Heinzmann disassembly

[rkosiorek]

what material is the gear made of? is it soft enough to machine? how easy does it file compared to a chunk of steel? if you can file it you can cut it. the same goes for the motor shaft.

most small gears are either made from a sintered metal or a tough steel and not hardened or heat treated. if it is sintered you can probably buy a new metal gear for a few dollars. if it is made from metal you can cut you could always cross drill and drive in a roll pin (some people call them shear pins). is the gear wide enough to take one 3/16" diameter? if you drill into the valley between adjoining gear teeth you should be fine.

a shear pin would probably be enough by itself, but if you insist on overkill you could go with using both the Loctite glue and a shear pin.

rick

 

[rkosiorek]

if the gear is sintered and not machinable another solution would be to lightly knurl the output shaft of the motor. knurling does not remove the material it forces the material into raised ridges. that would incease the diameter enough for a press fit.

back it up with a touch of Loctite glue when pressing it into place and you will be good to go.

rick

 

[kbarrett]

I'm not sure how I am going to proceed here.

If I do get stuck with this, I may just sell it as is for a few bucks, and let anyone here experiment with glue or rebuild solutions.

This is rapidly getting past my capabilities, and into machinist land.

 

[kbarrett]

Thanks for the offers, folks.

Tyler bit first, so he has first refusal.

If he chooses not to, I'll post it in the used for sale section.

 

[dnmun]

kris was right, it is loose. i decided to see about some loctite, ended up using a combination of J-B weld and some permabond bearing retainer. gobbed on too much J-B weld, but i wanted it to set up and fill in the space under the gear where it butts down onto the inner part of the shaft bearing, filling the void between the bottom of the gear and the shoulder of the motor shaft, about 1/4 mm depth. the J-B weld wicked up the side of the gear and i spent a lot of time wiping it out with toothpicks, but it is all over the dust cover on the bearing, gonna keep moving it to prevent a bond to the plastic of the dust cover and keep all the J-B weld on the inner part of the bearing. this is permanent, i hope.

post edit: i think the J-B weld was 4x what i needed, i think the magnetization of the iron filings in the epoxy is what caused it suck itself up onto the gear faces, which is how it gets deep into cracks in cast iron to seal fractured blocks and bearing mounts, great stuff. but i think the chemistry of the retainer adhesive also caused it to create strong capillary drive, and it might have been more than enuff by itself. i noticed in the picture how the flash reflected off the curved surface of the permabond which you can see pulling itself all over the surface and the stobe of the flash is concentrated in that dot above the shaft by the curvature of the surface of the film when it set up, and it looks solid, not thin and runny wimpy like it was when it came out of the dropper. good stuff. there was metal gone on the inside which is why i used the JB, but maybe the permabond woulda been adequate. at the bearing shop they had the two different formulations of loctite, 202 (.005" interference) and 638 (.015), the Permabond bearing retainer that i used was not rated in that way but it seemed capable of .015" voids in my estimation.

View attachment 1

 

[rbelisle1]

So, how did the glue and bearing retainer work. My heinzman made a funny noise today and I think it might be trying to spin the same gear. I will need a repair soon and would like to avoid the machine shop if necessary. If the glue didnt work, I was thinking to pin the gear to the motor!!!!!!!

bob in phx

 

[dnmun]

this gear was totally loose, came off in my fingers. if you had a similar problem, there would be no torque. the motor would spin and nothing would come out of it.
kris was right to not expect machine shop to fix it, but i do think the bearing retainer may have been sufficient just 10X the cost of J-B weld, so i used both.
i am fairly confident it is strong enuff because the J-B weld filled in the space under the gear face where it butts up onto the inner bearing shoulder, locking all of that together.
i still do not have this wheel on the road yet, but i am fairly confident that the fix will be permanent, unless heat can cause it to flake off, but i doubt if that will happen.
i think this is the only way to fix it, the gear faces will not ever run smooth if you try to drill through them to put a pin in, and the torque on the gear is not that large because of the reduction through two stages to require a pin.
in this case the gear had fouled and pushed some of the metal off the shaft as it was pressed back on, there was some metal debris under the gear which had spalled off the shaft when the gear had gouged it out as it was pressed back on.
i think that amount of metal removed would have exceeded the interference limit that the loctite was qualified at, so that was why i decided to add the J-B weld, because it is so strong at metal-metal bond and could fill the voids. i just used too much/and then it tried to suck itself up onto the gear faces, which is what i worry about most for durability if it flakes off and gets in the gear and causes more rapid wear.
if you end up with your gear slipping, you just will not move, noise could be something else, maybe something came off the motor or brushes and got into the gears, even worse is if you have to replace the brushes, do that brush replacement 'and then you will be a man, my son'.

