What comes after Cobra "Z"?
01-04-2015, 11:55 AM
#1
Thread Starter
My Feedback: (1)
Join Date: May 2003
Location: Orangeville, ON, CANADA
Posts: 8,658
Likes: 0
Received 2 Likes
on
2 Posts
What comes after Cobra "Z"?
I have the plan set for the old Cobra Z pylon racer from Pilot. First RC kit I ever saw in a plastic bag. It's a tiny thing, but with a big ugly square firewall up front big enough to stick out past a Norvel plastic tank mount and resulting in enough fuselage space for two contemporary radio systems. At 100 sq in +-, there is no excuse for it to come out heavier than 10-11oz, and should be less.
So I've been picking away at a new design based on the same outside envelope, and with the recent re-commissioning of the laser cutter it is time to get at it.
Built up wing with skinny arrow shaft lower spar (cheap, straight, crazy tensile strength). I'll build in a ply side mounting plate and semi-open engine bay. Three split 1/4" balsa rings that stack up to make the nose blank, with the side profile defined by the engine mounting plate. bla bla.. a few details to go.
[ATTACH]2060588[/IMG]
So I've been picking away at a new design based on the same outside envelope, and with the recent re-commissioning of the laser cutter it is time to get at it.
Built up wing with skinny arrow shaft lower spar (cheap, straight, crazy tensile strength). I'll build in a ply side mounting plate and semi-open engine bay. Three split 1/4" balsa rings that stack up to make the nose blank, with the side profile defined by the engine mounting plate. bla bla.. a few details to go.
[ATTACH]2060588[/IMG]
01-04-2015, 12:28 PM
#2
After the Cobra Z perhaps the Nuclear powered 6 counter rotating prop driven Zornon Z II
The power output of the engine started with 4 counter rotating 3 bladed props but proved to lack enough load on the engine and would shear blades past 60k rpm.
Here is the only known rendering of the pylon plane #77 as camera's were not allowed on the flight line by penalty of death.
The power output of the engine started with 4 counter rotating 3 bladed props but proved to lack enough load on the engine and would shear blades past 60k rpm.
Here is the only known rendering of the pylon plane #77 as camera's were not allowed on the flight line by penalty of death.
Last edited by Pond Skipper; 01-04-2015 at 01:34 PM.
01-04-2015, 12:49 PM
#3
Thread Starter
My Feedback: (1)
Join Date: May 2003
Location: Orangeville, ON, CANADA
Posts: 8,658
Likes: 0
Received 2 Likes
on
2 Posts
The forward mounted vertical fin might have had something to say about directional stability as well.
This thing should be small and light enough to haul with just about any beam mount 1/2A engine. If I like it I'll do a ver B for firewall mount as well.
I had to do a quick gratification project on the laser cutter for giggles, and I had this funky chicken doorbell ringer that my wife somehow found me for Christmas.. I used 1/4" Home Depot poplar form their "project wood" department. Cuts like butter. Next thing is to saw off some 1/4" Sitka spruce..
This thing should be small and light enough to haul with just about any beam mount 1/2A engine. If I like it I'll do a ver B for firewall mount as well.
I had to do a quick gratification project on the laser cutter for giggles, and I had this funky chicken doorbell ringer that my wife somehow found me for Christmas.. I used 1/4" Home Depot poplar form their "project wood" department. Cuts like butter. Next thing is to saw off some 1/4" Sitka spruce..
01-04-2015, 01:13 PM
#4
That turned out great...!
I think those would sell and be worth your while if you priced them high enough.
There are a lot of folks out there who want unique things for their homes and price isn't that much of a consideration to them.
It could also be sold as a kit.
The Zornon Z II is pretty cool, but I don't know of it could keep up with the Chill Factor X.
I think those would sell and be worth your while if you priced them high enough.
There are a lot of folks out there who want unique things for their homes and price isn't that much of a consideration to them.
It could also be sold as a kit.
