Harley Generator Question

[hogluvr]

I bought two generators off a guy, one was supposed to be a Model 51 and the other a model 52. When they got here I realized they were both model 51.

Now comes the crazy question: Are all model 51 generators fan-cooled? One has the fan on it, the other does not. According to what I read in Palmer's book they are all fan-cooled. The one with the fan has the number stamped on the body, making it '56-later. The one without the fan has the zinc tag, making it an earlier model. At first I thought someone altered the generator without the fan, then I started browsing thru my Panhead manual. It has a breakdown of a two-brush fan-cooled generator, as well as a breakdown of a two-brush without the fan, with an end cap, etc. very similar to a 32E generator, which is identical to this earlier generator. Can any Harley generator experts here help me to clear this up??

Mike

[Perry Ruiter]

I don't know that the sobriquet "Harley generator expert" applies to me, but as far as I know all model 51 generators were fan cooled and should be noticeably longer than a 32E. The model 52, externally looks the same as a 32E. The changes in a model 52 were all internal (brushes and holder, field coils and pole shoes). If the second model 51 looks the same as a 32E and is supposed to be a model 52, it sounds like the guy simply put the wrong tag on it when he restored it ... Perry

[hogluvr]

Perry,

That was my first thought, until I compared the two side-by-side. They both use the same body, but the end casting looks like a 32E without the third brush. And the 32E I have is considerably shorter than either of these. Thanks for the info on the model 52, I am looking for one of those for my Pan and was wondering how to tell the difference between it and a 32E if there are tags missing, sounds like it would be next-to-impossible. I will try to post pics in a little bit.

Mike (generator newbie)

[hogluvr]

Here's a pic of the three generators: the air-cooled 51 on the left, the non air-cooled 51 in the middle, and a 32E on the right for comparison.

[hogluvr]

Let's try this again:

[hogluvr]

Here's a pic of the 51 and 32E side-by-side without the end caps, you can see they are nearly identical except for the "vent slots" on the 51: the air-cooled 51 is similar to these also.

[Rub]

The earlier radio generator 32ER is not fan cooled but has the long armature without provision for the fan. The one odd generator you have may be made up of parts of a 32ER and 51R.
Robbie

[Perry Ruiter]

Your middle generator is a model 51 too and is a fan cooled albeit without the fan. It has the longer body, you can see the air flow slots milled in the end casting and the body. It also looks like it has the ratcheting drive gear. The only reason a regular chrome end cap fit on was likely because someone hacked the end off of the armature where the fan bolts.

Attached is a comparison shot of a stamped body model 52 and a 32E generator ... Perry

[hogluvr]

Thanks Perry and Robbie,

I've thought along both your lines. I'll probably end up taking this thing apart for further inspection, at first glance it doesn't appear like the end of the armature was hacked off, but that was my initial thought. Didn't Harley also make a Model 48 radio generator, without the fan? Maybe this thing was cobbed together from parts from that one too. Either way, I probably cannot run this thing the way it is even if it tests out OK, it would likely burn itself up without the fan...

Mike

P.S. Thanks Perry for the picture of the 52 & 32E generators, I'd better find a 52 with either the tag still intact or the stamp, it looks impossible to tell them apart otherwise.

[Perry Ruiter]

Mike - if the armature doesn't look like some Neanderthal hacksawed the end off then Robbie's probably right. It could be from an earlier non-fan cooled radio generator. I think the model 48 was fan cooled so it would be from the earlier 32E2 or 32E2R. When on the hunt for generators keep in mind there is also a model 52K which was used on the K model (and 57 Sportster?). This is a two brush generator that looks like a regular model 52 so read the tags carefully ... Perry

[hogluvr]

Thanks Perry,

I had heard about the 52K generator, but didn't realize it was a 2-brush. Trust me, after this I'll be MUCH more careful when looking. Unfortunately I'm only able to get to a handful of swap meets in a year's time, and most of those deal mainly with newer stuff, finding older stuff is sometimes like looking for a needle in a haystack. And this is the kind of thing that sometimes happens when doing deals over the internet.

Mike

[Rub]

Mike,
As to your comment about burning up the generator, remember that heat is a by product of the load and output. Unless you are running a ton of accessories or an early radio you will never stress the generator. And all the radio generators used voltage regulators, not relays, so current was regulated and provided as needed, not just on or off.
Robbie

[hogluvr]

Thanks Robbie,

Yeah that's a good thought, thanks for clearing it up. If it ends up on my Pan, it will be bare-bones anyway, no extra lights or radio. Maybe I can find a use for this thing after all...

Mike

[hogluvr]

OK,

Bought a box of generator parts, included in the lot is the majority of a Model 52 generator (sometimes you just get lucky!!)

Anyway, the field coils are still installed in the body, but it looks like they got banged around a bit and the insulation is tattered. I addressed this question before, didn't get a real answer though:

Does anyone know what I could use to re-wrap the field coils? Palmer mentions using fiberglass or white cloth tape, then dipping in a suitable varnish. I suppose I can find the tape, but what is a suitable varnish? I googled some things, and found someone using Egyptian cotton and knotting sealer? Couldn't find those around anywhere. Another mentioned varnished cambric tape, it's made by 3M and widely available, I just don't know if that would have to be dipped in something afterward, it comes with or without adhesive backing. Has anyone had any experience with doing this? If so, what did you use and how well did it work? I've got enough parts to build a couple more generators and have 3 more sets of ratty field coils, I'd like to save these things if possible...

Mike

[Perry Ruiter]

Originally posted by hogluvr
Does anyone know what I could use to re-wrap the field coils? Palmer mentions using fiberglass or white cloth tape, then dipping in a suitable varnish. I suppose I can find the tape, but what is a suitable varnish?

You can use anything that insulates. I remember taking apart a model 52 generator that had the field coils wrapped with crepe paper. The field coils were fine. On field coils I use a white cloth tape I buy a roll at a time from my local electric motor repair shop. They also sell me a spray can of insulating varnish. If you live in some small burb and don't have a local electric motor shop, hunt one out the next time you go into the big smoke ... Perry