Panther 92

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ykachuro
Posts: 110
Joined: Wed Aug 30, 2017 8:17 pm
First Name: Yuri
Last Name: K
City or Town: St John + Steamboat
State or Province: USVI + CO

Re: Panther 92

Post by ykachuro »

Gentlemen, thank you for the helpful comments.
The Panther is such a versatile design! It allows us a great opportunity to experiment with so many different options, materials, etc. while still remaining in the designed safety envelope.
My choice of protruding rivets is a personal choice and is perfectly acceptable from the standpoint of safety. Many think that flush rivets are more pleasing to look at. I actually prefer the "naked", "rough" " industrial" look of the protruding rivets.
The same goes for stainless rivets. That choice is perfectly acceptable from the safety point of view. Stainless rivets are a perfectly acceptable options from the safety prospective. There are pluses and minuses with stainless rivets -- like with most everything in aviation. I'll creat a separate topic where I will try to explain my current choice. And for avoidance of doubt, I didnt mean to imply that the BSP/C rivets are not safe or less safe to use as designed.
Ditto regarding not priming and not painting -- perfectly acceptable from the safety point of view. Just a personal preference -- different strokes for different folks.
I would be very grateful if you find the time to comment on my building practices, especially to the extent you see anything questionable and/or compromising safety.
Now back to pulling rivets! :)

psalter
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Joined: Sun May 19, 2013 6:50 pm
First Name: Paul
Last Name: Salter
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Location: Green Cove Springs, Florida

Re: Panther 92

Post by psalter »

Rick is correct in saying that stainless CCP rivets are a challenge to drill out. They were mainly only used for aluminium to steel connections.

Another reason why it is not necessary to use CCP all around is structural design. A properly designed joint has the skin yield first in an overload condition, not the fastener. So, you can install a fastener a 1000 times stronger, and it won't change the strength of a well designed joint a bit. Why do this? A joint usually has a row of fasteners, if one fails, more load is transferred to the remaining fasteners. If the fastener is the critical item, the other fasteners would fail right away with the extra load (zipper affect), that would be bad news. If the skin is designed to yield first the skin will start to distort and give some warning before total failure. This hopefully will be caught in pre-flight or other inspections (another reason to perform inspections). Thus the extra strength of the fastener is irrelevant.

Just a reminder if you decide flush rivets on the skin to cage joints, the cage should be dimpled not countersunk. There is not enough material for a countersink without getting a knife edge in the steel (not a good practice). There is no doubt the dimples in the cage are not as nice and clean as in the skin where you can get the male and female die. I have built one, and helped on a second Panther with flush rivets on the cage, there is around 240 hours between the two Panthers with no issues.
Paul Salter
Team Panther
Engineer and Builder

jamesmil
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Last Name: miller
City or Town: wilmington
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Re: Panther 92

Post by jamesmil »

Hi guys, hope you don't mind if I put my two cents in on this.
I used flush rivets on the aft fuselage, tail feathers, and wings and protruding on the main cage. I would have liked to used flush rivets all over but I didn't feel I could get a good counter sink on the steel cage for a good looking rivet.
If you feel that flush rivets might be a challenge try to find someone who has built an aircraft with flush rivets and talk with them, also make full use of this forum as it is one of the best tools in your tool box

PlaneDan
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First Name: Daniel
Last Name: Heath
City or Town: Lexington
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Location: Lexington, SC USA
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Re: Panther 92

Post by PlaneDan »

If I knew what I know now, when I started, it would be protruded. In fact, I do not think that flush should even be an option where the skins are attached to the fuselage steel cage. Personal, experienced, opinion.
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ykachuro
Posts: 110
Joined: Wed Aug 30, 2017 8:17 pm
First Name: Yuri
Last Name: K
City or Town: St John + Steamboat
State or Province: USVI + CO

Re: Panther 92

Post by ykachuro »

Rick, thank you! I hear you loud and clear. Like I said, those are working thoughts that will guarantee to change. The more important point is that I've decided to go with protruding head rivets -- no dimpling and cosmetics are in the eyes of the beholder.

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at7000ft
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First Name: RICK
Last Name: HOLLAND
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Location: Castle Rock, CO

Re: Panther 92

Post by at7000ft »

Just my opinion concerning the CCP rivet, may sound like a good idea until you have to drill out a few. And since Dan designed the Panther for aerobatic category using the spec rivets (which are simple to drill out), all CCPs are not necessary.

rh
Rick Holland
N6819Z

ykachuro
Posts: 110
Joined: Wed Aug 30, 2017 8:17 pm
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Last Name: K
City or Town: St John + Steamboat
State or Province: USVI + CO

Panther 92

Post by ykachuro »

My tail kit is arriving today. While waiting, I built a large, portable, adjustable work table.

Posting the link to the future photo log:

https://www.icloud.com/sharedalbum/#B0x5oqs3qKz8eJ

My main objective is to finish the build. Hence, i will strictly stick to the plans, will make the process as simple and straihtforward for myself as possible while focusing on structural strength, lightness and performance. Cosmetics are in the eyes of the beholder.

For now my working thoughts are:

- short wing
- IO320 or 340
- CCP rivets all around
- as many pre-built components as available (wing spars, tanks and canopy?)
- no priming
- no paint (other than fiberglass)

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