Avoid damage to ArcusM fuselage from Cobra fuselage jack

[Dave Nadler]

This happened to me and at least two other Arcus owners:

What happened?

While raising the fuselage to de-rig, the fuselage jack assembly rotated.
The hydraulic jack tower is jammed into the fuselage, and the gear doors are bent.
The trailer rails slid forward into the trailer.

If this happens to you, you will need a couple of floor-jacks to lift the rails under the fuselage dolly.

I was very lucky to escape with no damage to the fuselage...

Why did this happen?

Spindelberger hinged the rails to the jack assembly at the front edge of the jack assembly.

If the ground is not perfectly level, the rail hinges are in front of the base of the jack.

Thus, the jack assembly rotates around the front edge of the jack assembly base...

This happened on relatively level pavement!

Suggested Fix

To prevent the jack assembly rotating, it is necessary to extend the base in front of the rail hinges.

1. Add arms extending forward from base tray. Don't add material under the base.
2. Replace the bolts mounting the hydraulic jack with counter-sunk heads. The bottom of the base should be flat.
3. Drill hole for hydraulic jack valve (easiest done before welding on arm ;-)

Best would be bend some material same as base tray.
Next best is some angle iron (cut angle so it does not go underneath base tray.
Warnings for welder: 

1. base tray is not quite wide enough; you will probably need to add material to avoid interfering with arms of jack assembly.
   
2. base tray is galvanized

Here's what I did (no problems now):

[Mark]

Thanks for sharing Dave

[Kees Van Schaick]

Hi all,

A member of my syndicate made the following adjustment to the Cobra trailer, taking the advice from Dave into consideration to fix this issue. See enclosed pictures.

Op maandag 22 augustus 2016 14:08:35 UTC+2 schreef Mark Zivley:

Thanks for sharing Dave

[Dave Nadler]

A good solution Kees.
I thought about fixing the problem this way, but I wanted to be able to
quickly remove the hydraulic ramp so I can roll the fuselage into my shop,
and I have only two pins to remove:


Also, the bottom of the jack assembly may not sit flat on the
ground with your partner's solution; hopefully it will not cause
you problems. Remember, Spindelberger installed the hinges
so the base could always sit flat on ground - very high loads.

Thanks!
Best Regards, Dave

[Arcusdriver Andreas]

I just want to share my solution to this issue. See pic.

In addition to the strap , I added some 8mm thick metal sheet between rail end and stop on the hub assembly.

Best regards

Andreas

[Erik Kurtz]

we solved it like this (also see the white distance-block)

All the best, Erik