Yak 55M 33%
It was may pleasure to receive one of the first Yak 55 from new production Krill Model. Following is how I did things my way, so this is not in any way assembly instruction.There are many ways how to finish this airplane and everybody has their own tricks and ways of doing things.
Airplane comes in 2 boxes, carefully wrapped in bubble pack and everything is secured inside.Small parts are attached inside the fuselage.
Landing gear assembly:
Mounting nuts are already installed inside fuselage, alu gear is predrilled,so only thing to do is attach wheel pants. I did use a nylon M3 bolt to prevent wheel pants from moving around wheel axl. Nylon bolt will break in case there is not so perfect landing and nothing else will get damaged. I do recommend to glue a small piece of plywood inside wheelpant to make it stronger.
Supplied tailwheel assembly can be istalled with 2 wood screws into plywood base already glue in from the factory. However I preffer to use regular 3mm bolts, going right through plywood which was doubled from rudder post opening.
When using engine 100-120 ccm I think 750ml tanks are more them enough.Flight time is around 10 minuts,depending on flight style. I also installed a smoke tank,also 750ml. However I only fill this tank to 2/3.I don’t use a smoke pump, I use electromagnetic valve.
I did make my own fuel tank holders and please have a look at pictures bellow how it’s made.
For those who don’t feel comfortable making these holders, they can be ordered from me.
Servos are installed through a root rib.Only thing that has to be looked at is making sure pre cut slots are long enough for throws used during 3D flying.
Stab tubes are carbon fiber and I did glue a beechwood ring inside the end and this is where I cut a 3mm thread for screws securing elevators to fuselage.
There is only one thing to do,glue rudder horns.Slots are precut and in the right place.I use 24 hour epoxy and I also made my own templates to align horn.I do drill a small hole at the bottom of the rudder and use this to put epoxy inside,where f/g horn and balsa wood block meet.This makes sure horn is glued rock solid. Also where rudder cable exits fuselage, I do use aluminum tube, but with another thinner plastic tube inserted inside,This will prevent any f/g and rudder cable rubbing against each other.Again please go to pictures bellow to see more details.
Firewall is set at 0 and 0.I did make my own stand offs,allowing engine to have a 3 degree right thrust. Ther are other stand offs available for different engines.
My stand offs were too “soft” at first, so I did make a ply box and sort of glued everything together. This did eliminate almost all vibrations. Krill model now offers their new engine box and it should eliminate need for stand offs.
Choke is controled by a 3mm threaded rod, going through rubber O ring and through cowl.
As you can see on pictures, I do use Festo and SMC products.
Cooling opening depends on used engine. I also did solder a brass tube,about 600mm long onto an opening on a carburator. This tube was bended so it fits inside the fuse, into so called “quite” area and engine runs better this way.
All muffler system was used from Krumscheid, only bending header has to be adjusted for this airplane.Comfort mount can be attached to silver board glued in from factory.I did choose to go a bit more complicated way and click on pictures to see it.
And openings in the cowl need to be stiffen up with a layer of c/f .
Radio gear intatlation:
I’m sure there are many ways of doing this,but on pictures you van see my own instalation. Always keep in mind that there shouldn’t be a need for any lead when balancing airplane. Propper CG can be adjusted by simply moving things around.
Muffler exits holes:
No need for any muffler tunnels, just exit holes. These are beefed up with carbon fiber cloth from inside. This shouls be done every time you make a hole in a f/g sandwich.
My own tips and hints: