vacuum for molding bodies
01-26-2007, 08:32 PM
#1
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.
01-26-2007, 10:41 PM
#2
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
http://www.google.com/search?sourcei...+forming+lexan
http://www.build-stuff.com/1001plans_hobby_vac.htm
01-26-2007, 10:45 PM
#3
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.
01-26-2007, 11:09 PM
#4
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.
01-26-2007, 11:28 PM
#5
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
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
01-27-2007, 12:42 AM
#6
we make speaker pods out of 1/8" abs plastic using a dayton heatgun and a shop vac with no problems
01-27-2007, 02:21 AM
#7
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 
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
01-29-2007, 04:47 AM
#9
I'm working on one at the moment. Its a fun project. 
01-29-2007, 04:48 PM
#10
Tech Adept
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!
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!
02-05-2007, 12:58 PM
#11
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.
God knows that the companies who sell the bodies dont want a lot of folks making their own.
02-05-2007, 09:31 PM
#13
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.
God knows that the companies who sell the bodies dont want a lot of folks making their own.
02-05-2007, 09:42 PM
#14
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
04-12-2007, 06:00 AM
#15
Tech Master
iTrader: (21)
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.