My new jacks with built in safety stands

[MARZ]

Working on vehicles I've always used safety stands, and have worried when using the standard long ram jacks. So I set out to make my own jacks that meet my needs. 

[HRM]

Nice! What did it take to make those?

Oh, wait--you just modded these:

[Bob_Belville]

I would caution that the relatively small base, 9-3/4" square, is not adequate. My "store bought" jacks are 24" square. One of the main uses for jacks is to swing the gear. This in turn requires entering the plane which needs to have a certain level of lateral stability. I've never seen an aircraft jack that did not have a wide base. 

http://jackhouse.com/aircraft-jacks.html

[DonMuncy]

I'm not sure I understand how you use them. I'm sure it is my ignorance, but it looks like you have to put the pin in place, then jack it up. But then how do you lock it in place (in case the hydraulic unit releases). 

[MARZ]

There is a latch in the front with 5 positions that click in.  The pin is to make adjustments to the length of the jack

[DonMuncy]

Ahh. I knew there had to be an answer.

[orionflt]

I have to agree with Bob, lateral stability is a must, and the more rod you have the less stability there is. I'm not saying this will not work well, just be careful, if the aircraft starts to twist on the jacks when you are off the ground it can be an expensive lesson.

Brian 

[MARZ]

@Bob_Belville If I were to extend a jack to the full length that those are capable of (40") I would agree with the need for a wider base.  The max lift needed for my (our) birds is 30" which will give 5" of tire to ground clearance.   I don't expect leverage against the stand at that height, but will definitely heed your caution at first use   

Thanks!

[Bob_Belville]

Just now, Mike Ropers said:

@Bob_Belville If I were to extend a jack to the full length that those are capable of (40") I would agree with the need for a wider base.  The max lift needed for my (our) birds is 30" which will give 5" of tire to ground clearance.   I don't expect leverage against the stand at that height, but will definitely heed your caution at first use   

Thanks!

I'd say it's fine to change a tire since 2 wheels remain on the floor.. 

How do you lift the nose wheel? Tail weight? Engine hook? Prop cradle?

[orionflt]

1 minute ago, Mike Ropers said:

@Bob_Belville If I were to extend a jack to the full length that those are capable of (40") I would agree with the need for a wider base.  The max lift needed for my (our) birds is 30" which will give 5" of tire to ground clearance.   I don't expect leverage against the stand at that height, but will definitely heed your caution at first use   

Thanks!

extending the 40" jack to full length even with a wide bade is dangerous! we have to do that when dropp checking the Lancair IVP, during that whole operation we have some one on the wing tip stabilizing it. it will yaw very easily.

Brian

 

[Guest]

While a novel idea, I wouldn't lift my airplane on them, let alone a customer's.  The liability would be too great.

Clarence

[Yetti]

Safety stands make things more safe because they are redundant.   I use saw horses with moving blankets for redundancy.

[Bryan]

I made my own:

• Harbor Freight: Tall Bottle Jack: ~$35
• Home Depot: Hardwood table top: ~$15
• Home Depot: 1" Electrical conduit: ~$2
• Home Depot: straps and lag bolts: ~$10 (total)

Fits perfect under my Mooney wing.

[Andy95W]

Simple, elegant, inexpensive.  If I didn't already have a set of jacks, I might build some like this.

One suggestion- bolt a piece of pipe on the tip1/4" taller than the tip to prevent the jack point from slipping of if the airplane really started to rock back and forth (and piece of mind).  What do you use for a locking mechanism?

[Bryan]

Good suggestion, however, my final product has a little deeper hole drilled (triangular bit) in the top for the jack points. They are solid when jacked. The rest of the jack would have to fail before they'd slip now.

[N601RX]

I built these about 5 years ago and have been happy with them. The legs are about 15" long each with leveling bolts and the original top inch or so of the ram was cut off just below the factory cross hole and a countersink hole was drilled in the top as deep as possible to match the LASAR tie down points. The locking collars were machined out to match the ram diameter and were tested on a press to have a slip force greater than 5000lbs. 

Wood of is strong across the grain but has very little strength along the grain, especially when the pieces are glued together. 

[MARZ]

Used the stands for the annual, and as suggested I was cautious at first checking the stability. My mechanic said they were as solid as any. No issues getting in or out of the plane while swinging gear.  

 

[RobertGary1]

Most of the aviation jacks I've used allow you to place pins in the shaft which prevents them from sinking over time. I feel like I'd want something similarly fail safe with home-brew jacks.

 

-Robert

[RobertGary1]

On 8/5/2017 at 7:41 PM, Bryan said:

I made my own:

• Harbor Freight: Tall Bottle Jack: ~$35
• Home Depot: Hardwood table top: ~$15
• Home Depot: 1" Electrical conduit: ~$2
• Home Depot: straps and lag bolts: ~$10 (total)

Fits perfect under my Mooney wing.

 

Why the electrical conduit?

 

-Robert

[Bryan]

Built another one of these yesterday.  @RobertGary1, the conduit is for building the struts. Its easy to cut and easy to bend.  Jacked my entire plane with two of these and a cherry picker yesterday to swing the gear diagnosing a small issue.  Very stable.

[RobertGary1]

11 minutes ago, Bryan said:

Built another one of these yesterday.  @RobertGary1, the conduit is for building the struts. Its easy to cut and easy to bend.  Jacked my entire plane with two of these and a cherry picker yesterday to swing the gear diagnosing a small issue.  Very stable.

 

You don't by chance have the pn of the HF jack you bought?

-Robert

[N6758N]

9 minutes ago, RobertGary1 said:

You don't by chance have the pn of the HF jack you bought?

-Robert

Curious to find this out as well. Or at least the length of the jack, I'll probably get mine from northern tool. I'm tired of borrowing jacks from friends every time I need to jack a plane!

[HRM]

47 minutes ago, RobertGary1 said:

Most of the aviation jacks I've used allow you to place pins in the shaft which prevents them from sinking over time. I feel like I'd want something similarly fail safe with home-brew jacks.

You just need to tighten a collar around your shaft, like this one from Climax:

[Bryan]

Harbor Freight: 3 Ton Heavy Duty Long Ram Hydraulic Flat Bottom Jack

P/N: 36468

They also have an 8 Ton jack that is the same height.  My first jack was the 3 Ton but over the weekend I was in a pinch and needed to build another so I purchased the 8 Ton (more expensive) but it was the same height.

After mounting on my hardwoord table-top (home depot), I have about 1.5 - 2in to spare under the wing on my M20K. (perfect height

I should get the collars but with so little "jacking" to get the wheels off the ground, there is little room for failure even if the jack does lose pressure.

[Guest]

You're trusting your life and your airplane to a jack mounted on a table top?  Yikes!

Clarence