lemme know if you need the bearing retainer or even the J-B weld, i can mail them in a jet pak or small box.

 

[rbelisle1]

My gear is not that loose. I think I caught it in time. Last night I took the motor apart and marked the shaft and the gear. I can tell you that the gear is indeed hardened. I went out today and got the "noise" after about 35 minutes of harder then normal running. Lots of stops and starts, holding the breaks etc.. I even stopped a couple of times, just to let the motor heat soak. Well at the end, there was a little motor sound, so I opened the motor up. Sure enough the gear and shaft had moved in relationship to each other. I tried to pull the gear, but I couldnt. I am guessing that heat would do the trick, but I think I am going to leave the gear on and try some machine work. My younger brother has a CNC mill at home. I am thinking that if we cut a fairly deep grove, from the top, into the flat gear face that extends through the shaft, we could then insert a steel crossbar. Then some glue or even pean the shaft edge over the bar should hold it in place. I think maybe around an 1/8 of an inch square cross bar would do the trick. There is a lot of meat to the gear, between the teeth and the shaft. What do you all think... I stole one of the gear pictures above and added (poorly) were I was thinking of adding a cross bar... What do you think... any idea on the depth the cross bar should be??????

 

[dnmun]

if you have not pulled the gear off yet and it is still open, why not just try using the bearing retainer or even crazy glue maybe, but the bearing retainer liquid is very runny and will pull itself into the joint and it will bridge all over the crown of the shaft to the inner part of the face of the gear exposed. i think that will stop any more movement, stop it early, i think kris lost so much metal because the motor was spinning the shaft inside the gear. if you can stop it now, maybe you won't have to do any machining. the bearing retainer won't prevent you from machining later either. too bad you aren't cross town, i paid $21 for the permabond brand of bearing retainer, the loctite was $43 and it is no different in my opinion, because i can see it is very effective, just like the loctite would be.

 

[Affliction]

Why not just cut a keyway into the gear and motor shaft and insert a hardened steel key as the gear is pressed back on?
Same idea as how drive sprockets are attached to small engines.
This would not be a fussy operation and could be accomplished with a dremmel.

 

[dnmun]

why not?

because the bearing retainer adhesive will do it better. i had never used the stuff before, but now it is right up there with epoxy and crazy glue for me. the stuff is as hard as metal almost, and it bonds a huge surface area by being so thin that it wicks into the cracks by some strong capillary action. if you go look at my final picture, the flash is concentrated into a white ball just above the end of the shaft by the curved surface of the bearing retainer that sucked itself from side to side and up on to the edge of the gear, and it is inside the 'interference' section between the gear and shaft too. you can see the slight blue ting of the permabond brand bearing retainer as a smooth surface around the top of the shaft. i think he should try it and see if this stops the problem, i will be glad to mail you my bottle, but call your machinist who works on your engine, (i have a guy who does my heads so i shoulda called him) and see if he has some, and just take the hub and glue it there, just a few drops will do it.

there is no need to machine the shaft, and it is too hard and too small to cut safely, i think it was miles who said this stuff is good, i agree.

 

[Affliction]

why not?

i had never used the stuff before,.

Point taken... I have used this stuff tho and under this application you need a strong mechanical lock to prevent rotation; not just some glue and an interference fit.
A permanent solution, tho it will make removing the gear impossible in the future, is to weld the gear to the motor shaft.
Think about it, if any of the gears need replacing in the future, by then the motor is garbage anyway.

