buddude8

My Feedback: (10)

this looks interesting. maybe with a jett90lx.

http://richmodelusa.com/index_1.html

crashed/burned

Hey Dude,

You need to build the F18 before you think about this. Your brother will have his done in another week maybe. LOL

buddude8

My Feedback: (10)

you can never have too many projects.

Kmot

My Feedback: (24)

That does indeed look very interesting!

soarrich

My Feedback: (98)

But slow! The prop's going to be in the wake of the fuse, not many prop choices, lots of intersections to make drag.

Will it be faster with the gear up? Most likely, but I bet it's because the wheel wells will cause less drag when full, clean fixed gear might be as fast.

bob27s

My Feedback: (19)

One thing that strikes me in these designs, is that they really do not give any consideration on how to accomodate a muffler or tuned exhaust on the engine. Disappointing.

I was pleased to see someone finally using a 90deg rotating nose gear.
(Btw F-20 ARF folks - that is the way to go on a retrofit - need not even be steerable)

MMallory

My Feedback: (1)

Bob,

I sent an email to Jett Eng. this morning asking for a tuned muffler for this type of application. I figure the normal Jett-Stream built to point straight down will be good enough. I'm actually quite surprised nobody has made a pusher muffler before. I guess many use the Pitts style.

I was looking for an R/C car or Heli header/pipe to fit my YS 45 for my Nitro Bobcat. I may be better off getting this plane and using the YS 61 with the Heli tuned pipe.

Mark

bob27s

My Feedback: (19)

Hi Mark,

Dub is out of the office for a couple more days. I saw the email too.

Im not sure the jett-stream can be modified or built differently for these applications. There is a reason it looks like it does So building one with an exhaust exiting somewhere else might not be possible - but may be worth looking at.

On the keecat, a turbo-jett would probably be the way to go. With that side mount installation, it would not look too bad back there.

Quite a few folks flying the Bobcat simply installed a diverter tube off of the muffler. One guy ran the exhaust down through a hole in the wing to allow it to exit below the plane. One bent up a horse-shoe shapped aluminum tube, and affiexed that (no photos). Sounds like that guy does tube bending for a living - it is think wall, and a tight radius bend (frozen/ice, sand inside?)

MMallory

My Feedback: (1)

Don't bends like that create backpressure? Diverters facing into the wind could be pushed back at speed. Changing the exit on the tuned pipe shouldn't change too much. Look at all of the reversed ducted fan props for the larger engines.

I would rather have a better engineered solution. For now, I will fly the plane with the YS 45 using a Pitts style just to get the test flights over with. Hopefully Dub will be able to create the ultimate solution.

Thanks,

Mark

bob27s

My Feedback: (19)

Not when done properly... turning is not a big issue. The key is the inside diameter of the extention tube. It has to be larger than the ID of the exhaust outlet. Too many folks use a diverter with a tiny inside diameter, and yes, that will affect performance. On the Jett engines, if you size the diverter so it fits "loosely' over the OD of the exhaust stinger, and then snug it in place with a clamp or tie-wraps, and keep it to a reasonable length - performance is not affected.

Dynamic pressure from facing into the wind might be a little bit of a problem, but due to the muffler angle, it does not face 100% parallel to the flight path - so the effect is not huge.

Biggest issue - is its hard to make something that does not look goofy.

soarrich

My Feedback: (98)

You might want to try to get a Byrons DF pipe, they where pushers.

MMallory

My Feedback: (1)

Rich,

I am not aware that they made one small enough for the .45 sized engines, did they?

Mark

aaviles

My Feedback: (1)

Bob this the Setup that you talking?


see this setup

I'm not a good picture taker, but here's my Bobcat. I've been flying the crap out of this plane so much that the cheap blue plastic
film on the top wing has pealed off in little small sections. Great flying plane. Everyone comments at the field how well it flares and lands.
Out of a dive, its got to be doing at least 125 easy.

