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 Post subject: Re: "Titan" air jack
PostPosted: December 24, 2010, 2:35 pm 
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Joined: July 8, 2008, 11:05 am
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Location: Just South of Charlotte, NC on Lake Wylie
Your welcome I'm glad you approve that I approve :wink:
It sounds like you have some pretty cool people at your local welding supply and the fact that the guy is called "Bubba" and he knew about air jacks makes it even better, my guys all have regular names :( .
$175 seems a bit high to me but definitely not out of line, and that refill price is sweet I wish argon was that cheap to fill.......
I totally agree with you and I too would be much more inclined to spend the $$ on an air jack set up if I was doing that style of racing. You're exactly right the cool factor and the lazy factor of the jacks just don't add up to the same as the cost of the bits and pieces needed for it. I found the same thing you did with the cylinders and valves. I'm going to keep an eye out at my local surplus places for some, since i'm probably going to be up there about once a week this semester since I have no classes on friday :mrgreen: and if I can find the bit and pieces I'll most likely get them as long as the price is right.........
:cheers:
Brian "The Scavenger" Gifford

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 Post subject: Re: "Titan" air jack
PostPosted: December 24, 2010, 4:03 pm 
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Joined: November 25, 2009, 8:47 am
Posts: 140
Location: Tecumseh, Ontario Canada
GonzoRacer wrote:
Yo Ted-
Went back and re-read your earlier post, found the formula for lifting power, so's I can size the air cylinders I'd need.


The formula gives you an "in theory" number, doesn't take leaky seals, general squidginess or the compressibility of air into account so... Be careful, and conservative.

Also, if you're ever looking to pull rather than push with a cylinder, remember you have to take the missing area, that the diameter of your shaft inhabits, into account.

Cheers, Ted


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 Post subject: Re: "Titan" air jack
PostPosted: December 24, 2010, 4:41 pm 
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Quote:
general squidginess


Wasn't he a Union officer in the Civil War?

Thanks, Ted, I've been using the 2 inch bore estimate and 200 lbs/sq in of air pressure, which gives a lifting power of 600 lbs. That's about 150 to 200 lbs more than I think each corner of the car should weigh. (Another reason for not buying the parts yet, I'm only guessing the weight to be lifted!)

Oh, and Merry Christmas, y'all!!!

JDK

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 Post subject: Re: "Titan" air jack
PostPosted: December 24, 2010, 5:24 pm 
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Joined: April 12, 2010, 5:40 pm
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Location: san francisco bay area
what about something like these?
http://shop.airliftcompany.com/product/271203/58343/_/Gen_IV_Dominator_Series_D2500_Single_12%22_port

Quote:
EasyStreet is proud to announce the first model from the brand new Dominator series line of air springs: the Dominator D2500! Featuring an unprecedented maximum restrained pressure of 600 psi, 7.7" usable stroke, and a load range of 294-2096 lbs.; this bad boy will give you the performance you crave. With more lift, a softer, smoother ride, and the lowest price in the industry; you can't go wrong with the new Dominator D2500!

might even be able to tuck them up in the bodywork and put magnesium plates on the bottom for custom visual effects at stoplights :wink:

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 Post subject: Re: "Titan" air jack
PostPosted: December 24, 2010, 8:36 pm 
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Hey Jack!
Merry Christmas, Dude!

Those would work just fine, Sir, but you've also proven my point. They're 97 bucks each, plus some shipping. Plus gotta mount 'em and put some kind of foot on 'em. I'm seeing 500 bucks again...

And draggin' 'em on the ground, throwing sparks into the unsuspecting Dweeb behind you in the minivan is, I'm sure, highly illegal. Would be fun, though, wouldn't it?!?!?!? :twisted:

JDK

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"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom


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 Post subject: Re: "Titan" air jack
PostPosted: December 24, 2010, 10:02 pm 
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Get some appropriately sized tubing for both the cylinder and piston, then get a shop to cut O-ring grooves in the piston, and presto. Of course the pistons will need retract springs, but that's not hard. It's all doable, and cheap if you work it right. It just seems like a lot of weight and bother for how often they're really used. Great for track use, but the other 99% of the time they're a weight liability, useless since a nitrogen tank isn't normally carried in the car (I hope.)

