making ali castings

[bigegg]

****** said in his first post that he wants the biggest pulley to be 10", Where on earth do you get 10" aluminium round (On a hobbyist type budget)? Casting is the ideal option.

can a "normal" lathe cut a 10" disk?
<edit> ML7 can cut a 10"x1.5" disk in the gap, so *could* just about cut a 10-6.5-4 pully.
wouldn't manage the 10-8-6-4 pully though - unless each pulley is machined seperately.

I suppose the same argument could be made for machining the foam pattern, but I'd argue that machining a 10" foam disk on a drill press is quicker/easier/safer than pushing a light hobby lathe to it's limits?

Obviously if the OP *has* got a proper lathe, then this is moot

 

[Big Pete]

I cast pulleys because they were going to cost me £26 each +VAT and shipping, and I wanted 6 of them. I build my foundry and cast them for ~£70 all in, and am still using it. I cast tube bending dies (pics in the link) and followers, the dies were machined to suit the tube, and even on a Student it isn't an easy cut, the dies are unbalanced which doesn't help, but on a 10" cut it would stall the motor if you got casual.

Unless you absolutely can't get anything else, swarf and tins are to be avoided, they generate huge amounts of dross because the surface area is so high, and they are also not usually a casting alloy. My feedstock of choice is ally wheels, which are cheap from the breakers, and are good solid seections so aren't too bad for dross. Ally manifolds/engine mounts and heads are good too, but I prefer wheels for anything serious. The alloy can be post cast heat treated at 150C for 3 hours, at which point it will machine a lot nicer, and be a lot stronger.

The advantage of home casting is, once you have the pattern you can make as many as you like. My foundry, which was paid for by the first job, has cast ~£600 worth of bending dies, plus blanks for more.

 

[DAPPH]

3 meters of 9&½" aluminium bar from Parker steel is £1400, that's £3.50 per Kg. You should get a length, make loads of pulleys and sell them on eBay for a profitMaybe not.

Plus delivery & vat no doubt ?

 

[Maker]

Plus delivery & vat no doubt ?

That includes VAT and I think they deliver for free.

 

[DAPPH]

Phew . I was starting to sweat with worry on that one .

 

[MattF]

Why cast when you still need to machine and for parts that can be bought off the shelf or bought and adapted most likely. Not saying it cant be perfected at home but better to fight only the battles you have to fight and win them all

Fair point, but I'd say it's better to nurture the 'can do' attitude when it exists. It's becoming a rarity these days, especially in the younger generation. I'd much rather see a youngster trying their hand at basic foundry work than playing on a games console, for example. Besides, we never became the engineering masters back in the day by making do rather than being creative.

Depending on what the application is, wooden pulleys are always a possibility too.

 

[Kent]

Fair point, but I'd say it's better to nurture the 'can do' attitude when it exists. It's becoming a rarity these days, especially in the younger generation. I'd much rather see a youngster trying their hand at basic foundry work than playing on a games console, for example. Besides, we never became the engineering masters back in the day by making do rather than being creative.

Depending on what the application is, wooden pulleys are always a possibility too.

I see your point about "can do" but I should rather foster a young guy in how to source and buy better as its a skill required in many trades that makes a massive difference to profitability or even getting a job secured. A line has to be drawn between pastime and paid work though on this one. I make a lot of my own kit for my fishing and shooting etc. I enjoy it and I can be creative but time wise I should generally be very out of pocket at any sort of hourly rate

 

[DanielW]

A little bumph,the best aluminium to cast is that of stuff thats already been castmthis will be pure good ally.

I've still got a couple of 100 scrap hardrive bodies from when I used to sandcast stuff,these scraphardrives where got from when I used to repair comps and also went round any comp repair shops asking if they wouldn't mind giving me their scrap HD's.

there is many items out there that are made from Aluminium but the like of swarf and cola cans are not worth bothering with.

Lets just see what we can muster for Aluminium.....

Coat hangers..the screw to wall type
Door handles.
Hardrives.
beer barrells

 

[DAPPH]

Gear box casings , various inlet manifolds , other car pipes & casings .
Scrapped wheels from local tyre fitters ( forget the big national tyre groups as they usually are in a licenced scrap carriers & storage & metal recovery scheme to comply with their ISO agreements )