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ahillworks Master
Joined: 18 Nov 2007 Posts: 308 Location: Orlando FL
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Posted: Sat Nov 24, 2007 2:07 pm Post subject: Vac Former in build progress. |
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Ok so these pictures do not do much for what I have gotten to so far but this is what it look like on the first day. I have purchased since then a 6cfm Robinair 15600 pump and a 7 gallon tank. I have also made a shelf for the tank. I am going out tonight to get the rest of the stuff to finish the table and then start on the heating oven for the top. Hope you like so far.
I hope it looks good. |
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cod Master
Joined: 05 Nov 2006 Posts: 322 Location: San Francisco
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Posted: Sun Nov 25, 2007 1:54 am Post subject: |
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lookin good. I venture to guess you will need more than 7 gals, but I can't tell how big that platen is. A 2x2 platen would do well with 30-50 gals _________________ <.o'> |
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ahillworks Master
Joined: 18 Nov 2007 Posts: 308 Location: Orlando FL
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Posted: Sun Nov 25, 2007 2:49 am Post subject: |
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cod wrote: | lookin good. I venture to guess you will need more than 7 gals, but I can't tell how big that platen is. A 2x2 platen would do well with 30-50 gals | Thanks alot the table is not big at all its like 2x1-4inch but the vacuum space is about 3/8 in all around something like that. Well any way more pics on how i am doing. I feel I am on the right track and need to make another trip to Homedep tomorrow for piping. Filter and gauge will be here in like 3 days so i have to wait. I added a back up valve for a shop vac for them just in case issues.
Hope you like so far =) |
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drcrash Guru
Joined: 04 Sep 2006 Posts: 705 Location: Austin, Texas
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Posted: Sun Nov 25, 2007 11:26 am Post subject: |
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cod wrote: | lookin good. I venture to guess you will need more than 7 gals, but I can't tell how big that platen is. A 2x2 platen would do well with 30-50 gals |
You should only need a big tank for simple 1-stage operation.
I suspect that a 7-gallon tank will be fine for a 2-stage (or 3-stage) setup like mine, if the platen is well-sealed and he gets a good seal around the platen edge.
For two-stage with a tank for the first stage and just the vacuum pump for the second, you only need the tank for the initial pulldown. Then you shut the tank shutoff valve, and if the vacuum pump can stay well ahead of leakage, you get better vacuum without the tank than with it.
With a vacuum cleaner, you can use the vacuum cleaner for the first stage, to pull the plastic basically down, then use the tank to pull most of the air out of the insides of the molds and platen, then use the vacuum pump alone for the long hard pull.
In that case you really have 3 stages. The vacuum cleaner reduces the volume of the space to be evacuated, by pulling the plastic mostly down. The tank pulls most of the air out of the remaining space in a hurry, but gets polluted in the process. Then the vacuum pump pulls out most of what the tank couldn't, and holds a high vacuum level until the plastic cools.
For either multi-stage scheme to work well, you have to keep leakage low compared to the pump's CFM rating. If the pump isn't pumping several times faster than the air is leaking in, it won't reach a high vacuum level. (Air is leaking it at ambient atmospheric pressure, but rarefied air is being pumped out. You need to pump about 10x faster than the leakage to maintain 90 percent vacuum.) _________________ 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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ahillworks Master
Joined: 18 Nov 2007 Posts: 308 Location: Orlando FL
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Posted: Sun Nov 25, 2007 9:30 pm Post subject: |
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Ok some updates. Will wait for the rest to finish and then the oven will be last.
Hope you guys like it and for those starting it may help. Keep in mind I did alot of reading before starting and it does pay off. Can't wait to test it when I am done. |
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TK 109 Guru
Joined: 11 May 2007 Posts: 712 Location: Galena, Ohio
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Posted: Mon Nov 26, 2007 9:42 pm Post subject: |
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very nice job!
may i make a suggestion? you may want to use metal rods for those transfer bars (?) that slide the frame up to the oven, as this will probabaly work a bit better for you that wood, i mean i can just see a quick jerk on that thing, and the wood wuold catch, and get bound-up in the mechanism, and therefore resulting in a bad pull. just a suggestion, or do you have that figured out? you ought to try old on the wood (maybe???)
