RE: SIG KOBRA
 

Here is a link to a pair of low-drag [link=http://www.hmracinginc.com/product.php?id=49]racing wheels[/link] that may be suitable for your Kobra.

RE: SIG KOBRA
 

Just ordered a Kobra and want it for speed. I have a 46 Magnum new in the box I'll never use-so here i go. The Kit say's i can build as a F-16 or T-38 is their any Differance in handling or can you recommend which way is best-Any help out their is appreciated.

RE: SIG KOBRA
 

Thank you Red, I already have them. They weigh nothing at all. They do make A lot of noise and haven't got A lick of cush on landing but in the unlimited class most the guys run them. Those had some really nice colors instead of the drab looking things I use.

RE: SIG KOBRA
 

Hi All Here are pics of my Kobra & Kougar..The Kobra is electric powered. The Kougar has a GMS 47 and ROCKS.Had to add some yellow to the Kougar so I can see IT better

Dan

RE: SIG KOBRA
 

Could you post a picture of this plane as a tail dragger. I'm building one and using a 46 engine. Getting rid of the nose gear will help with the added weight?? Shortened Ailerons? Like to see that. Thanks Grey Beard

RE: SIG KOBRA
 

In this case there is no tail wheel, just A skid. That will eliminate some weight and these planes aren't on the ground much and they come up on step right away. If I am doing one of these planes as A normal tail dragger I would do A pull/pull rudder with two extra wires out the bottom for the tail gear tillers connected to the rudder control arms, very easy to do.
I had my grand kids for A week so I just went back to building the fuse, epoxy is setting up right now on two of the formers and maybe tonight I will put in the fire wall and another former.

RE: SIG KOBRA
 

Thanks for the reply, I'm studing the plans tonight and was wondering where you would mount the main gear if making a tail dragger. I have a Magnum 46 going in and i think?? this may be a little heavy and the main gear should be under the leading edge of the wing?? Do you have a specific spot.

RE: SIG KOBRA
 

Click on the last three photos and then enlarge them and you can see where I mounted the LG blocks. I have them set in the ribs just like the stock ones with the angle set so the wheel axles are even with the leading edge.
If I was building this one as stock but as A tail dragger I would use A pull/pull rudder and have the tail wheel as A pull/pull also with the wires going to the rudder servo. There are other ways of doiing it but this would be the easy way for me.
If someone else has any ideas on this they should join in and help you out too. ;) I just like using the pull/pull system when I can. I make up my own systems using stainless steel, plastic coated 30# fishing leader. Very light and easy to work with.

RE: SIG KOBRA
 

Just maidened my Kobra today, after working on it for about 3 years (I'm not the fastest of builders...). Mine is powered by an ASP 25, and currently I have a 9x5 Master Airscrew prop. Not a lot of power with that setup, I needed lot of elevator throw to get it up in the air (the suggested throw of .25" was not enough). Once airborne, it flies very nicely!

Mine weighs about 1500 gr with fuel (3.3 lbs), and even though the battery is as far back as possible, the CG is still a bit too far forward. It would be nice with more power, but fitting a bigger engine would make balancing even more difficult. Maybe I'll convert it to electric instead, but for now I'll just fly it as it is, but will try some other props.

RE: SIG KOBRA
 

Thanks Gray Beard, Took your advice and making a Tail Dragger also going with pull/pull rudder and tail wheel. I'll post shots as i progress. Started this Saturday.

RE: SIG KOBRA
 

Servo bays worked out nice-very light, using HS81MG.

RE: SIG KOBRA
 

I ran into problems with the pull/pull rudder because of A couple of different things. The fellow I'm building it for wants me to put the turtle deck and canopy on it so I can't hatch A bay from the top for the rudder servo. The biggest problem is the standard size of servos.
I'm mounting the elevator and rudder as far back as I can and there just isn't A lot of room for them in the fuse. Can't get the angle for the rudder I needed.
With A Webra 55 going up front and an 8oz tank I need to shift everything else as far back as I can.
Wow, I just came up with A thought writing this. Maybe I can get the rudder servo in the way I want it and have it hidden in the turtle deck? Think I better go look at this brain storm right now.:D:D

RE: SIG KOBRA
 

I was just looking at the pull/pull, with the F-16 tail configuration, the rudder control horns will pull up because of the angle-????????????? have to think on this. The elevator servo is definately going in the rear. I'll have pictures in a couple days.

