Well I finally did it. After many post's on this forum, talking with numerous people including my instructor I just last week dropped the cash to get a complete trainer setup.

The setup I chose is as follows:

JR Max66 radio set
Boomerang 40 ARF trainer
Thunder Tiger Pro 46
flight box, starter etc

Each of these came highly recommended from here, my instructor and the hobby shop where got them.

I'm really happy with the setup and have nearly completed building it. I get the feeling however, that the boomerang 40 manual was written assuming that one has done all this before, especially when it comes to Propulsion and linkages. It is in these two areas where my questions abound.

Propulsion
1) The instruction manual says " use pieces of foam rubber to hold the (fuel) tank in place". What does this mean? Do I jam peices of foam down beside the fuel tank until there is no movement whatsoever? Do I somehow secure the tank so that it can't fall out?

2) The "vent" tube goes to the muffler for back pressure, the "Fuel Pickup" tube goes the the carb.....What does the "Fuel fill" line plug into? This isn't explained in either the boomerang manual or the engine manual.

3) The engine wasn't exactly a perfect fit onto the engine mount....Is this normal? Have a look at the picture...The manual does not mention anything about making sure the shaft of the engine is perfectly perpendicular the the thrust line of the fuselage. Does it look straight enough to you?

Linkages
1) The connection to the servo's is my main concern. The ARF kit included the linkages as shown. Two nuts, a brass cylinder and an Allen Key screw. Should the brass cylinder rotate freely? So that the pushrod never has any lateral bending on it.

2) The manual has a section on control throws. It's just a list of up and down numbers. How do I set control throws? Does this really matter?


The other thing which has really annoyed me is the fact that the manual switches between imperial and metric units at seemingly random points throughout.

Anyway...that's all I can think of at the moment ..Thanks for reading

CHeers

dy

Propulsion
1) The instruction manual says " use pieces of foam rubber to hold the (fuel) tank in place".
Use foam rubber under and on the sides of the tank. The tank should not be jammed in so tightly that it can't move at all, but the foam should provide vibration cushioning.

2) The "vent" tube goes to the muffler for back pressure, the "Fuel Pickup" tube goes the the carb.....What does the "Fuel fill" line plug into? This isn't explained in either the boomerang manual or the engine manual.
With the engine out in the open, and the carb fully accessible, you can use the fuel supply line for fueling. Simply pull it off the carb, fill the tank, and replace it. The third line is not necessary.

3) The engine wasn't exactly a perfect fit onto the engine mount....Is this normal?
Looks straight enough to me. Adjust it until it's as centered as possible in the mount. I do see your fuel lines are much too long. Shorten them so they make short, gentle curves, with no binding and no excess slack.
Linkages

1) The connection to the servo's is my main concern.
Those are EZ Connectors. Easy for the beginner to use, but I, personally, don't like them. The brass cylinder should rotate freely, but not wobble. BE SURE to tighten the set screw well!!!

2) The manual has a section on control throws. It's just a list of up and down numbers. How do I set control throws? Does this really matter?
Yes it matters. The amount of control throw governs how your plane flys. I'd set the elevator with about 20-25 degrees of movement each way, and the ailerons about 25-30 degrees. This angle is measured at the control surface. A protractor is good for this. The rudder should have all the movement you can get, and the nose wheel should only move about 1/4" each way.

Now you see why I seldom recommend an ARF. The plane often needs modifications, and many times, as you've found out, the instructions are marginal, at best, for a beginner.

Make sure all the control surface hinges are glued in well. Tug on each one. The fuel tank klunk should be about 3/8" away from the back wall for proper fuel draw.

Keep asking questions, we'll get you through it.

Dr.1

I would shorten up all of your fuel lines to begin with. If you can take the plane to a RC field, they should be glad to help you set this puppy up. Other than that you look like you know what you are doing. I don't like the fuel filler line . If I am correct it can cause you to flood your engine if you fill the tank to fast. Keep in mind I never used one.

I like ARF planes especially for a trainer. If you crash it at least you don't have to worry about all the time you spent putting the thing together. ARF planes are getting more and more expensive. Heres where I like the kit part of the hobby. Kits are a dime a dozen and cost the same to assemble them.

alrighty...finally got a chance to respond...

fuel lines too long...check...fixed

now as for the third fuel fill line....I still have a third hole in the fuel tank. What do I do about that?

Assuming it fits well, install a 1 inch piece of fuel line and find a suitable solid piece of metal or plastic (round of course and a snug fit) and plug the loose end. You will then fuel by disconnecting the line to the carb and pumping fuel into that line. Have the muffler line disconnected as you fuel or watch VERY closely so that you do not pump fuel into the muffler when the tank fills up. This would be necessary even with the 3-line method. On future planes, with cowled in engines, you may need a 3-line system but not for most trainers or sport planes. If you do disconnect the muffler line, pay close attention to which line goes where. If backward, it will not run properly long at all. Many color code the lines.

Some areas, Im not sure about OZ, its hard to get different colors of fuel tubing. I put a wire tie loosely on the carb-tank line, that way I can't mess it up without trying really hard!

Did someone else mention to make sure you know where your muffler- tank line is pointing as you fill? It really stings to have the fuel squirt out into your eye. I usually keep it pointed downward with other hand on kill switch of pump. course if your using a hand pump, you can be pretty close with a simple count.

