Basic Vacuum Forming and Vacuum Machine Building

[Big Al]

A Regular Guy's Guide to Vacuum Forming,

Hey Everyone My name in Al and I am a avid modeler and hopless BSG and SW fan from way back and I thought this would be a good topic for me to share some info on this particular subject.

By no means am I any kind of expert on the subject of Vacuum forming however I have made many parts and learned everything I know by trial and error.

My knowlege on this topic is completley from self study and application and I simply do what every diligent hobbyist would do!...Try and gather as much information on the subject as possible and then apply it.

This topic will be on the basics of vacuum forming and self made Vacuum form machines.

My personal experience with Vacuum Forming and building VF Machines comes from building R/C Model Aircraft from the time I was 10 and haveing a need to make scale parts for our Aircraft projects. However any one who is making costumes can benefit from same Vacuum Forming info.

The principals are all the same, You make a plug, select the correct plastic, and have a machine that heats the plastic then you can pull the Plastic over the plug thus forming your part........I have built many plugs to mold several different types of plastics and pulled every kinda aircraft canopy, scoop, bubbles, Hatches, Doors, Plugs, R/C Car and Truck Body's, Panels, Moter mounts, and alot more. and in all different scales from very small to very large.

A Plug can be made from several different types of material depending on your needs and it can be said that the quality of your plug is the first important step in Vacuum Forming and we will also discuss that here.

As with your plug, Your parts are only as good as the machine you have to pull them.

So if your interested I will be starting with Book recomendations then equipment.

From there we will move on to the Plugs, Tools, Plastics, Technique and Part Pulling.

I will tweek and edit my posts as necessary and try to be as accurate as I can. Sometimes I will update or add info or pics to my posts as I find it or correct errors and misspellings.

I hope you will enjoy this subject and please feel free to ask questions and give imput.

Please try to stay on topic, However there are other processes that are very relevent and go hand in hand with Vacuum Forming and you are welcome to disscus those topics here as well, such as Rotocasting, Sculpting, Materials, CNC, Fiberglassing, Vacuum Bagging etc..

Again I am no expert!...Just a hobby guy who has spent alot of time on this subject out of a necessity to make my own parts.

[Cylon-Knight]

POST ON BIG AL! I am SOOOOOOOOOOOOOOOO interested in making my own vac form machine and making some projects. So much cool stuff to learn and try - thank you for sharing what you know with the rest of us.

I love this topic! (And it JUST started.) I think it is probaby a broader topic than just for Halo Master Chief. I'll start a new section for this and other topics like it.

[Big Al]

Vacuum Forming Basics


This is the first Book I would recommend to anyone interested in Vacuum forming
"DO IT YOURSELF VACUUM FORMING by Douglas E. Walsh
[attachment=2]Cvr_Vacuum_Forming_Hobby.jpg[/attachment]

You can order this book from Castcraft

We will talk about this company later as they also carry the next book I will talk about.

This company also carries plans for two very cool full function machines you can build that are every bit as effective as a commercially built one.

DIY Vacuum Forming is a great book for getting started!

For the most part this book Covers Process and Technique and ways to build small home style machines on a shoe string budget
take what you can from this book but I will be discussing better middle of the road machines that are not dirt poor simple but a little more sophisticated but still don't break the bank later in this forum.

The Topics covered in the book are:

The Basic Process

Types of Plastic

Mold and Plug Materials

Heat Sources

Vacuum Sources

Tips and Examples


What's great About this book is it teaches you the process from the begining and the book practices what I like to call K.I.S.S. Not the Band ..... but KEEP IT SIMPLE STUPID!....You can spend alot of money Buying technical books on Vacuum Forming and become so confused youll give up!.

My recommendation to you is........ don't do that!

You do not need a Ph.d in Vacuumformology, and a Masters Degree in Plastic Polymer compounds to make a part for a hobby project. Just Sayin!

Vacuum Forming can be as simple as making one very small part to a complexed industrial process of manufacturing thousands of parts at once or making very large parts such as Lage Business Building Signage .......The Regular Hobby Guy doesn't need all of that information.

But we do need enough information to get a near to perfect or "The Perfect part" with non comercial Means.

That can be tricky! That's why it's important to understand the process and this book gives you that.


