Tom's Casting Journey

[thd9791]

Hi folks.

I thought it would be nice to document this.. I'm working on a mold of R2D2's taser arm tip (I checked with Ryan) and I'm doing it in Telephone Solder. I've done this with the Phantom menace red buttons and Yuma Control Boxes.. just realized I could do michell knobs too, oh crap

Anyway, I've come a long way. I started with high-impact beige Smooth-On, moved to their Onyx stuff and then started working with a company that produces much more reliable SFX materials but they advertise for hobby stuff, MPK, so it's easily accessible as a residential person. It's taken me a while to dial in what I need for different things... anyway, as I wait for side #1 I thought I would hunt through my pictures and collect them here.

I literally can't find my old disasters from like 2015 or earlier, but just imagine me with a paint scraper and chemicals trying to clean up spills from molds that hadn't sealed, parts that didn't cure, *shudders*


Eventually I moved onto more complicated things


and bigger things!


And then started making masters to mold



Some things failed miserably


My most recent run and the pigment disaster



At a recent engineering fair I made a museum display with some of my greeble casts

I'll upload pics of the R2 thingy soon

 

[thd9791]

Got 'em! My first molds, pulled from facebook

 

[Mottrex]

Cool thread I love molding and coming from a dental background had access to various materials mainly resins but more importantly a messy place to work in my spare time..

Nothing better than being able to leave a mess and just walk away without having to clear up all the time.

Nice metal castings by the way, I mainly use putter with the red high temp silicone which works a treat with no breakdown to the mold.


Good luck with your build!

 

[thd9791]

Oooh any tips learned from dental casting? That’s so cool!!!

I just tried a knob and some voids/depressions kept getting trapped in the bottom.. realized I need an exit gate lol so this is good, I can re-work my R2 mold a little, I think the threaded portion is too thin

 

[thd9791]

PSA: I have used this can on 5 different projects and none of them have stayed separate. I don’t.. there could be a lot of factors but I’ve lightly and heavily coated projects and they’ve all come out as a solid brick of silicone lol


My comlink stayed separate… and that was Vaseline and art paint thinner got that tip from a buddy who worked on SW Ep3 coincidentally

 

[Halliwax]

Tom, in all seriously and sincerity. I have had the pleasure of watching you grow over the years. You basically started off with nothing but a dremel

You slowly grew your tool collection, and with more tools you learned more and more skills sharing all your updates here

Some of the stuff you have accomplished, with the little amount of tools you have has totally impressed me

You are a classic example of working hard, applying yourself, and getting the job done

I am very proud to call you my friend

 

[scarf man]

Well said Halliwax I totally agree with your sentiments. thd9791 you've come a long way, and continue to delight and surprise with your skill and dedication to research in particular.

 

[thd9791]

WOW thank you Danny, I am also extremely grateful to have friends like you share tips and encouragement, I’ve felt the same way seeing your projects on here

And you as well scarfman!

 

[The 48th Ronin]

Here's what you want, Tom:

Works every time.

 

[Halliwax]

WOW thank you Danny, I am also extremely grateful to have friends like you share tips and encouragement, I’ve felt the same way seeing your projects on here

And you as well scarfman!

Danny? Halliwax only knows 1 Danny, he’s got a bad reputation in town I don’t want to be confused with that guy

 

[thd9791]

Heyyyyy my first attempt at a bottom up pour gate worked

 

[Halliwax]

Came out great!

 

[thd9791]

Thank you! Here’s another pour spout lesson that im just learning. In a gravity pour the lowest gate is your limit. I thought I was only evacuating air

Anyway, I decided to re-route the exit. I’m going to take an xacto and slice a vertical spout just like the other one! Need a little silicone to block the exit

 

[thd9791]

 

[greenmachines]

OK, I get that it is a useful idea but safety guy (my internal voice) kept yelling, "No...Wait.... not toward your finger...whoa, hold, uh, umm, aaaaaaghghgh" and I had to turn it off. Obviously much better with a blade than me.

 

[Mottrex]

Oooh any tips learned from dental casting? That’s so cool!!!

I just tried a knob and some voids/depressions kept getting trapped in the bottom.. realized I need an exit gate lol so this is good, I can re-work my R2 mold a little, I think the threaded portion is too thin

I guess obvious things like adding vents and sprues for one.
Centrifugal (Spin) casting the old way to cast an object gives awesome results but not for the faint hearted. It doe give greater detail to the lower melt alloys.
Under cuts and prevention another one

Split casting is prolly the one less well known which is basically two halves of a mold filled with a material resin in my usual case which is then clamped and placed in a Boiler to cure. The benefit is under pressure forces any bubbles and creates a dense structure(thats how pretty much Every denture is made)

Pressure vessels again cures cold cure resins quickly and under pressure. Cold cure was developed to make both orthodontic appliances/retainers and commonly to fix dentures, I used this method called Salt n pepper for many other projects including dental fangs face masks and various props and figures over the years.
Even duplicating military badges for a Strangelove uniform for an event.

Once molded the salt n pepper technique is fantastic for making greeblies in minutes.
I found out quite early on that good old humbrol acrylics could be used to colour our resins and resulted in many prank dentures behind sent out to dentists. It was also used for some of the first multicoloured Orthodontic appliances/clips/retainers for children.

Having vacuum forming machine I used to make sports guards/gum shields but having an eye for it made vampire teeth and many other styles that could be worn by a client and friends alike.
In these cases it payed to survey a cast of a client's teeth to avoid any undercuts which could cause breakages to the appliance or purely not fit.

Oh plaster of Paris can be your best friend or your worst enemy...
Thermal expansion
Cold mold seals
Vaseline
All to be taken seriously to avoid both headache and literally pain..

 

[Mottrex]

OK, I get that it is a useful idea but safety guy (my internal voice) kept yelling, "No...Wait.... not toward your finger...whoa, hold, uh, umm, aaaaaaghghgh" and I had to turn it off. Obviously much better with a blade than me.

That's very much like when I see people on YouTube using dremels in a haphazard manor.
I use high-speed dental motors 36000rpm and above. We were trained to use them using Diamond cut and tungsten bur and blades. Those cut off discs could slice into flesh if not handled correctly..and sometimes did.
But enough of my dental foe pars... I could be here all day

 

[thd9791]

Well, I’m slowly destroying this mold. I already cast some resin ones with screws embedded in the tail, but today I got a cheap crucible and went ahead with my original plan!

I’m thinking I get one of those cheap sand boxes if I want to keep this up. You make the mold each time right?

Anyway I’m also thinking I might cut, drill and tap the ends for the screw thread… we’ll see. I’m making a few and I’ll put extras out there for people

 

[Media Man]

Sand casting would be great for that! Get some delft clay for casting.

 

[eethan]

good job on those metal casts