Building Questions....Any ideas would be appreciated.

[rebelweems]

I am designing a sci fi model/toy. I am inspired by the GI JOE APC from 1984..This is the base of my idea. I am wanting to clean out the back by removing the seats and pegs for the old action figures...I figure not issue there.

I am wanting to build a an area that is 2 or 3 times larger than the area already available. I am hoping to make the canopy portion so that it can be opened to expose the inside with out it looking like a cheap toy.


I am in the early planing stages of a project. I am looking for some advice on how to get around a few frustrating things....

1. I get so frustrated that when ever I make a Cockpit, or cabin for a space vessel the seems of the cardboard seem to show. How can I get that smooth finish with styrene so that seems disappear and look like they were either welded?

2. Resin casting...Which company offers the best resin for making plastic parts?

3. I am also going to use some 2.5 inch miniature astronaut's to place into the model. Sadly the quality of those you find online are not that great and even worse they are not posed as I would like them to be. What is the best techniques for cutting them, and reshaping them to match the needs of my model?

4. I am also geeking out on the thought of making it lighted, which I do not think will be a big issue, but if I want to install a rotating radar dish should I use a remote servo or a simple motor geared down to move slowly?

That should be enough for now. I am still sketching out the model details. I know its going to take some time as this is not my first time.

[Kylwell]

1 Aves and a smoothing tool to sculpt the joints.

2 Smooth-on.

3 Look around for 1/24 scale ones. To repose, cut the joint areas down, pin into position and resculpt with more Aves.

4 Either.

[en'til Zog]

For an antenna spinner you migt try this very small gearhead motor from the electronic goldmine. I have found them to be quick, reliable, and honest.

http://www.goldmine-elec-products.com/p ... ber=G16300

[Tankmodeler]

1. I get so frustrated that when ever I make a Cockpit, or cabin for a space vessel the seems of the cardboard seem to show. How can I get that smooth finish with styrene so that seems disappear and look like they were either welded?

Well, when working with styrene (or any sheet product), the best bet is to make sure the fit it darn near perfect to start with, that will mean less filling.

If what you are left with is a small thin seam, then running a bead of Mr. Surfacer 500 into the seam will generally fill the seam perfectly and require very little clean-up. Especially if you can have access to the back and run the 500 into the seam from behind. Capillery action will bring it to the front.

If the seams are a little larger (say .5mm to 2mm) I'll generally use what is called spot & glazing putty., Squadron green & white putties are amongst this group as are the spot & glaze putties available from autobody shops far 1/3 the cost of the equivalent hobby product (note to self). These are solvent based putties and, because of that, bite onto the surface better than epoxy putty. They can be sanded easily and are generally only a little harder than the styrene making matching surfaces easy. Like the Mr Surfacer, this stuff "dries" so there is some shrinkage. Overfill the seams a little and the clean-up is easy after it dries.

For larger gaps & for creating entirely new contours I'll use an epoxy putty like Aves or Miliput or even old fashined A+B. Putties come in many types and have many different properties both when pliable and when cured. Do NOT get the filled putties available at the DIY stores as plumber putty and the like. These cure too fast and too hard for most modellling purposes.

All of the epoxy putties are quite a bit harder than styrene so making sure you et a smooth finish is more difficult, I use files a lot for epoxy smoothing sanding only at the very end.

As mentioned, the epoxies "cure" as opposed to "dry" and therefore do not shrink. The down side is that the adhesive properties of epoxy on styrene aren't great. The stuff doesn't stick too well. If you flex a joint with epoxy filler, there's a good chance that the seam will pop open or the part will come off. Just be careful and it won't be an issue.

HTH

Paul

[rebelweems]

I am very grateful thank you. I am just in the blue print stage, as we all know that a model builder whom does not plan, plans to pay allot more for their works.

I am choosing the scale of my design around 15mm miniatures. Research show's that based upon the images, and web sites visited. The basic diameter of an individual 15mm miniature sci-fi character is that of a US penny. With this in mind it makes my designs allot easier.

I am considering using an empty Listerine Bottle. Here is a web link to a basic image of it.

http://www.target.com/p/listerine-ultra ... pla&ci_kw=

The shell of this is perfect for my model as I am wanting to have it lay flat as if it were piggy backing on a vessel capable of landing and taking off with vertical thrust. I am trying to avoid the "Firefly-Space 1999" genre of ship design.

