Machined Steyr receiver and outer grip

[Skin-Job]

Hi Everyone,

Did anyone ever manage to produce machined Steyr receivers and outer grip frames as direct replacements for the Coyles?

If not, is it now possible to have accurate versions 3D printed in sintered metal?
I know this method used to produce very rough results, anyone seen any recently?


Karl

[joberg]

Good question...3-D is certainly an option (don't know what kind of material you'd use for the final printed product).
Someone with the necessary knowledge could do a CAD and do it themselves or farm it somewhere else

[Skin-Job]

I have had a lot of brass castings made by a very advanced technical foundry here in the UK.

Another possibility is to produce a new master (I will not be party to recasting someone else's work) and have waxes injected into a mould of it, then send for lost wax casting in white bronze or stainless steel or aluminium.

My foundry does all these metals, and more.

Karl

[DaveG]

We've had some parts made in sintered metal. It's a very cool process but since the original material is a powder, the finished piece has a bit of a granular texture to it. Not a machined look at all. And it's VERY expensive.

The idea posted about doing a lost wax investment casting is more valid. A foundry i've used can do Stainless steell as well. One thing to keep in mind is that both the wax and the metal shrink a little as they cool. The final part is about 5 percent smaller than the original pattern.

I've always wanted to do a bronze version of the blaster, kind of Steampunkish. Now that would be cool!
_________________
Dave

"I just want to say people... Get A Life! Move out of your parent's basement! It's just a movie!"

[joberg]

Sure thing guys, Lord knows that metal work, molding techniques and the type of metal used into the finished piece can add to the price for sure...
Dave, the bronze gun is a good idea and you're not the only one who thought about using anothter type of metal to get another look for that prop.
I even thought about mixing metals to make it more interesting; not only in terms of colours but the challenge that this kind of project will bring to you (and the tears )
The Steampunk (or even DieselPunk) is a great idea; bronze, copper, stainless, alu, etc...

[Skin-Job]

I think I may have been misunderstood. The bronze I was talking about is white bronze. It's a silver colour similar to bare steel, very slightly yellowish.

Dave, I've done a lot of work with my foundry and by using specialist waxes and casting methods you can get the shrinkage down well below 5%
I've had castings done which are less than 1% smaller.

The 5% you're talking about is likely compound shrinkage caused by slight shrinkage in the silicone rubber mould of the master model used for casting waxes, the waxes themselves (by far the biggest culprit usually) and the slight shrinkage of the casting itself.

Clean, precise castings using the lost wax method are far more achievable these days.


Karl

[racprops]

I looked into these years ago.

BUT the shrinkage and keeping all the detailing was near imposable to correct.

NOW a DAYS a very good 3D scan and some over sizing in cad COULD correct for these problems.

It might take a few tries to get the master sized to allow for the shrinkage of all the parts,(wax mold, wax, casting mold, metal castings, each may have a different shrinkage rate...etc) but it is possible but a lot of work.

I think you will have to tweak FOR each metal to get it to come out at the correct size.

One other problem I ran into years ago was that lost wax castings I tried were all different from each shot. Not two were of the same size and shape. I found it very unusable.

None the less I am willing to give my OK for you to work from one of my models IF I get copies.

Rich
_________________
I never have enough time to do all I want to do!

[Skin-Job]

I think I'm having a hard time being heard,,,,,



I made the Mal Model 47 and Model 47A replicas. During production of the first Mal model, the shrinkage was a problem. Compound shrinkage as I explained above.

On the Model 47A run, COMPOUND shrinkage was under 1%
Very minimal loss of detail. The castings were silicone brass. Very hard.... for brass.

It is possible these days, times have changed. You may not need to allow for shrinkage if it's just 1 or 2 per cent.

I know you looked into lost wax castings, Rich. I was told by one of the foundries I ultimately rejected


Karl

[racprops]

That is cool.

Both what you did and now what can be done.

Rich
_________________
I never have enough time to do all I want to do!

[DaveG]

Karl

Nice work on the Mal 47s! I've always wanted one if those but only found out about them too late.

I just did a 1/4 scale bronze Rocketeer helmet and had the shrinkage issue. It was not in my molds, which I had made previously for some resin castings. I would say that the foundry's wax castings were more likely the culprit, they were less than precise in making them. For the helmets it was not an issue. For gun parts it would be more so. I am looking into making my own waxes for future projects. And some other foundries in my area.

Do you have any information available on the type if waxes that performed the best for you?

Cheers

Dave
_________________
Dave

"I just want to say people... Get A Life! Move out of your parent's basement! It's just a movie!"

[hirohawa]

If there is a legit way to do this that would yield great results I could lend a real Steyr receiver to the cause.

[DaveG]

[racprops]

[hirohawa]

Yup!

Mine is a 1967 with the 4 digit serial numbers and proof marks all in a row (not over and under) just like the real deal.

[racprops]

There you go.

Rich
_________________
I never have enough time to do all I want to do!

[joberg]

This is getting interesting by the post...sorry Karl if I misunderstood you, I was reading into stuff I've always been interested in and that's why I jumped to conclusion
Casting in metal is another science altogether and it's fun to have specialist on the board to "show and tell".

[Skin-Job]

Dave,

Thanks for the nice words about the 47s.

Can't be specific as to brands of waxes, due to a promise to the foundry. Can tell you the good waxes are green. The darker, the better. Purple, blue and pink, not so good.

Slim pickings, but I hope it helps.




Karl