Basic Vacuum Forming  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       


Premier Pilot 1/4 scale full body pilot
Seller:  Ren DiLeo
Details:   $99.00   |  9/21/2008   |  Classified Ad
We will rotate YOUR AD in this spot if you select "Forum Featured" when placing or editing your ad!

All Forums >> RC Airplanes >> RC Scale Aircraft >> Basic Vacuum Forming
Page: <<   < prev  1 [2] 3 4 5   next >   >>  

Login
Message << Older Topic   Newer Topic >>
Basic Vacuum Forming - 8/27/2002 4:25:14 AM   
Chad Veich



Posts: 2811
Joined: 12/13/2001
From: Litchfield Park, AZ, USA
Status: offline 		Canuck1, thank you and please do give it a go. I think a lot of scale modelers out there are missing out because they think that some processes are only for the "experts". I hope to follow up with some more vac forming articles and also will do some on making molds for casting as time permits. Unfortunately, time does not permit right at the moment .

Sean, the last architectural modeling firm I worked for used some type of dental casting material on occassion but I never tried it for vac form molds. Don't know if it was the same stuff you mention but it worked just like plaster. Best regards to all.

(in reply to Chad Veich)
       Post #: 26

Vacuum form comments and question - 9/30/2002 11:52:54 PM   
Joe Bennett



Posts: 48
Joined: 9/27/2002
From: Temecula, CA, USA
Status: offline 		Group,

Another item that can be used for the bed of the vacuum form box is phenolic board that is available from many electronic stores. It is usually available with a .10 inch hole spacing (1/10th inch) and in many different sizes. This material would allow for finer detail vacuum forming it seems, and it is very reasonable in price. The plaster of paris plug material is great, but care must be given to insure that any sharp edges (such as on canopies) are very flat bottomed so that the vacuum forming process does not shatter the plug edges as it forms the plastic over them. A question for those who vacuum form, is there ever the problem of TOO much vacuum? I am using a 6 gal. 2.0 HP shop vacuum, and it sometimes seems to provide too much suction. Ideas/suggestions/comments? Thanks for all the great info too Chad...............I have learned alot in just a short time from your posts........

Joe Bennett

< Message edited by Dark Overlord -- Sep 30 2002 7:06PM >

_____________________________

Electrons - not just for breakfast anymore!

(in reply to Chad Veich)
       Post #: 27

Basic Vacuum Forming - 10/1/2002 3:24:28 AM   
mucksmear



Posts: 195
Joined: 2/26/2002
From: Berkeley, CA,
Status: offline 		Joe,

If you do indeed have too much vacuum, you could always install a bleed valve somewhere along the hose between the vac and the forming box. Or even on the box itself (this would be easier to reach if too). Most household vacuums have a little sliding "door" that acts as a bleed valve. Often this door is located on the rigid tube just before it connects to the flexible hose, close to where you grip the tube.

All,

Any other suggestions for building a heat source other than using the kitchen oven?

When I worked in a model shop, we had a couple of nice self contained units where the heating elements were housed in box that was supported directly above the vacuum box by post in each corner. The tray that you clampled the plastic into slid up and down on the 4 posts, ensuring proper alignment each time. They were basically ceramic cones with nichrome wire coils laid out in a spiral on the inside surface of the cone. The cones screwed into what looked like light bulb sockets in the heater box.

I don't know where to get those heating elements.

Other suggestions?

-Elliot

(in reply to Chad Veich)
       Post #: 28

Basic Vacuum Forming - 10/1/2002 4:11:39 AM   
JoeR


 

Posts: 22
Joined: 4/10/2002
From: Bemus Point, NY, USA
Status: offline 		This place (http://www.build-stuff.com/#Hobby-Vac%20Construction%20Plans) sells a heating element for a 12" x 18" stock size.

(in reply to Chad Veich)
       Post #: 29

Basic Vacuum Forming - 10/1/2002 4:41:43 AM   
JoeR


 

Posts: 22
Joined: 4/10/2002
From: Bemus Point, NY, USA
Status: offline 		Here is another that uses an electric grill heating element and cookie sheet with drilled holes for the suction surface. Pretty resourceful solution.

(in reply to Chad Veich)
       Post #: 30

Basic Vacuum Forming - 10/1/2002 5:28:16 PM   
Steve Collins


 

Posts: 2137
Joined: 12/21/2001
From: St.Charles, MO, USA
Status: offline 		Robby,

I discovered that Balsa USA has large rolls of clear plastic. I use a regular vacuum forming machine that I bought a few years ago that has a 12" X 18" table. The rolls they supply are perfect.

_____________________________

Steve Collins

(in reply to Chad Veich)
       Post #: 31

Basic Vacuum Forming - 10/1/2002 5:34:48 PM   
JoeR


 

Posts: 22
Joined: 4/10/2002
From: Bemus Point, NY, USA
Status: offline 		Any idea what the thickness of the Balsa USA material? Cost?