RE: SIG KOBRA
 

Micro tail wheel and servo in the rear for the elevator. I hope the tail wheel hold up, it is very light weight, but then I don't expect this plane to stay on the ground long.

RE: SIG KOBRA
 

The 46 magnum installed, tough fit-their is little room for anything. Will have to drill holes in the bottom of fuse to run the motor mount bolts.

RE: SIG KOBRA
 

Here is the Pull Pull on the Rudder and rear servo for the elev.

RE: SIG KOBRA
 

French, do you have your wires going through that yellow push rod material?? I don't see it in the photos. Just wondering.

RE: SIG KOBRA
 

No-at the time of the photo I just have the hole in the fuse, I may use push rod tube, a small peice when i do final assembly, or may not and have the wire run through a small hole in the monokote. I put it together to check operation, control throw and get a prebalance and weight. 3lb-4oz so far. Balances nose heavy at this time.
PS-my first attempt at pull-pull?

RE: SIG KOBRA
 

I use the push rod tube for A couple of reasons. One is so the wire doesn't cut it's way through the wood like A saw. Another reason is if you run the stuff through the fuse it's easy to get the wires in and out when needed for repair and adjustments.
How far along are you in this build?? I had hopes of getting this one as light as I could but I have an 8 oz tank in there and A WEBRA 55 with A tuned muffler so I have hopes of staying under 4 pounds. Using two micro servos and three standard size. The elevator servo is all the way back in the fuse. The rudder servo is mounted behind the wing under the wing mounting blocks. I have the throttle servo mounted back behind the wing. Plan on using the RX and battery and switch to get the CG with.
So far the only hard part was getting the engine and muffler in there and and building the cowl around it and still be able to get the engine in and out. Tomorrow I may be able to get the tail feathers on it so I can set the incidence.
Nice little plane but not A lot of room for the things I'm doing! :D

RE: SIG KOBRA
 

WOW-I have the same issues! I am done with the construction except for the tail wheel assembly that I'm going to make myself, the micro one in the pictures won't hold up and i need a little weight back their anyhow. All my servos are HS81MG, battery is 750 mAp NiMh-Very lite. The 46 engine is cowled and I can take it out. I will post pictures Thursday or Friday. If you want anything specific let me know. Thanks for the inspiration on making it a Tail dragger. Even after beefing up the wing & Misc. I should be at about 3lb-4 to 6 oz without covering???

RE: SIG KOBRA
 

Finished the construction-Took the day off from work. I took your advice Grey Beard, added the tubes for the pull/pull wire exits. The weight of the plane came out to 3lb-3oz. The CG is 2-3/4 from LE so I need to work on it. Batt/RX everything is to the rear. Made my own tail gear and was hoping that was enough to balance at 3-3/8. Going to paint the canopy and turtle deck today and do some final sanding.

RE: SIG KOBRA
 

Started the covering-liked both examples on the box so i'm going to use both.

RE: SIG KOBRA
 

Finishing the fuse and cockpit area. Painted the monokote at the front, and glued down the canopy and Turtle deck.

RE: SIG KOBRA
 

Looking Good!!! Fast build too.
I ran out of epoxy over A week ago and building came to A fast hault. I got everything done that I could but wanted to leave things open so I could get at them. I ran out when I tried to lay in the stab. I still need to set up the rudder and elevator controls.
Yesterday I laid in the wing, got the incidence set then used the epoxy to lay in the wing hold down blocks. Later in the day I used some of my angle stock and used epoxy to put some support under the blocks.
Wasn't getting the engine cowled A thrill. :) I have it mounted on it's side and the muffler header was right at the mid point of the fuse sheeting so I had to remove A lot of wood. I had to drill four holes in the cowl so the owner would be able to get A socket in there to get at the engines lock nuts. I had to do that to my Hots too but I have A YS 1.10 stuffed in that.
This one has A tuned muffler, I wish it was A tuned pipe. It's too big and too heavy but it's what the owner wants and it really makes his engine come alive.[8D]
I should have some photos next week. I have people staying here all weekend so I can't work on it.

RE: SIG KOBRA
 

Glad to hear your back after it. It has been fast-100+ hours this month building. Wanted it ready by the first week of october. 2 guys in my club have faster planes than I-"Can't have that". I'll be done with the plane Saturday and post several finished pictures. Please do the same as you go-You gave me good ideas. Mark