Casting Aluminium (not aluminum, you yanks just cant spell gooder!!!!)

[artie on edge]

Hi groupies, today was the day I cast my final drive housing and am offering a photo shoot of the process plus some hints.

Many of us could cast our own stuff but just dont cause it is a whole lot of "black magic". The truth couldnt be further from reality.

The next few pages are my experiences... rightly ot wrongly, its what i done. You dont agree??? Go grow flowers..... and enjoy that process.... got any ideas which will help me  (and all others) please post right here..now..no do it now!!!!

[artie on edge]

Ok...firstly some back ground.

I have built the Edge products Barracuda (based in Australia). This is a fine vehicle for play but as Im a die hard racer I found a few issues which I didn agre with and proceeded to alter. No critisism of the design. I was simply taking it further than its design parameters (full scale racing). Otherwise good job Tony and the team at Edge. (www.edge.au.com)

One of these issues was the final drive, end result was I needed a housing with certain parameteres which I couldnt buy. Outcome? Cast the fu^%$3 myself.

The following is my journey, I have thoroughly enjoyed myself (as have my mates who helped) and I have a very serviceable unit (2 actually).

Next page....

[SPEC]

All right,
I planted my flowers...where's the pix?...Flowers will be under a few feet of sno before they come up here

[artie on edge]

Firstly the design had to be finalised and I think I was on to MKV before I was happy.

A life sized drawing was created and glued to 3mm MDF




and this was screwed to 35 mm particle board and a flush trim router bit was used to create a 35mm thick copy of th edrawing. As my unit needed to be 70mm thich I added another layer of particle board and again the flush trim router created a 70MM thich plug.




This was filled with spack filler and sanded and then sealed with polyurethane sealer.

 


 

 

[artie on edge]

The foundry is one I built many years ago and has made many parts for full sized off roaders. Today was its first foray into superlites... Go Foundry!!!

Ok casting sand is a very complex mix of ..... sand and cooking oil..... sorry I cant be more exotic but yes folks..thats it!

A fine sand is mixed with ANY oil, some use use used engine oil, I dont like the smoke. Its bad enough with new clean cooking oil, the cheaper the better.

The sand (about 40kgs) is mixed with around 4 litres of oil and mixed and mixed and mixed until the sand will reatain its shape when squeezed and can be broken into parts.

Then a layer of sand is placed in the casting box and the mold placed on to this. Sand is then slowly hammered into place around the mold until its level with the molds upper surface. Smoothed and then the mold is withdrawn from the sand leaving the hole you wanna fill with molten metal.



Sounds easy, it isnt, you might need acouple of goes and some repair work to end up with a workable mold.

[artie on edge]

Im sorry I didnt get a pic of the pour happening but i can only do so much at once.....

The foundry is a really good piece of gear and over the years has mort than paid for itself when various pieces of alloy "stuff" has broken and couldnt be replaced.

[artie on edge]

So it was poured and it all went really well. The trick to casting aluminium is to not get it too hot. Basically its really easy. The crucible (about 2 litres capacity) comes out red hot. Its then sat on heat bricks until its black and then the pour happens. The indicator is a nice bright shine to the metal when its broken from the mold.




I used an open cast technique this time because the unit was so intricately shaped. Normally the mold would have a top and pour holes with several vent holes.

A closed mold has the advantage of reducing shrink back or sunken surface.

As I was moolding to 70 mm and the desired result was 60mm, I had material to waste so an open (simpler) mold style was chosen

[artie on edge]

Ok what did we end up with? two housings, both of good (non porous) quality and one already partly machined.

 

And the pair, one not yet desflashed or had its bum wiped



The main drawback of an open cast is the amount of flashing you end up with having to trim off. The semi finished casting took 3 minutes to transform from that butt uggly unit in pic two to its prisitine self. Not too much trouble overall.

I had a great day, I love creating stuff and during the week will introduce these to my mill. I always use the belt linisher before I mill (as in the pic of the single unit). This will remove any residual sand grains in the casting surface which mill bits DO NOT LIKE!!!!!!

[VLADD]

That's EFFEN COOL Artie

[Whiplash]

One of the coolest posts on here yet!!!

[405dentech]

That was awesome. I thought that i had a few fabrication skills. Killer job!!!

[phelpsracing1]

Yes I would have to agree that is awesome. I want one of those!!

[Rick S.]

Do any of the companies selling drives with housings like this use an aluminum extrusion
instead of a casting? I've always wondered why I haven't seen them extruded  vs. cast.
Not for building just 1 or 2 of course, but for large quantities. Have them extruded in 25' lengths and slice off what you need.
Very nice by the way.

[fabr]

HUGE expense for extrusion dies for something that size.

[Rick S.]

Have you priced it out?
We've had dies made for extrusions near that size where I work.
We do sell a ton of extruded rail though. Some are 30' lengths.