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DaBraink
Samba Member
Joined: August 12, 2005
Posts: 172
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 Posted: Mon Jun 27, 2016 1:18 pm Post subject: Re: Fulcrum type floor jack |
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What is the approximate weight of one rear tire being lifted?
Also, the flat section is obviously to stabilize the load, but there is an additional angle at the end of the flat spot on the bottom, is that for giving additional clearance when mounting an inflated tire?
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chrisflstf
Samba Member
Joined: February 10, 2004
Posts: 3439
Location: San Diego
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| Posted: Mon Jun 27, 2016 6:19 pm Post subject: Re: Fulcrum type floor jack |
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| I dont think it is a jack. Looks like just a pic of a guy with a tool, or part next to a vw. It doesnt look like it would lift high enough to get the wheel off the ground. Why the pointed bottom? Also, that big circle at the top. Cool pic, though anyway |
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easy e
Samba Member
Joined: May 28, 2008
Posts: 3931
Location: 1 hr north of Santa Barbara
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| Posted: Tue Jun 28, 2016 9:20 am Post subject: Re: Fulcrum type floor jack |
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| DaBraink wrote: |
What is the approximate weight of one rear tire being lifted?
Also, the flat section is obviously to stabilize the load, but there is an additional angle at the end of the flat spot on the bottom, is that for giving additional clearance when mounting an inflated tire? |
If car weighs 1,800 lb... approximate weight at one rear tire is 500 lbs. Lifting at the jack point lifts the driver's side (front & rear). Additional angle... don't know, but seems like it might give you a scuzz more lift. It'd be hard to get that last little bit of elevation out of it.... and be over at the tire at the same time. Maybe it could be reversible... and tip towards the rear.
| chrisflstf wrote: |
| I dont think it is a jack. Looks like just a pic of a guy with a tool, or part next to a vw. It doesnt look like it would lift high enough to get the wheel off the ground. Why the pointed bottom? Also, that big circle at the top. Cool pic, though anyway |
Care to share what kind of tool/part you think it is? Did you see the example jack of similar type (on the previous page)? The pointed bottom... DaBraink just asked the same thing. The big circle... kinda like a gear shifter with a round ball... comfortable to grasp. But that would only make sense if it was meant to be grasped up top... like if it was pulled... which then pulling would raise the car... like a jack.
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MrPolak
Samba Member
Joined: June 20, 2004
Posts: 1337
Location: AG ,atnaltA
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| Posted: Tue Jun 28, 2016 8:15 pm Post subject: Re: Fulcrum type floor jack |
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| EverettB wrote: |
| Malokin Martin wrote: |
| It really seems like it would need more of a nub (height) if it was meant to switch out a tire though... |
I was thinking that too but maybe you are supposed to double pivot it until the long arm is on the ground and you stand on it to hold it in place.
I think it might be high enough at that point. |
I think you nailed it - double pivot. Once you move past the second pivot car's weight will hold it down. |
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BarryL 
Samba Member
Joined: November 01, 2004
Posts: 14259
Location: Casa de Oro, California
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| Posted: Wed Jun 29, 2016 9:41 am Post subject: Re: Fulcrum type floor jack |
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| easy e wrote: |
| Care to share what kind of tool/part you think it is? |
Whatever it is it does click two flats until the eye is on the ground. I believe it is made of cast aluminum at the base and the handle is steel if not also cast aluminum.
When put to use it will move the car forward and twist it if used only on one side. I believe there is a jack hole pin that either slides or is quick release so it can be used on either side.
I think it is a lock for anti theft or a lock for parking infraction. I believe there would be one on each side simultaneously pulled down. Once down they would stay down and a rod would be placed behind the front wheels through the eyes and locked until fines were paid or security was not needed. |
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easy e
Samba Member
Joined: May 28, 2008
Posts: 3931
Location: 1 hr north of Santa Barbara
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Abscate
Samba Member
Joined: October 05, 2014
Posts: 22653
Location: NYC/Upstate/ROW
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| Posted: Wed Jun 29, 2016 5:22 pm Post subject: Re: Fulcrum type floor jack |
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| easy e wrote: |
| MrPolak wrote: |
| You need to use the ratio of distance of the lever pull to the distance the jack point moves. In this case the mechanical advantage is rather high since the car moves vertically only a small distance. |
Is this better... (Beetle is 4'-11" high)
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Not quite as the lifting moment would be the horizontal component of the lifted part normal to the tool axis as shown, and the lifting ratio would change as you applied force, but for a SWAG its really close.
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easy e
Samba Member
Joined: May 28, 2008
Posts: 3931
Location: 1 hr north of Santa Barbara
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| Posted: Wed Jun 29, 2016 5:49 pm Post subject: Re: Fulcrum type floor jack |
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Moments & forces are different units.
As theta decreases through the motion... applied force decreases. SIN 0 = 0
Then it's flat on the resting point and part B of the problem enters, for the second pivot point... if taking the handle to the ground.
Figuring that would be the same principle... don't think I'd characterize it as a SWAG though. I could write the equation for force at any point... but one academic exercise is enough for me. Go for it.