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 Post subject: Re: "Titan" air jack
PostPosted: March 16, 2012, 1:45 pm 
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Location: Waterford, MI
$500 may sound like a lot for an airjack system.. but you can't even buy one high quality racing jack cylinder for that much (seriously)

i'm liking the thinking in here and i might go to a solution like this... I'd love to use legitimate air jacks, but the operating pressure is CRAZY!!! but then again if i'm gonna roll with a tank of nitrogen to the track it really doesn't matter...

i'd use it like twice per track day... switch to race wheels and tires... switch back to street stuff.

it would look AWESOME though, and that's the real seller :P

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 Post subject: Re: "Titan" air jack
PostPosted: March 17, 2012, 7:45 pm 
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One of my 'drifter' friends installed one of these:

Image

in the trunk of his 240sx, since he needs to change rear tires more often than the fronts. It works, and it was cheap, compared to air jacks. He bolted to the roll cage.

That would be an electric trailer tongue jack.


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 Post subject: Re: "Titan" air jack
PostPosted: March 17, 2012, 11:11 pm 
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Always Moore!
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Location: Pittsburgh, PA
I'm a little late to the party - this is what I've come up with for a small portable tire changing jack:
Attachment:
DSC05428.JPG


Its not air and its by no means quick but I think it will do the trick and I have less than $25 into it. There will be a pair of tabs on the front and back of the chassis that the rod-end will slip in between.


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 Post subject: Re: "Titan" air jack
PostPosted: March 18, 2012, 1:07 am 
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Joined: July 6, 2008, 11:15 am
Posts: 1047
Location: Cave Creek, AZ
In my Yamaha Rhinos I needed a quick but light jack, so I got one of those cheapie screw jacks that Toyota and Nissan put in their little trucks years ago. I welded a 3/4" nut to the cranking eyelet and Voila'; I use my cordless impact gun and can have the front or the rear off the ground in about 10 seconds. Works great and if the battery goes dead, you can still use a regular ratchet wrench to lift it the slow old fashion way. You can weld a 2" deep round pocket on the bottom of your vehicle to catch the tip of the jack thereby keeping it from rolling off the jack.

Tom

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 Post subject: Re: "Titan" air jack
PostPosted: March 18, 2012, 5:32 pm 
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Location: Columbia SC
Aluminum floor jack.. Brunnhoelzl warrior. Light, fast, will cost less in the long and short run. Pneumatics shouldn't be done on the cheap, you WILL regret spending so much effort
on something that will be marginal or will break. Have a lot experience there in other situations. Machining your own is a disaster unless you KNOW what you are doing and do a lot of R&D. If you are doing pneumatics just spend the money on proper equipment. Otherwise buy a good jack.

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 Post subject: Re: "Titan" air jack
PostPosted: March 18, 2012, 5:42 pm 
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The linear motor is a great idea. No nasty compressor or nitrogen bottles.

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 Post subject: Re: "Titan" air jack
PostPosted: March 18, 2012, 7:40 pm 
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Hi JD,

I made a lever jack for my FF years ago, like the one shown in the previous pictures, and it worked well but it did take some reefing on the handle to get the rear end off the ground. Had to have a pretty heavy duty handle to stop it bending. The jack itself was 1" square tubing and angle. It was really handy that it went over center so that it "locked" upright...I had a safety pin that slid into the hinge area to stop it from accidentally being lowered on my head.

Thinking about the air jacks, it occurs to me (but I may be wrong in this thinking) that the cylinders need to be so big and the pressures so high because the cylinder doesn't employ any type of leverage, its just a straight push. So, what if you used smaller cylinders pushing through a lever, sort of like inboard shocks? Second thought, screws have a sort of built in leverage so, if you're not too worried about lift speed, how about a powered screw instead of an air cylinder? And, if you are only concerned about changing tires, then you'd only need two of them, one in the middle of each side of the car, then the car would be a tripod when it was jacked, one jack and the two offside tires would support it.

My $0.02 worth and it may not be worth that much.

Bill

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 Post subject: Re: "Titan" air jack
PostPosted: March 19, 2012, 10:26 am 
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Hi Bill-
Ya know, honestly, I saw activity on this thread and was surprised all to heck... I hadn't looked at it, or thought about air jacks in months! :shock: I was kinda daydreaming when it all started, and it became obvious that air jacks or whatever were a silly luxury that I don't need for track days/hillclimbs where you don't do pitstops per se. I can use my el cheapo floor jack or some such...

Although, those F1 style "lever" jacks (that do look a lot like Dave's "furniture dolly" would be kinda cool on the front...

Talk amongst yourselves, I'll sit over here in the corner and listen in...
:cheers:
JDK

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Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom


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