Best place to cut?

cjensen · #1 04-02-2007, 02:50 PM

This is a cross post from RBer's to get the most exposure...

I need to shorten the aft arm of my flap weldment (silver) so it is the same length as the electric weldment.

Where would the best place be to cut this? I am going to cut it, and then take it to a welding shop to get it welded properly. I'll be hacking about an inch and a half or so out of this.

Should I just cut it right in the middle? Fore? Aft? Help!!

RV7Guy · #2 04-02-2007, 03:09 PM

And, Why do you want to do this?

cjensen · #3 04-02-2007, 03:12 PM

So I can mount the manual weldment in the same location as the electric one. The arm is a bit too long to match up with the flap actuator link if left alone.

Dayton Murdock · #4 04-02-2007, 03:15 PM

This might work

Cut under the U shape weldment thru the welded area, shorten up the remaining tube, grind the weld off of the "U" shape with out damaging it, and then re-weld it onto the tube

rvbuilder2002 · #5 04-02-2007, 03:23 PM

This may not work very well.

Having shorter arms than the orig. manual flap handle will give you more leverage and make the handle easier to pull.

The problem with it is that because of the shorter arms, the handle will have to be pulled farther back to get the full travel for full flaps.

Many builders with manual flaps found it difficult to get the last notch because the handle was getting so high and far back beside them in the cockpit. Your modified setup will make that even worse.

Why not just install it in the normal location and patch over any existing holes in the baggage side panels?

As for your question... the easiest way to modify your weldment would be to use a cutting disk, cut the clevis off the end of each tube (and reuse if you do it properly), shorten the tubes the required amount, squeeze the tube slightly like the originals were and re-weld the clevises.

jcoloccia · #6 04-02-2007, 03:25 PM

Take it to your local EAA welding dude (every chapter has at least one). Let him decide how to do it. I would personally make a scarf joint right in the middle with a smaller piece of tubing inserted between the 2 halves and a rossette on either side. But that's just me.

frankh · #7 04-02-2007, 06:01 PM

and grind off the remaining tube. You don't need to remove all the weld from the U bracket as this is a perfectly good joint. If gas welding (which I prefer cus I'm good at it) this will avoid distortion somewhat.

Then hack as much tube as you need and re-weld. This should be a little stronger than cutting a section of tube out but that would work also.

Either way its an easy welding job.

Frank

RV7Guy · #8 04-02-2007, 06:35 PM

Quote:

Originally Posted by cjensen

So I can mount the manual weldment in the same location as the electric one. The arm is a bit too long to match up with the flap actuator link if left alone.

Thought you going to do something else

Find a shop with a steel bandsaw.

Keep pound'n away.

mannanj · #9 04-02-2007, 08:28 PM

See AC 43-13-1. Can't rember chapter and verse at the moment but it is in the metal tubing section. To satisfy 43-13, you'll probably have to cut the tube at the proper angle, 30 deg. if I rember correctly, (scarf joint) remove the required material at the same angle and insert the next smaller dia. tubing inside, (at the prescribed length), and drill the outer tube with holes for "rosette" welds to hold the inner tube in place. You join the outer tube with the inner tube centered. As was stated above, your local EAA chapter probably has a welding "guru" with much more experience than I. I personally do not like welding over places that have been previously welded.

jcoloccia · #10 04-02-2007, 10:42 PM

Quote:

Originally Posted by mannanj

See AC 43-13-1. Can't rember chapter and verse at the moment but it is in the metal tubing section. To satisfy 43-13, you'll probably have to cut the tube at the proper angle, 30 deg. if I rember correctly, (scarf joint) remove the required material at the same angle and insert the next smaller dia. tubing inside, (at the prescribed length), and drill the outer tube with holes for "rosette" welds to hold the inner tube in place. You join the outer tube with the inner tube centered. As was stated above, your local EAA chapter probably has a welding "guru" with much more experience than I. I personally do not like welding over places that have been previously welded.

Yes, exactly...you explained it much better than me!