foundry work - aluminum pulley

[celsoari]

Step by step how I build an aluminum pulley

Greetings from Brazil


Celso Ari

[DIYer]

Thanks celsoari! We've added your Casting Mold to our Forging and Casting category,
as well as to your builder page: celsoari's Homemade Tools. Your receipt:

Casting Mold by celsoari

tags: pulley, casting, molds

[IAMSatisfied]

I always appreciate your contributions, Celso!

[JeffEck]

Is it stronger to case the block vs using a round extrusion that is the same diameter? I am a novice and have no idea, I can get just about any shape in any size I want at a local store, cusious why the choice is to cast the block vs cust it off the end of a round bar? Your work is beautiful, at times I really want to learn to cast as well as you! -jeff

[Crusty]

Go price some aluminum in that diameter and you'll learn why he cast his own from scraps. It's hideously expensive if you can even find it in that short of a length.

[JeffEck]

When I'm not buying full stick for jobs I goto The Yard Store, they price aluminum at $2.5/lb down to $1.5/lb for cut offs. I looked at an online supplier that I have used once, 3 inches of 8" 6061 round was $58. About a year ago I purchased 3" of 6" round and 5" of 4" round, bill at the yard store was $60. (I was building a base for a ball turning attachment for my 14" Rockwell lathe) I think they sell online. Is that is more expensive than casting, considering the time of the guy working? Thanks for responding, can't learn anything in a vacuum..

[Crusty]

Those are sweet prices but casting is nearly free if you're scrounging from the scrap pile and not putting a dollar value on your time.

It doesn't take a lot in the way of equipment and the learning curve isn't steep with aluminum casting, and it puts a world of new possibilities into your hands once you're set up because you can quickly produce aluminum castings that with some finish machining can become useful things. Dave Gingery produced a whole series of books detailing building a machine shop cheaply (with a metal shaper even) made from castings using a charcoal furnace and wooden patterns in green sand molds. These days there's even folks making castings from Styrofoam patterns coated in plaster of Paris in a variation of the lost wax process which is even easier than green sand molding.

It's fun melting metal and opening the flask after a successful pour can be a real hoot.

[Karl_H]

Is it stronger to cast the block vs using a round extrusion that is the same diameter?

Good case made for cost. Does anyone know about strength?

[DIYSwede]

For me personally, I'm into casting mostly for cheapness, but also to get the stock sizes and forms I need.

2nd: No pure Al (like ladders, extrusions, beer cans) in my melts, only stuff that has been cast before:
My favorite is the AlSi10Cu3Fe die-casting alloy ("383"-ish), which I can get for free from discarded office furniture stands at work.

This alloy has excellent corrosion and casting properties (even in sand casts), machines nicely with short swarf,
but the Si content makes it rougher on HSS than pure Al. I've got abt 100 lbs of those cut-ups to melt.
Cannot be aged/ heat treated (though some research reports claim to have managed that, too) nor anodized.
Properties: 80-100-ish Brinell hardness, 45-50 ksi tensile strength and a mere 1000-1100 F melting point. Cold ages in a month.

This alloy could also be combined with ZA-8 Zamak to get a lo-creep bearing alloy with better properties than bronze
at very high bearing pressures and lo rpms:
Metallurgy for DIY:ers - Meccano Gallery

Just my 2 cents
Johan

[celsoari]

I always appreciate your contributions, Celso!

Thanks Bro