anyone here with a vacuformer?

[ashrond]

Just as the title says anyone here with a vacuformer? I have questions about materials and requirements.

Specifically can I use foam (which I would think would melt) or balsa, and does the balsa need holes in it or something to suck the air out?

Also what kind of plastics can be used and how thick? I want to use something in dark blue. Anyway I know about as much about vacuforming as I do about car engine re-building so I’m trying to collect some general information and possibly someone who I can higher to do the work.

[Tankmodeler]

Just as the title says anyone here with a vacuformer?

Yep. Also have specified stuff for industrial vac forming.

Specifically can I use foam (which I would think would melt)

It rather depends upon what foam you are talking about, but if you mean expanded polystyrene foam, then no, it will melt and/or stick to the plastic being drawn over it. HOWEVER, if you shell the foam with something like a thin layer of Aves, it should pe perfectly fine for a few pulls. Make sure it is a high density foam and not a really low density foam as the pressure may crush it even if it doesn't melt.

This should suggest to you that foams aren't the best material, but you can get away with it, maybe, if you're lucky (or good).

or balsa,

Perfectly good material. Make sure the pattern is solid and not hollow and surface it with something, like varathane or something similar. Polishing the varathaned surface is also good.

and does the balsa need holes in it or something to suck the air out?

It all depends upon the size of the pattern (the thing to be copied), and the amount of draw you want to get (i.e. how much releif from the original flat sheet). It's one of those things you develop with experience.

Also what kind of plastics can be used and how thick?

Any theremoplastic that can be made into a sheet can be vacuum formed and the thickness depends upon the draw, the material and the speed of the setup you have available. For the old Mattel vacuform, the max is about .015"-.020" unless you increase the heat input by using an incandescent light bulb when you can get up to about .025" for parts with a shallow draw.

Commercial sign vac formers can use sheets up to .150" thick.

I want to use something in dark blue.

Sure, why not. The trouble will be finding dark blue sheet to work from. If you were talking on a commerical scale, you can get sheet made for you in any colour you want. For a hobby purpose, though, it likely isn't available in a material & thickness that's any use to you.

Also, one thing to remember is that as the sheet is stretched over the pattern, the colour will change, becoming thinner,and lighter and more translucent in those places with the biggest stretch. White will almost certainly provide a better end product unless you are prepared to spend a LOT of time mucking with the shape and the plastic to achieve a uniform colour. It very likely can't be done without seriously compromising either the shape of the pattern, the moulding time and pressure, the thickness of the sheet (increasing it) and therefore the size of the machine you are working on to minimise the stretch and achieve consistency in the colour.

so I’m trying to collect some general information

HTH

possibly someone who I can higher to do the work.

There use to be a lot of aircraft kit makers who made vacform kits that might have undertaken such work, but with the arrival of resin kits, almost all of them have died off. Vacform kits are more difficult to build and don't have anywhere near the same level of detail as resin can capture.

If you an find a small, friendly sign company, many of them vacform signs and they might be willing to work with you to make your parts. They'll have access to more materials and larger machines and a heck of a lot more experience. They'll also be looking for more money as this is their living.

If I may ask, what sort of thing are you looking to have made and how big is it? THat has a lot of bearing on the end solution.

Good luck.

Paul

[ashrond]

Thanks for the quick response!

As I seem to love pain, and overly complex projects; I have an RC sub project, specifically using the seaquest model. Now originally when I planned the project everything fit inside the plastic model, however I forgot to include the water tight container in my measurements. basically all of the parts WILL fit inside, however they would probably have to be wet, and this was a problem, so I decided to build an enlarged model using a 3d pantograph which I will also be building.
The current dimensions of the model are 2"x3"x18" and I will be up scaling it to 5”x3 5/16” x 30” not THAT MUCH LARGER however it will be more than enough. Now there are allot of inaccurate "details" on the model, so I will be concentrating on the macro shape. And will be replacing a few details (missile tube doors, and a convex circle on the neck) having either 3d printed or laser cut them to be glued onto the balsa master or the vacuformed model. I will also be building the upscaled model in 5 parts, top, bottom, left and right sides, and the rudder, i THINK this may make vacuforming easier, i know it will make copying the model easier.
I will be also sculpting a second hull for a friend
http://atlantisdsv.newcapequest.com/lib ... rofile.jpg
which will be 3”x6”,28”

Once the hulls are finished in balsa, I want to have them both vacuformed at the same time, maybe in black plastic (can you do Rubbermaid plastic? Just a thought) so we can then begin installing the electronics into the hulls.
That’s about the fat of it!

