R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 01-26-2007, 09:32 PM   #1
Tech Regular
 
corradopsi's Avatar
 
Join Date: Jun 2004
Location: pa
Posts: 329
Send a message via AIM to corradopsi
Default vacuum for molding bodies

how many inches of vacuum is needed to pull lexan to mold bodies? i have an old high power vacuum pump just taking up room in the closet and thought this might be a good way to put it to use.
__________________
Mine: Nomadio Sensor; T2'007, Keyence, Express; ZX-5 SP, Mamba Max; XB8, OS V-spec and NR P5; ProBoat Shockwave 36
My Son: Futaba 3PM; T4 RS; Clodbuster; TT-01;Zig-Zag racer
corradopsi is offline   Reply With Quote
Old 01-26-2007, 11:41 PM   #2
Tech Regular
 
RoachRacing's Avatar
 
Join Date: Jan 2003
Location: American Fork, Utah
Posts: 327
Send a message via ICQ to RoachRacing Send a message via AIM to RoachRacing Send a message via Yahoo to RoachRacing
Default

i think you can find anything really with google

http://www.google.com/search?sourcei...+forming+lexan


http://www.build-stuff.com/1001plans_hobby_vac.htm
RoachRacing is offline   Reply With Quote
Old 01-26-2007, 11:45 PM   #3
Tech Addict
 
Iceracer's Avatar
 
Join Date: Feb 2006
Location: Canada
Posts: 656
Trader Rating: 1 (100%+)
Default

Isn't the lexan heated until it is soft before its molded? Wondering if you realize this. We used to have a machine to do this in high school and it worked great for duplicating items. I would typically make a plaster or WEP (water extended polyester) mould (or is it mold?) over which the plastic would be molded. It is a sheet, clamped in a frame above a heater element, which when soft is lower over the object which sits on a perferated surface through which the air is drawn out. The sheet and frame is lowered, the air quickly drawn out, then you pause while it cools and rehardens.
Iceracer is offline   Reply With Quote
Old 01-27-2007, 12:09 AM   #4
Tech Regular
 
corradopsi's Avatar
 
Join Date: Jun 2004
Location: pa
Posts: 329
Send a message via AIM to corradopsi
Default

yes im aware i need to make a table and frame, and that i have to heat the plastic. just wanted to know if the pump i have is strong enough to do the job. i havent hooked it up to a vacuum gauge yet but i will if someone can give me a definative answer.
__________________
Mine: Nomadio Sensor; T2'007, Keyence, Express; ZX-5 SP, Mamba Max; XB8, OS V-spec and NR P5; ProBoat Shockwave 36
My Son: Futaba 3PM; T4 RS; Clodbuster; TT-01;Zig-Zag racer
corradopsi is offline   Reply With Quote
Old 01-27-2007, 12:28 AM   #5
Tech Champion
 
Scottrik's Avatar
 
Join Date: Sep 2004
Location: Billings, MT
Posts: 6,212
Trader Rating: 245 (100%+)
Default

There are a couple major factors, only one of which is IF your pump draws down to vacuum. The other factor (and where lesser pumps fail) is you've got to be able to bring a substantial VOLUME down to vacuum and do so fairly quickly.

Then things like drawing hole diameter and length add into it. And what thickness material you plan to use (Protoform "light" or Tamiya)?

This isn't something anyone here has experience to answer for you. Time to go to the Vac-Forming sites and fora.

Scottrik
__________________
Congressmen should wear uniforms like NASCAR drivers so we can identify their corporate sponsors.

THE REVOLUTION WILL NOT BE TELEVISED -Gil Scott-Heron (1949-2011)
Scottrik is offline   Reply With Quote
Old 01-27-2007, 01:42 AM   #6
Tech Apprentice
 
Join Date: Jan 2007
Posts: 65
Trader Rating: 1 (100%+)
Default

we make speaker pods out of 1/8" abs plastic using a dayton heatgun and a shop vac with no problems
azfabguy is offline   Reply With Quote
Old 01-27-2007, 03:21 AM   #7
Tech Adept
 
RPage's Avatar
 
Join Date: Sep 2004
Posts: 195
Trader Rating: 2 (100%+)
Default

Vacuum being the absence of matter, it will not take much of a pump to pull a thin sheet of pliable lexan over a mold. The hole diameter and length would be used to help figure the conductance, but that would only be needed if you were trying to figure out the pumping speed. Pump size is going to help with the pumping speed, but pumps of a similar type/family/class are going to have roughly the same ultimate pressure. The chamber/vessel size and desired time to reach a given vacuum pressure are going to dictate the size of pump needed. Although a crude form of a vacuum pump, a shop vac theoretically would be more than enough to pull a lexan body as AZfabguy says. A strong vacuum and a good seal will pull more vacuum than most people realize