Here is the Three step Process of Vacuum Forming a Part

[attachment=1]Vacuum_Forming_Process_pg6.gif[/attachment]

Stage 1: Heat your Plastic untill it sags Caution! To much sag can ruin yer part!

Stage 2: Transport Your Saggy Plastic to your Plug

Stage 3: Vacuum pull the Warm Saggy Plastic over your plug forming your part.

Simple huh?.......Well let me tell ya that one wrong move or wrong plastic selection or under heating the plastic, over heating, or a number of things can ruin your part....

The most common deffect that occurs is webbing. This can be caused by lack of vacuum, Not applying your saggy plastic evenly over your plug during pulling, or premature cooling of the plastic (Thermal difference from one side of the plastic or spot cooling)

Blisters and bubbles can occur in clear plastics if you over heat the plastic or heat it to rapidly.

That's why it is very important to have a machine that is somewhat substantial because the better your machine is, the easier it is to stabalize these challenges.

That doesn't mean you have to have or build a large exspensive machine! The home boxes do work! I just don't like them personaly.

The better your machine is built the more even the heat will be distributed as well as the vacuum

I do not recomend useing or building the "Vacuum Box" Type of machines because you have to use your kitchen oven to heat your plastic then move it over to your box and it can result in a bad part not to mention stinking up the house with melting plastic chemical smell. There is a risk of fire as well.


Here is a Type 2 Vacuum Box with a modifide Bicycle Hand Pump. It Works! ....but has alot of drawbacks!

[attachment=0]Type_2_Vacuum_Box_pg64.jpg[/attachment]


NEXT POST: Vacuum Pumps, shop vacs, 1 stage and 2 stage Machines, Low Vol Vacuum and High Vol Vacuum,

The Book "SECRETS OF BUILDING A PLASTIC FORMING MACHINE" and the Ralis Kahn Machine!

[GoldCylon]

Right on. To bad I am heading out the door to read all of this, but I will return for more details. Thanks.

[Cylon-Knight]

ROCK ON AL!!!

[Skullbeast]

Thanks, that's what every cylon needs. Cylon field repair kit. I'm going to build one.
We have 4 at work that are old school. To large and huge wasters of plastic.

[GoldCylon]

Build me 3 please. 4x8, 4x4, and a 2x2. I'll be set for life.

[GoldCylon]

Well hold it I did build one once. Wasn't completed but real close and traded it to Joe. He lost it in a move.

[Skullbeast]

I ordered the desk top to see how it goes, I'll get a bigger one if I like it.

[Big Al]

Advanced Machine Making


Ok this is the Next book " Secrets of Building A Plastic Vacuum Forming Machine by Vincent Gingery"
[attachment=1]Building a Form Machine.jpg[/attachment]

This is a companion book to the the plans Cast Craft sells and a great addition to the first book.

This Book is a little more advanced and covers the topic of building a quite sophisticated machine.

This book has the plans and detailed information about building a completely self contained machine.

Even though this book is about building a machine with a metal frame, this book is also very heplfull if you decide to build the Proto Form Machine that Cast Craft sells the plans to that is constructed from wood.
[attachment=0]proplanphoto.jpg[/attachment]

Although I have not built this Machine, I bought the plans for it a few years ago.
At that time you could buy the plans from them in Hardcopy Bluprint form. I have a 1" binder that all the plans fit in but I think they stopped selling hard copies and have went digital so if you order from them now it's a download and I think a PDF.

Back to the Book!

This book covers the basic process as well but goes into more detail about the Plastics, Technique, Vacuum sources, Plumbing, Valveing, Molds Vs. Plugs, Vacuum storage Tanks, and so on.

Both Books are a must for the guy ready to make his own parts and machinery.

And although I found it helpful to read them cover to cover, some people simply use them as reference books on each subject they come upon.

Here is the link again for Castcraft

[Big Al]

Commercial Machines

Next up I'm going to talk about some commercial machines that are out there if your wallet can afford the luxury of buying a already made machine rather than build one.

I will cover some of the Hobby grade Vacuum boxes but I'm not going to spend alot of time on them because you will see that there are other options that are so much better.

Let's start with this one.

If you are around my age or older you will remember this baby boomer toy for boys that was as popular as the E-Z Bake oven was for the girls.


