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DarthVader1 Expert
Joined: 04 Nov 2007 Posts: 193 Location: Phenix City, AL
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Posted: Thu Nov 29, 2007 8:14 pm Post subject: LOOK WHAT I'VE SCORED FOR ABOUT $80-something.... |
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Well, actually about $110-something (including shipping)...but for a thing that it's over the $150 mark...it was a good deal for me.
It's a SHOP-VAC, 16 gallon, 6.5 HP of brute sucking force.
I will be using this baby in my future THURSON JAMES styled vacuuforming machine. My big first step, to construct what I need badly for my project. It's gigantic (size-wise....and I mean...EVERYTHING IS BIG), from the parts, the unit, and even the hose (it's a 2 1/2" wide hose). If I grab the tube and hose, I look like a MIDGET grabbing that thing....number one reason that thought me: Time to get something smaller to attach to the machine....and probably clean my shop with...and much "manageable".
TK 560 used a SHOP-VAC with 3 HP (according to his video), and he did a good job with it, so I've decided to look for "BIGGER-THE-BETTER", more in terms of HORSEPOWER. The only thing I need to buy for what I need, is a hose adapter from 2 1/2" to 1 1/2"....that should do the trick.
Next...it will be ALL the wood needed for both carts, and the HARDIBACKER 500. I will be working with the aluminum plastic-holding frame a little after that. _________________ Robert
BH/TK/TB/TS 060
Last edited by DarthVader1 on Thu Nov 29, 2007 8:35 pm; edited 1 time in total |
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ahillworks Master
Joined: 18 Nov 2007 Posts: 308 Location: Orlando FL
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Posted: Thu Nov 29, 2007 8:29 pm Post subject: |
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Good job really. I got a ridgid for 29.99 5 hp 12 gallon during the black friday sale. |
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kayaker43 Expert
Joined: 13 Jun 2007 Posts: 175
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Posted: Thu Nov 29, 2007 10:31 pm Post subject: |
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Don't want to burst your bubble, but this info can be useful to others too.
The Shop vac size is almost irrelevant,.. Bigger canisters just cause a lag in response time, and more HP just means more flow, not vacuum, which is not very important to us. All shop vacs flow more than we need, and all have less vacuum than we want. In fact, I've never seen one do better than 4-6 in.hg out of a possible 29.9. The big hose won't help either, but it does make it feel stronger becuase the vacuum grabs more surface area when you stick your hand over it. A real vacuum pump would cause injury if you stuck your hand over a hole that size.
Its hard to convince people that some big howling shop vac that dims the lights is still a very weak vacuum pump, but stick a gauge on it and you'll see.
Here's another piece of shop vac trivia... When you plug the intake and the vac starts to scream, it not pulling harder, its actually stalling the impeller and unloading. Think about it, if it was pulling a load, it would dim the lights and slow the rpms. What you hear is the RPM increasing because its unlaoding, and you will notice the room lights may even get brighter.
The only way to make a shop vac pull harder is to have one suck through another one, but it only gives a 50% increase which is still a very low number. _________________ Doug Walsh
www.build-stuff.com
Hobby-Vac and Proto-Form machine plans
Also other plans books and videos for people who like to build things |
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drcrash Guru
Joined: 04 Sep 2006 Posts: 705 Location: Austin, Texas
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Posted: Fri Nov 30, 2007 7:02 am Post subject: don't buy a shop vac for vacuum forming |
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Don't buy a shop vac for vacuum forming, and don't expect a high-HP shop vac to pull significantly harder than one with half the horsepower rating.
Unless something has changed, the 6.5 HP Shop-Vac only pulls about 10 percent harder than the 3 HP model. That's not worth the price difference, and the horsepower ratings are really bogus.
Neither pulls any harder than a good used canister vacuum from a thrift store. A canister vacuum is much less bulky, too.
(I've been very happy with a 1000-watt Shark hand vacuum I got for $2 or $3 at the Goodwill Outlet store. It pulls as hard as my old 5.5 HP shop vacuum and takes up about a tenth of the space.)
Here's an older thread where we thrashed that stuff out:
http://www.tk560.com/phpBB2/viewtopic.php?t=783 _________________ 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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TK 109 Guru
Joined: 11 May 2007 Posts: 712 Location: Galena, Ohio
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Posted: Sat Dec 01, 2007 7:10 pm Post subject: |
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i got a 5 hp 4 gal ridgid vac, the futuristic-looking-one. sound familiar, ahillworks?
eh, my wet/dry vac sucks ok for my application. some jobs DO get tough, though, and the "vacuum-box with one hose sticking out" idea is one i've heard a few times. i should try it someday. but for now, no complaints.
listen to kayaker43 and dr. crash, though, they know what thier talking about! _________________ -Alex
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DarthVader1 Expert
Joined: 04 Nov 2007 Posts: 193 Location: Phenix City, AL
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Posted: Sat Dec 08, 2007 11:23 pm Post subject: |
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Well, I am not a scientific kinda guy, but all I could say is this.....based on the horsepower, and the original instruction by TJ for his Vacuuforming machine.....if I convert the hose into a 1 1/2 instead of the "out-of-the-box" 2 1/2" hose, using a shop-vac converter to half the hose size (actually, half the dimension, with same horsepower).....I feel it will be improving the sucking power by half, by doing so.
