Sort of a personal opinion here, but I always figured that Adel clamps were designed by someone who forgot to weld a tab or fitting where he needed it. I do have some Adel clamps on my airplane, but for the most part they are around a hose or cable and attached to a tab provided for the clamp. You can see a couple in this photo.Do what you can to keep the use of Adel clamps to a minimum.
Last edited by Neil; 05-25-2012 at 10:50 PM.
Two builders, five opinions. Here is what I have discovered about welded tabs:
- Even if you buy the tab to weld on, it is going to be more complicated an operation than slipping on an adel clamp.
- Back side of the tab is hard to paint; place to rust.
- Ever had to adjust/move a welded tab?
- Heating can cause the tube to distort.
- I have never heard of a tube with oil in it exploding but I have had a weld “hole” itself when welding a sealed container (tube welded at either end).
- I once saw a Jungmeister (old-timey aerobatic biplane) that had its fairing strips TIED to the fuselage tubing. They could have used welded tabs but string was sufficient and lighter (I believe they used heavy twine and then varnished over it to seal the knot).
That having been said, welded tabs sure hold things securely and don't cause unsightly lumps in the cover like adel clamps on longerons.
Best of luck!
Hmm...I'm hearing different things here!
My gut reaction is to agree with Neil on keeping them to a minimum and mounting things the "right" way. However, the flexibility and ease of an Adel (or Adel-like) clamp is very appealing since, for one thing, it would mean that I would still have the option of where things get mounted down the line. To weld tabs, I need to figure out (correctly!) how I want everything mounted today even though I won't be attaching hardware/components/etc for at least another several months.
Will the FAA balk at using clamps for anything other than ancillary hardware?
-Tony
Recommended practices for MS21919 cushion clamps are commonly violated, nearly every airplane has at least one improperly installed. When practical, the backside of the clamp should rest against a structural member, not to exceed the recommended angle. Neil S. has it exactly right!
Tony, simple flat metal tabs are very easy to instally and not really that difficult to relocate when something needs to be changed. But it is a homebuilt and you can do whatever you wish.....the FAA isn't going to care.
Last edited by martymayes; 05-27-2012 at 08:25 PM.
Fair enough - guess I'll just steel my nerves, plan my tabs as best I can, and weld them in place. I'm concerned about the ones I will discover down the road when the fuselage is epoxy coated and new welding is not an option. We'll cross that bridge when we get there.Originally Posted by martymayes
-Tony
My SA-3A Playboy is on the gear waiting for the daughter to graduate to be completed and I’ll have to admit to a few extra ears and tubes. Most of them are the result of my wanting to improve on Ray’s design and then finding he was right after all. Think I’ll leave them as reminders of the process even if they add a little to the GW.
Wasn’t there at the time but am told WWI pilots referred to their aircraft as kites. I have to be reminded occasionally that this vehicle I am building needs to be more a kite than a Mercedes. Maybe we can trade pictures.
I agree that Ray was probably right when he drew up these designs all those years ago. I'm trying to keep from making any changes since what's in the plans has worked just fine so far for other builders. It will also, in theory, get me in the air faster than if I had to reinvent the wheel...
-Tony
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