 

[dnmun]

i guess it was richard who first recomended loctite blue adhesive, then lawsonow, and miles, and i finally used something identical to it. i think it is permanent, better than welding even because there is no thermal stress on the gear from the welding. it is physical enuff imo.

i was hoping rbelisle would try just the bearing retainer if his gear is not totally loose already. the gear on this motor was totally loose, i pushed it back down the shaft of the motor armature with my fingers, and it came off with litle effort from my knife blade and a fine bladed screwdriver, i can testify it was loose. the shaft was spalled out from the way the gear had been pressed on originally and then it was hogged out by spinning on the shaft. not a lot, but it was visible in the first picture.

since i could get the gear off, i could clean out all the grease with solvent, but if rbelisle cannot get the gear off, he can't clean all the grease out of the way, so i was hoping the capillary nature of the permabond would suck it around any grease at the top of the shaft and into the interference fit between them, and if that would solve his problem, it might be a fix for others without all the hassle i went through.

this must be a common problem, so a simple fix like that would help a lot more people than fancy machining too. if someone has a gear really loose like this one, and can take it off easily, then i would recommend that so they could clean the shaft and gear with solvents, and then use the permabond(loctite) bearing retainer, or maybe just a little J-B weld instead, especially if the shaft is spalled badly like this one.

if his continues to slip, he can take it apart and clean it then when it gets loose, and bearing retainer from this try can be cooked off with a torch before he glues it together the final time then.

 

[rbelisle1]

It all fixed, no more gear movement. The bearing retainer worked like a charm. 400 miles later and its still holding.
I put the motor in the toaster oven and got it up to about 110 120 degrees. Then I pooled the bearing retainer on the top of the shaft, so that gravity would help the wick action of the fluid. Well as it cooled, it wicked right in. I also put a dab on each of the ball bearing where the bearing touched the motor housing. Not to much, but it was enough to keep those big bearings from spinning in the holder...

its all working great!!!!!!!!! thanks for all the great sugrestions!!!!!!!!!

 

[dnmun]

that's great, the bearing retainer is right up there with crazy glue imo. except it can withstand even more shear force i think, and not as thin as crazy glue, but close. congrats, i still have not got my wheel in a bike, so glad you were able to provide some testimony. i bet this is a lot more common than we know of. maybe it will get diagnosed properly more often now, and fixed.

 

[lawsonuw]

that's great, the bearing retainer is right up there with crazy glue imo.

I'll second that! Though I have used "crazy glue" on one part. (well Loctite brand super glue) Normally super glue sets instantly on contact with metal parts and makes assembly impossible. But the specific plastic in this part interfered with the retaining compound's hardening, super glue worked just fine.

@rbelisle 1: I'll have to remember the trick of heating the joint gently next time I want glue to wick into a tight spot.

Marty

 

[rbelisle1]

I also wanted to add that the easiest way to handle the brushes when it comes time to reassemble is ... thread. I took some fairly heavy thread and tied a big loop around the brush and the brush holder. I had my daughter (small fingers!!!) push in the brush, while I tied the knot. 4 loops later, I just slid all the parts together. Once the parts were back together, a quick snip of the thread and a small tug and the all the threads came out. The brushes were in place and I could finish the reassembly of the case!!!

Hope this helps some one...

bob in phx.

 

[gmouchawar]

I use zip ties. I pull them so that the brushes are all the way in. I insert the rotor most of the way till it hits the ties.
Then I cut the ties and pull them out. The rotor then seats all the way.
The advantage is that the ties just hold their position so you can do it alone.
Watch your finger as the rotor has a lot of pull from the magnets.

 

[texduck88]

Hello everyone. I am a new forum member and also a newbie to e-bikes. I found a never ridden e-bike, one of the ones from Lee Iacoca's company. It has a 400w rear Heinzmann hub. The motor was pretty much frozen up. I could roll the bike forward but not backwards.

