Snow Trac wip (rescaling Matchbox diecast to 1/56 approx - UD 29/1)

[Silent Invader]

Still on schedule 

Moulds of the plasticard parts made from RTV rubber



They now need 48 hours to 'dry' then I'll drop cast the metal masters.

A problem with drop casting (ie, using gravitational rather than centrifugal force) can be getting metal into the nooks and crannies before it cools too much to flow properly. The big pour hole will help, as it will be completely filled so the weight of the excess  will hopefully force metal into the finer hollows (such as the tank tracks).

We shall see!

[Mason]

Great stuff!

Looking forward to these.
 


I used to work in a sculpture founders as a sand moulder and caster, so fully appreciate your reservations regarding gravity and metal cooling.
Of course that was on slightly larger moulds than these.
 

[v_lazy_dragon]

Good luck Steve - my attempts at drop castng have always been iffy, although in retrospect that may have been from the mould outgasing and cooling the metal prematurely

[Silent Invader]

Yes, it will be interesting to see how it works.

Don't forget though that I am using these moulds to produce metal masters to be vulcanised, so I can go hotter with the metal and the mould, as I haven't got to get many casts from them. 

(Fingers crossed as I really don't want to have to remake the tracks..... ) 

[sandsmodels]

splendid work, but you can vulcanise the plastic masters i do it all the time, you just need the right rubber discs.
if you need help just pm me
shaun
s&s models

[Silent Invader]

Thanks Shaun.  Well that's me educated then: i'd thought styrene was too low temp for vulcanising (tho I suppose a low temp silicone would do it).

[OSHIROmodels]

You really are a one man band aren't you 

You'll be making your own cnc machine next (or a laser  ) 

cheers

James

[von Lucky]

I'm off travelling for a week and this place is churning out wargaming gold. Nice one Silent Invader.

[sandsmodels]

Thanks Shaun.  Well that's me educated then: i'd thought styrene was too low temp for vulcanising (tho I suppose a low temp silicone would do it).

when i was shown this then 'new' silicone low temp rubber i was mightily impressed, back in the early 90's,  now it takes less than a day to go from a plastic or resin master into metal parts either for sale or more multiple masters.
it is great stuff if you can use it properly
you could even use 'g' clamps and your kitchen oven, (wife permitting!)
if you have mould boxes.
glad to help

[Silent Invader]

Thanks Shaun

Sooooooo, I'm about a week behind schedule as I while I was able to successfully drop cast 99.9% of the metal masters, that bit that wouldn't fill was an absolute pain to recreate ..... Damn tracks !

Anyways now fannied around with and I have masters than can be vulcanised for spin casting moulds. Yay.

This next round of mould making should be in the next day or so.

[Too Bo Coo]

Looks great Steve!  Cant wait to see it in stock for my greedy Scavengers!

[Mason]

Great result!
 

Good man.
You can put me down for at least two sets, maybe more if I can pick up the chassis on ebay at a reasonable price.
 

[Silent Invader]

Well thank you but let's await production castings  before we get carried away  (who am I kidding, I bought 9  ).

[snitcythedog]

A problem with drop casting (ie, using gravitational rather than centrifugal force) can be getting metal into the nooks and crannies before it cools too much to flow properly. The big pour hole will help, as it will be completely filled so the weight of the excess  will hopefully force metal into the finer hollows (such as the tank tracks).

Looks like you know what you are about, since your venting is done very well.  I am hoping that your mold works well.  Interesting project all around.
Snitchy sends.

[Too Bo Coo]

Very impressed with your talents!