RE: Mig 15 With Jetcat P20 Build Thread
 

Nice one bro, she looks the goods. After I seen ya post that HK had the red one in stock I also immediatly ordered one. Mine will be EDF, 8s set up approx 3.3 kw.

Got my first turbine waiting for me when I get home from the Sim, exciting times.

Matt

RE: Mig 15 With Jetcat P20 Build Thread
 

It will be a squeeze getting 2 4 cell packs in her as the ducting is so big. You might be better upping the KV of the motor/Fan and going 6 cells. Wait till you get it and you will see what I mean

Dennis

RE: Mig 15 With Jetcat P20 Build Thread
 

Thrust Pipe

The thrust pipe I am using is the one I got with my Habu 32 kit in the sports kit. It is just the right length. You have to fix the belmouth on however and fix on some front mounting pieces. I used offcuts from an old pipe I had. The Habu 32 sports kit comes with a rear mounting metal and outer wooden ring and screws and I used this to mount the pipe at the rear by the bulkhead next to the rear bottom Hatch.

This whole job was a bit of a pain and took me about 2.5 hours. I always hate mounting thrust pipes. It has finished up very solid though and I have managed to add very little weight.

At the top mounting you will see I have had to drill a hole in the rear of the canopy to clear the bolt head

Dennis

RE: Mig 15 With Jetcat P20 Build Thread
 

Hey Dave the midget............. Havn't you got any work to do I can see You :D

Dennis

RE: Mig 15 With Jetcat P20 Build Thread
 

Rear Hatch

The rear bottom hatch is held in place by 4 preapplied magnets. Mine was quite a poor fit as can be seen in the pics below. All I did was push on it to splay it out and stuck it with selotape front and back. You should always have a dit of selotape on all planes I recon.................Oh and an elastic band :D


Dennis

RE: Mig 15 With Jetcat P20 Build Thread
 

I scanned through the thread but did find if you weighed the bare kit? empty weights are always intresting

RE: Mig 15 With Jetcat P20 Build Thread
 

Well as I have never had any instructions I am now pondering the CG. I have 2 other Mig 15's which both fly well see below. I have an Alfa and a J Perkins or OK Mig.

On the Alfa the length of the wing root is 210 mm and the CG is 123 mm from the front = a Percentage of 58 %

On the OK Mig the wing root is 225 mm and the CG is 143 mm back = a percentage of 63 % back.

If I therefore use a Percentage of say 60 % on the P20 Mig and the Wing root is 290 mm this gives me a CG of 174 mm.

To be on the safe side I think I will set it at 170 mm from the leading edge.

This has come out about 23 mm in front of the centreline of the main wheels which would seem correctish

Dennis

RE: Mig 15 With Jetcat P20 Build Thread
 

I never did weigh her but she was quite light. When I get a moment I will weigh the red one

Dennis

RE: Mig 15 With Jetcat P20 Build Thread
 

I am quite pleased because to balance her at 170 mm from the leading edge at the root I have only got to add 65 g of lead which for a Mig 15 is quite good as they are notoriously tail heavy

Dennis

RE: Mig 15 With Jetcat P20 Build Thread
 

Well I have finished the Mig.... Here are a couple of pics of her on the floor. The all up dry weight is 2.8 KG which is 6.16 lbs. I think the P20 at 5.25 lbs of thrust should be just about right. I just hope the silver colour is ok to see.

The fuel will add about another 1.8 lbs but should not be there for landing :D.

Now on to my RC Paraglider

Dennis

RE: Mig 15 With Jetcat P20 Build Thread
 

Dennis

See you tonight for the maiden then.

John

RE: Mig 15 With Jetcat P20 Build Thread
 

But it is raining like mad and blowing a hoolie. I will bring it along however

Dennis

RE: Mig 15 With Jetcat P20 Build Thread
 

Dennis

It is sunny here now and the wind has dropped a little. Forecast is not that bad for 7 pm. At least you could start it up and drive it about a bit!

John

RE: Mig 15 With Jetcat P20 Build Thread
 

I received a copy of the instructions from KMP. They list the CG as 5.75in back from the leading edge of the wing where it mates to the fuse. I think I attached the pic.

RE: Mig 15 With Jetcat P20 Build Thread
 

any way you can share the plans? I never received any with my plane

RE: Mig 15 With Jetcat P20 Build Thread
 

I posted the word doc file I received from KMP on hobbyking's site where they are still selling these jets.

RE: Mig 15 With Jetcat P20 Build Thread
 

The Mig I have built is not the KMP one however it is Pro EDF.............. I am not sure that these are the same planes

RE: Mig 15 With Jetcat P20 Build Thread
 

It is the same plane made by Pro EDF and it was distributed by KMP.

RE: Mig 15 With Jetcat P20 Build Thread
 

Many thanks

Dennis

RE: Mig 15 With Jetcat P20 Build Thread
 

Success

Well today I thought I would start the engine and give the Mig a Taxi test. Well she ended up being flown and I was very pleased indeed. My trusty test pilot 3dFlip did the honors.

The takeoff run was quite long and we used half flap and the P20 had plenty of power to lift her off. The plane flew a dream and needed next to no trim. The CG was perhaps a little nose heavy but if it is pushed further back I think it would give a few issues on the ground. The landing was good also with a very small bounce and she also landed quite slowely. The pilot reported that the flaps caused next to no trim change and we managed to fly fo 4.25 minutes and only used one of the 2 tanks. So an 8 minute flight is easily acheivable.

All in all I was very pleased indeed. For those interested in this model I would say to get the red one as she was a little difficult to see against a grey sky.

The thing that most impressed me was how quiet the P20 was and also how easy it was to start...... This is a lovely little engine

The power in the climb was excellent and vertical was no problem at all. In my view now that she has flown I would say that this airframe is a perfect partner for the P20...

I feel like I need another P20 :D

Thanks to 3DFlip for another excellent test flight.

RE: Mig 15 With Jetcat P20 Build Thread
 

Well done Dennis and pilot.

It would be nice to see it fly next time you plan to go, as I am always interested in airframes of this size.

John

RE: Mig 15 With Jetcat P20 Build Thread
 

This little engine is so addictive that I've just sold one of my bigger turbines to buy another one. I'm so pleased with the ease of use of the little Jetcat that the bigger turbine will eventually be replaced with a P100 when they become available.

Good to see you have success with the Mig. Now we need video:D

RE: Mig 15 With Jetcat P20 Build Thread
 

Thanks Dennis for letting me play with the P20 :D:D I was very impressed with how it ran and how quiet it was ( I think its time to buy one [X(] )

I don't think I have ever seen Dennis look so nerves. The Mig Flew very well, I am looking forward to seeing Dennis fly it.

John

RE: Mig 15 With Jetcat P20 Build Thread
 

Very nice :-) good with some options beside the Habu32 that has the looks too :-)

RE: Mig 15 With Jetcat P20 Build Thread
 

Dennis, good to hear it all went well, and enjoy the little Mig especially on those long dreamy summer evenings we are having here in the UK [:@]

marcs