Panther Sport Aircraft Forums

Makes total sense! Thanks Dan. Yeah, I figured if I did use Q, I would use them sparingly now that I see cost. If shear matches stainless, I might use Q to avoid dissimilar metals on head. Saw the builders manuals and plans for first time last night. Top notch.

P.S. Every time I see pt- or vt- etc I think of the southeast Asian tail numbers for aircraft from pictures on airliners.net...it's uncanny....and its everytime I come across em...I need to retrain my brain with some word game or sudoku or something.

We have never used the "Q" rivets due to cost. They Should work fine.In bulk the "Q" rivets are 3 times as expensive Typically when we want a more vibration resistant rivet we choose a stainless "N" rivet. In our test the skin has always failed before the rivet , both from a failure and a "loosening" stand point. All aluminum riveted aircraft structures over time will have a area or two that the rivets "work" and a few will need to be replaced. If sealing the rivet is the goal , it really doesn't take much time to put a tiny dab of proseal in each rivet before painting. And its probably the one area in your project you can get some less skilled labor to help with (..... I hesitate to call it dumb work...)
Good questions !

As the name of the game is flexibility with the Panther, and with plenty of engineering, the N is clearly sufficient bc that is what the structure was designed for. But, because you can use pulled or solid, I might use Q's around the spar and other structural items where solids aren't mandated, like wing spars, and use the N on skins. Although Q's seal better, so maybe they would be good on skin too. Not sure. Definately more expensive.

Vans builders seem to think about 10-14000 Rivets for their airframes. Assuming 10000 for panther, at 10 cents a piece differnce, that is another $1000 for build. A little pricey.

Btw, for those that have wondered what the difference in weight over airframe for pulled vs solid rivets, I did a very rudimentary comparison based on data from a couple of sites.

.36 lbs is weight of solidbutton-protruding head aluminum rivets per 1000
.2 lbs is weight of solid countersunk aluminum rivets per 1000
1.2 lbs is the weight of 1000 cherry N without being installed and without mandrel being cut off.

Assume 10000 rivets, and assume cutting mandrel off N loses 50 percent of its weight at least.

I would say you gain 5-7 lbs max at 10000 rivets. Is 5 lb savings worth bucking all of those if you can countersink a pulled rivet for looks and drag????

Not for me.

Again, if someone more experienced sees a flaw in that, let me know.

Is the Q "less tolerant" to surface grip thickness variations than N? That could explain it if so.

Was looking through Textron/Avdel catalog and the Q pulled rivets seem to be structural pull, vs N non structural. The main difference being slightly different finish which makes it more resistant to vibration. Aside from .12-15 cents a rivet for Q, vs .05 for N, any reason the Q wouldn't be the preferred pulled rivet for Panther given the structural rivet designation in a still simple pulled rivet? Spruce sells them side by side on the same page. Textron catalog listed examples of use, and the strengths are:

1/8 BS rivets on both

Q 350 shear 325 tensile
N 200 shear 325 tensile

Seemingly same weight but mandrel is secured and seals the hole with a head that curls over.

Q-Self-plugging rivets

HIGH SHEAR STRENGTH
Cherry Q Rivet mandrel plugs the entire length of the rivet sleeve, providing full shear strength values for structural or load-bearing applications.
SEALING CAPABILITY
Specially designed mandrel of the Q Rivet is engineered to effect a seal, upon installation which offers resistance to leakage
VIBRATION RESISTANT
Rivet sleeve curls over end of mandrel to insure its positive retention.

Just curious if engineering design deemed the Q unnecessary overkill for some specific reason. Seems like
Vibration of aircraft would be the defining factor to Q from N.

Thanks guys! Looking forward to tail kit!