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View Full Version : Designing and creating a Lightweight pulley



dasicvtec
30-04-2010, 11:23 PM
Hi

Id like to design and create my own lightweight pulley. Id like to make the alternator and water pump pulley into aluminum. This really is more of a side project for me as the performance gain is negligible(probably none at all - but its extra bling!) but i want to learn how i can create my own parts.

The alternator pulley (pictured) only weighs 400g. Although if i do this project and complete it, then i don't see why i cant create a custom Under drive pulley (which connects to the crankshaft). I don't have Air con or power steering in my car so i can delete one notch/belt section on the pulley. The crankshaft pulley is made out of steel/cast iron and weighs 2.5kg so savings could be significant if.

Here is a pic of the original pulley.
http://img693.imageshack.us/img693/4324/dsc00990kz.th.jpg (http://img693.imageshack.us/i/dsc00990kz.jpg/)

At this point in time, the way i think something like this is created is by the use of a CAD program. So id learn and use a CAD program which should create a design of it, then i would take the design/saved file i create to a Machinist and they would use there own CNC machines to create it from aluminum ?

Any help would be appreciated. Thanks

note: please don't start about how a lightened under drive pulley is bad for the car because it unbalances everything. thanks

markismaximus
02-05-2010, 10:01 AM
you could use something like solidworks to model this. but if you've never used CAD programs you'll probably need about 50-100 hours practice to be able to model something like a pulley. Alignment is crucial so you'll also need accurate measuring devices (vernier calipers etc) to get correct distances.

you may be better off contacting an engineering company such as http://www.kilner.com.au/. give them the pulley and say I want this in aluminum with a new diameter of X. mm.

also be prepared to pay dearly. A lot of engineering manufactures have a minimum dollar value per job, and as its a one off item they cant make any decent money on it and will try charge you the earth. call around


on my previous car I replaced the cat and decided I would fit it myself to get some practice welding exhaust pipe. as there was a temp sensor just after the cat I needed a bung. both the bung and flanges were done in solidworks.

I turned the bung on my dads lathe and had the flanges laser cut. just an example and a pulley would be a lot more complex than this small project

mugen_ctr
02-05-2010, 03:57 PM
solidworks would be the easiest cad program to use in terms of creating such parts as what ur asking, but if ur wanting to learn it, it would cost heaps jus for a few sessions, better off getting some whos in the engineering field to create what ur after.....
Its simple to create something, but to get it to work, is another story, calculating all sorts of variables to make sure it wont break underload etc..... u dont want this to fail when ur reving 7000rpm!

honestly, ur better off buying an aftermarket pulley kit, as they been through all that hassle.......