How to build an Alternator bracket?

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Gary Boutwell
10+ Years
10+ Years
Posts: 2758
Joined: Wed Apr 23, 2008 10:10 am
Zip Code: 70401
Tractors Owned: 3 barns full of Cubs and implements in various stages of disrepair
Location: LA, Hammond

How to build an Alternator bracket?

Postby Gary Boutwell » Tue Oct 06, 2009 8:45 pm

Boutwell has been pondering how to install an alternator on a Cub.
The problem is not the alternator, but the bracketry.
Do the installation in such a way as to be neat and orderly AND not cut that beautiful hood.

Thanks to Yogie, Boutwell got this inspiration.
Yogie has built these brackets for a universal fit for a Delco 10SI alternator.

That alternator works fine, but is designed for faster turning automotive engines.

The problem turns out to be what alternator would be more suited to the slow turning Cub engines. The problem was pretty easy to solve. What engines turn as slowly as a Cub? Other tractors of course.

Went down to my local IH dealer, (always in ones best interest to cultivate friendship with the parts department personel) and voiced my delimma to them.

Immediately they suggested a Nippodenso alternator off a Kubota. About the same diameter as a Cub genny, works at low RPM's, one wire, very easy installation and very reliable.

Here is the technical stuff about the alternator:
Lester # 12199
Part No.1247801ND
Alternator -Nippondenso type Farm, Industrial & Truck Alternator 40 amps., 12 volts
Used On: Kubota Farm, Utility Tractors
Replaces: 100211-465, 34070-75601, 34070-75602
Lester: 12199

Enought about the alternator, now for the custom built bracket.
This is a off take of Yogie's idea. Thanks, Yogie, for sharing this with me.

Please keep in mind this bracket is custom made for the above alternator. Therefore, no measurements are included. One will need to get measurements from the alternator they are using.

The bracket begins with 1" x 1/4" flat bar. Basically making two 90 degree bends.


There are three 90 degree bends in the bar. The first 2 are simple. Vise up the bar, heat and bend.
The 3rd is more difficult. This is the way Boutwell solved the problem.


Now that the main part of the bracket is done, measure the additional post to be welded on.
The main considerations here are twofold: (1) get the post welded up straight and true & (2) make sure the alternator mounting post will fit. Check this out!


While you are set up to build one, might as well build more! Just a little more time and material, but down the "road", one will be glad for the extra investment.


Now for a test fit before sandblasting, priming, and painting:


The brackets fit and work very nicely. Now for the top tension rod to hold the tension on the drive belt.

This small and easy bracket is made of 3/4" x 1/8 inch flat bar. The original was 3/4" x 3/16", my supplier didn't have that dimension. So I did the best I could with what was available.


Again, vise and heat, bend to your calculations.


Bend carefully, this thin material will deflect. Need to hammer it flat.


Test fit it and mark the last hole. Boutwell did 2 holes and cut out the space in between to form a slot to allow for the belt to loosen over time.


Its finished (except for painting the bolt heads).
Nice and snug!


Don't be afraid to give this a try. Material cost less than $5.00. Did 4 brackets and 3 tension rods.
Took most of 2 days, but well worth it.

Good luck and keep fabricating!
Louisiana Cub Fest, March 5 & 6, 2010
Gary Boutwell
Hammond, LA

3 barns full of Cubs of various condition

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