Boeing 737 rudder pedals construction

[mauriceb]

Awesome to see them put to good use Maurice, and Im still elated you bought them from me! They obviously went to very capable hands. I wish you the best in getting them interfaced.

Thanks Eric, but I must say, I did hate you now & then . Just kidding of course, but maybe you can answer the question about the gas springs. Do you know/remember what was the force needed to compress them? I guessed about 20 to 25 lbs. Is that close enough you think?

Thanks,
Maurice

[Tomlin]

I really dont recall how much weight it took- I bought them from an auto parts place called Pep Boys, and the guys there just let me go in the back and take 'em outta the sleeves and push on them. Did I mail them to you in the sleeves? If so look up the numbers on there.

[mauriceb]

I really dont recall how much weight it took- I bought them from an auto parts place called Pep Boys, and the guys there just let me go in the back and take 'em outta the sleeves and push on them. Did I mail them to you in the sleeves? If so look up the numbers on there.

Good idea. Will check now

[mauriceb]

What weight of compression are the gas struts?

As I said, I don't know for sure, but here is the Manufacturer & part number:

Its a SACHS LIFT-O-MAT Part #: SG459005

Maurice

[Bob Reed]

As I said, I don't know for sure, but here is the Manufacturer & part number:

Its a SACHS LIFT-O-MAT Part #: SG459005

Maurice

If these are the "shocks" that hold open a rear hatch on like a mini van they require about 18lbs to compress, but that is with the wight of the door hanging from it. These doors are made from various materials some are steel, some are fiberglass and some aluminum. So it depends on the ones you have.

[Michael Carter]

I've pushed quite a few automotive lift-struts. All lengths and diameters. I'm here to tell you most won't even compress with all of my body weight on them at 180 Lbs.

I'm looking at some struts from McMaster-Carr that are lightweight compression and also some that are adjustable, once. Meaning after you let the air out of them they're set and cannot be re-inflated.

I'm thinking of replacing the heavy springs for my yoke with struts. If my math is correct, I need about a 17-20 Lb strut to get a force of about five pounds at the yoke.

[mauriceb]

I've pushed quite a few automotive lift-struts. All lengths and diameters. I'm here to tell you most won't even compress with all of my body weight on them at 180 Lbs.

I'm looking at some struts from McMaster-Carr that are lightweight compression and also some that are adjustable, once. Meaning after you let the air out of them they're set and cannot be re-inflated.

I'm thinking of replacing the heavy springs for my yoke with struts. If my math is correct, I need about a 17-20 Lb strut to get a force of about five pounds at the yoke.

I can push mine fairly easily, so no way they need 100+ pounds.

I just did a little experiment with dumbbell weights I had lying around (I knew these would come in handy some day ) and the spring was able to lift at least 45 lbs (that all I had). So, my new guesstimate is that they are at least 50 to 60 pounds. 45 lbs was not enough to compress and I had to push on the weights a bit more to get the spring to compress.

They feel just right though for the pedals (for me at least) and the pedal pressure can be changed by moving the springs closer or further from the pivot point to increase or reduce the leverage. The net force for me doesn't feel more than about 20 pounds, but I could be way off since legs have much more power than arms.

Maurice

[W9XE/Project777]

If you would like to get a close measurement of the pull of the springs you can use a simple fish scale to give you an idea how much friction is on the pedals. By attaching the scale to one of the pedals, hold the other end of the scale and pull evenly. The gauge will give you your breakaway lbs of pull and the weight through even travel. This is a good was to test yoke friction as well.

We used this method on our Bell Helicopters for adjusting collective friction with both hydraulics on and off. Simple but works

[spitfire9]

Those hydralic/spring struts used to close screen doors have a screw on one end to adjust tension.
I wonder how those would work?

[mauriceb]

[QUOTE=W9XE/Project777;42998]If you would like to get a close measurement of the pull of the springs you can use a simple fish scale to give you an idea how much friction is on the pedals. QUOTE]

Have you read my post about 'Insane builders'. Likely not . Insane builders would worry about duplicating the exact force required to push the pedals on a real plane. Me, I'm happy because they just feel good to me whether they need 20 lbs or 200 lbs

Seriously though, if I had a fish scale I would do the test out of curiosity (or to satisfy the curiosity of insane buuilders , but I won't have time for fishing until "the year 2525... if man is still alive" thanks to the million things I still have to do in this damn flight deck. So, I won't buy a fish scale until that time. . Excellent suggestion though.

Thanks,

Maurice