Aircraft jacking poll

[JimB]

I have an engine hoist and when I jack the plane I have the cowling off so I use it. It's easy and no additional gear is required. 

[Igor_U]

On 11/14/2022 at 4:38 AM, N201MKTurbo said:

Why not leave it on jacks overnight? My jacks will barely fit under the wings when all the way down so if they droop all the way down nothing bad happens. I’ve left it on jacks for weeks.

Earthquake!

It happened to a friend of mine when one hit Seattle in early 2000s. It was right at the moment when they jacked his M20F for a gear check. He was lucky as it didn't crash but said it was memorable experience. 

 

Having said that, I left mine on the jacks quite a few times over the years.

[carusoam]

Jacks are to be feared…

There is a nice bravo around here that slipped off the jacks…

jack stands are good…

hydraulic jacks with collars are good… collars keep the Jack from lowering itself….

 

falling off the Jack can make prop strikes and gear up landing look good…. 

 

PP thoughts of misery only, planes don’t fall off Jack stands very often….

Best regards,

-a-

[Jpravi8tor]

On 11/6/2022 at 1:01 PM, Shadrach said:

I happened to have a picture and was able to crop an image of the set up. I’m told the weight of the 4x4s helps to dampen any movement.

Archimedes would be proud!

[FlyingDude]

Just bought modified marine jacks from Minderman marine in Port Clinton , OH. Pictures to follow.

I worked with chief machinist Dan to modify the tip of the lifting rod to fit mooney hoist point. He said they’re willing to make aircraft jacks and would post on our vendors forum… 

[Fly Boomer]

9 hours ago, FlyingDude said:

Just bought modified marine jacks from Minderman marine in Port Clinton , OH. Pictures to follow.

I worked with chief machinist Dan to modify the tip of the lifting rod to fit mooney hoist point. He said they’re willing to make aircraft jacks and would post on our vendors forum… 

Looking forward to more on this.

[FlyingDude]

Pictures.

[A64Pilot]

That’s very interesting, do you have a price? I assume you buy your own bottle jack?

[FlyingDude]

3 minutes ago, A64Pilot said:

That’s very interesting, do you have a price? I assume you buy your own bottle jack?

Please call them for price. 
yeah, i got my own bottle jacks. I had a couple in the garage but it turned out they “died” (they were from a garage sale anyway), so got 29$ harbor freight ones.

Bottle jack is not a must. You can stabilize the rod with the through hole at the bottom and twist the screw. 

[A64Pilot]

I’ve used the screw jacks believe it or not but jacking supports under a house. For a one time use they are fine, but for something like an aircraft jack I’d pop the $60 and have bottle jacks

Shipping may kill the deal though.

I particularly like the jack stand design as you can spin the lock down after jacking and even if the jack fails airplane isn’t moving. I never though of putting a bottle jack under a jack stand, pretty smart.

Currently I borrow the neighbors I think they are jack house jacks, but there is no lock

[FlyingDude]

I flew in to pick them up  so can’t say much about shipping rates. But initially they had mentioned that they ship stuff all the time.

[Kelpro999]

34 minutes ago, FlyingDude said:

Pictures.

Use extreme caution! It looks like the full load is being supported by the bottle jack base and Not the “A” frame. Maybe I’m missing something?

[FlyingDude]

24 minutes ago, Kelpro999 said:

Use extreme caution! It looks like the full load is being supported by the bottle jack base and Not the “A” frame. Maybe I’m missing something?

The weight is supported by the collar screw. As the bottle jack is pumped, the collar screw is twisted. 

 

Aircraft are never supposed to be left hanging on hydraulic jacks. You must always have a mechanical lock, clamp, etc.

[Fly Boomer]

1 hour ago, FlyingDude said:

Pictures

So, the screw moves freely through the top collar of the jack stand until you run the lock back down to the collar?  Once the screw is up, and once the lock has been screwed beck down to the collar, can you remove the jack?  Is there anything connecting the top of the jack and the bottom of the screw?  Sorry for all the questions, but I have never seen this arrangement before.

[A64Pilot]

49 minutes ago, Kelpro999 said:

Use extreme caution! It looks like the full load is being supported by the bottle jack base and Not the “A” frame. Maybe I’m missing something?

The big screw at the top of the jack, if you spin it down as you jack the airplane up worst cast it could fall whatever lift you get out of one pump.

”real” aircraft jacks are this way, raised by hydraulics but have a collar that spins down as a safety.

So yes the bottle jack is holding 100% of the weight for a short time, but so what, it’s rated for 8,000 lbs, lifting a Mooney should be well less than 1/4 of that. The concrete floor should certainly handle the weight.

