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View Full Version : I want to design something gun related...


mroels
08-12-2012, 5:07 AM
Basically I had a cool idea but I have zero design experience. Can't draw to save my life but want to try to do this. I'm not seeing $$$ signs or anything but just think it would be a cool little project, even if I just get my vision into a physical model I'd be happy. I know that at some point i'd need help if I want a final safe working product but the initial design I want to do myself. So I need to learn how to create a model.

The final product would plastic (think magpul). As of right now I'm thinking of using hardening clay to create a model, then some sort of plaster to create a mold, and finally use a liquid plastic to cast a final product.

Right now my main interest in finding the right type of clay to make a model. Preferrably something that could be sanded when dried so that I can really shape the model in detail.

Again, I have no experience other than watching some youtube videos for the last week. Any advice on methods, products, websites to look at would be great. Thanks!!

CBruce
08-12-2012, 11:34 AM
Try super sculpy. Oil based modeling clay that you can bake to harden. Can get it at Hobby Lobby or other craft stores. Might lose some mass when baking, can't remember offhand, but pretty sure there's a similar type of modeling clay that doesn't. More expensive though.

Petra
08-12-2012, 12:57 PM
While SolidWorks and a 3D printer would be my weapons of choice for such a project... you could, depending on the nature of the part, rough it out in plastilene clay (which is very firm, but workable with tools and doesn't dry out), make a mold of the roughed out clay part (using urethane), cast it in resin, then refine the cast part (many casting resins are really simple to work with and can be trimmed/shaved/sanded easily).

Dantedamean
08-12-2012, 1:05 PM
There are types of silicone you can look into. Make a clay model cast it in plaster then poor the silicone in it. Or a urethane resin my work too. I've never used urethane though.

G lock
08-12-2012, 1:33 PM
Easiest way would be to design in CAD, or perhaps wood depending on how complex your part is

loosewreck
08-12-2012, 2:26 PM
Sorry this is the shortest I could make my response:

Yes CAD is the easiest way to go, however if you don't have access to it, Sculpy is one way to go, but it can be very hard to sand after baking. If you go this route, remember that you can use automotive surface fillers like, Bondo and Metalglaze to make changes to the form.

I personally prefer to use 10-12# polyurethane foam (http://www.ficicomposites.com/FICI_CoreFoams_Web.pdf). After cutting it down to an approximate shape with a band saw, its very easy to shape down to a final shape with hand tools, files and 80-100 grit sandpaper. You can quickly knock out several "sketch models" until you get what you need. Automotive surface filler such as Bondo and Metalglaze again is commonly used with the foam to modify or add other shapes. Don't be afraid to improvise to create forms, like using aspirin for buttons.

When you're all done making your form, painting it with white or gray rattle can model paint will make it presentable for a professional discussion.

Also, if you wish to make it a "finished" or "presentation model" you can paint it with automotive or model paints, preferably with an airbrush or HVLP gun. Before painting you'll prep the surface with automotive primer and surface fillers, progressively sanding with finer and finer grits of sandpaper as you would a car. The process may have to be repeated several times, eventually leading up to wet sanding (if you require a smooth finish). A textured finish can also be achieved with either spray techniques or textured paint media, both in the primer or paint stage. Part lines and most surface breaks are usually simulated with Chartpack tape, which comes in many different widths. Again, don't be afraid to improvise when creating details.

Or you can skip the final paint after the primer prep stage and use the prepped model to take RTV (room temperature vulcanization) molds from. Then use some type of resin to cast a part/parts from the mold.

Be aware, molds are usually only cast from a model or part in order to create identical duplicates, like wheels for example. Also, this method requires some prior experience and can become costly. You most likely will also have to prep the surfaces of the cast resin parts due to air bubbles and imperfections. Imperfections can be minimized or avoided, but it takes experience or specialized equipment.

From my experience, the plaster molds you spoke of is usually used when fiberglass or carbon fiber parts are needed to be cast. Also, the process will usually damage the original.

There is no one way to create a presentation model and if you're good, no right way, from my experience its always been a hybrid of what I've explained and some of the methods the other posters wrote about. Time, budget, and the form dictate the methods used.

If you're in S.Cal, you can swing by Art Center College of Design (http://www.artcenter.edu/accd/index.jsp) and talk to some of the Model Shop guys and students. Some of the materials will also be available there, like the Chatpack tape and RTV silicone. I've heard you can also do the same over at Cerritos College (https://cms.cerritos.edu/plastics/events.htm). If you're in N. Cal, you most likely can ask around at the SF Academy of Art (http://www.academyart.edu/industrial-design-school/index.html).

mroels
08-12-2012, 10:47 PM
Thanks for the replies.

CAD and 3D printing is something I don't have access to, plus I wouldn't be able to draw the design as I am terrible drawing anything.

The polyurethane foam looks interesting, where does one get small blocks. Im only finding larger chunks for building purposes. I probably need 6"x12"x12" to allow for margin of error and making adjustments.

loosewreck
08-13-2012, 1:07 AM
Give the schools a call, they might know who sells smaller quantities.

Petra
08-13-2012, 9:21 AM
Thanks for the replies.

CAD and 3D printing is something I don't have access to, plus I wouldn't be able to draw the design as I am terrible drawing anything.

I realize that you stated that CAD is not an option, but I'd just like to toss some information out there: good CAD software (like SolidWorks, Pro/E, etc.) is not like using Adobe Illustrator/Photoshop--it doesn't matter if you can't draw. The part designs you make in these programs are dimensionally and mathematically driven (e.g. if you want a cylinder, you define a radius for a circle, define an extrude distance, and the software does the rest). Additionally, I'd contest that you do have access to some free simple CAD tools... SketchUp (http://www.sketchup.com/) is one example (though, the free version has kinda been gimped) and eMachineShop (http://www.emachineshop.com/) also offers a free CAD tool which can be used with their machining/rapid prototyping services.

mroels
08-13-2012, 10:22 AM
Give the schools a call, they might know who sells smaller quantities.

Will do, thanks!

mroels
08-13-2012, 10:26 AM
I realize that you stated that CAD is not an option, but I'd just like to toss some information out there: good CAD software (like SolidWorks, Pro/E, etc.) is not like using Adobe Illustrator/Photoshop--it doesn't matter if you can't draw. The part designs you make in these programs are dimensionally and mathematically driven (e.g. if you want a cylinder, you define a radius for a circle, define an extrude distance, and the software does the rest). Additionally, I'd contest that you do have access to some free simple CAD tools... SketchUp (http://www.sketchup.com/) is one example (though, the free version has kinda been gimped) and eMachineShop (http://www.emachineshop.com/) also offers a free CAD tool which can be used with their machining/rapid prototyping services.

That is cool. Thanks for the info. I'm gonna try to get my hands on some foam, if not use clay, and design my part. Once I'm satisfied I'll try to get it into the eMachineShop software and see how much it would cost.

dholla
08-13-2012, 2:37 PM
http://www.techshop.ws/

RangerJoe
08-13-2012, 4:12 PM
Or you could look 4 posts below your and find this!

" Have an Idea, or need something designed? "

http://www.calguns.net/calgunforum/showthread.php?t=599233