the pressed in sleeve to make interference fit onto the spindle shaft.

I hope this all makes sense. You can do all this work on a small lathe, size-on-size will already be an interference fit.

Good luck, will cost you less than $50 if you find a willing machinist.

 

[TylerDurden]

Ja, I wuz thinkin: just sweat a thin coating of bronze to the bore of the gear and press the sucker back on. It probably only needs .001" reduction in diameter.

:?

 

[fechter]

Get it really clean and stick it on with blue Loctite. That stuff is amazingly strong. Not much lost if it does not work.

 

[kbarrett]

It ain't the free wheel that's broken ... it's on the other side of the drivetrain.

I'll get a bit of dry ice, and see if I can shrink the gear shaft enough to get it off without damage.

Looks like I am going to miss that e-vent in PDX today ... I get to tear my bent down, again, and put the c'lyte back on.

 

[lawsonuw]

Get it really clean and stick it on with blue Loctite. That stuff is amazingly strong. Not much lost if it does not work.

For gluing gears to shafts I prefer to use glue designed for the job. Loctite 603 "retaining compound" or one of it's relatives will be far stronger. A nice tight and clean glue joint will take some pretty massive torque. (McMaster #91458A34, worth every penny. won't go bad on the shelf either)

Marty

P.S. Loctite 603 is pretty thin, it might be able to wick into the loose joint and lock it down.

 

[RB Cats]

I remember a posting on the Le Lococa E bike Yahoo discussion group,about bearing slippage on a 36V Heinzman Motor. One of these postings is dated March 11, 2007. According to this posting, there are two concentric rings made of steel that appear to fit together, only by friction. However, there need's to be some type of glue (epoxy) between these two plates. Otherwise the motor will slip when any torque is needed. I'll try a some up the fix it one of postings.

Remove the 6 philips head screws and separate the two parts of the motor. On the side the hub, where the spokes are attached, there is a cog. If this cog slips easily in both directions, then two steel concentric plates are slipping and need to be glued (welded)together. This cog should only turn one way, it should not be bi-directional.

Some one stated in this thread on yahoo that they tried to use some type of epoxy glue, but it would only fix it for about a month. They thought that the epoxy was breaking down due to heat and then the slipping would start again. I suggested using locktight thread sealant (the red colored) type as it can with stand a higer temperature (500 degrees F) However, I never got a reply back to see if they tried it.

I also remember a converstion that I had with a engineer a Tres Terra about trying to up grade my 24 volt E-bike to a 36 volt version. Tres Terra is the company that spun off EV Global. He told me not to go up in power as the early Heinzman hub motor could not handle any additional power and this hub would start to slip.

I hope that helps, if you need additional info I would contact Heinzmann.com or e-lectricwheels.com for them to repair this motor.

RB Cats

 

[TylerDurden]

This is the gear that slips:

 

[kbarrett]

On the side the hub, where the spokes are attached, there is a cog.

Again ... it isn't that cog.

 

[kbarrett]

This is the gear that slips:

Thanx. It looks like someone here can actually read what's there, instead of what they expect to be there.

 

[kbarrett]

I finally got to talk to a human at Heinzmann ...

No spare parts in the US. Basically, you send it back for warranty work, or you get to replace it. No repairs.

The gear is just press fit, and it is not supposed to turn in place ... ever.

He suggested either having it laser welded in place, or pull it and remake the shaft.

He also warned about re-assembly ... apparently one of the plant workers in Pocatello has lost a fingertip to those magnets.

Anyone know a good laser welder in Portland?

 

[csmarr]

As an alternative call a chromer. If the bore/shaft fit is not worn too much you can have the bore of the gear chrome plated, heat it up and shrink it on.

 

[Miles]

For gluing gears to shafts I prefer to use glue designed for the job. Loctite 603 "retaining compound" or one of it's relatives will be far stronger. A nice tight and clean glue joint will take some pretty massive torque.
Marty
P.S. Loctite 603 is pretty thin, it might be able to wick into the loose joint and lock it down.

+1

Loctite 603 or 638(for joints with more than 0.1mm diametral clearance).

 

[kbarrett]

Attempts to re-press the gear in have failed ... it presses back in fine, but the secondI put it back on the bike, it just spins out again.

I don't think glue is going to work here ... that shaft takes an awful lot of torque.

It is starting to look like toast to me.

 

[Miles]

I wouldn't be too disparaging about "glue"

 

[lawsonuw]

I wouldn't be too disparaging about "glue"

Agreed! stuff is quite strong.

How large is the slipping press fit? I'll assume it's the gear that's slipping, not the rotor of the motor. From the picture I'd estimate ~1/2 inch diameter shaft and a 1/2 inch wide gear. Loctite 603's data sheet says it can reach 4,000psi shear strength in a steel-steel joint. I'll assume your joint is good to 1000psi to be safe.

First how big is the glue joint? Width * Diameter * pi = 0.7854 in^2
how much torque is that? (Diameter / 2) * 0.7854 * 1000 = 196.4 in-lb

I rather doubt that the heinzmann motor can even generate that much torque at stall!

Marty

 

[recumbent]

As an alternative call a chromer. If the bore/shaft fit is not worn too much you can have the bore of the gear chrome plated, heat it up and shrink it on.

You would have to get an anode the size of a piece of wire to fit inside that small a gear, but it would definately work.

I used to do chrome plating for 5 years and you will get about .003" buildup per hour with something this small, so you got to watch it closely, .0015 is probly enough.

edit: for timing mistake.