Casting 1.5"x12" Al Rods

[cg 2005]

I have an upcoming project that requires a couple dozen 4.5" Al rods that have multiple diameters. The rods are not structural so I decided to cast in lieu of purchasing the 1.5" by 6' rods.

I put together a mold using 1.5" pipe, which actually has an I.D. of ~1.6".

The mold was preheated as the melt became molten.



My melting pot holds about 41 cubic inches of molten metal. Since the rod mold has a 21 cubic inch capacity I used another set of molds for the overflow material.



After cooling to room temperature the rod was pressed from mold.



The cast rod was trimmed and the initial turns made.





I lost about 3" of length due to shrinkage but only about 0.125" off diameter.



The finished rough cut rod was 1.490" x 9".

I anticipate no porosity on the interior. I find that all the porosity tends to occur at the mold interface.

All in all I am very pleased with the casting.

 

[sniggler]

wow what alloy are they and what are they for.

bob

 

[cg 2005]

This melt was a bunch of 6061 floor drops that were bent.



I have requests to make a dozen of these highway pegs and the mounts for some BMW enduro riders.

 

[sniggler]

Re: Casting 1.5"x12" Al Rods

Will you heat treat them?

 

[cg 2005]

Re: Casting 1.5"x12" Al Rods

Will you heat treat them?

- - - Updated - - -

Will you heat treat them?

No reason to heat treat. These are not really structural pieces. I am open to your suggestion as to why I should heat treat them.

 

[sniggler]

When annealed 6061 is around 20% of it's potential strength. It's a motorcycle foot peg that is structural all the way! The hole in the peg may elongate under the load if the material is too soft.

Bob

 

[cg 2005]

I understand the loss of strength. With regard to these pegs being structural parts, they carry the load of the rider's resting leg. They are not placed in a location on this particular BMW model that allows the rider to stress the part with his entire body weight by standing on the peg. I suppose even those limited forces could define the part as a structural member. I would whole heartedly agree that the main pegs for the rider and passenger should be considered structural members.

 

[Pacer]

A tip for casting in a metal piece like that pipe -- Smoke the inside walls before pouring and I will ease removal of the casting a LOT.

An acetylene torch with just the gas burning and let the smoke get all inside the walls - for a smaller piece candle smoke will do, or anything else that will give a sooty smoke. I also keep a spray can of graphite that I coat the walls with on occasion, I think it actually works better than smoke.

 

[cg 2005]

Thanks, l have some graphite. I'll give it a go this PM.

 

[sniggler]

No i think they are still structural I,m a motorcycle nut, i commuted from L.I. to NYC for years on them. i own 7 or so right now. so i'm riding along on the highway pegs sudden pothole, obstruction moron stopshort in front of me again i brace my self no time to switch pegs highway peg failure = a big shift in weight and maybe loss of control and a crash.

1977 Harley Davidson Superglide FXE (first bike)
1981 Honda cx500 2 units
1983 Honda cx650 2unit
2006 Honda 599
2004 Suzuki DRZ400
2006 Suzuki DL1000
2010 Honda VRF1200