JD generators

[Tommo]

As far as I'm aware D1 is the 1929 only adjustable third brush generator.
1926 to 28 used the D generator with a 4 start timer drive worm for twins and a 6 start one for singles.
My 1926 single has a D generator with no other stampings on it other than the serial number.
If this new system lets me I'll put up some photos that may help on the next post.
A few minutes ago I one finger typed a long post only to be told the page I wanted to post it on was no longer available.
Half an hour typing lost so it' probably time I quit this forum, it's now so frustrating to use.

[Tommo]

Lets see how this goes.
The first photos shows left to right B,C,D, and D1 base differences which are easy to see.
The most significant difference is where the wire exits the generator on the "C".
Notice how the end cap is different and how the wire protector is different and the locating screws screw in from the end rather than the top as on the "D" series.
The second photo shows B,C,D and D1 drive end view with the B having only two screws holding the end housing on where as the others have three.
The last picture shows the casting number differences (L to R) C,D and D1.
All three are different and the D1 casting number is on a small raised platform.
Also note that on the "C" the retaining screws are countersunk into the housing and on the "D and D1" the screws have raised platforms that have a machined face.
I'll put this up quickly before this one times out on me.
I've just noticed that I forgot to point out that the "D and D1" bases are both drilled with the extra hole so they can be fitted to singles as well as twins.

[RichO]

Tommo, This post is so you can let me know what you think of this information. '17 to '19 were Autolite generators? '20 had the switch in the end cap? '24 to'25 had brushes on swing posts? Model D has notch in cover for third brush lever? Cover for '24 to '25 have embossed ring (ridge) w/ dot like in center? '20 to '23 and '26 to '27 have spray paint cap like end caps? Inquirying minds need to know. Thanks, Rich

[exeric]

A few minutes ago I one finger typed a long post only to be told the page I wanted to post it on was no longer available. Half an hour typing lost so it' probably time I quit this forum, it's now so frustrating to use.

Tommo, that has happened to me, and it's enough to make a person run out of the house screaming. Now, when I know I'm going to write something long, I write it in 'Word' then copy it, and paste it here. Please don't leave this forum, Peter.

[aumick10]

Tommo,
I have a slightly different understanding of the D series generators.

My understanding is that D models were used from 26-29 big twins, with various versions. All these had the 4 tooth timer drive gear. Pt no 1649-18
D1 models were used form 26-32 singles, with the 6 tooth timer gear. Pt no 1648-26

The parts book shows and end cover 1696-26 for 26-28 twins and late singles. Description is Commutator end cover with oiler. Perry Ruiters document says the oiler didn't start until 28. I am inclined to believe Perry on this point, as I have a D on my 26 that doesn't have a hole for the oiler.

The adjustable third brush is a 29 only part, along with it's own end cap. The parts book doesn't specify any models so I have to assume it was fitted to the D and D1.

The right end plate has one pt no for 26-29 singles and big twins. A different end plate is specified as 30-32 singles. This may explain the slight difference in your casting no boss, or it was an undocumented casting change.

Hopefully, all this research should help us come to a consensus of what fits what.
Cheers

[ihrescue]

If this new system lets me I'll put up some photos that may help on the next post.
A few minutes ago I one finger typed a long post only to be told the page I wanted to post it on was no longer available.
Half an hour typing lost so it' probably time I quit this forum, it's now so frustrating to use.

Real sorry about your work and then losing it Tommo, very frustrating. It has some funky characteristics agreed. Eric mentioned about drafting a response either in Word or even a notes app on your computer and then copy and paste it into your response area after you have refreshed the page. Its a PITA and I hate to have to offer work arounds.

