Anyone do alu casting?

[Tinbasherdan]

As above, I’m trying to make a shifter conversion with a friend that issues the standard landrover parts in a new housing. I have a pattern that can be used

anyone fancy a go?

 

[julianf]

I dont, but im building up to doing so...

As in have got as far as bread tin ingots, and have a cope and drag, and greensand, just never actually done the rest yet (for various reasons)

How large is your pattern?

 

[brightspark]

a picture and size helps

 

[Tinbasherdan]

120 wide, 140 long and about 80 tall

 

[Tinbasherdan]

the grey bit only, the shifter ball is seperste

 

[brightspark]

where's the pattern u made u cant use an original because it will shrink on cooling and be smaller

 

[sako243]

Why is this not a surprise... Calling @8ob

 

[Tinbasherdan]

where's the pattern u made u cant use an original because it will shrink on cooling and be smaller

That’s a 3D printed pattern, we are assuming there will be some machining. Off the top of your head how much extra should be given on a pattern to account for shrinkage

 

[8ob]

That’s a 3D printed pattern, we are assuming there will be some machining. Off the top of your head how much extra should be given on a pattern to account for shrinkage

On all the stuff I have done it's been an 1/8" in the foot, where you get a mass like in the middle of that casting it tends to pull on cooling and will curl ( a bit).

Bob

 

[Tinbasherdan]

On all the stuff I have done it's been an 1/8" in the foot, where you get a mass like in the middle of that casting it tends to pull on cooling and will curl ( a bit).

Bob

Ah grand job. Have you any thoughts on it?

 

[ukracer]

As above, I’m trying to make a shifter conversion with a friend that issues the standard landrover parts in a new housing. I have a pattern that can be used

anyone fancy a go?

@doubleboost has just got his gear out again..

 

[Seadog]

@doubleboost has just got his gear out again..

 

[8ob]

Ah grand job. Have you any thoughts on it?

Yep, fill in all the drilled holes including the big one where the shifter is, get rid of the bull nose at the front and make it so it will release/reverse out of a sand mold, machine all the cleverness back into it from the blank casting.

Bob

 

[brightspark]

Ah grand job. Have you any thoughts on it?

make a core for the centre when its cast reduce the mass

 

[Tinbasherdan]

Yep, fill in all the drilled holes including the big one where the shifter is, get rid of the bull nose at the front and make it so it will release/reverse out of a sand mold, machine all the cleverness back into it from the blank casting.

Bob

The bullnose is there for the centering spring on the shifter mate, without it it flops around like a cock in a sock

 

[8ob]

The bullnose is there for the centering spring on the shifter mate, without it it flops around like a cock in a sock

I didnt mean do away with it, I meant change the shape of it so that if the thing is pressed into a mold it will reverse out without tearing the sand. Brightsparks core is a good idea if it can be centred properly.

Bob

 

[Tinbasherdan]

I didnt mean do away with it, I meant change the shape of it so that if the thing is pressed into a mold it will reverse out without tearing the sand. Brightsparks core is a good idea if it can be centred properly.

Bob

Ahh gotcha

 

[graffian]

That’s a 3D printed pattern, we are assuming there will be some machining. Off the top of your head how much extra should be given on a pattern to account for shrinkage

I made my patterns 3% bigger.
It was the figure given to me by the foundry.

 

[minimutly]

I dont, but im building up to doing so...

As in have got as far as bread tin ingots, and have a cope and drag, and greensand, just never actually done the rest yet (for various reasons)

How large is your pattern?

Mee too, started making a melter to convert alloy wheels.

 

[ronan]

I see a lot of people doing 3d printed patterns, makes things easier i suppose if you're not too good with woodwork.