Hey, I an not scientific about this, just being as practical as it could be, since this is mainly to do just a mask, and that's about it......unless people comes to me to do some vacuuforming projects...............let's see...I will post progress as soon as I get pics and sucessfull stories to tell....really soon, _________________ Robert
BH/TK/TB/TS 060
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drcrash Guru
Joined: 04 Sep 2006 Posts: 705 Location: Austin, Texas
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Posted: Sat Dec 08, 2007 11:53 pm Post subject: |
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DarthVader1 wrote: | ...if I convert the hose into a 1 1/2 instead of the "out-of-the-box" 2 1/2" hose, using a shop-vac converter to half the hose size (actually, half the dimension, with same horsepower).....I feel it will be improving the sucking power by half, by doing so.
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It won't. It won't improve the sucking power at all. _________________ 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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kayaker43 Expert
Joined: 13 Jun 2007 Posts: 175
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Posted: Sun Dec 09, 2007 9:11 am Post subject: |
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Nope,.. same sucking power, if only it was that easy
Actually the bigger hose fools most people, it feels like more suction on your hand because it grabs more surface area. Also the way the big hose shortens under vacuum adds to the illusion of power.
The illusion of power is the driving force here. Why make a wimpy small quiet vac cleaner when you can charge more money for a huge noisy one that makes the ground tremble, and the lights dim. They play up on that by rating it as 110 inches of waterlift instead of 4 inches of mercury,... then rate it at 6 "peak" HP even though its really only 2HP.
They do these things to make money, but we are also using vacuum cleaners in a completely different way. High flow, not vacuum is really what picks up dust better. _________________ Doug Walsh
www.build-stuff.com
Hobby-Vac and Proto-Form machine plans
Also other plans books and videos for people who like to build things |
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TK 109 Guru
Joined: 11 May 2007 Posts: 712 Location: Galena, Ohio
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Posted: Sun Dec 09, 2007 9:14 am Post subject: |
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how and when does a shop-vac reach its "peak hp"? just wondering... _________________ -Alex
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kayaker43 Expert
Joined: 13 Jun 2007 Posts: 175
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Posted: Sun Dec 09, 2007 9:53 am Post subject: |
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It reaches peak HP in someones imagination!
One HP is around 750 watts so a 15 amp house circuit can only support less than 2.5 HP. They are measuring that microsecond surge on start up that is so short it doesn't blow the breaker. You can see it when the lights dim momentarily as you flip the switch.
Apparently some marketing genius measured almost 38 amps for a microsecond and declared it 6HP ???? Sadly I suspect a well designed motor would have less of a current surge on startup and rate lower on "peak" HP?
I get a kick out of the new crop of upright vacs too. They are about 5 lbs of function with 10 lbs of cheap plastic styling added for sales appeal. I wonder if an engineer built an ultralight whisper quiet upright vac that worked better, if anyone would buy them? Oreck sort of did this and seems to do well but even it could be better.
For some strange reason the vacuum cleaner industry is dedicated to "Form over Functon" _________________ Doug Walsh
www.build-stuff.com
Hobby-Vac and Proto-Form machine plans
Also other plans books and videos for people who like to build things |
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TK 109 Guru
Joined: 11 May 2007 Posts: 712 Location: Galena, Ohio
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Posted: Sun Dec 09, 2007 11:56 am Post subject: |
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huh, interesting... _________________ -Alex
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ThorsgaardFoundry Novice
Joined: 03 Sep 2007 Posts: 30
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Posted: Sun Dec 16, 2007 7:35 pm Post subject: |
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120V... 15 Amps....8 Ohms.... 1800 Watts....= 2.4 HP with no loss. (which is bogus)
Ohm's law sez you ya only need 30 Amps and a 120V motor to get 4.8 hp. - with no losses.
HORSEPOWER=(120V x 30A)÷746watts (746 watts =1 HP)
I've never seen a vacuum cleaner that claims it has a 30 amp motor..Buuut.... Wal÷Mart isn't open yet here in town... |
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cod Master
Joined: 05 Nov 2006 Posts: 322 Location: San Francisco
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Posted: Mon Dec 17, 2007 5:29 pm Post subject: |
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ThorsgaardFoundry wrote: | 120V... 15 Amps....8 Ohms.... 1800 Watts....= 2.4 HP with no loss. (which is bogus)
Ohm's law sez you ya only need 30 Amps and a 120V motor to get 4.8 hp. - with no losses.
HORSEPOWER=(120V x 30A)÷746watts (746 watts =1 HP)
I've never seen a vacuum cleaner that claims it has a 30 amp motor..Buuut.... Wal÷Mart isn't open yet here in town... |
you have access to 30 amps of power on one breaker ?
I dunno about 'no losses'. ShopVac designs are just not set up to hold much vacuum. They will never go over a certain 'inches of merc' . the design isn't close to being airtight, like a real vac pump. they is designed to move a lot of air fast, but not with a lot of vac pressure. _________________ <.o'> |
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ThorsgaardFoundry Novice
Joined: 03 Sep 2007 Posts: 30
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Posted: Mon Dec 17, 2007 8:00 pm Post subject: |
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yeah... Getting 30 Amps in one circuit ain't a problem (Vee don' need no steeenking breakers...) But only the most ELITE vacuum cleaners have even only a 12Amp motor..
Yeah - and thats figuring it with no loss. Vacuum cleaners are designed like leaf blowers.. Using a vac cleaner to hold vacuum would be like trying to use a leaf blower to inflate a tire.
Some vac formers do use just a shopvac as the only means. And it will work for thin stuff and small scale. and not deep draws, I suspect.
Jest sayin.. |
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