Anyone here able to do a little cnc milling or know a cheap place?

[Bki26]

Usually make these out of some plate but now I've started casting ali I'm tempted to try making them in one go by gravity casting but would need a mold for it, 80*80mm 10mm thk plate.

The whole thing could be done with standard endmill then just a 2.5mm ball nose endmill for radius parts, total size is 50*45mm 5mm thk.

 

[Fastdruid]

Can try here: https://www.machining-4u.co.uk/

 

[Bki26]

I really should convert my Cmd10 mini mill to cnc..

 

[Bki26]

Can try here: https://www.machining-4u.co.uk/

Thanks for that, posted.

 

[m_c]

If I've got the correct ball nose mill, I'd give them a go.
Only thing is, surely you need some dowels to align the plates?

 

[Bki26]

If I've got the correct ball nose mill, I'd give them a go.
Only thing is, surely you need some dowels to align the plates?

Probably would help, dunno why I'm just thinking of just aligning the corners as that's assuming the plates are same dims/machined in same location

I'll add two in opposite corners to the model lol

 

[gaz1]

make the form out of wood with a wood router

 

[Bki26]

make the form out of wood with a wood router

Would just burn when you pour molten Aluminium in it and practically be single use. Plus I'd still need to get it cnc made.

 

[julianthegypsy]

Would just burn when you pour molten Aluminium in it and practically be single use. Plus I'd still need to get it cnc made.

I think he's talking about sand casting....

 

[brightspark]

what you looking at making split metal mold instead of casting in sand using a pattern

 

[Bki26]

I think he's talking about sand casting....

Ahh, yea that could work but lot of time/effort sorting sand/making mold when all I'd need to do for this method is clamp the two plates pour in the ali and then separate and repeat.

 

[Parm]

Ahh, yea that could work but lot of time/effort sorting sand/making mold when all I'd need to do for this method is clamp the two plates pour in the ali and then separate and repeat.

I’ve seen that done a good few times, they call it high pressure or injection casting

Moulten Ali is forced in under pressure, a common technique for many car parts

Will gravity feed work? I think you need an opening to put in and then a vent hole to allow hot gases to escape

 

[Bki26]

I’ve seen that done a good few times, they call it high pressure or injection casting

Moulten Ali is forced in under pressure, a common technique for many car parts

Will gravity feed work? I think you need an opening to put in and then a vent hole to allow hot gases to escape

The large central hole is to feed it, two smaller holes either side are for venting.

If I have a large enough head (couple inches) it should be enough to force it in or I can attach a pipe to the central hole and shrink the vent hole size and use a rod to apply pressure

 

[Agroshield]

If I have a large enough head (couple inches) it should be enough to force it in or I can attach a pipe to the central hole and shrink the vent hole size and use a rod to apply pressure

With the relatively large mass of the steel mould, might it not act to chill the aluminium very fast before it reaches the edges? Would you need to preheat it somewhat?

I do not know how much the aluminium will stick to the mould once solid, but as well as the locating/register pins, perhaps drill and tap one side for some bolts to jack it apart if needed.

 

[daedalusminos]

I've not done any gravity casting of aluminium, but If what I have done is anything to go by:

Fill from the bottom and vent at the top (the last thing you want is something blocking the vent
Put your fill and vent ports on the split line - makes getting the moulds apart easier.

Personally I'd prototype the theory before spending too much, try casting a solid block or disk - something where you can cobble the moulds together yourself.

 

[Johnnybravo]

I used to make aluminium diecasting tooling. All the molds I made were rough machined from tool steel,leaving 0,5mm on all surfaces. Sent for through hardening. Then finished machined in the hardened state before being sent out for nitriding.All the tools were heated and the core side had water cooling to get the part to stick to that side as the tool was opened. Ejector pins then pushed the part,with the sprue and the overflows still attached,off the core. The part then went into a trimming tool to have all the unwanted bits trimmed away.

The last lot of tooling I did was for the stadium lights used in the 2010 football world cup in SouthAfrica. It was a good contract, Tooling for five or six BIG castings …Also did the diff covers for the 4x4 Toyota Hilux with the diff lock. Still have those drawings on my computer

 

[Johnnybravo]

Diff , cavity side insert. Big yellow circle is where a Beryllium Copper piston forced the aluminium in.