Wheel Replication

[GazB]

I'm considering trying to replicate wheels for an older HEMTT kit I have (the Tanker, which doesn't seem to exist anywhere anymore). I currently have a set of resin ones I'm using on another M977, but these are actually too small in diameter to be entirely correct. Since the DEF wheels I was looking at were both expensive and snapped up almost instantly, I've looked into the possibility of creating moulds of the tyres and hubs from the Italeri M1120, which I also have.

 

I've never done casting before so I'm a little unsure as to the process. I don't really have the ability to buy all of those pressure components and stuff, but I've been looking at this product: http://www.greenstuffworld.com/en/inicio/545-silicone-putty-300gr.html

 

Been wondering what would be easy stuff to pour into it, and what the best way to cast these wheels would be. I've considered assembly of the tyres and hubs, then making three moulds for each of the types. Its how to position the wheels in the mould that I'm wondering about. A single piece mould would provide the best result but, trying to get the wheel out again (I considered adding a small stick to create a channel) is something I'm not sure about. A two piece mould could work but, I don't know how I could pour a liquid into both and get a good result ultimately.

 

Any advice on this would be much appreciated

 

Gaz

[Hotel Papa]

Doesn't look like a mould to pour this into is of any concern, as its a rather thick putty, kneaded by hand. How I would go about this:

 

Mount the master on a base (which will form your pour block / funnel), modeling a pour gate.

 

Knead up the putty and fully enclose the master and pour doohickey with copious amounts of putty. Set the whole shebang on a flat surface with the pour gate oriented upward, squishing the bottom to form a solid base for later.

 

Once it's hardened, use a fine blade to cut an scour along the pour gate and as far around the perimeter of the wheel as is necessery to work the wheel free from the mould. Pull out the master. Using silicone has the advantage that you can work from single piece moulds, as they stretch and bend easily and snap back into their original shape.

 

Pour to your heart's content.

 

If you don't like "blobby" hand kneaded moulds, you can use what many use for casting liquid silicones: Lego. I'd start as described above, then squeeze the mould into a Lego frame instead of just setting it on a flat surface.

Edited April 11, 2017 by Hotel Papa
typos / semantics

[GazB]

6 hours ago, Hotel Papa said:

Doesn't look like a mould to pour this into is of any concern, as its a rather thick putty, kneaded by hand. How I would go about this:

 

Mount the master on a base (which will form your pour block / funnel), modeling a pour gate.

 

Knead up the putty and fully enclose the master and pour doohickey with copious amounts of putty. Set the whole shebang on a flat surface with the pour gate oriented upward, squishing the bottom to form a solid base for later.

 

Once it's hardened, use a fine blade to cut an scour along the pour gate and as far around the perimeter of the wheel as is necessery to work the wheel free from the mould. Pull out the master. Using silicone has the advantage that you can work from single piece moulds, as they stretch and bend easily and snap back into their original shape.

 

Pour to your heart's content.

 

If you don't like "blobby" hand kneaded moulds, you can use what many use for casting liquid silicones: Lego. I'd start as described above, then squeeze the mould into a Lego frame instead of just setting it on a flat surface.

 

Thanks for the advice 

 

Gaz

[GazB]

Oh, one more thing. I've been looking into the various resins around and they all seem to be large bottles or tins and rather nasty stuff. In fact the only epoxy resin I found that looks like what imagined (with the two syringes), is the AK Interactive water stuff. Everything other one was an adhesive. So I'm wondering, can something like liquid plaster or hydrocal be used, just for ease?

 

Gaz

[TheRealMrEd]

Gaz,

 

You could use "Durham's Rock Hard Water Putty". It's a powder that you add very small amounts of water to, then mix. Pour into your mold (has to be liquid tight) and let dry. Will have about same consistently as hardened plaster when done, so not as tough as resin. You may also have to glue it on with canopy glue or the like. Play around with the water/mix ratio  and see what happens. Good news is, it won't stick to plastic, so no mold release needed.

 

The Durham's is carried by the big box lumber stores in the US, can't say where you might find it in UK.

 

Good luck,

 

Ed

[Black Knight]

On 12/04/2017 at 9:54 PM, GazB said:

Oh, one more thing. I've been looking into the various resins around and they all seem to be large bottles or tins and rather nasty stuff. In fact the only epoxy resin I found that looks like what imagined (with the two syringes), is the AK Interactive water stuff. Everything other one was an adhesive. So I'm wondering, can something like liquid plaster or hydrocal be used, just for ease?

 

Gaz

for very small quantities you can use Araldite or similar two-part epoxy glue

An alternative is David's Fastglas fibreglass resin, minimum quantity tin is about 125ml

[GazB]

On 6/4/2017 at 9:32 PM, Black Knight said:

for very small quantities you can use Araldite or similar two-part epoxy glue

An alternative is David's Fastglas fibreglass resin, minimum quantity tin is about 125ml

 

Cool, thanks

 

Gaz