Now That I have established basic scale, I will use the only software I currently possess MSPaint, which by the way is great when your on a budget and can not afford AUTO CAD.

BTW...If any of you can recommend and good 3d software for modeling please let me know.

I have found this web site for my styrene first order.

http://www.hobbylinc.com/htm/evg/evg9002.htm

What do you think?

[Tankmodeler]

I am considering using an empty Listerine Bottle.

OK, well, that could be a problem. Very little in the adhesive line is going to stick to that sort of plastic. I bet it's PET (Poly Ethylene Terapthalate[sp]) just loke a pop bottle. The key to success in this willbe finding something you can use to bond styrene to that stuff with. Contact cement may work. Try it on a pop bottle. Once you have a couple of large bulkheads bonded to the bottle you can then bond other pieces of styrene to the bulkheads.

BTW...If any of you can recommend and good 3d software for modeling please let me know.

Google sketch-up is free and there are a couple other free 3D modelling programs out there.

What do you think?

Perfectly fine. If you find yourselfneeding any particular size, Evergreen probably also makes that, as well. Most of us have a modest horde of Evergreen and Plastruct sheet and shapes. Note that "Plastruct" makes a LOT of engineering shapes (channel, I-Beam, H-beam, tube, rod, etc) in LOTS of sizes. Much if it is in ABS, which uses a diffferent glue, but they also make much of the shapes in Styrene. Just note what you might end up buying.

All good stuff. Just test adhesives on that bottle first. It may be a real problem. If you get an adhesive to work, make sure any bulkheads you install as a base for further work all go in nice & square to teh axes of the "ship". That way any thing you glue to those bulkheads will line up better and have fewer seams.

Oh, and clean the bottle well first. Don't just empty it, clean it with soapy water, rinse well. Then lightly abrade the surface you are gluing to and finally rinse with isopropyl alchohol. You want that surface as clean as you can get it to enhance the chances it will bond. Make the bulkheads go the entire width of the bottle as when the contact adhesive really dries out, it still might peel away form the bottle. Remember, PET exists because it is cheap and because it is almost entirely non-reactive, thos make bonding to it really tough. There may be special adhesives for it, but I don't know what they might be.

When doing a bonding test let the adhesive dry out completely, 2-3 weeks and then flex the bottle. That should tell you how well it's bonded.

HTH

Paul

[rebelweems]

Hey..........en'til Zog

How do you even wire something like this Precision Mini Gearhead Motor up?

[rebelweems]

Have JB Weld would that work as an adhesive?

[Kylwell]

Somewhat but like any epoxy you'd need to rough the surface up a touch to give it a better bond. PET, PETE, HDPE, PTFE, UHMW, etc are in a group known as 'low energy plastics' that are damned near inert which means it takes a particularly active glue to attach to it. Now there are ways around it, thanks to chemicals, primers that'll stick to it & glues but they can be pricy and require venting to use.

[Tankmodeler]

Hey..........en'til Zog

How do you even wire something like this Precision Mini Gearhead Motor up?

miniature gearhead motor by Sayama part# 12SM-AT3 operates from 1.5VDC up to 12VDC.
No load current is about 18mA and RPM at 12VDC is about 58.

So you wire 1 or 2 1.5V batteries in series with the motor and a switch. Assuming that the item you attach to the motor shaft actually runs freely, the rotational speed will be either 7.5 rpm (1.5V) or 15 rpm (3V).

Simple. If you want to vary the speed below those numbers, add a low voltage rheostat (potentiometer) in series and that will step down the speed. You'll have to talk to a real electrical hobbiest exactly what rheostat would be best.

If those speeds aren't fast enough, you can add more batteries up to 12 V to get the full 58 rpm. If you need faster than that you'll need to get a small gearbox that can mate to the motor to step up the speed. But now you're in the zone where you'll need to get more info and/or spend more money.

Paul

[rebelweems]

I am new to the styrene world..So is there a good flexible clear styrene that is about 1 x 3inch in strips that could pass for good windows?

I was thrilled when I found Warhammer 40k bits on Ebay. These when painted up a bit will serve as my main thrust for my drop ship. I figured 6 of them spaced out to equalize the thrust for vertical lift off's.


http://www.ebay.com/itm/Blood-Angels-ST ... _500wt_716

Those pieces glued on, plus allot of hull mods, thin styrene stacking to make the hull look thick and add dimension...So new at this part.....What thickness would be best for that?

Still do not know what to do for the main engines. Swiveling engines are cool of course, but tough to model.

