Options for jacking up an RV-12iS

[LettersFromFlyoverCountry]

Vans' W&B procedure instructs you to roll the airplane onto 2 inch blocks for leveling. That would require either a steep ramp or a long one or a REALLY good head of steam. After levelling it tells you to roll it off the blocks then put the blocks on the scales and roll it back on, thus requiring an even steeper or long ramps or something close to taxi speed. :*).

I thought I could lift each wheel, slip the blocks under, then repeat on the other side. Level, then roll the plane off and repeat with the weight scales and blocks.

I don't have the proper jack to accomplish this. although the Jenga model favored by Van's for lifting a wheel looks practical but sure looks heavy to move around a hangar.

I do like the 4x4 angle cut to be parallel to the floor method and clamped to the gear leg and lifted with a bottle jack method, but interference with the brake line would concern me.
This method is basically the Bogert ADJ-FPP method (is that even made anymore?) although it's difficult to do with wheel pants on, I would think. And it doesn't give you a lot of floor space around the wheels because the jack is in the way.

Is there any reason not to put a tie-down ring on the top of the wing (the hole is already there, just needs to be enlarged to 3/8") and use my engine hoist?

 

[jsalley]

Bob - We did the weight with two guys, one young, and one not young (me). Using a step stool to get a good angle, I lifted a wing tip with the handhold, and my young helper used his back while crouched under the wing to lift while sliding the scale under the tire. The nosewheel was easy to lift by pushing down the tail. I’d guess the scales were about 2 1/2” tall (they’re used by the shop to weigh King Airs and bizjets).

 

[LettersFromFlyoverCountry]

Bob - We did the weight with two guys, one young, and one not young (me). Using a step stool to get a good angle, I lifted a wing tip with the handhold, and my young helper used his back while crouched under the wing to lift while sliding the scale under the tire. The nosewheel was easy to lift by pushing down the tail. I’d guess the scales were about 2 1/2” tall (they’re used by the shop to weigh King Airs and bizjets).

Did you put blocks on the scales. I don't quite understand why the Van's procedures has you putting the wheels down on blocks after taring them on the scales rather than putting them directly on the scales.

 

[jsalley]

No - we did not use blocks. I didn’t see the need, nor did the A&P that was helping.

 

[CTCole]

When I got to this step, I went through the math (it's simple trig) to see how much difference the blocks could make in determining the c.g. It's much less than measurement error of the variables, so I don't understand why it's there, and I skipped it.

 

[dbhill916]

When I got to this step, I went through the math (it's simple trig) to see how much difference the blocks could make in determining the c.g. It's much less than measurement error of the variables, so I don't understand why it's there, and I skipped it.

my engineering school had this bit of advice posted on the wall in a classroom: "Don't measure with a micrometer, mark with chalk and cut with an ax."