REALLY nice job, can't WAIT to see those pulls, man! _________________ -Alex
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ahillworks Master
Joined: 18 Nov 2007 Posts: 308 Location: Orlando FL
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Posted: Tue Nov 27, 2007 7:02 pm Post subject: |
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Thanks,
When I get more money the Slide will be converted to metal but untill then it works for now. Friend of mine if giving the supplys for oven by next week. So we will see how it all fits together once done. Had to make a few mods to the oven boards so the plastic will be heated even. I will post more later once I am done and make a pull. Wish me luck!
Anthony H. |
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TK 109 Guru
Joined: 11 May 2007 Posts: 712 Location: Galena, Ohio
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Posted: Tue Nov 27, 2007 8:30 pm Post subject: |
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good luck anthony _________________ -Alex
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ahillworks Master
Joined: 18 Nov 2007 Posts: 308 Location: Orlando FL
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Posted: Wed Nov 28, 2007 7:38 pm Post subject: |
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The gauge came in YAAAAA!! now the filter is tomorrow. So close lol.
Later |
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ahillworks Master
Joined: 18 Nov 2007 Posts: 308 Location: Orlando FL
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Posted: Thu Nov 29, 2007 8:32 pm Post subject: |
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Sooooooooooo PO right now. Order the inlet filter and the company sends me a filter regulator. Errr. So sent them an email and left a message and will call tomorrow. Hope they over night the correct one since I had to wait 6 days for this one.
=( |
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TK 109 Guru
Joined: 11 May 2007 Posts: 712 Location: Galena, Ohio
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Posted: Sat Dec 01, 2007 7:02 pm Post subject: |
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bummer...
that tends to happen. just be paitent, man!
_________________ -Alex
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ahillworks Master
Joined: 18 Nov 2007 Posts: 308 Location: Orlando FL
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Posted: Sat Dec 01, 2007 10:19 pm Post subject: |
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OK was a smart _ss and hooked up the wrong filter to see where I am at on the pull. I got to -20 hg on the gauge at around 1 minute and 20 seconds. I am sure I got a leak some where because I could tell by the sound of the pump. Also on a Robinair (never used one) does it make a mist of smoke like out the exhaust? And lol funny to say it’s quite but makes a bubble sound when it gets higher in HG on the gauge. Over all I was happy to see it pulled to 20. But what is the time length on a 6cfm pump and what are some things I should look at to make a tighter seal? Posting Pictures on Monday when the right filter comes. Also Am I supposed to get to 25 hg? Or is 20 fine? I am making detailed RC car molds and negative molds so kind of seeing where I am.
EDIT: Started looking at these bigger machines and woundering do i need a bigger tank or no? |
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ahillworks Master
Joined: 18 Nov 2007 Posts: 308 Location: Orlando FL
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Posted: Mon Dec 03, 2007 7:55 pm Post subject: |
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Well here are some updated pictures.
Oven pictures will be later. Sorry there dark.
http://video.google.com/videoplay?docid=-2027694575518204979
And a video to see my concerns. Let me know what you think. Also there is another post for opinions on the pull of the pump input would be great. |
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ahillworks Master
Joined: 18 Nov 2007 Posts: 308 Location: Orlando FL
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Posted: Tue Dec 04, 2007 1:57 am Post subject: |
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Well I changed the piping around and got a better responce but will leave it at that. Last pics will be the oven once done and then the first pull. Hope this has helped some of you who need some ideas how to make one. If you have any questions feel free to ask me.
Thank you all who has helped me in the process and to those still helping (doug). Also thanks to the owner of TK560 because with out this form and the books I would be lost. I hate reading but I guess when you have a heart for something it lets you see how much reading and research you would do.
Anthony H |
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jegner Site Admin
Joined: 30 May 2003 Posts: 2144 Location: Texas, USA
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Posted: Tue Dec 04, 2007 3:42 pm Post subject: |
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Looking good!
Jim |
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