I have disassembled the hub to the point where I can see the small gear that was being repaired earlier in this thread. In other words I removed what I think is the gearbox. It was held on by 5 phillips-head screws. Lightly clamping the assembly in a vise, I am now able to turn the center gear by with a pair of pliers. There's allot of resistance though. The motor housing has corrosion and it looks like it might have been submerged. Maybe a flood?

My thought is I need to continue the disassembly so I can inspect the interior components. I've searched for info on how to replace the brushes thinking that procedure might get me there. Has anyone taken these motors apart this far? I'm probably more brave than skilled, but I'm willing to try.

I don't have allot to lose since I only paid $75 for the whole bike.

All help appreciated.

Thanks,
Mark

 

[dnmun]

yes. stop already. don't pull that gear off the motor shaft. no need to in any case. does the motor turn? if the brushes have somehow become jammed and it doesn't turn, i would recommend going to the other side of the motor and reaching through the tiny space and hook the back end of the brushes through the stranded lead embedded in the back end of the brush, and pull the brush back away from the commutator without taking anything apart. if the brushes are jammed you can loosen them that way, and if the shaft is seized then, it would be in the bearing anyway, maybe. you may have to put a small plastic poking tool at the commutator brush contact spot, but i cannot imagine how they could have become seized. i thought i was lucky to get my heinzmann for about the same price, rear hub? have pictures?
are you sure it would not turn backwards? or did it take a lotta pressure to turn it?

 

[dogman dan]

If you really do have gear problems, I have just fried a motor, and could sell it to someone needing anything besides the magnets and brushes. 24v motor. Made a lump of coal out of my christmas present to myself.

 

[texduck88]

dnmun -- When the wheel was assembled and on the bike, it wasn't able to roll the wheel backwards. seemed to be totally frozen. with the gearbox removed i can turn the small center drive gear -- the one that appears to be on the commutator shaft -- using a large set of pliers. it's really hard to turn - takes a bunch of torque. i'll try to take some pics tonight or tomorrow and post them. yes, the e-bike is a rear-hub system. i'll try your suggestion of seeing if the brushes are free or frozen.

dogman -- i think the gears are ok. they look pristine, but i'll keep your offer in mind. i appreciate it.

more later. thanks for the replies.

mark

 

[dnmun]

why not see if you can connect the motor to the controller and get it to spin while out of the bike, since the motor is disconnected from the wheel you don't have to worry about it spinning, and once it starts running free you may be half there, if the bearings are rusted, you will know right away, the bearing under that gear on the motor shaft is a sealed bearing, it should be ok, but if it is rusted, then you would need to pull the gear off the shaft, until then try to avoid it since it may end up galled when you press it back on. i could turn the small gear and motor shaft with my fingers so you have something dragging, i was thinking the brushes had gunk goobering them onto the commutator, but that really is just an idea, it could be in the bearing at the end where the brushes are too, maybe just a little WD40 using the little red plastic tube to feed it right onto the bearing, but not too much to ruin the grease, if the bearing end up bad, i bet you can find direct replacements at a bearing shop, usually they are stamped with either a part number or dimensions, and bearing are actually reasonably standardized. bol, dm.

 

[texduck88]

Here are some photos.

http://www.flickr.com/photos/11077979@N02/sets/72157601325651085/

I was thinking about your suggestion to hook this up to a battery, but the only battery I have is a 36v for my other e-bike. I've read some posts where others have driven 24v Heinzmanns with 36v and they seem to say it's ok as long as current is limited.

I'm thinking I can connect the 24v motor to the output of the 36v controller and gently apply 36v at low current. That would at least give some indication of whether the motor will respond.

Thoughts?

Thanks
Mark

 

[dnmun]

i don't think the 36V will hurt it, maybe dogman can advise, but if you can get the motor spinning, maybe it will free up, you can tell by how long it takes to spin down i guess, why not run this motor at 36V when you put it back together, the current 24V controller may work at 36V too, since it is brushed, but i don't know that for sure. BOL,dm