[ynneb]

I have descided to also make a vacuum froming machine for plastic sheet moulding. This will then enable me to carve shapes on my CNC router and then copy them in plastic. I am hesitent to say what I want to make. ( dont want other doing the same thing )

I will mention some of the things I wont be making though, but could be made by other in this forum.

Plastic wheel carts. ( wheel borrows)
Plastic ponds for the garden.
Platitic sand pits for kids.
Etc


Any comments or design ideas would be appreciated.

I will put a stepper motor on the gas adjustment so as to justify it been in the CNCzone.

[buscht]

http://www.halloweenfear.com/vacuumformintro.html

I made one of these and it works pretty good.

T

[ynneb]

Nice looking machine buscht.

You mentioned that you used it regularly. What do you form with it?
EDIT: Sorry I didnt read your next page. Now I see what you make with it. Very cool.

Do you manage to make much money from this machine?

[buscht]

That's not my website, I just copied the machine. I used it for making prototypes of various parts for work.

Your idea looks very workable. Its important to get good even heat distribution and the alignment of the vacuum ports are very important. I tried just using a grid, similar to pegboard and it didn't work very well.

I then made a spacer board where I put vacuum port holes just around the perimeter of my mold and it worked much better.

[High Seas]

ynneb-
looks like you wanna make some bigger parts. I built one like this: http://members.aol.com/GCGassaway/vacuform.htm
works great. Did a lot of chasing about to get the plastics - and have tried oven and heat gun both. Didn't have the heating elements for the one like buscht built.
:cheers: Jim

[njtermite]

I was looking into building my own machine to, but I don’t have the space for it right now.

buscht, or High Seas,
Would you be willing to vacuum form something for me if I sent you the mold? Is so could you email me with rates or any other information

Thanks,
Mark
[email protected]

[ynneb]

I have a suspicion these covers were vacuum formed. I also have a suspicion the mold was cut on the same machine. It makes a good finish doesnt it?



Yes, I suspect if you had holes evenly spaced on a peg board it wouldnt work as well as having them around the perimeter of the mould.

I guess there are two ways to vacuum mould aswell. One where you suck the plastic into a cavity ( That would give a nice outside finish the exact shape of the mould) and the other where you suck the plastic over the mould. ( That would have a more rounded apearence on the outside but the inside was exactly the shape as the mould was.)

I guess you may need to have small holes in the mould itself to cater for indentations if the shape requires them. ( Does that make sence?)

I am doubting my initial design now. I think the down and forward movement of the machine will drag the plastic across the mould a bit and therfore stretch it in a slightly horizontal way causing stress lines. I think there is wisdom in the straight up and down design.

[buscht]

Benny, for some reason I cannot see the 1st picture you posted about the covers. I have seen parts trimmed two ways.

1. For high volume work, you would make a cookie cutter type tool that is the shape of the perimeter of the part and stick the formed part and cutter in a press and punch it out.

2. For lower volume or parts with holes, etc. Either a 3,4, or 5 axis router is used to trim the part and cut out the openings.

I would agree that a straight down pull is better. The material is in a plastic state and is very easy to distort. That is actually what is happening anyway, but hopefully controlled with the mold.

Professional molds sometimes have holes in the mold itself for helping mold into indentations. That is correct. I doubt that the shape you show would need them.

It is much easier to form over a male mold rather than in a cavity.

Also, tight corners and straight walls are difficult to mold. You want a draft angle in the mold. Your picture shows a perfect shape to mold.

I have used a textured plastic for my parts. This is normally on the outside of the part. It helps hide imperfections.

njtermite, I'll have to pass on your project. I don't have time to get my own projects done. If the parts are not too large, you can heat them in an oven and make a small vacuum box using a shop vac. Somewhere on the internet are directions for this. I've seen this done by people who make plastic canopys for airplane models. Space might not be an issue for something like that.

Good luck.

[High Seas]

njtermite - PM enroute
:cheers: Jim

[ynneb]

I am thinking of a way to make the vacuum chamber more efficient.
I was thinking that if there was a chamber where the vacuum sucked out all the air, and just when you were about to pull the plastic down you would release this vaccum into the other chamber that connected to the mould.
I was thinking this would give a real boost to the preformance. A bit like a capacitor action.
Is this idea just overkill and unnecessary?

