Wing Jack

[John Mininger]

On 5/15/2023 at 5:01 PM, Fly Boomer said:

I wonder if that box and jack would still fit under the wing if the tire were flat, sitting on soft ground?

I also made two additional "boxes" that are 4" and 8" high. You can probably see them in the background of one of the pics.

I'm sure that some combination of 4, 8, and 12" would work on soft ground.

[Fly Boomer]

12 hours ago, John Mininger said:

I also made two additional "boxes" that are 4" and 8" high. You can probably see them in the background of one of the pics.

I'm sure that some combination of 4, 8, and 12" would work on soft ground.

That's very cool.  No matter what the clearance is, some combination will do the job!

[FlyingDude]

On 5/5/2023 at 1:56 PM, A64Pilot said:

OK it’s put together and it works, a few caveats of course.

First I used the stand @rickseeman recommended, not the original I looked at, his fit better and besides was cheaper.

Second the threaded rod portion as your moving it, it’s length is the limit that you can jack up, so you have to have it fully screwed down and then using the sliding tube portion of the jack adjust it so it just fits under the wing with the screw portion fully down.

There is enough lift for a Mooney, but this may not work for an Oleo strut airplane, if we had a longer screw portion, ideally 7” longer that would be perfect.

Second there is a “window” on the adjustable sliding tube, when the bottom of the threaded portion is in that window, that’s it, you should stop jacking up or there won’t be enough of the threaded portion sticking into the pipe to be safe.

I bought an 18” portion of 1.25 “ galvanized pipe and cut it into two 7” pieces, one for each jack, on one end I welded on a thick fender washer for the jack to push against and I then welded it 100% around to the threaded rod portion of the jack, initially I didn’t weld it, but as I’m jacking so the threaded rod is up high in the tube, I wanted the additional security of 7” more pipe still sticking into the jack stand and feel that 100% weld out is justified, of course real thick tubing would be much better than galvanized  plumbing pipe, if you weld galvanized, be sure you have good ventilation as the gas burning zinc gives off apparently isn’t healthy.

OK you get this thing and the first thing you see is there is a cap on the bottom acting as a stop for the legs that fold, it’s screwed on with an internal wrenching bolt, remove it, then you see a washer in the tube with three spot wells, that’s what the cap screws to, drill out the three spot wells, then drive it out the bottom. You can weld the portion that slides up and down to fold, or what I did was drill a hole through the tube and the clamp screw screws through the tube, securing the ring that slides up and down, so it can still fold but it’s held secure.

If you have one in your hand all this will make sense.

Using a hacksaw or band saw cut off the V on the end of the screw, keeping all the length you can of the screw, the screw is solid steel, so take a 1/2” bit and drill into the sawed off part to center the jack point.

To jack the airplane up, position the jack stand under the airplane with the screw fully screwed in, then simply put the jack under the center of the stand and start jacking, as the airplane is lifted keep the barbell looking locking ring tightened so if the jack fails the aircraft can’t fall. Watch the jack stand legs, for some reason one may not be carrying its share of the weight, the BFH is to make an impact adjustment so that all three legs are carrying the load, check that every inch or two.

Once fully lifted I take the load off of the jack, but keep it there just in case. Your not getting it out anyway as the piston won’t collapse without weight on it

https://www.amazon.com/dp/B09Z367HM5?ref=ppx_yo2ov_dt_b_product_details&th=1

https://www.amazon.com/dp/B07WTKXP1V?psc=1&ref=ppx_yo2ov_dt_b_product_details

Personally I think it’s more secure than most aircraft jacks and as it doesn’t rely on hydraulics to hold the airplane up, just to lift it, and even then if you keep moving the lock down even if the jack blew nothing bad would happen, the airplane would drop the 1/4” or so that you had the lock up.

The little jack just barely fits under the stand, but it does fit. Whole thing took less than an hour to put together. The down side is your limited by the length of the screw portion how much you can raise it as a jack. Ideal would be about an 18” screw with lock ring that would give you over a foot of lift.

 

In this configuration, when you pump the bottle jack, the weight is resting on the bottle jack and not the tripod. The tripod can even be lifted by the ram. Since the botti jack has very small footprint, the plane can move. You can transfer the weight on the tripod by welding a bracket between it's legs and resting the bottle jack on that bracket.

[A64Pilot]

4 hours ago, FlyingDude said:

In this configuration, when you pump the bottle jack, the weight is resting on the bottle jack and not the tripod. The tripod can even be lifted by the ram. Since the botti jack has very small footprint, the plane can move. You can transfer the weight on the tripod by welding a bracket between it's legs and resting the bottle jack on that bracket.

You could, but by keeping the big screw device snug you keep the theoretical lifting to almost nothing, say 1/8”.

Even if lifted by 1/4” the stands legs will come into contact with the floor with just a tiny bit of movement side to side.

To get the bottle jack into the stand it has to be first pushed up into the bottom of the stand and then the bottom moved to the side, meaning that there is about .5” less clearance than the height of the jack, so if there was a bracket, you wouldn’t be able to separate the jack and stand, and you would lose the folding capability, although it’s not really very useful in my situation.

Interesting point, that would turn it into a “real” jack, bears considering.

Perhaps even a section cut out of large pipe that welded into the tube so that you could place the bottle jack in? Still puts the weight onto the stand and not the floor, but could still fold.