The Zornon Z II is pretty cool, but I don't know of it could keep up with the Chill Factor X.
01-04-2015, 05:19 PM
#5
Thread Starter
My Feedback: (1)
Join Date: May 2003
Location: Orangeville, ON, CANADA
Posts: 8,658
Likes: 0
Received 2 Likes
on
2 Posts
35 minutes from conception to all the parts cut.
I jut picked up an armload of "project boards" from HD, all 2' x 2' and various thicknesses and materials. MDF, spruce ply, bla bla.Good to know what you can work with. This stuff is killer for jigs and fixtures.
I jut picked up an armload of "project boards" from HD, all 2' x 2' and various thicknesses and materials. MDF, spruce ply, bla bla.Good to know what you can work with. This stuff is killer for jigs and fixtures.
01-05-2015, 09:48 AM
#11
Thread Starter
My Feedback: (1)
Join Date: May 2003
Location: Orangeville, ON, CANADA
Posts: 8,658
Likes: 0
Received 2 Likes
on
2 Posts
Yeah that's the one!
I can't imagine a situation where, given free reign on design, that a twin engine setup could possibly be faster - maybe with the exception of an inline pusher-puller setup where the frontal area is kept the same as one engine. Then the question is what level of efficiency is the rear most engine working at.
Suffice to say that it was one cool looking project, it simply did not have the earth shattering potential some thought it would. Everybody was out to lunch on the speed predictions!
It would be interesting to hold that picture next to this one, and tally people's guesses as to which are the faster.
I can't imagine a situation where, given free reign on design, that a twin engine setup could possibly be faster - maybe with the exception of an inline pusher-puller setup where the frontal area is kept the same as one engine. Then the question is what level of efficiency is the rear most engine working at.
Suffice to say that it was one cool looking project, it simply did not have the earth shattering potential some thought it would. Everybody was out to lunch on the speed predictions!
It would be interesting to hold that picture next to this one, and tally people's guesses as to which are the faster.
Last edited by MJD; 01-05-2015 at 11:17 AM.
01-05-2015, 11:20 AM
#15
Thread Starter
My Feedback: (1)
Join Date: May 2003
Location: Orangeville, ON, CANADA
Posts: 8,658
Likes: 0
Received 2 Likes
on
2 Posts
It managed to hold them back to about 150mph. Didn't quite make the 220-230 imagined for it. My point was that if one engine can't make, let's say, 220 on an optimized single engine airframe - then two of them never will.
01-05-2015, 02:00 PM
#17
Thread Starter
My Feedback: (1)
Join Date: May 2003
Location: Orangeville, ON, CANADA
Posts: 8,658
Likes: 0
Received 2 Likes
on
2 Posts
For sure, it is a way cool aircraft and must have been loads of fun and terror. And a twin sport plane looking like this and zipping around at 150 is nothing to complain about! About the only thing it didn't do was go as fast as predicted. Other than that.. far out!
Our local club has a twin Jett powered Quickie, again it sounds cool but is no faster than the singles that I can tell.
The Hot Kanary was sorta close but it had fat airfoils. And a fat fuse. Mine flew great but that was ages ago and it lived a short life, I recall something fell on it like a drill press vice or something equally destructive. Had my old blue head ST-X.45. Still got it, strong durn engine at the time. Maybe the Anorexic Kanary should be conceived? I have many, many time sat pencil in hand and pondered a tiny insane hot bipe for .40-.50 engines.
Our local club has a twin Jett powered Quickie, again it sounds cool but is no faster than the singles that I can tell.
The Hot Kanary was sorta close but it had fat airfoils. And a fat fuse. Mine flew great but that was ages ago and it lived a short life, I recall something fell on it like a drill press vice or something equally destructive. Had my old blue head ST-X.45. Still got it, strong durn engine at the time. Maybe the Anorexic Kanary should be conceived? I have many, many time sat pencil in hand and pondered a tiny insane hot bipe for .40-.50 engines.
