Subject: Generator 4 of 7



------------------------------------------------------------------
(3542)   Sun 21 Jul 91 23:25                             
By: Don Kulha
To: All

------------------------------------------------------------------
The higher amperage alternators are more difficult to find.  Try 
your local auto electric shops, they may have a source for these 
high amp jewels.  Regular alternators up to 70 amperes are usually 
available from junkyards at less than $20.  Alternator rebuilders 
can provide rebuilt units from $40. to $150.  These alternators are 
a good investment.  They are designed to run under the hood of a 
hot car on a Summer's day.  In the type of service we give them they 
run cool and last a very long time.  I've seen these alternators 
last over 10 years with just the replacement of bearings and brushes.

The more modern alternators contain their voltage regulators within 
the alternator's case.  These internal regulators need to be 
disabled 
before these alternators are useful in this system.  If you can't 
do this yourself, then take the alternator to an alternator shop 
for help.  Some alternators have what is known as an "isolated 
field", 
these need to have one field lead grounded and simply feed positive 
energy to the other field lead.  The older Delco types are very 
simple 
and straight forward to use, they require no modification.

Getting it all together- Assembly
We originally bolted both the alternator and the motor to a wooden 
slab about 16" by 24" and 4 inches thick.  Be very careful on this 
step.  If the motor pulley and the alternator pulley are not 
properly 
aligned, then the unit will wear belts out very rapidly.  These 
units 
work best on heavy metal bases.  There is a lot of vibration and 
the wooden slabs give up after a few years.  Either add a sheet of 
1/4" to 3/8" steel between the wood and the motor/alternator, or 
make the base completely out of metal.  A local welding shop made 
us a base out of 3/8" steel plate with a welded 1" by 2" steel 
square 
tubing perimeter for $50.  You can see it in the photograph.  If 
you can weld the materials cost about $18.
INSERT FIGS 1

We coupled the alternator to the motor with an "A" sized Vee belt.  
Keep the belt length to a minimum by mounting the motor and 
alternator 
close together.  We use belts between 28 and 33 inches in total 
length.  
The stock pulley on the alternator works well.  The best sized motor 
pulley is between 5 and 6 inches in diameter.  This pulley ratio 
gears up the alternator for better efficiency while allowing the 
motor to run about 2,200 rpm.  We have had very poor results with 
the lightweight cast aluminum pulleys.  These light pulleys were 
not up to the job and broke frequently.  We're now using cast and 
machined iron pulleys (such as the Woods SDS pulleys) that work very 
well and are extremely rugged.

--- ConfMail V3.31
 * Origin: Sonoma Online RFE, Fido V12T/HST/V.32 (707)545-0746 
(1:125/7)
: 125/7 151/1000 1003 223