Homelite generator

I bought an interesting generator at the weekend from Matt the Sawyer (hi
Matt ;o)) ) It is a 1944 ex-USAF battery charging set. It is fitted with
suspension springs and sits on a rack-mounting platform arrangement that
leads me to believe that Matt might well be right in his assumption that it
was a type used as an in flight APU for Boeing B29's .
The model is HRU 28A constructed to specification 94-32313-A on contract
number W30-053AC-482. The serial number is 250404. It is a 28 Volt 70 Amp
dynamo. If at all possible, I'd like to know when it was supplied and to
where.
Any clues, Gentlemen?
On Monday, I hauled it out of the car and was delighted to find that it is
mostly aluminium. A two stroke with die-cast close pitched finning and fan
cooling, it has a very neat WICO ignition generator and rope starting pulley
at one end of the crank and a direct drive generator at the other. It is a
nice piece of design work and considerable effort has been taken to ensure
lightness and ease of use. Of all the generators of this period I've seen,
this is by far the best designed I've come across and innovative use has
been made of available space with the control box and petroil tank being
tucked neatly away under the unit. The whole thing looks to me like a "clean
sheet of paper" design.
It had obviously not run in a long time, the tank no longer smelling of
hydrocarbons and having a mixture of rust and old paint inside it, which I
hoovered out! There was no spark as Matt had told me, although a meter on
all the components indicated that they all functioned OK and the coil
provided a spark when flashed with 12 volts. I'd cleaned the points
initially with wet and dry in situ without any improvement. However,
removing them showed a thick oxide layer that took 800 grit wet & dry on a
solid base plate to remove. That done, a spark appeared at the genuine
original shielded plug and a whiff of Gypsy's Breath down the carb made it
fire.
Hoorah!
Reassembling the petrol tank to the frame, sealing and refitting the carb
took about an hour and then it was crunch time. It did rotate on the starter
button, but wasn't happy. Removal of the inspection plates at the commutator
end showed seized brushes and a blackened comm. It took another hour to
clean it up, but then 24 volts whipped it round at perhaps 1,500+ RPM.
It took quite a bit of winding to make the carb pull fuel up the long pipe,
but in the end it fired and ran well, settling down to a steady pace on the
carb adjuster screw. There was no charge from the leads, but investigation
showed a broken ammeter lead and fixing that produced well over 30 five
volts, regulated again according to speed at the carb.
I think the carb will benefit from a good clean, but aside from that it is
in good enough condition to respond to an oily rag restoration, "USAF" still
being stencilled onto the airforce blue paint of the petroil tank.
Thanks Matt, I'm very pleased with it. ;o))
Regards,
Kim Siddorn