MY SETUP:
YS 61-AR engine w/10x8 APC Macs pipe.
4 -3421 JR in empenage, 2 - JR 4131 in wing, 2 Futaba thro/steering
PPG clear coated
two tanks, 16oz & 8 oz Hayes
Bolt on wings ( interior 8-32 / blind nut 2" from LE)
old P&E functional struts from 1989 sitting around wait for a home.
Tetra wheels
6V 2000 mah NiH
8.5 lbs

I cut open the main gear support structure and reinforced the gear block and capped the cutout area with 1/8 ply.
Stripped off that ugly green anti glare and repainted it black. Looks much better, at least to me!

[link]http://image2.rcuniverse.com/forum/thumbnails/25785/Fd92974.jpg[/link]
[link]http://image2.rcuniverse.com/forum/thumbnails/25785/Mh19974.jpg[/link]
[link]http://image2.rcuniverse.com/forum/thumbnails/25785/Gz75204.jpg[/link]
[link]http://image2.rcuniverse.com/forum/thumbnails/25785/Br11868.jpg[/link]
[link]http://image2.rcuniverse.com/forum/thumbnails/25785/Ce70248.jpg[/link]
[link]http://image2.rcuniverse.com/forum/thumbnails/25785/Vu70325.jpg[/link]
[link]http://image2.rcuniverse.com/forum/thumbnails/25785/Pu52019.jpg[/link]

soarrich

My Feedback: (98)

Don't know, but it's a good excuse to put a 90 in it.

TOMMYSTA

My Feedback: (15)

Here's a thought...Davis Diesel Products (the boys who those diesel conversion heads for glow engines) also make a strap on pusher type pipe with the outlet facing to the back of the plane. I used one of those on my YS 45 on a Combat Models F16 and it worked great. May have lost a of bit rpm not using a conventional tuned pipe but it worked great.

Thanks
Tom

aaviles

My Feedback: (1)

Hi Guys i Prepared to Buy this Jet and i think put in he a BVM.91 DF .

gehr2box

Be prepared for some frustration with the retractable nose gear that comes with it.

Saw one today at the field and the nose gear steering linkage is weak and sloppy. It was not ready to fly yet, so I don't have any info on performance. Another problem, that may just be a rigging was that the gear over-rotated when it retracted (wheel turns 90 degrees during retraction), would not lay flat in the wheel well and bound up on the internal structure. Looking at the installation and the manual everything looked to be setup correctly, but nothing we did would get it to lay down properly.

Bud

(for Pete's sake

aaviles

My Feedback: (1)

Thank you for your comment are good to know those things to be pending. But it is something that has arrangement not everything it is perfect
if you know something but you allow us to know[8D]

Not yet him and bought waiting some comments on the acting of the airplane in action.
Thanks

kenazzo2000

can any one tell me how the keecat flies thanks

gehr2box

I posted this reply in the Bobcat discussion thread:

Funny you should ask. I flew a buddy's KeeCat today. It has a ST 75 for power. Nice roll rate and plenty of power for vertical manuveurs. It is not nearly as fast as my Bobcat, but is a much more relaxing plane to fly. I guess the speed was in the 60-70mph vs BobCat's 90-100 (keeps getting faster as the 55ax breaks in . I think part of it is the wing loading and the other is the tail moment being a little longer. My BobCat weighs in at 6lb 14oz. His KeeCat was 2lb heavier. The prop he is using is a zinger 11x8. He could probably get more speed with a higher prop pitch. He had a little trouble with the nose gear retract not locking down after one of his landings, but otherwise the gear held up well.

tconnell

My Feedback: (7)

I have mine about ready to put on the gear. Picked up an OS 91 FX this afternoon at Hodges Hobbies and will be putting on the 14x7 3 blade pusher. That should move it along right swiftly.

Don't much like the way the nose gear stearing looks, but when I start to hook that up I might modify it to my liking. Also think there are too many servos to get the work done. But that's the way it is.

Will post then I get the plane ready to fly.

Later,

fastmachine

hi, can someone tell me what servos to use in keecat, are they all standard size servos

LDM

My Feedback: (15)

Is this comparitive to the Nitro RC version ?

fastmachine

ya its gona run with a irvine 53 engine, can not find any info on what servos to run,

MMallory

My Feedback: (1)

Pick your servos based on your flight style and the expected speed you will fly the plane. If you are trying for high speed you should have proper linkages and 60 or more oz. . Standard will work for a sport flyer. Coreless and digital will be more precise.