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vacman Newbie
Joined: 04 May 2007 Posts: 13
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Posted: Thu May 24, 2007 12:49 am Post subject: My Vacuum Forming "Machine" |
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Here's what I made... Please note that I'm a university student majoring in business... I have NEVER built anything before. My hobby is bodybuilding, but I am starting another online business and this will help me make what I need.
I used the 1 hole method after reading various posts on the internet. The forming surface is 20"x20". I found some nice wire mesh in Home Depot, and I layered it on 3 times. I'm using a 3.5 horse power shop vac to provide suction, and 2 large grittles (whatever they are called) as my oven. I went the 'easy' route with the oven, the grittles set me back $20 a piece, I took them apart and put the heating plates together to make up a 21"x20" heating surface.
No fancy flip mechanism here... just "pick up and place". The oven side of the stand is attached by a bolt to the vacuum table. It can be taken apart and transported.... to the dump if things don't work out
I'm still calling around trying to find the best prices for PETG here up in Canada, so not pulls yet... and I don't think they make "for sale" signs that big... but maybe I'll look around tomorrow see if I can find something to test with.
I still need to mount a power bar and a foot switch for the vac.
Questions and comments welcomed.
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jzawacki Novice
Joined: 12 Jan 2007 Posts: 70 Location: Illinois
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Posted: Thu May 24, 2007 10:28 am Post subject: |
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I can't wait to find out how the griddles work out. I had thought about them, but since Dr Crash didn't mention them, I figured they weren't a good option, as he seems to be the man when it comes to "budget" tables. If they heat up evenly, I think you have great surface coverage. |
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vacman Newbie
Joined: 04 May 2007 Posts: 13
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Posted: Thu May 24, 2007 10:55 am Post subject: |
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I tested them out before I took them apart. Once the surface heats up it gives off heat evenly on the entire surface. Another nice thing about them is that they have actual temperature settings not just "1-2-3" (hot, hotter, hottest). They were actually $40 a piece, but I got them on sale. |
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jegner Site Admin
Joined: 30 May 2003 Posts: 2144 Location: Texas, USA
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Posted: Thu May 24, 2007 11:09 am Post subject: |
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Looks great!
I'm aways interested in how other folks approach this' tec-knowledgy'.
The griddles are my biggest concern. Cold spots, esp. on the edge and corners. If your oven is not a few inches larger than your platen, you run the risk of having cold corners.
Also the temp control was an issue with my Sunbeam indoor electric grill. When it finally got hot enough, it would cycle on and off. I hope yours does not do this!
Good luck!
Can't wait to see your first pull!
Jim |
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jzawacki Novice
Joined: 12 Jan 2007 Posts: 70 Location: Illinois
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Posted: Thu May 24, 2007 3:43 pm Post subject: |
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Isn't cycling on and off what you want to maintain the proper temp? |
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jegner Site Admin
Joined: 30 May 2003 Posts: 2144 Location: Texas, USA
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Posted: Thu May 24, 2007 3:56 pm Post subject: |
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jzawacki wrote: | Isn't cycling on and off what you want to maintain the proper temp? |
Yes and no. Hard to explain, but you want to control when and for how long the cycle is. Most of the cheap controls found on toasters and grills, don't give enough precision to control it they way you might want.
Case for me with the Sunbeam Grill, was about the time the element got hot enough to melt the plastic, the darn thermostat would cut the thing off. The plastic would then cool down, and I would have to wait to for it to kick back on, and by then, the plastic was not much good. |
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jzawacki Novice
Joined: 12 Jan 2007 Posts: 70 Location: Illinois
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Posted: Thu May 24, 2007 4:04 pm Post subject: |
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Oh.. so you would be better off either jacking it up to full power or remove the thermostat and use an external source to cycle the power. |
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vacman Newbie
Joined: 04 May 2007 Posts: 13
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Posted: Fri May 25, 2007 2:50 pm Post subject: |
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I'm using mine for PETG, and I've read that the forming temp is between 90-120 degrees Celsius. The max setting on my grittles is 220 degrees Celsius. So I don't think there would be much of a problem because of the low forming temperature of PETG rght? |
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jegner Site Admin
Joined: 30 May 2003 Posts: 2144 Location: Texas, USA
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Posted: Fri May 25, 2007 3:08 pm Post subject: |
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Well, I can only speak from my experience. The Sunbeam grill claimed heat up to 400 degrees, and HIPS has a much lower forming temp. I think there is an option for this to work but just a friendly disclaimer regarding what the heater can do, vs. what it does for your vac forming needs. |
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vacman Newbie
Joined: 04 May 2007 Posts: 13
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Posted: Sat May 26, 2007 12:30 am Post subject: |
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Thanks for the tip. Hopefully all will go well. I still need to actually buys some material to try to do a pull. Hopefully by middle of next week I'll have a supplier and by the week after I'll have done a test pull. |
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drcrash Guru
Joined: 04 Sep 2006 Posts: 705 Location: Austin, Texas
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Posted: Tue May 29, 2007 7:30 am Post subject: |
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jzawacki wrote: | Oh.. so you would be better off either jacking it up to full power or remove the thermostat and use an external source to cycle the power. |
That's what I found. Rather than remove the thermostat, I copied Charlie and used a wire tie to hold the contacts shut.