[Tankmodeler]

As I seem to love pain, and overly complex projects;

Yes, I believe you are correct.

maybe in black plastic (can you do Rubbermaid plastic? Just a thought) so we can then begin installing the electronics into the hulls.
That’s about the fat of it!

Well, just to be absolutely clear, I a) don't have a vac form machine nearly large enough for this (I own a Mattel vacuform, very small) and b) I'm not in the business of making parts of vac formed anything for anyone. Sorry.

Next, the "rubbermaid" plastic. Rubbermaid uses a lot of different plastics, but most of theirs are Polyethylene or Polyethylene blends and don't glue woth cr@p. You don't want to use that for a model. You want styrene or ABS.

When making a vacuform kit, you are most likely to have sucess if you make the hull in two large sections, probably upper & lower in the case of the Seaview with the sail and the rear fins as separate units, each in two parts. To use a positive pattern, there can be no undercuts. The pattern will get caught in the plastic. Also, you can't have any areas where there is a recurve or concave section as the plastic will bridge over the "hollow" and not suck down over the pattern. If you can't avoid that, then you need internal venting to draw out the air, but that's complicated and an iteriative process of find out how much venting and whether the machine you are using can do the job at all.

If the shape is too complex, you may have to go to a negative mould and suck the air into the holllow shape of the parts. This produces the best external detail because you can detail the surface of the mould and it is reproduced, in negative, on the plastic when it forms.

With parts 30ish inches long, you are definitely going to need a pro shop as very few hobbyists (i.e. none I have ever heard of) have 36+" machines.

Also breaking the hull down into 4 circumferential parts is going to be a stone cold b!tch to build as you'll need precise and frequent bulkheads inside the hull to get the parts to align correctly and it will always be a lot weaker than one made in two halves.

Without being nasty, it's apparent that you have no idea what you're getting yourself into. This is a really major project and you need to find a shop who will do it before you invest any more time in it and then use them to help you plan it properly as a lot of what you do will depend upon what their machine can do.

Seriously, man, this is a huge job you're setting yourself up for. I'm not kidding.

Also, the 3D pantograph you are planning to build yourself is also a pretty significant project. If you can't produce it quite accurately with smooth movement in three axes, it won't work properly at all. It all hinges on finding a shop to make your vac formed hull, so finding that shop to make the parts should be the first thing you do and then work upwards from there.

Paul

[ashrond]

It’s rare that I can ask a question and get back a wealth of information from someone like this. Yes this project is still in the planning phase, and may be there for a while but I usually have 3~4 projects going concurrently.
The vacuformer looked to be the real issue from the start, as I’m not TOO worried about enlarging the ship, even if the pantograph only produces a rough shape, I can clean that up in no time with some sand paper and effort. However, I know next to nothing about vacuforming which is why I’m asking (knowledge is power). As for why I was thinking about doing the model in 4 sections, it is because of the contours, mainly on the side of the ship.

http://i69.photobucket.com/albums/i69/a ... 001016.jpg
http://i69.photobucket.com/albums/i69/a ... 1000-1.jpg

It occurred to me that it would probably be easiest to use the pantograph on the 4 sections sitting face up, and my thinking was that perhaps the vacuforming would work best that way as well. I really want to keep this model as just top and bottom, but there’s that central sphere and the open spaces in between it and the rest of the ship to worry about.
I know that people still vacuform proton packs, so that may be my first attempt at finding someone who has a vacufromer the size I need as I believe that they are about 30~ish inches long.

You see the parts of the model, and the final shape, do you have any incites on how to best go about getting a successful copy from vacuforming?

[Mad-Modeler]

Considered doing a fiberglass-hull made over a mockup?

Won't be all that much heavier and can be done fairly cheaply & quickly in your garage, etc?