This is the Vac-U-Form by Mattel and came out in the late sixties.

[attachment=9]Vac u form 1.jpg[/attachment]
[attachment=8]Vac u form 2.jpg[/attachment]

Cool huh?......It came with all kinds of plugs for making car bodies for your hotwheels as well as alot of other plugs for making many things.

[attachment=0]Vac-U-Form Poster.jpg[/attachment]

This machine, as small as it is, is a Flop Over style or also known as a Flip Flop style.

These are still available today and are a great introduction to Vacuum Forming.
You can get these on E-bay all day long!

E Bay Vac-U-Form Listings


Later They made a larger desktop version similar to the machine I was looking for. The coolist part about this machine is the Heaters.
Unfortunatly they made very few of them and are hard to find. I found pics of this one on the net.

[attachment=7]RedVac-U-Formmachine.jpg[/attachment]

Here is a shot looking at underside of the oven

[attachment=6]RedVac-U-Formoven.jpg[/attachment]

These are the Heaters. they are a ceramic type that screw into sockets like a light bulb.

[attachment=5]RedVac-U-Formheatingelement.jpg[/attachment]

The last one shows how the plumbing, electrical and Vacuum motor and how everything is contained in the base.

[attachment=4]RedVac-U-Formbaby.jpg[/attachment]


This next Machine is used in dental offices for making teeth impressions and is a little pricey for the limited use.

I like the Blue one!

[attachment=3]Dental Form.jpg[/attachment]

I have never used one of these machines and from the looks it appears to be a plunge type.


Next is the Commercialy built Vacuum box. Too Pricey and Not enough features for my likeing.. However you can buy them in different sizes for larger plastics and they do work!.

[attachment=2]VF-12x12-VAC_FORMER-2T.jpg[/attachment]


Here is the link for the Vacuum Box if you wish to explore the sizes and pricing but again I do NOT Recommend these.
Widget Works


Warm Plastic is another company that sells these boxes


Here is one I Like very much.

This is a Table top unit made by Centroform called EZ Form. Very cool machine but again a little pricey (Around $900).

[attachment=1]centroform-ezform-sv-1217-220v-tabletop-vacuum-forming-machine-B.jpg[/attachment]

You can purchase these machines from Robot Shop


Next Up The Ralis Kahn Machine

[Skullbeast]

Of the commercial ones the red vac I used 16 years ago at college for all of our projects and I use the proform dental at work daily. Our others are homemade.

[Big Al]

Skull Beast:Of the commercial ones the red vac I used 16 years ago at college for all of our projects and I use the proform dental at work daily. Our others are homemade.

That is very cool that you were able to use one of these machines and roger on the proform dental.

I think the proform dental or one equivelant at the time (Late 60's) is probably the insipration for Mattel's Vac-U-Form but I'm not keen on the exact history.

My angle at this art form is the simpler the better without sacrificing the quality of your part.

I'll bet that little Proform makes some killer parts?

and I'm not sure because I havenn't use one or even seen one close up but from the looks of the pic, the machine appers to be a small table top unit for makeing dental parts? but I'm guessing they are about the same size as the the Vac U Form is that true?

If you noticed the machines have 2 methods of plastic transport the old Vac U Form has a "Flop Over" Operation but the Proform Dental has a straight plunge down over your plug. I found the latter to be the best for the most consistant pulls.

The flop over method, works good but in some cases you have problems because when the plastic is ready, the trasport flops over and makes initial contact with you plug at a 45 degree angle and pulls unevenly sometimes ruining your part.

Just my 2 bits
Big Al

[Big Al]

The Next topic is the Ralis Kahn Machine!

The photo is Ralis Kahn's machine and This is the machine I decided to build and it works great!
It's been awhile since I read his bio and reviewed the plans but I believe he makes costumes and props and you can find out everything you want to know at the link below.

The link takes you straight to the building blog for this machine and it's worth it!
The best part is you can get all of the parts at your hardware store! The Oven/Heater unit comes from Wall Mart (Sunbeam Portable Electric Grill) and is a breeze to assemble.

Holloween Fear.Com, Ralis Kahn Machine

This is the Machine I would recomend as a first build instead of starting with small box type units an working your way up. to me it's a waste of time and money to build a unruly box type when what you need is machine capable of pulling all the size parts you need from big to small!

