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Need some scratchbuilding tips for making an alternator bracket from plastic strip.


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In addition to making the actual bracket, I'd like to know:

1) How can I make a realistic slot in the bracket for the tensioning nut?

2) What's the most realistic way to mount this bracket to the cylinder head?

The goal is to make the bracket look like it's supporting the alternator (as opposed to the "magic fan belt").

I know there are P/E units out there, but in this case I'd rather build than buy.

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I know there are P/E units out there, but in this case I'd rather build than buy.

And kudos for that! It's easy to buy something, and I do when I can't make it, but it sure doesn't give you the satisfaction that making it from scratch does.

I've made a couple of brackets like you're considering, but I've found that metal is a little better medium. You can use a piece of beer/soda can or pick up some thin sheet aluminum at the hobby store. I like to add the holes and/or slots before cutting it to shape, so I rough the piece into a triangular-ish shape first. For the slot, you can drill adjacent tiny holes and then carefully connect them with the point of your hobby knife. Cut a tiny strip of sandpaper to fit in the slot and finish it. Once you get your holes/slots made, then carefully sand and file the piece to its final form. This is where working with metal is better, IMO - it won't snap as easily when you're trying to form it.

Another alternative is to us flattened wire - you can flatten copper wire with pliers or in a vise, bend it to shape, and then make your holes and slots in it. It's very malleable and won't break while you're working with it.

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Don't forget the mount on the bottom of the alternator as well. I tend to use a short piece of bell wire where I remove small sections of the insulation on either end and insert one side into the head and the other to the bottom ear of the alternator. This adds strength to the assembly as well as positively positions the alternator. Then, you can use chartpack tape, masking tape or other medium to make realistically thin belts.

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OK, Monty. I am sure this qualifies as scratch building.

I applaud you for saying "no" to my pet peeve: gravity defying alternators.

This will get you what you want. Only it's akin to killing mosquitoes with a hand grenade.

You will need:

.020 inch sheet styrene or an old credit card.

one push pin

one block of wood

one dark marker

a pin chucked in a pin vise

an x-y axis machinist vise

drill press

miniature shaping bit (the one shown is part of a 5 piece package from MicroMart)

Chuck the bit in the drill press and set the speed to the slowest

Cut a piece of the styrene and darken it with the marker

Use the pin to mark all cuts

Use the push pin to hold the styrene on the wood block which is held in the vise.

Your goal is to cut three concentric arcs into the styrene like this:


To mount the bracket I suggest piano wire set into the engine block and small diameter brass tubing to hold it away from the block.

Good Luck!

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