No vacuum forming experience, but I did stay at a Holiday Inn last night jk... 13 years of playing with high vacuum systems has taught me that vacuum sucks
RPage is offline   Reply With Quote
Old 01-27-2007, 06:28 AM   #8
Tech Elite
 
Join Date: Oct 2003
Location: Green Bay,WI
Posts: 3,006
Trader Rating: 1 (100%+)
Send a message via AIM to R/C Anonymous
Default

A local guy here makes his own 1/12th scale and touring car bodies. They look really realistic and good.
__________________
Geoff C.
R/C Anonymous is offline   Reply With Quote
Old 01-29-2007, 05:47 AM   #9
Tech Regular
 
JRXS_chris's Avatar
 
Join Date: Aug 2005
Location: Manchester, England
Posts: 386
Default

I'm working on one at the moment. Its a fun project.
JRXS_chris is offline   Reply With Quote
Old 01-29-2007, 05:48 PM   #10
Tech Adept
 
Join Date: Nov 2003
Location: St.Louis, MO
Posts: 171
Default

Anybody else old enough to rememberr Vacuforms as a kid? You heated a Velveta sized piece of platic hot enough to burn your skin, then put it over a mold of a car and pumped the handle to vacum it into shape. If you did'nt burn yourself, you got a chance to slice your skin cutting the car out.

There were'nt many personal injury lawyers around at that time.

After your Mom kicked you out of the house because of the smell you went outside and threw Jarts straight up in the air and tried to catch them!
rollover is offline   Reply With Quote
Old 02-05-2007, 01:58 PM   #11
Tech Champion
 
snoopyrc's Avatar
 
Join Date: Oct 2006
Location: Tunnel Hill GA
Posts: 5,046
Trader Rating: 2 (100%+)
Default

People want to know how to do this. Is it just not as hard as people make it out to be? I would love to be able to make my own touring car bodies. Everything from forming the clay or resin or whatever it took.

God knows that the companies who sell the bodies dont want a lot of folks making their own.
__________________
www.battlefieldraceway.com Racing videos at http://www.youtube.com/snoopyrc
snoopyrc is offline   Reply With Quote
Old 02-05-2007, 10:08 PM   #12
Tech Addict
 
Join Date: Aug 2001
Location: Daytona Beach FL
Posts: 565
Trader Rating: 2 (100%+)
Send a message via ICQ to SirSpeedy Send a message via AIM to SirSpeedy Send a message via Yahoo to SirSpeedy
Default

Sounds like you guys all need to get in the body business and put the big guys out of work. Got if all figured out....
__________________
Tim Davis
SirSpeedy is offline   Reply With Quote
Old 02-05-2007, 10:31 PM   #13
Tech Elite
 
Join Date: Oct 2003
Location: Green Bay,WI
Posts: 3,006
Trader Rating: 1 (100%+)
Send a message via AIM to R/C Anonymous
Default

Quote:
Originally Posted by snoopyrc
People want to know how to do this. Is it just not as hard as people make it out to be? I would love to be able to make my own touring car bodies. Everything from forming the clay or resin or whatever it took.

God knows that the companies who sell the bodies dont want a lot of folks making their own.
The one I've seen locally is carver out of baltic birch and then some bondo or something to fill some spots smoothed over with alot of small holes drilled in it to suck the lexan inward ...Something like that.
__________________
Geoff C.
R/C Anonymous is offline   Reply With Quote
Old 02-05-2007, 10:42 PM   #14
Tech Initiate
 
Join Date: Feb 2007
Posts: 25
Trader Rating: 2 (100%+)
Default

I've got a production vacuum former in my shop that has been sitting unused for about year. The machine is in great shape. It's a QVAC PC1824 18 x 24 model, so I would think it would be big enough even for a monster truck body. If your close enough to me in central Alabama, you are more than welcome to come make stuff on it. You can look at it at www.qvac.com
kaye7877 is offline   Reply With Quote
Old 04-12-2007, 07:00 AM   #15
Tech Master
 
Join Date: Mar 2002
Location: upstate New York
Posts: 1,364
Trader Rating: 21 (100%+)
Default Thread revival

Another question on this.I have a couple of out of production bodies that I would like to back pour and make for myself. My question is..what can I use to make the mold without damaging the lexan bodies that I'm using? One more,anyone have any leads on where to get sheet lexan of the correct thickness (standard RC body).Thanks,Mario.
lotus1 is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Fiberglass Molding your RC Body LuisR Oval, Larger Scales and More 1 07-09-2008 02:07 PM
Can someone Vacuum a Shell for me? SammyXp Painting, Designs, Graphics and Photography 68 11-24-2007 04:10 PM
body molding ? Taylorm Painting, Designs, Graphics and Photography 15 10-22-2007 08:05 PM
Molding bodies... Taylorm Painting, Designs, Graphics and Photography 18 01-15-2007 10:17 AM
Molding a lexan body?? rystang Painting, Designs, Graphics and Photography 0 04-22-2006 10:14 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 03:34 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net