This is a great machine, I built mine to exact specs with the single stage Shop Vac and successfully pulled many parts, then I modified my machine for 2 stage operation.

This is pic of a Ralis Kahn Machine built by a guy in New York [attachment=0]Ralis Kahn Mod 1 Large.jpg[/attachment] You can see he has modified the machine build to his likeing and it looks great!

This machine will make alot of large size parts but is a little small for things such as chest plates and back plates.
My main use for this machine was for making Clear Canopies and Cowlings for my models and worked Great!.

For really deep pulls, such as pulling a cowling for a 7th scale P-47, it was necessary to make a 2 section plug then cut and mate the parts using plastic fill to hide the seam, sand then paint. A little more work to get the part I wanted but still works great!

Next topic Vacuum sources, Pumps, shop vacs, storage cans.

[Big Al]

Vacuum Sources


Ok next up is Vacuum sources so let's start simple
Your vacuum source is very important! It's the "VAC" In vacuum forming fer god's sakes!
Here is a list of some Vacuum Sources and their suck power!


Vacuum In.Hg.

Single Stage Vacuum Cleaner Motor 3.7 to 4
Two Stage Vacuum Cleaner Motor 5.6 to 6.6
Mouth Suction 15
Hand Pump 27+
Modified Tire Pump 27+
Electric Vacuum pump 27+
Air Vacuum Pump 27+
Air Compressor (used as Vacuum Pump) 27+


SHOP VACS! Every man has one! or should have one and I don't mean the little apartment dweller kind, I mean at least a 12 Gal. these seem to have enough vacuum to pull some good parts as a one stage and they make a great first stage for a two stage!.......did ya get that? LOL!


[attachment=7]Ridged Shop Vac.jpg[/attachment]

Here is the link Home Depot Shop Vac


You can pick up these kind of vacs around 50 to 80 bucks and they are well worth it!
Used ones arn't that bad either and you can get those for even less but the vacuum must still work good or you should just buy a new one. Used vacs somtimes have broken blades or cracked fans and will not provide a good suck!

I use one of these type of shop vacs and mine is a 10 Gal. but the new ones are 12 gal.

Most Shop Vacs pull between 3.7 and 4 inches of vacuum so you want the vac to be at the higher end and the bigger vac does the job!

There are alot of ways to create vacuum the shop vac is the first because it's the most basic.
The alternate to the shop vac is the Electolux style vacuum canister.

[attachment=6]Electrolux3vac.jpg[/attachment]

I know guys who use these and get good results! I don't have the specs on the vacuum but my friends use them so they must be suitable. These are very easy to intagrate into a machine.

My Mother had one of these!...

[attachment=5]electrolux901.jpg[/attachment]


You Can Build one from a Vacuum Motor:
These are cool and you can get them from old vacuum cleaners or if you can spend a little money on a new one you can get some great sucking power! You can build a housing box for them or intagrate them into your machine for a great built in vacuum.

[attachment=4]Vacuum-MotorBlower-5DVY8_AS01.jpg[/attachment]

Here's the Link! Grainger/DOMEL-Vacuum-MotorBlower


This next one is the one I have and it's a 3/4 HP Rotory Vane Pump and is awsome!.
This is a Gast Pump and can be purchased through WW Grainger.

[attachment=3]Vacuum-Pump-4F741_AS01.jpg[/attachment]

Here's the Link: Grainger/GAST-Vacuum-Pump

Although I would highly recommend one if you have the means, the gast is kinda high end and you can still get some great results with these type of pumps that are made for air conditioning system evacuation and the don't break the bank!

[attachment=2]image_1813.jpg[/attachment]


You can buy these pumps from Harbor Freight and they work extremely well!

Harbor Freight Two-stage-3-cfm-air-vacuum-pump


Here's their smaller one

[attachment=1]image_4020.jpg[/attachment]

25-cfm-vacuum-pump


They also carry this particularly handy and extremely nifty device!

[attachment=0]Air Vacuum.jpg[/attachment]

This turns your Air Compressor into a Vacuum source!

Air to Vac Device

I have one of these and it works great if you have a med to large air compressor.