I would like to make a model that appears as though it is produced from plastic. I would like to produce it in a slipcast type manner.

I have seen model making materials, where the mold is a silicon/rubber type material which is peeled cut away from the end product. The end product being produced from I’m unsure?? setting plastic, resin. The mold material did not stick to the end product, whether this was through using a release agent or the actual mold material I’m again unsure.

Anyone know what I’m on about and where could I source these materials?

http://www.tiranti.co.uk/subdivision_product_list.asp?Subcategory=51&Subdivision=

Sounds like you are talking about vacuum casting?

http://www.materialise.com/materialise/view/en/372680-Bosch+vacuum+casting+sander+.html?cat=2423049

You will need some mould release.

It can be a bit tricky to get a good model depending on the shape. You might be better off getting a model maker to do it all for you, or maybe a different method like SLA. You’ll get a better result and it’ll probably work out cheaper. Its fun to play with if you want to have a go, though.

Thanks for all the help, I’ll have a look tonight after work. Model maker is probably out the question, as it is just for my own design work at home as the design work in my current job is both soul and portfolio destroying. like you say it will be good fun!!

Another way would be to make the part in something like MDF then make a mould from it with fibre glass, but you’ll need to be able to get the part out (google ‘draft angles’). A fibre glass mould will be stiffer and last longer, just depends how many parts you plan to make, and how much time to invest in it. When I’ve used silicon rubber I’ve always used a vacuum pump as it’s full of air which can make a mess of your mould

How bigger model would you be looking at making and what is it off?

normally it’s a hard PU resin injected into a silicone mould.

this is what we used to do when making wheels for 1/4 scale concept cars, make a pattern part from ureal, then take a silicone mould of the part, and reproduce the wheels using a hard PU resin.

the design of the mould is very time consuming as you have to design a fill hole to put the material into, and several drains so that air can bleed out of the mould.

Try a Rapid Prototyping company. They will be able to produce exactly what you want in small volume with a very quick turn around, from a CAD model/drawing.

This may turn out to be cheaper than attempting the tooling yourself?

i actually do quite a lot of rapid prototyping these days. depending on the type of machine used the item needs quite a bit of finishing, but it’s a godsend.

obviously you need to produce the object in cad data, and the model has to be built to pro engineer acuracy 0.02mm and can have no intersecting surfaces.

the last set of wheels i did were RP on an FDM machine, which i think is the cheapest, but SLA will give better results.

I was going to suggest as JacksonPollock but it depends on the size. We get prototype engine components made via rapid prototyping. It can be expensive though but I know a couple of companies that offer competitive prices

How bigger model would you be looking at making and what is it off?

1:5 most probably and it will be of furniture/product. In this case a simple stool.

Sounds like you are talking about vacuum casting?

Looks like that could be it.

What is ureal? What your talking about pinches definitely sounds along the same lines as what I need.

thanks for the advice.

I managed pretty decent results using a silicon mould and fast setting polyurethane resin for my battery holders.

Production items used a rapid-prototyped pattern, but initial tests were with a simple wood/cardboard pattern.

Cheers, Rich

It can be expensive though but I know a couple of companies that offer competitive prices

By all means I am interested in the companies?? but I would like to learn more about model making and also feel it will be a bit expensive at this stage.

What is ureol? What your talking about pinches definitely sounds along the same lines as what I need.

ureol is a really high density foam you can get it in different grade from soft to hard. It’s what most model makers use to make stuff. also known as model board, chemi wood etc etc.

To be honest, if you only need 1 of what you’re designing, you don’t really need to resin cast it, after all you’re going to have to hand make an original part to make a mould of before you start.

Getting a company to do it may not be too expansive, esp. if you have CAD data. Seems like a few on here do it, in the past I’ve been pleased with the results from Arrk, but it depends what you need.

I used to have a machine in house, but when the machine was busy with work already, we used to outsource it to a place called http://www.amtech-rp.co.uk/ in the north east. Alot of the students used to get their stuff done their too, they do student discount.

If you sign up for Materialize you can get online quotes, worth a go to get a rough idea of how cheap/expensive/obscenely expensive a part may be 😮

https://nextdayoqaos.materialise.com/

To be honest, if you only need 1 of what you’re designing, you don’t really need to resin cast it, after all you’re going to have to hand make an original part to make a mould of before you start.

it is more for the aesthetic than anything, plus it would be nice to learn a new method.

I think the cost of silicone moulding something like that would quite quickly put you off that method! you’d rapid prototype for about a 3rd of the price.

Obviously there are size constraints, but RP would be much much cheaper.

Really the tiranti stuff does not seem that dear. Won’t rapid prototyping cost £500+

Some sort of supported latex mould? (mold?)

Won’t rapid prototyping cost £500+

Depends how big, I’ve paid less then £100 for some parts, but they were fairly small. I think there’s alot of people out there doing rapid prototypes so it’s a bit competitive.

We’ve had parts for well under £100. Try Calibre Models. It’ll need spray painting for a nice plasticy finish. Moulded PU is good for tough coloured finished, though. We’ve used in exhibitions and it takes a beating.

nah no way alot of the final year models at my uni were rapid prototyped and they were £70-£100.

the wheels off this were £250 for the bare models which i finished and painted by hand (but there is 4 of them)

CAD Data

real deal

I’m waiting for an excuse to use these guys: http://www.protolabs.com

Would polyester resin be good a watched a few videos and it looks easy to use and cheaper than other resins.