Lama Continued

The Lama progresses slowly. It is now April and Top Gun for helis has been cancelled. The target now is the nationals and June is very rapidly approaching and this thing has not turned a blade yet. It's time to start preparing it for flight. Most of the major work is done, the final details can be added when its flying and I have spare time. One major problem is how to get the wires from the front cabin to the rear compartment without them being seen. There will be 4 servo type triple wires and 2 power wires for the starter.

What I decided to do was to run a stainless steel thinwall tube down to the back under the fuel tank plate, but then I had the idea of running it down the center and putting a V section in the front end. First I cut 2 pieces of tube at the right angle.

Once in the vice, they stay there. I brazed them together and then cut the top off and cleaned out the hole thoroughly. Then I cut another piece of tube and brazed it to the top of the V.

A lick of paint and it looks like this mounted up.

From the side you can't see it but from above it looks like 2 more support tubes.

The next part of the process is to wire up the computer for the turbine and plumb it in. All of the parts go in the back of the heli under the turbine so the leads are as short as possible.

The small tank is a BVM Ultimate Air Trap which stops any air bubbles from reaching the turbine and putting the fire out. I have placed it right at the back so I can see it fairly easily and if there is any air in it, I know its time to land as it only gives me about 30 secs fuel.

Running the wires underneath and up through the baseplate leaves me with a nice clean installation.

A few more scale items are getting fitted. The skis and basket are done. The full size seems to have a basket on one side or the other but not on both. The anti slip paint on the landing gear is also done.

The cold air intake for the turbine exhaust is done as is the air filter system for the turbine itself. Of course, these items are purely scale and do not actually touch the turbine on the model.

The two oil tanks for the engine and transmission are also done

I finished the mirror heater wire and its control wire

The last major piece is built. This is the cargo hook frame which hangs underneath.

This is the fullsize

2 major items were needed to finish this machine, a fuel tank and an exhaust. I told my two suppliers what I wanted and they turned up trumps for me. First was Tam at Tamjets who made this super exhaust system

The rear section is a loose sleeve with matching holes in it which can be rotated 90 degrees so that for static it looks like a tube and for flying it has the holes.

Len Mount was kind enough to create the fuel tank for me and he did it in an amazing 3 days from a telephone conversation and a few photos of the full size. It consisted of 2 parts, the main tank itself and covers for the mechanics to simulate the top section of the tank

A couple of fittings were machined up and fitted to the base of the tank with JB weld

And then some brackets were made up to support the tank under the frames but a hefty blob of PFM went under the tank to fix it to the baseplate for added security.

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A few rivets and panel lines made with primer followed by a coat of paint soon had it looking the part.

Now it was time to put it all together and set it up for flying. The first time I hovered it I had two problems. Firstly it would not maintain a hover for more than 10 seconds without the turbine over heating due to the weight. How it had got so heavy is beyond me. The second problem was a vibration in the carefully painted rotor system which I could not tune out. The engine problem was solved by shipping a spare turbine back to Peter Jakadofsky in Austria and having him convert it to the latest PJW-LE spec which had 30-40% more power. The second problem was solved by exchanging the rotor head off my other turbine Lama. I then got in touch with Jeff Green at MRC Altech and he managed to arrange a new head to be shipped directly to me from Japan.

Its a curious thing, but Hirobo have a bad habit of ignoring the loctite needed on these heads particularly the axle for the blade holders. I ended up stripping down both heads and rebuilding them with lots of green loctite to get them to work properly, and I also found that the older one flew better than the new one so while I had it apart I painted the blade holders.

This is how it turned out

And finally, after a bit of an adventure, I did win the 2004 Nationals with it. This is the Nats story