Canopy Struts dont compress

rockitdoc · #1 10-28-2021, 12:51 PM

Anybody experience this?
Just tried closing my canopy for fitment and discoveted the struts wont budge. Is this typical of nee struts?

Jetmart · #2 10-28-2021, 01:45 PM

If the glass is not installed yet and you are pulling down on just the frame for the first time it takes a fair bit of pull. I remember thinking I was over stressing it the first time. Totally changes once the glass is in it. It becomes perfectly balance with only light forces required. Suggest trying to pull it down from the centre to avoid any twisting.

rockitdoc · #3 10-28-2021, 02:23 PM

Quote:

Originally Posted by Jetmart

If the glass is not installed yet and you are pulling down on just the frame for the first time it takes a fair bit of pull. I remember thinking I was over stressing it the first time. Totally changes once the glass is in it. It becomes perfectly balance with only light forces required. Suggest trying to pull it down from the centre to avoid any twisting.

The struts (Stabilus Lift-O-Mat) do not move at all. I removed them (Ugh!) and tried pushing on them in a vise. No movement. I must be missing something? Are they locking struts?

rvbuilder2002 · #4 10-28-2021, 02:56 PM

Quote:

Originally Posted by rockitdoc

The struts (Stabilus Lift-O-Mat) do not move at all. I removed them (Ugh!) and tried pushing on them in a vise. No movement. I must be missing something? Are they locking struts?

There is no way you would be able to push them with them clamped in a vice.

As already mentioned, they are designed to support the weight of the entire canopy frame and bubble assembly.
The bubble itself is quite heavy.
If the bubble is not mounted to the frame, it takes a lot of force to pull the frame down to its closed position.

rockitdoc · #5 10-28-2021, 03:24 PM

Quote:

Originally Posted by rvbuilder2002

There is no way you would be able to push them with them clamped in a vice.

As already mentioned, they are designed to support the weight of the entire canopy frame and bubble assembly.
The bubble itself is quite heavy.
If the bubble is not mounted to the frame, it takes a lot of force to pull the frame down to its closed position.

OK. Good to know. But, then lowering the canopy frame in Step 5: Section 38-20 with the struts connected makes warping the frame a real possibility. Perhaps the instructions in Section 35-21 Step 1 should not instruct connecting the struts to the hinges. This would make lowering the canopy frame much simpler, and eliminate the possibility of bending the frame. Just a thought.

JDA_BTR · #6 10-29-2021, 07:10 AM

I would recommend not installing the struts until after the canopy is installed. It will come on and off a few times anyway, and having them off makes it easier. The struts might have been one of the last things I did. If you wire to a molex in the provided clip similar to what the wings have then you can connect the canopy wiring at the end too without any problems.

I did all my electrical, riveted the front panel, and then did the struts last.

rvbuilder2002 · #7 10-29-2021, 08:22 AM

When the canopy is in the closed position with the struts fully compressed, they impart a high load into the mechanism and the fwd fuselage. This load can change the shape of the canopy frame a bit.

For this reason the plans are written the way they are so that the struts are in place (and imparting their influence) when the canopy is being fitted.
It is not difficult to move the frame to the closed position without doing any damage. Pulling in the aft center (as already suggested) is easy after climbing into the cockpit. An alternative if you have a helper available is for the frame to be pulled down with one person on each side working together.

gasman · #8 10-29-2021, 12:34 PM

Quote:

Originally Posted by rockitdoc

The struts (Stabilus Lift-O-Mat) do not move at all. I removed them (Ugh!) and tried pushing on them in a vise. No movement. I must be missing something? Are they locking struts?

Holding the big end of the strut and the other end on a block of wood on the floor, push down with your body weight and the strut will compress.

To check the pressure, place the block of wood on a bathroom scale and compress the strut the same way, only this time, compress it 1/2 way... hold it there and read the scale.

Going from memory (not a good thing) I think the scale should read 27 to 30#. The same strut comes in many different pressures.

JDA_BTR · #9 10-30-2021, 05:58 AM

Well, I'm glad my canopy fits without setting everything up with the struts on. I didn't see a warning in the plans that it was important to have the struts on while fitting the canopy....

romaja · #10 05-22-2023, 07:46 PM

Updating an older thread:

I am at Step 5: Section 38-20 with the struts connected and am concerned about bending my canopy frame trying to get the struts to compress and close the canopy as I am imparting a lot of force and to no avail. I wonder if it is even possible to close the canopy without the weight of the plexiglass and the new stronger struts? Reading this older thread I am wondering if anyone else has come up on this problem since and a possible remedy. As mentioned earlier in the thread, the procedure should be done with the struts installed.

Best,
Jim