Know quiet a few RC-shops that their own bodies for an airwolf, etc model.
Also easy to seal the halves as you already got all the supplies.

Never did a such an RC model myself we made our own Armour & weapons for re-enactments games that were made from plaster casts of our team-members.

[Tankmodeler]

Seaquest!!

I thought you were making a Seaview!

You probably couldn't have picked a subject less amenable to vac forming if you tried. My ghod, all the concavities in the upper surfaces of those parts! The only way to get even the basic shapes out of that will be to either vent a positive master or create a negative mould.

A far better way to do this would be to pantograph the parts you have in the proportion you want in balsa and then make moulds to make fibreglass parts. It's still not going to want to hold together well under construction and you will have a real b!tch of a time getting the hull sections to line up right when building, but at least the basic shapes will come out relatively easily.

Vac forming is NOT how you want to do this shape. Seriously, it's not the right way at all.

Paul

[ashrond]

I was thinking about cutting certain sections out of the balsa master to aid the suction and help the shape conform. Luckily most of the sections I was thinking about removing are in the depressions, and I can make inserts for the 2 pieces I care about replacing, the "crest" and the "sonar array" on the top near the front.
I have highlighted the sections in red that i intended to remove, if you still don’t think it will work then I’ll start looking into the fiberglass copy (luckily I know a guy for that).
http://i69.photobucket.com/albums/i69/a ... 6-Copy.jpg

[ajmadison]

I believe the original question is, can kit parts be used as the master for vacuuming forming (inexact) copies of them?

The answer is yes. The A/C guys do this all the time with kit canopies, either to make (more in) scale or accurate framing, or to make a copy that is clearer/thinner than the kit part. If you're handy with a vacformer, its actually easier to draw a couple of layers of sheet and manipulate them, rather than either fix, polish, or redo a kit canopy.

One trick the A/C guys do, is add some putty or playdoh behind the kit part to provide some additional thermal mass so the kit part doesn't absorb all of the heat.

However, no matter what you do, do not go into any kind of "production." You can make onesie-twosie copies, but don't plan on making five in a row.

How do I know this? Experience, dude, experience.

[Tankmodeler]

if you still don’t think it will work then I’ll start looking into the fiberglass copy

Given this shape and the thickness of plastic you'll need to make a structurally sound hull, the edges of any of the sunken areas on the hull are going to become quite indistinct. Remember, you are folding plastic over any corners & edges. They will lose any sharpness and become quite rounded. This is why sharp edges are not recommended for vac forming. If that's still OK, you can proceed, but you'll need a lot more holes drilled into your pattern than you envisage. The holes can be relatively small (under 1/8") but you'll need a bunch of them all over any areas that are concave. Even a little. The number & size of the holes is really driven by the capabilities of the machine you will use. This is why you need to work with a specific moulder to answer these questions.

This shape would still be much better if a negative mould was made from your pattern. That would require even more capability from your moulder, though, limiting your potential choices.

If you are dead set on vac forming, well, you can, I suppose. Anything is possible. But this shape really is not what anyone would choose to vac form. Fibreglass moulding is a much better process for this one, believe me. That won't be easy, but it will be easier than vac forming.

Paul

[Blappy]

This reminds me. I want to build a 12" square vac box for making large clear domeish windshields.

[ashrond]

Just found out that a family friend has a vacuformer, tucked away in his garage that may actually be large enough.

Given this shape and the thickness of plastic you'll need to make a structurally sound hull, the edges of any of the sunken areas on the hull are going to become quite indistinct. Remember, you are folding plastic over any corners & edges. They will lose any sharpness and become quite rounded. This is why sharp edges are not recommended for vac forming.

Just had a thought what about a thinner plastic for the vacufrom process, to preserve the edges and then re-enforce the plastic by applying fiberglass resin and a few bulkhead strips to the inside?

If you are dead set on vac forming, well, you can, I suppose. Anything is possible. But this shape really is not what anyone would choose to vac form. Fiberglass molding is a much better process for this one, believe me. That won't be easy, but it will be easier than vac forming.

I’m looking into fiberglass molding ATM, also just trying to come up with what will be the simplest solution to the problem, that’s why I keep asking ya stuff.
Thanks for your patience and your answers, they are greatly appreciated.