‘Sure you can remove the jack if you wanted to so long as you screw the screw down, just let pressure off of the jack and pull it out.

I’ve never done this either, but the advantages become really obvious once you look at it, much better than the Jack house aircraft jacks I borrow.

On edit, yes while raising the aircraft the frame of the jack stand has no weight on it, it’s just there, but if you keep up with the screw collar it’s safe.  I think I understand your concern now

[FlyingDude]

15 minutes ago, A64Pilot said:

yes while raising the aircraft the frame of the jack stand has no weight on it

One pump on the hydraulic Jack lifts it by 1/2”. If it explodes, the plane will fall off 1/2”, provided that you keep twisting the collar. I think that’s better than the original aviation jacks* I had where you’d first jack the whole thing up and then clamp the shaft. Anyway guys, I have no financial gain in the sale of these jacks. I shared them here because this thread was useful in helping me reach this solution…

* originally designed for beechcrafts with single support structure that would align the jacks perfectly under the house points. 

[Kelpro999]

49 minutes ago, A64Pilot said:

The big screw at the top of the jack, if you spin it down as you jack the airplane up worst cast it could fall whatever lift you get out of one pump.

”real” aircraft jacks are this way, raised by hydraulics but have a collar that spins down as a safety.

So yes the bottle jack is holding 100% of the weight for a short time, but so what, it’s rated for 8,000 lbs, lifting a Mooney should be well less than 1/4 of that. The concrete floor should certainly handle the weight.

‘Sure you can remove the jack if you wanted to so long as you screw the screw down, just let pressure off of the jack and pull it out.

I’ve never done this either, but the advantages become really obvious once you look at it, much better than the Jack house aircraft jacks I borrow.

On edit, yes while raising the aircraft the frame of the jack stand has no weight on it, it’s just there, but if you keep up with the screw collar it’s safe.  I think I understand your concern now

 I see how rather benign using it in the hanger is now. My first concern was born from where I have to lift mine.. outside, uneven, unstable ground uphill in the snow both ways kind of thing.

  I do like how light weight they look. When I made mine 20yrs ago, I also chose light and portable over heavy beasts. Portability was primary. Now I see they can be bought everywhere. 

[A64Pilot]

Depending on the price I think it’s brilliant, wish I had thought of it, I’ll call tomorrow and price them.

I’ve been looking unsuccessfully for a set of used jacks for two years, a set of Jacks AC Spruce sells, I think are $800 for a set, so I’ve been borrowing the neighbors, and as how the reinforcements seem to be electric conduit with the ends smashed don’t look to be high quality either. So I think theses stands are both stronger and more stable.

https://www.aircraftspruce.com/catalog/topages/alphaJacks5.php

[FlyingDude]

4 hours ago, Fly Boomer said:

So, the screw moves freely through the top collar of the jack stand until you run the lock back down to the collar?  Once the screw is up, and once the lock has been screwed beck down to the collar, can you remove the jack?  Is there anything connecting the top of the jack and the bottom of the screw?  Sorry for all the questions, but I have never seen this arrangement before.

The rod screw and collar nut assembly is independent of the stand. It moves up and down freely. Down motion is limited by the nut on collar obviously. When the hydraulic jack pushes the rod up, the nut also moves up. You should keep screwing it down to the collar.

 The original configuration requires you to turn the collar screws to lift the load while holding the bottom of the rod fixed by means of the hole

[MikeOH]

Is there a recess on the top of the red end piece for the jack point to rest in?  The picture almost looks like the jack point can slide off the end of the jack end piece!

[Kelpro999]

23 minutes ago, MikeOH said:

Is there a recess on the top of the red end piece for the jack point to rest in?  The picture almost looks like the jack point can slide off the end of the jack end piece!

Like this one?

[FlyingDude]

24 minutes ago, MikeOH said:

Is there a recess on the top of the red end piece

Yes…

I kinda feel insulted though…

[FlyingDude]

6 minutes ago, Kelpro999 said:

Like this one?

No. Machined on the tip of the rod per my specs (Lasar tie down/ hoist screw). They can machine any pattern I guess. No additional components. Single rod with a grooved tip.

[Kelpro999]

5 minutes ago, FlyingDude said:

Yes…

I kinda feel insulted though…

Don’t feel insulted! I see most of your photos show the lifting point inside the tip

[FlyingDude]

3 minutes ago, Kelpro999 said:

Don’t feel insulted! I see most of your photos show the lifting point inside the tip

Because it’s grooved for that…