[bensidus197217]

Did some assembley of parts I will be using and did some design brainstorming. I get an overall idea of what I'm building then start to piece things together as you will find out. Max talked about tail rotor difficulties on these things so I took that to heart right away and came up with a plan. At first I thought about a pulley to replace the tail drive gear but that would mean guide pulleys and finding the perfect length 450 belt so I didn't think that would go well. I have some 500 parts left over so I checked a tail rotor gear I had and found the 450 belt ran smoother on that than it does on the 450 tail gear itself. Did some measuring and found the distance from first to third cog on the 500 gear was .114 the distance from the first to third cog on the 450 belt is also .114 this is good. I will have to do some mating of the two parts which will be fairly easy and by making up this part it will close to double the tail rotor speed. When counting the cogs the 450 tail gear has 11 teeth the 500 one has 19 teeth and it runs smoother on the 500 gear than the 450 gear. The reason I know that is because I mounted both gears in my vise and ran the belt on them by hand.

[bensidus197217]

Tried to take the plastic gear off the shaft, that didn't work I broke it in half so it's time for plan B. So now I think I'll take the aluminum 500 belt shiv off it's shaft make a hub and put it in place of the 450 belt shiv that way I can change those parts with less hassle.

[Jimmy P]

Jim would it not just be easier and way less trouble to just use a smaller pinion and also with less pitch on the head to overcome the tail issues?

[bensidus197217]

Thanks for that input James I see where your coming from and what you say can work with a bigger motor pinion. I plan on using the ten tooth pinion I'm getting for two reasons one is more torque from the motor to compensate for lower scale head speed and two lower head speed is more scale like. Keeping the above statement in mind that setup will also lower the stock tail rotor setup RPM which will give me lousy tail control so that is why the need for increased tail RPM with the setup I'm planning. The reasons I'm making my own airframe are to shorten the mainshaft (if I can drill it) and tuck everything as tight as possible into the upper portion of the fuse plus place electronics as much out of the way as possible to allow for more room for my cockpit and to make it easy to access all parts if repairs are needed. Now you ask why go to all that trouble? I have two working 450 helis now one semi scale Hughes 500 the other a boom and pod and a FBL100(bullet proof little thing) so I can fly one of those when I want to fly and that leaves time for this long term project. I plan on attaching the cockpit directly on the removable part of the fuse to make it easily out of the way when working on the mechanics.

[bensidus197217]

Originally Posted by Max

I have this body and the only watch-out I have is the tail effectiveness.

That big-ass rudder tends to affect the tail rotor function. The big rudder acts as a baffle restricting the amount of air-flow through the tail blades. The blades are spinning but they dont get enough air to push against.

Me sure you have a good RPM on the head (thus tail) to provide effective tail rotor thrust. You will know if you dont have effectiveness, when the fuse does a lot of unnecessary yawing.

To get the tail rotor effectiveness up, some guys have had to change pinions, others recommend longer tail blades. Either way, keep that in mind if it flies like crap when you first maiden it.

Max do you have a two or four blade tail rotor? Do you have a two or four blade main rotor head? Thanks for any info. Jim

[Max]

Originally Posted by bensidus197217

Max do you have a two or four blade tail rotor? Do you have a two or four blade main rotor head? Thanks for any info. Jim

I used a stock 2 blade tail that came with my HK450

Here is my build thread on this baby

http://z10.invisionfree.com/AMACforu...showtopic=1268

With the original frame, it flew like a doll.

When I swapped out the frame for another one, it flew like crap. The problem turned out to be TR effectiveness due to lower RPM I had on the heli. Once RPM was raised and longer tail blades were used, problem went away

[bensidus197217]

I've got a four blade tail rotor on the way and a four blade main rotor is here. I'm installing a ten tooth motor pinion for more torque and slower head speed, a bigger tail gear shiv to increase tail rotor RPM for better tail authority. I'm in the process of building more own airframe made to fit this fuse for maximum room for cockpit detail. Last night I made up the main shaft bearing blocks all within .001 of each other today I will line bore them and tonight I will start making the side plates for the airframe.

[bensidus197217]

Max I tried to get your build thread but it said I don't have permission.

[bensidus197217]

This is the start of the machining, first we have the block of raw material that will be used. First comes the cutting of the bearing blocks roughly to size without wasting much material. The blocks were milled to make them square for line boring then fastened the blocks into my milling vise. Once I drilled the through holes in the blocks I then placed each block in my four jaw chuck and cut the bearing bore so the bearings have a snug fit level with the top of of the block. The measurements of the blocks are all within .001 of each other the next step is making the airframes. Below are the pictures.

[bensidus197217]

These are the aluminum plates I took to work on which used the sheet metal brake to form the bends. Bending them was a bit of trouble because our break is made for larger items so I did have to do some shimming to do the bends. I then drew my cutout lines on my material then began cutting with hacksaw, drill press and files what you see is the basic final shape. I placed it in the fuse to see how it looked and lines up. Next thing is to install the tail boom, tail and main rotor then see how it looks in the fuse and adjust accordingly. Heres some pics.