Technical ELECTRICAL, Alternator in Generator disguise

After effectively ruining my 3-brush generator in my roadster I decided to build a alternator in a generator. One of my buddies has one of the Electortech conversions, which I had a chance to study.
The first task was to find a alternator small enough to fit into a 59ab generator case. electrotech uses a Mitsubishi alternator, of which similar models can be found on tons of different imports and domestic cars.
HOWEVER, even after spending hours at the local parts store and looking through the books I could not find one that was the same size as the one used in the Electrotech conversion. I think it is probably a commercial (tractor, forklift...) type of alternator. Maybe I should have given up at this point....

Anyway, I finally decided to go with a generator which was 1/4" larger in diameter than the stock generator case. I used a Lester#14708 alternator. The place I got it from sold it for around $50 without core charge! (supposedly rebuilt and tested)

The idea is now to actually make an aluminum case to fit the alternator but still use the ofiginal front end plate assembly (the piece that mounts to the flatty manifold)

First picture: cut off the mounting ears of the alternator with a hacksaw and clean up the diameter on the lathe. (see next post)

Please hold your posts until I posted all my pictures. There are about a dozen more...

 

OK here is how I turned the outer diameter down in the lathe:
I removed the pulley and put the shaft in the chuck of the lathe. I made a small brass dowel to replace one of the front bolts of the alternator. This keeps the alternator from spinning freely.
Next, carfullly spot the center on the back of the alternator. Then , use the live center to support the alternator while slowly taking off the diameter until the steel stator (black ring) is reached.
Only take small cuts. remember the front and back half of the alternator are only held together by friction at this time!

 

Now comes a tricky part. Because the shaft of the alternator is very short, a shoft extension will have to be machined. This extension screws on and provides a the surface to mount the new bearing. The bearing mounts almost right over the end of the generator shaft and the original bearing would have not provide enough meat for the internal threads and the bearing on the outside. The solution: the next bigger size bearing.

The increased inner bearing diameter also resulted in a increased diameter by 2mm! And I say "mm" because Ford actually used metric bearings in his generators (more power to him...).

I will show how to fit the larger bearing in the front end plate in the next post.
Here's the picture of the extension shaft. The bearing sits on the second largest diameter and the threaded nut (ring at bottom) is used to screw down the inner bearing race on the extension shaft.
Also shown is a ford pully, which I ended up not using.

 

before I go any further I want to show all the parts that went into making the conversion. It took several trips to the scrap yard to get all the pieces I needed...

the short aluminum tubing pieces will be used to adapt the front and back plate (Ford pieces) to the now bigger case.

 

To enlarge the bearing cup in the front end plate I machined a round fixture that centers on the shoulder with the diameter of the old generator case. It is a solid round and has a small center at the left side for the live center of the lathe.
This fixture is used to center the front end plate while tightening the 3 jaw chuck. This guarantees that the front end plate runs true.

The lathe is a 14"x40" and just big enough to do this job without hitting the bed...

 

After making the initial cut, check the diamter accurately. Bearings need a tight fit (in this instant I chose a .0004" clearance and will use some loctite to keep the race from spinning)
After the bearing cup is machined, machine a new groove for the retaining clip.

Lastly I also machined the shoulder which located the old generator case. This is important, wlse the alternator will not sit concentrically in the new case.
Needless to say, run the lathe at a very slow speed when doing this....

 

Here is the fornt end plate with the new bearing installed and the freshly machined outer shoulder. The diameter of this shoulder is not so critical because we will have to make the adapter piece to fit this new diameter.

 

Next is the new case: I started with a piece of aluminum tubing which ony needed a hair ( actually a RCH) of material removed to fit the diameter of the alternator plus a gap of approx. .015". (This gap will be shimmed during the final assembly).
The outside of the case was machined as well and then polished.
Note: the length of the case is exactly the same as the Ford case and will aloow the alternator to be used with standard dual intakes!

 

Next step is milling some slots for air circulation. I made the slots nice and big. Hopefully the alternator will not overheat...