Mike Love
AMCA Forum
Moderator

[Tommo]

Wow! That's a serious amount of questions.
The early generators were known as "REMY" in the parts books.
The centrifugal switch finished with the introduction of the Model "B" generator.
Both Model "B" and "C" had swing post brushes but each model had brushes of different design.
This is where I disagree with what is being posted as I have only ever seen the external adjustable third brush on "D1" generators which therefore have the notch for the lever.
I've spent some time this morning photographing stuff which I'll put up next on a separate post

[Tommo]

Three photos here show end caps.
The first one is "D" series
The second photo shows a "B" end cap removed with the J slot visible.
The last one is "B" on the left and two "C" end caps to the right of the "B"
The "B" appears to be parkerised and all the others look like they were painted originally.
I hope this answers your questions RichO

[Tommo]

Now I spent some time, about two and a half hours, this morning removing armatures from four "D1" generators I have to satisfy myself that "D1's" were fitted to twins.
In every case I found a 4 start worm so for me I'm saying that "D1" indicates an external adjustable third brush generator.
I also went looking for evidence of what was fitted to singles.
My 1926 is very original and has 3864 miles on the speedo which I'm sure is genuine and it has a "D" generator fitted.
I also found another "D" in my stash that has the twin mounting hole full of grease and oil so it was obviously fitted to a single.
A photo of it's base is attached here.
I know what I think but I'm also very open to be proven wrong

[RichO]

Peter, Thank you so much. I believe I now have enough information to sort through my generators and affix them to their proper motor. Thanks again, Rich

[Rubone]

Thanks for the info Tommo, sorry to hear you are having issues on here. I've never had anything drop off or disappear for any reason.

[Tommo]

With regard to using HD parts books it is essential that you consult them year by year and not just one or two of them.
Dad got from the NZ HD importer, what Frank Jones, one of the brothers that were the importers of the time, called their bible.
It is a bound volume of all the parts books from 1915 to 1932 and I've attached a couple of photos of that book.
For example you may be using a 25-29 book that covers your 27 and then go to the 26-30 book that also covers your 27 and find a supersession has occurred and although it has the same part number it obviously has been modified in some way or another.
If you're really particular about what should be on your 27 the 23 to 27 parts book is the one you should be using.
What I'm really saying here is be very careful using parts books as it's easy to wrongly interpret the information if you are not using all the information that's needed to come to a definitive decision.
I hope this makes sense as I fear it may time out on me again if I don't post soon.

[Tommo]

With regard the casting number platform on the "D1" I posted earlier I have to say all 4 of my "D1's" have that same platform under the casting number.
I totally agree that the end cap and oiler are a 1929 only part but I do not agree that the "D1" is a single only fitment.
Lets not cloud the issue by bringing in later post 1929 stuff we should try to keep it to the 1929 and earlier HD generators
I hope I have answered all those questions asked by RichO and aumick10 ask again if not.

[aumick10]

I totally agree with you on the unreliability of using a single source for information. I have three parts books that cover 1909 to 1939. Not all individual years are covered.
I also use internet searches and written articles when trying to find out information. Sometimes this is conflicting, and sometimes not.

I reviewed all my parts book to see if I could find any reference to a "D1"generator.
In my 1922-27 book, I found the reference in the attached photo.
Do you have the same information in your bible to confirm this?


D1 generators.jpg

[Tommo]

That's put the cat amongst the pigeons.
Sorry about the delay responding but I've just had surgery done on my foot.
Firstly I hold up my hand and say I'm wrong here and after checking through parts books I should have practiced what I preached.
Sorry Everyone.
The following was found.
1922-26 Parts book D and D1 1926 models
1922-27 Parts book D and D1 1926 & 27 models
1924-28 Parts book D and D1 1926- 28 models
1925-29 Parts book D and D1 1926-28
1926-30 Parts book No mention of them at the start of that section.
So although it doesn't definitely identify what fits what it's fair to say the D1 is for singles.
Now my question is why do all the adjustable third brush generators we see here in NZ have D1 badged carcasses?
I'm going to remove the carb off my 1926 single so as I can get a better view of the generator badge and confirm that it is as I thought a D and not a D1
I'm away for post surgery inspection now but will continue with my findings when I can