I had a similar-but-different problem with the infinite switches (stove top type heat controls) in my two-burner hotplate. Infinite switches are pretty crude, and they'd cycle on and off at random and overly long intervals, so I couldn't ensure that I'd get the same heat at both ends of the oven.
So I just set them to all-the-way-up and left them there, and came up with the rectifier heat controller to turn the heat halfway down for both burners:
http://www.tk560.com/phpBB2/viewtopic.php?t=606 _________________ Paul (a.k.a. Dr. Crash)
Tired of buying cheap plastic crap? Now you can make your own! www.VacuumFormerPlans.com |
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jzawacki Novice
Joined: 12 Jan 2007 Posts: 70 Location: Illinois
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Posted: Fri Jun 01, 2007 9:26 am Post subject: |
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Yeah. I remenber the rectifier switching.. But that kinda screws my current plans.. so I will just have to wait and see what happens. I can't give both elements the full 2000 watts on a single circuit and they tested fine set at half both on the same circuit. But I didn't wait long enough for them to start cycling on and off.. I guess when I get the oven done I will have to figure out a good way to measure the temperature all over in it. |
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drcrash Guru
Joined: 04 Sep 2006 Posts: 705 Location: Austin, Texas
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Posted: Fri Jun 01, 2007 9:37 am Post subject: |
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jzawacki wrote: | Yeah. I remenber the rectifier switching.. But that kinda screws my current plans.. so I will just have to wait and see what happens. I can't give both elements the full 2000 watts on a single circuit and they tested fine set at half both on the same circuit. |
I'm a little lost... what kind of heat control do you have to set them both at half? (I'm not sure what you mean by "they tested fine" here.)
If it's infinite switches, realize that an infinite switch turns the heat from fully off to fully on at squirrelly intervals, so sometimes both will be fully on, and you'll draw lots of amps for unpredictable times at unpredictable intervals. If both full-on draw too many amps, you may unpredictably blow a fuse now and then.
Quote: | But I didn't wait long enough for them to start cycling on and off.. I guess when I get the oven done I will have to figure out a good way to measure the temperature all over in it. |
Harbor Freight puts touchless infrared thermometers on sale cheap every few weeks. I got the $60 one with a gooseneck for $40 on sale, and really like it. I think that they have a $40 one that goes on sale for $20 sometimes, which is basically the same thing without the gooseneck, which you don't really need. (It has laser pointing, and goes up to something like 480 F.) They have an even cheaper one but it only goes up to 210 F or something like that, which isn't enough. _________________ Paul (a.k.a. Dr. Crash)
Tired of buying cheap plastic crap? Now you can make your own! www.VacuumFormerPlans.com |
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drcrash Guru
Joined: 04 Sep 2006 Posts: 705 Location: Austin, Texas
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Posted: Fri Jun 01, 2007 9:39 am Post subject: |
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jzawacki wrote: | Yeah. I remenber the rectifier switching.. But that kinda screws my current plans.. so I will just have to wait and see what happens. I can't give both elements the full 2000 watts on a single circuit and they tested fine set at half both on the same circuit. |
I'm a little lost... what kind of heat control do you have to set them both at half? (I'm not sure what you mean by "they tested fine" here.)
If it's infinite switches, realize that an infinite switch turns the heat from fully off to fully on at squirrelly intervals, so sometimes both will be fully on, and you'll draw lots of amps for unpredictable times at unpredictable intervals. If both full-on draw too many amps, you may unpredictably blow a fuse now and then.
Quote: | But I didn't wait long enough for them to start cycling on and off.. I guess when I get the oven done I will have to figure out a good way to measure the temperature all over in it. |
Harbor Freight puts touchless infrared thermometers on sale cheap every few weeks. I got the $60 one with a gooseneck for $40 on sale, and really like it. I think that they have a $40 one that goes on sale for $20 sometimes, which is basically the same thing without the gooseneck, which you don't really need. (It has laser pointing, and goes up to something like 480 F.) They have an even cheaper one but it only goes up to 210 F or something like that, which isn't enough. (It's mainly for things like finding out where your house is poorly insulated.) _________________ Paul (a.k.a. Dr. Crash)
Tired of buying cheap plastic crap? Now you can make your own! www.VacuumFormerPlans.com |
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badger Novice
Joined: 03 Sep 2006 Posts: 63
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Posted: Sat Jun 02, 2007 4:42 pm Post subject: |
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I'm really curious how these griddles worked out for forming.
badger |
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