[vacpress]

I have used a homebuilt vacuum table to make hundreds and hundreds of posters : www.vacuumstudios.com. i have also designed a new device that can be built from 95% hardware store materials, and heating elements from indoor electric grills...


I have some 3d models and documentation if anyone is interested. Its mostly constructed of alumium angle and rivets for the parts near heat and the forming platen - the part that moves up and down.

[teilhardo]

yes, yes, please post some documentation, you can probably put it int he gallery or in the ftp section. The more hardware parts the better.
Thanks,
Tei

[High Seas]

vacpress - I second Tei's request for info on your system. I built a vacuum table that I use with the "wife's" oven and my shop-vac, but an all up desicated system is far preferable! Maybe a list of your material sources, thickness and other how - tos would be worth a few beers too!
:cheers: Jim

[vacpress]

Well, jsut cuz ive taken so much from the net and not done any repaying I will make a quick page and link to it here later tonite.

I have 3d data in solidworks format only... If you want, get Edrawings, a free solidworks vierwer, and i will email you the files.. More specifcs on the machine:

Its built on a wooden frame. The oven is built of sheet steel and rides on aluminum C chanel. The oven could either be made with nicor resistance wire, or canabalized electric cooking apparatus.. Ovens, industrial toasters?, etc.


I have never built the machine, so there are not pictures
I use a simple vacuum table and an oven to make posters. Ive made hundreds this way.

The main mechanics are made of 1/4 x 1in alumium plate, alumium L chanel, etc. ANd rivets. The rivets are not shown. I also planned on welding some of the joints.

In short. these are not comprehensive blue prints.

However, I will make the page

I have 1 3d Rendering of it online, buried within a portfolio of somewhat dumb work i have online.. its a first draft of a website. a flash macromedia exercise.. to find it. follow the link below, go into the "3dcad portfolio" and scroll through till you find the former.. requires flash!
Regards. Robert

www.vacuumstudios.com/rg.html

PS.. i guess.. from 1994-96 i ran a private 1-line BBS out of my bedroom at parents house.. ANSI art and MOD music related.. and hacking! WOO. i guess I have contributed before.

[teilhardo]

Thanks a lot Vac!*

[ynneb]

Vac, Mod music, that was somthing I was interested in too. I love its concept and the way it plays the same on most soundcards unlike midi. But I guess that wouldnt fit into CNC that well. Hey how about a CNC piano player or guitarist, now that would be a feat, making robotic fingers.

[vacpress]

i know a guy who builds guitars - he also built a 16-solenoid basic-stamp driven robotic guitar.

As promised:

http://www.vacuumstudios.com/vformer.htm


Tell me what you think. I put it together in 2 hours tonite. Its not terriably detailed, but it is a decent start.


I have a 3 axis Mill in similar format, but more like 18 pages almost done. I may release it for free. Its in book form and has 3 PCB designs, schematics, build photos, parts lists, etc. Plans. Its been so much work I may try and self publish it.. Or if some sort of opensource CNC thing works out, i would GPL style public license the thing. This to.

ciao, robert

[teilhardo]

NICE PICTURES VAC!!
How long did it take you to draw those in SolidWorks?
I think that it is a great start to great plans.

-Tei

[ynneb]

Hey vacpress, I gather you have a fast connection. Ive been to your web site and its has very big files for what they are. I have taken the liberty of optimising your pdf files down to 75k with very little loss. Would you be offended if I put those optimised files in this thread?

By the way, I really like your design.

[vacpress]

The solidworks stuff took 2 or 3 hours. The layouts and stuff took another 2 or 3 hours.. Doing to origional sketching and "ideation" took 2 or 3 hours.. This is not my speciaty. Im an industrial design student. I usually use solidworks to draw pretty toasters n stuff.

yneeboffered to make the aparently large .pdfs into much smaller 70k pdfs. that would be great, if you do it, hopefully upload them into the file base here also?

Oh- if anyone wants to see other work - i put a bunch of pictures into a "member gallery". I have 10 pages of an estimated 15 or 20 pages on that one.. Its supposed to be a response to the shady treatment ive gotten from j "crank" kleinbauer who thinks hobby cnc is a full time engineering profession. Gotta admit i love the window channel tho.

regards.

robert