(in reply to Chad Veich)
       Post #: 32

Vacuum forming - 10/1/2002 5:56:36 PM   
Nickrc3



Posts: 402
Joined: 1/12/2002
From: Miami, FL, USA
Status: offline 		JoeR and Chad;

Great information guys! I'm interested in posssibly building a small vacuum forming machine to reproduce small scale parts. The unit described in the site JoeR provided certainly sounds like just the ticket, but may be overkill for the limited use I intend. What is your opinion on the simpler shop-vac design, say of the one from CrossHobby Tools? Does the amateur hobbyist really need the heating element built into the vacuum box?

Thanks guys,

Nick

(in reply to Chad Veich)
       Post #: 33

Basic Vacuum Forming - 10/1/2002 8:32:59 PM   
Joe Bennett



Posts: 48
Joined: 9/27/2002
From: Temecula, CA, USA
Status: offline 		mucksmear,

Bleeding part of the vacuum off with a valve of some sort should do the trick. Should be easy to install in the box I have built. Horrible thing, to have too much vacuum, but could be worse I guess. Now, just have to investigate that electric grill heating element (maybe Lowes has them) to heat the plastic. Hobby People sells 9"x12" sheets of various thickness clear plastic at reasonable prices (check out their catalog). Great for canopies.

Joe Bennett

_____________________________

Electrons - not just for breakfast anymore!

(in reply to Chad Veich)
       Post #: 34

Basic Vacuum Forming - 10/2/2002 7:54:53 PM   
Chad Veich



Posts: 2811
Joined: 12/13/2001
From: Litchfield Park, AZ, USA
Status: offline 		Too much vacuum?! What a nice problem to have! As you can see, the stuff I'm using is BASIC. Still, it does the job for me about 99% of the time. The phonolic board idea is one I will pursue as I'm finding peg board to be less than stellar and am looking for a replacement. The only experience I have with ready made vac formers is limited and I don't recall who made the one I used. It had its own heating element and the plastic clamped into a frame that was hinged between the element and the vacuum box. You simply let the plastic get hot and then swung the frame over the forming bed. Made alignment no problem! However, it was not a large machine and still cost somewhere in the neighborhood of $750. Regards, Chad.

(in reply to Chad Veich)
       Post #: 35

Basic Vacuum Forming - 11/13/2002 12:30:33 AM   
MARS ENFIELD


 

Posts: 21
Joined: 3/28/2002
From: GOODLAND KANSAS
Status: offline 		I WAS WONDERING IF YOU COULD MAKE A ZERO TYPE COWL,SIXTY SIZE,WHAT THICKNESS OF MATERIAL WOULD WORK
I THOUGHT ABOUT ONE OF THE SPUN ALUMINUM COWLS USING IT AS THE PLUG.ANYONE HAVE ANY THOUGHTS OR IDEAS.PLEASE EMAIL ME AT [email]MENFI5@HOTMAIL.COM[/email]

_____________________________

MENFI5

(in reply to Chad Veich)
       Post #: 36

Vacuum Forming problem - 1/7/2003 9:30:38 AM   
Leadfoot-RCU



Posts: 106
Joined: 1/8/2002
From: Kitchener, ON, CANADA
Status: offline 		Chad,

I was wondering if you had any advice in regards to a problem that I'm having with vacuum forming a park flyer cowling.

The cowling measures approx. 2.5" wide x 2.5" long x 1.5" high

The problem I'm having is that it is a rather square shape and the plastic is folding over on the corners at the base of the mold. I've tried a couple of different things to correct or eliminate this, but haven't had any luck....

Any advice you could offer would be greatly appreciated.

Thanks,

Steve

_____________________________

Revver Brother #85

(in reply to Chad Veich)
       Post #: 37

Basic Vacuum Forming - 1/7/2003 10:02:19 AM   
Chad Veich



Posts: 2811
Joined: 12/13/2001
From: Litchfield Park, AZ, USA
Status: offline 		Steve, this is a common problem anytime you are making a "deep" pull. I wish I could tell you that I had found a sure fire prevention but I have not. Sometimes if you block the part up off of the forming surface you can force the webs to form on the excess portion that will be trimmed off. Also, try making a pedestal for the part that angles outward away from the mold. The webbing forms much more easily when you are pulling near vertical and an angled base can ease that a bit. Two things I have found really important in preventing webbing is to make sure you don't over-heat the plastic and to force the sheet down over the mold VERY RAPIDLY. That last thing may be the most important. Don't give the plastic enough time to fold over on itself during the forming process and you've solved the problem. Good luck and let us know if what works for you.

(in reply to Chad Veich)
       Post #: 38

Basic Vacuum Forming - 1/7/2003 11:17:20 PM   
BillHarris



Posts: 835
Joined: 12/20/2002
From: Jasper, AL, USA
Status: offline 		Good tutorial, Chad. Vacu-forming is not that difficult once you get the hang of it.

I'm forming a windshield for a DeHavilland Beaver, which is mostly flat, but with a 90 deg flat curve on the outside side. I've initially tried to heat the .030 plastic and manually lay it over the plug since there are no complex curves, but it hasn't worked to my satisfaction. The flat section needs to be flat and the curved end smooth. I'm getting about 90% "perfect", but I'm being picky.

--Bill

(in reply to Chad Veich)
       Post #: 39

Basic Vacuum Forming - 1/8/2003 9:28:01 AM