Suggestions?

[rebelweems]

I am going to get the radar dish to spin revolution per second would do I think. Trying to avoid killing batteries too quickly. Rechargeable might do the trick. Could actually make the Variable resistor accessible via screw driver.

I was wondering if sound effects that are button activated could be down as well? Any one ever tried this?

I loved how toys in the 80's had sound effects, not near as good as today's technology....The wretched sound of Darth Vader's Tie Fighter blaster ughhh..LOL

[Tankmodeler]

I am going to get the radar dish to spin revolution per second would do I think.

Well, thata's 60 RPM, so the full voltage no-load speed is very close (58 RPM) but you are talking about 8 1.5 V batteries. That's a bunch! A big battery pack and a lot of mass. I'm sure you can get a cheaper lower voltage motor that will work. Look for hobby electrical supplies online and I'm sure you'll find thousands of them of all kinds.

I loved how toys in the 80's had sound effects, not near as good as today's technology....The wretched sound of Darth Vader's Tie Fighter blaster ughhh..LOL

Personally, I don't like my models to be likje toys. Nothing "works" nothing lights, nothing moves. making htings move & light in these scales inevitably involves making compromises that affect the accuracy of what I'm trying to build. Pluss things that move, break and getting in to fix a broken motor or wire will inevitably wreck the model.

Paul

[Tankmodeler]

I am new to the styrene world..So is there a good flexible clear styrene that is about 1 x 3inch in strips that could pass for good windows?

Evergreen make clear sheet in various sizes.

Those pieces glued on, plus a lot of hull mods, thin styrene stacking to make the hull look thick and add dimension...So new at this part.....What thickness would be best for that?

I'm doubtfull that adding to the outside of that bottle is going to work at all, to be frank., As we said before, the plastic simply doesn't want things to bond to it. In fact, it's designed so things don't stick.

Also, when adding stuff to the outside of a model made from a thin material, unless you can precurve the stuff you are adding to the outside, the outer material will deform the inner material. Very thin layers of styrene (.005" maybe .010" thick, but no thicker) may be able to be built up without too much distortion, but the sorts of glues tha might stick to the PET bottle (like contact cement) will dissolve such thin styrene.

Paul

[rebelweems]

Ok so if using the Listerine bottle is not good due to adhesive issues, then what material would be best for the core structure?

Sorry for the noob questions just do not enjoy wasting money on mistakes.

[Tankmodeler]

Ok so if using the Listerine bottle is not good due to adhesive issues, then what material would be best for the core structure?

Sorry for the noob questions just do not enjoy wasting money on mistakes.

Well, if you want it hollow and you want it of complex shape, then sheet styrene and epoxy putty will become your constant companions.

Build the shape up from bulkheads of styrene & sheet it over with styrene. You can then add smaller details to that to achieve the level of detail you want. All the normal model glues will work.

Dramatic or really complex shapes can be formed by laying down Aves (or another epoxy putty, many are equally good) and carving, filing and sanding to the shape you want. Be prepared to apply & shape several layers to get what you want, but it is a good medium for creating complex shapes with crisp detail.

When creating the shape and bulkheads, think in advance where you want to mount the motor and battery pack and where the cockpit and any crew compartment will go.

If doing an interior, build it up first and then build the ship around it. Much stronger that way. It wil also tell you how much space you have for things like motors and batteries and will allow you to plan your wiring and switches accordingly.

Make sure the joints are tight and square. Square corners and parallel surfaces are important.

Be accurate, make sure symetrical shapes really are symetrical, the eye can pick out an error in a pattern faster than you can say "oh crap!".

Reinforce anywhere you think it might be weak. Build in a place to mount it, if it isn't going to sit on the ground.

In other words plan well. Execute that plan just as well and the model will be a success.

Oh, and welcome to the world of scratchbuilding.

Paul

[Kylwell]

Or check out Joe Brown's article on using insulation foam and epoxy putty to build shapes & shells.

[Joseph C. Brown]

Here's what Kylwell's talking about:

One of my build examples: Farscape One, foam covered with putty:
https://picasaweb.google.com/1067338929 ... ldingNotes

Here is a build that I am currently doing with foam, then covering with epoxy:
https://picasaweb.google.com/1067338929 ... ldsFor2012

And here are the class notes from the scratchbuilding with foam classes that I taught for several years at Wonderfest:
http://www.starshipmodeler.info/wfest2k ... ss2003.doc