 

Now we can make the adapter ring to fit the front end plate and the new case. The adapter ring will be mounted to the front end plate with two screws in the location of the old, long bolts that held the generator toghther.
The case is screwed to the ring with four screws around the circumference.

The picute shows the front end plate with adapter ring and the alternator with extension shaft. The treaded will be screwed on the threaded portion of the shaft after mating of the two assemblies. The little black tool (similar to a compass) has two pins at each end and is used to tighten the ring.

 

It's time to assemble the thing. Slide the alternator assembly in the case, tighten the screws and give the pulley a spin. If everything is done correctly, there should be no noticeable wobble of the generator in the case (remember we have a slight air gap).
Two set scews at the middle of the case are evenly tightened and engage in the black ring (stator) of the alternaotr and keep the alternator from spinning in the case.

Now take some shim stock (I used flashing material) and evenly center the alternator on the inside of the case in three places (120 degress apart). This should be done tightly to ensure no movement between the parts and also to help heat transferr from the alternator to the case. Use loctite to secure the shim pieces if necessary.

 

Another piece of tunbing was used to make an adapter piece for the old cover. I drilled a bunch of cooling holes in the cover to help air flow.

 

Wiring: the mitsubishi alternator needs 2 wires. One is obviously to the terminal post, the other goes to a spade connector and hooks up to the accessory position of the ignition. Basically you need to set it to 12V to turn the alternator on.

I machined a brass extension for the terminal. It will stick out of the rear cover through a plastic insulating bushing.
The second wire is routed through the old lubrication hole. the plug was replaced with a insulating terminal post.

The little hole at the 9 'o clock position is directly over a boss in the generator housing, in which a screw has been placed. By moving the screw out, the axial slack of the generator in the case can be eliminated. (the screw head presses against the underside of the adapter ring)

 

Here is the finished "Galterator" mounted on the car.
As I said earlier, I ended up making a new pulley from scratch and also the extension for the fan. The new extension is a fraction fo the weight of the old steel contaption which led to the demise of the old Ford generator and pulley.
I used a plastic fan blade to minimize weight.

The alternator works great and I finally have bright lights!
Only time will tell if ther is enough cooling and how long the conversion will last. I consider drilling more cooling holes in the front of the case.
I have driven the car for about 10 hours without any problems so far.

 

Here is a shot of the roadster with the exposed engine.

Was it worth it? It took about $120 in materials and about 60hours to finish the project. I don't want to make another one for a long time and I understand why Electortech wants $400 for their conversion. I will stick with my day job for the time being...

Mike

 

Neat! My Dad and Uncle are threatening to do the same thing! They are worried about overheating the alternator also...

Any room in your design for an internal fan???

 

Impressive, thanks

 

wow,all that work just for a little can on the back of your alt...just kidding looks great,man.good work and good job actually KNOWING what it was you're working on!you sounded like either an alt. sales man or repair man!
creepy

 

why cant we have more posts like that? thats awesome! ive gotta get me a good size mill/lathe. there are so many things that can be done. thanks for the post.

trey

 

Best Tech post so far!! Finally somebody actually did it!!
JimV

 

Thats why we keep you around Swissmike! I hope you don't vomit when you see my roadster...shit....you can eat off his. Incredible work! Oh and yeah...that shit went down in FLA....go figure.
Tim
MBL

 

SwissMike again I have to say you are the man man. thats a great read!!!

 

Wow Mike! Thanks for shariang and writing this up!
Great work. This is techomatic material!

 

Excellent article. I'm printing that one off and keeping it in my files.

 

thanks guys!
I still have a bunch of pictures from when I built the top for the roadster. I will post those shortly.

Tim, the Orlando Rumblers show is February 13. You better be driving (or towing..) that heap of yours over here! I want to see it..

 

That was a good tech post, thanks for sharing.

 

That was awsome! Thanks.

(It does make $400 seem reasonable...)

 

Excellent!!!

Thanks for the info.

 

Mike if you checked your PM's you'd know how far along we were.
Tim
MBL