Since no one actually answered your question regarding that third fuel line coming from the tank, that is your fill line. You can fill the tank one of two ways: 1. remove the fuel line that goes from the tank to the carb or needle valve (if it is a rear mounted needle valve) at the point where it goes to the carb or needle valve. You connect your fuel supply to that point. Disconnect your pressure line from the muffler and point it away from you (as suggested.. fuel in the eye hurts!). Begin fueling until fuel runs clear out of the pressure line. The tank is full. 2. Leave all fuel lines where they are. On the third line, you will put a cap in that line, a plug of some sort, to prevent fuel from coming out from pressure when normal operating. You remove that plug from the third fuel line and connect that to your fuel supply and, again, disconnect the muffler pressure line and point it away from you, and pump fuel into the tank. When it runs clear from the muffler, the tank is full.

In case number 1, disconnect the fuel supply from the tube and reconnect the tube to your carb or needle valve and reconnect the muffler pressure tube to the muffler. In case number 2, disconnect the fuel line from your supply and re-plug that line so fuel does not run out of it. Reconnect the muffler pressure line to the muffler.

I made a crude drawing of what you would expect to see. Hope it helps.

Your're ready to fly.

DS

And if you connect the muffler pressure tube to a small container you will save fuel ( $$$$ ) and not get it in your eyes. I use an extra hunk of fuel line and pump the excess back into my fuel can. I use a small clear plastic connector between the muffler tube and the fuel tube to the can so I can see when the tank is full. Probably only get about 3 or 4 extra flights a year but the ground LOVE's it. ENJOY !!! RED

We use old prescription bottles with tubing epoxied thru the lids but you could also use an old (or new) fuel tank. Keeps tables clean and fuel out of eyes and mouth if it sprays hard. [:'(] That stuff tastes bad.

OK....following on from here.

I started the engine for the first time today. I followed break in procedure to the letter.

Basically it said to start with the needle valve fully closed (lean), then turn it back 2.5 turns for a good starting point.

I'm not sure what I was doing wrong but there were a couple of things that had me concerned.

Firstly; I had great trouble getting it to idle at low revs. It would just stall. I am quite sure that the cause of this was vibration. This vibration IMO was not huge, it certainly didn't seem to be causing the plane much discomfort. I'm also sure that my instructor's .46 size motor idles much lower than what mine was. The vibration went away after as I increased the revs.

The other thing that I was concerned about was the fact that the instruction manual says, with the rich mixture I was using that I should see "dense smoke" coming from the exhuast. No matter how much I richened the needle valve I never saw any smoke.

Also, I found that when the mixture was very rich, and I as I opened the throttle there would be a point where the revs would actually decrease. I did not notice this with a leaner mixture.

Also, I don't know how hot these glows are supposed to run. But mine was hot. I was also very afraid to make the mixture too lean and I made it quite a bit richer than the instructions said. Both the muffler and the engine were WAY to hot to touch after running the motor for about 2mins at moderate RPM.

I'm also afraid to fully open the throttle. The thing sounds like like it's about to explode.

I have to wait another week before I see my instructor again so any help would be good.

cheers
dy

dydx , it has been some time since i was in here as my computer suffered a terminal disease.Congratulations on getting your modelling equipment. Now hot motors , YES , they do run extremely hot , about 300degrees hot, so don't touch after running them , unless you want burn blisters. 2 Dense smoke. No you wont find dense smoke, but if you are running rich , you will see and feel excess fuel coming out of the exhaust. 3:- While running your motor extremely rich will cause some vibration, so lean it off a bit. In fact right now you can start your motor , go full throttle, and lean the mixture till the motor reaches full revs , NOW open the needle valve a full half turn, and you can now go fly on that setting. A few tanks of fuel later you can then lean it out to achive full power. Remember at full revs that motor will be doing about 14000 revs, frightening isn't it ? It wont explode . The reason your motor was stopping at low revs was because you had it TOO rich. So now go and enjoy flying to the maximum.
the_madgenius , instructor Yeppoon, Australia

Cheers mad_genius.

I cranked her up again today. Took your advice; this time she ran ALOT better.

And oh the power! I was afraid that the tether may rip the entire tail assembly off.

I'm still concerned (less but still concerned) about running it 'too' lean. The manual raves on in bold capitals about not running it too lean. I was wondering. What are the things too look for to know whether your engine is running too lean?

dy

Hey there,

great to see another Aussie joining the addiction, or rather the hobby As for if it running to lean, the engine will run hotter the normal(but that is sometimes hard to tell). It will also most likely cut out at full throttle due to fuel starvation. There will be an absence of fuel spitting out the exhaust and no smoke.

One thing to remember is that we have altitude to account for. Engines do lean out some once you go up due to pressure changes so it is always good to be a little rich without being too rich if you get me. All my engines have a decent trail of smoke blowing once in the air.

Hope that helps,

Fly-guy

Your instructors engine idles at a lower speed because it is COMPLETELY broken in. As your engine settles in, you will gradually improve your idle characteristics. If you were trying to get "dense smoke" at idle and adjusting the "hi speed" needle valve, that will have no effect except as you saw. Idle mixture and hi speed mixture have separate adjustments. It is a balancing act.

hi Fly-guy, I have been addicted for many a year , having started at Tingalpa back in the very early 70's. I now fly with Rockhampton Model Club. What club do you fly with ?
Dydx , next weekend let your instructor set your engine for flying, he will set it rich for your next few flights , and gradually adjust the needle valve till the motor is running at full power. So DON'T touch the needle valve setting as once set it vary seldom needs to be readjusted.
the_madgenius {Bill}