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Spreadsheet for Bus RPM, based on gearing & tire size (Excel format)
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mandraks
Samba Member
Joined: November 28, 2004
Posts: 7047
Location: Lawrenceville, Ga
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| Posted: Thu Jun 30, 2016 10:18 am Post subject: Re: Fulcrum type floor jack |
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| Abscate wrote: |
| easy e wrote: |
| MrPolak wrote: |
| You need to use the ratio of distance of the lever pull to the distance the jack point moves. In this case the mechanical advantage is rather high since the car moves vertically only a small distance. |
Is this better... (Beetle is 4'-11" high)
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Not quite as the lifting moment would be the horizontal component of the lifted part normal to the tool axis as shown, and the lifting ratio would change as you applied force, but for a SWAG its really close. |
One thing it would certainly do, make it difficult to open the door 
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MrPolak
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Joined: June 20, 2004
Posts: 1337
Location: AG ,atnaltA
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| Posted: Thu Jun 30, 2016 6:09 pm Post subject: Re: Fulcrum type floor jack |
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| easy e wrote: |
| MrPolak wrote: |
| You need to use the ratio of distance of the lever pull to the distance the jack point moves. In this case the mechanical advantage is rather high since the car moves vertically only a small distance. |
Is this better... (Beetle is 4'-11" high)
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Based on what I see the lever length ratio is closer to 1:7. |
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chrisflstf
Samba Member
Joined: February 10, 2004
Posts: 3439
Location: San Diego
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| Posted: Thu Jun 30, 2016 6:10 pm Post subject: Re: Fulcrum type floor jack |
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| I think the guy in the pic is just trying to figure out - How the heck do I get this in the car? If it was a jack, why isnt there a pic of it in use? I first thought the part he was holding came from a Harp. |
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DaBraink
Samba Member
Joined: August 12, 2005
Posts: 172
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| Posted: Thu Jun 30, 2016 9:47 pm Post subject: Re: Fulcrum type floor jack |
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If used as a double pivot, That would explain the curvature in the handle and the size of the round part at the top which would rest on the ground and allow someone to get their hand under the handle to pull it back up, instead of laying flat on the ground.
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BarryL
Samba Member
Joined: November 01, 2004
Posts: 14259
Location: Casa de Oro, California
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| Posted: Fri Jul 01, 2016 9:04 am Post subject: Re: Fulcrum type floor jack |
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| DaBraink wrote: |
| ...the curvature in the handle and the size of the round part at the top which would rest on the ground ...instead of laying flat on the ground. |
And maybe slide it on pavement or cement to push the car back from where it levered it from. |
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easy e
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Location: 1 hr north of Santa Barbara
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mandraks
Samba Member
Joined: November 28, 2004
Posts: 7047
Location: Lawrenceville, Ga
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| Posted: Sat Jul 02, 2016 11:22 am Post subject: Re: Fulcrum type floor jack |
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| chrisflstf wrote: |
| I think the guy in the pic is just trying to figure out - How the heck do I get this in the car? If it was a jack, why isnt there a pic of it in use? I first thought the part he was holding came from a Harp. |
getting it in the car should not be a problem? fold down the back seat and slide it in from the passenger side, easy peasy
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Uli
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'53 3-Fold Oval, L35 Metallic Blue, looking for a narrow hatch panel |
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Who.Me?
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Joined: July 14, 2014
Posts: 2207
Location: UK (South)
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| Posted: Sat Jul 02, 2016 12:54 pm Post subject: Re: Fulcrum type floor jack |
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If it is a jack, it doesn't seem very stable. Wouldn't it just fall over on to its side, if you pushed the handle all the way down to the ground?
If the handle wasn't all the way down (e.g. just pivoted on the first part of the hook), you'd have some control to stop it tipping.
I wonder if it's actually a lifting hook for pipe or heavy tubing? One of a pair?
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Looking for info on my truck's history. Are you from Campbell California or nearby. Do you recognise it? ... http://www.thesamba.com/vw/forum/viewtopic.php?t=636786 |
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cru62
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Joined: December 31, 2002
Posts: 4117
Location: Margaritaville.....24/7
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| Posted: Sat Jul 02, 2016 4:18 pm Post subject: Re: Fulcrum type floor jack |
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Don't forget that a Bug only has one jack point on each side as opposed to a Bus with two. So, you are actually lifting 1/2 of the mass, not 1/4.
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BarryL
Samba Member
Joined: November 01, 2004
Posts: 14259
Location: Casa de Oro, California
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| Posted: Sat Jul 02, 2016 6:54 pm Post subject: Re: Fulcrum type floor jack |
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| Who.Me? wrote: |
| Wouldn't it just fall over... |
The unofficial consensus is that there is a pin or peg going sideways into the jack point to keep it stable if it is a lifter thing. |
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Abscate
Samba Member
Joined: October 05, 2014
Posts: 22653
Location: NYC/Upstate/ROW
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| Posted: Sun Jul 03, 2016 4:24 am Post subject: Re: Fulcrum type floor jack |
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I think you would need a horizontal peg to keep this thing stable, near the base.
Apologies to easye, you did use the right normal component in your caculation, the blue line fooled me on the graphic.
The required force drops on the first lift, then gets nasty on the second pivot point where the advantage drops to about 4:1
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BulliBill
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Joined: July 09, 2004
Posts: 4572
Location: St Charles, MO
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| Posted: Sun Jul 03, 2016 7:59 am Post subject: Re: Fulcrum type floor jack |
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Man! You guys are so much smarter than me. But I am better looking...
Bill
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Thornton VW - Stockton
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