Magnum Tazer 800 Build

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Building the head, you'll find a few new items that are now stock equipment, part of our continuing improvements without redesigning the whole helicopter!!

An Intrepid Original, often imitated , is what my father termed the Heim ball, in deference to Ewald Heim, where he got the idea, is the plastic ball on the head axle. This centers the head axle in the head, allowing the dampeners to do their job properly by not being compressed by the weight of the heli hanging on them. The weight of the heli is supported on the hard plastic ball instead.

It also creates a fulcrum or pivot point for the up an down movement of the rotor system, IOW, if one rotor blade and grip goes up, the opposite side MUST go down. Similar in action to the old swing heads, if you flew heli's back then....

The newest dampeners, again something from the creative mind of Malorie Zastrow (she found the material and source and she and I together found a way to cut and shape them), are a 1 piece rubber available in 2 different hardnesses, 65 and 70 durometer.

They're shaped to fit into the head perfectly, so must be pushed into the recess, leaving a little bit sticking out to compress against the shims.

These new dampeners will not "squish" out with hard cyclics or heavy payloads. The soft ones (65 durometer) are suggested for cameraships and Industrial birds wanting smooth flights, the harder ones (70 durometer) for tightening up the head for 3D style flying.

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With the dampeners in place, select the shims you want to fine tune how hard or soft you want your head to feel.

You MUST install at least the .040 shim (the thickest) leaving the choice between the .008 and the .015, or both.

Make sure that you put the identical shims on BOTH sides, then install the C-clips, which is made easier by using the proper tool, then using a tool you can make yourself out of an 8mm id tubing, pressing them into place with the head axle bolt.

If you look closely at the C-clip, you will find one side has a sharp edge, the other side a rounded edge. This is from the stamping process when they are manufactured. We want the sharp edge to be facing outward which helps to keep the C-clip engaged in the groove on the head axle.

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Installing the seesaw into the head is made easier if you make a stackup of the bolt, bearing, and 2 ea brass washers.

This is one of two places that I do suggest red loctite, holding the seesaw in place, start the bolt into the seesaw, drawing the bearing into the head.

Repeat for other side, then center the seesaw in the head and install the bearing retaining screws.

The seesaw should rock up and down freely.

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The seesaw endcaps are installed with the setscrew digging into the groove on the seesaw, keeping it from rotating.

Install the ball and verify that it is pointing straight out.

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Slide the aluminum blade grips onto the head axle.

Grease the substantial thrust bearings, installing them onto the head axle in the blade grip.

Note the ID of the thrust washers, the large ID goes in first, then the ball cage, then the small ID washer. If you're unsure which is which, slide them onto the head axle. One will be looser than the other.

Secure the blade grips to the head axle with the large 5X16mm SHCS and washer.

You may notice a very slight amount of in and out play on the blade grips. This is because there is no longer any pressure from the o-rings pushing against the blade grip bearing. The C-clip has taken up that pressure, allowing the blade grip to rotate more freely than ever before, giving much improved collective quickness and precision.

Again, thank Malorie for impressing upon us the importance of this change, which was first brought to us by Ray Hostetler quite sometime ago, but only recently implemented.

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Our blade grip pitch arms are replaceable if bent in a crash, no need to buy a pair of $100 blade grips if you bend one...

Set the tension on the bearings just as you did with the washout arms, using the 3mm nut as a jamnut.

The bell/hiller mixers do offer different ratios for flybar authority, that's the reason for the 4 holes and the different lengths of each leg of the mixers.

The pitch arm also has 3 different holes, these allow adjustment of what is known as "Delta". We'll cover these adjustments in another thread.....Sorry.

The pitch arms have a flat milled on one side where it attaches to the blade grip. This is to help you to install it square to the blade grip AND to keep it there.

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Place the head onto the mainshaft, lining up the hole for the "jesus" bolt and running it in, but do NOT tighten yet.

Tighten the pinch bolts instead, a little at a time alternating sides until tight.

THEN go back and tighten the "jesus" bolt.

The pinch bolts are what actually holds the head to the shaft, centering it accurately to the shaft, the "jesus" bolt is more for location up and down than anything.

And yes it can be a safety, or redundant fixing to the shaft, but a 3mm bolt will NOT withstand some of the weight that we carry on our Industrial Birds, the clamping action of the pinch bolts WILL.

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Flybar is next, we use a 4mm stainless flybar with cut threads.

The flybar arms are secured with a setscrew, but we do NOT put a flat on the flybar. We feel that a flat would create a stress riser, leading to breakage at that point.

If you feel a setscrew is not sufficient, you can replace it with a standard 3mm SHCS of appropriate length. I have only does this when I stripped out the head of the setscrew, and did not have an immediate replacement except for a 3mm bolt....Otherwise the setscrew has been sufficiently strong to hold the flybar in place.

Level the flybar arms when installed, and measure both sides of the flybar to ensure you have it centered in the seesaw.

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The stock paddles are plastic with a very sharp edge, I like the orange ones to match the landing gear!!

When installing these paddles, turn them on at least 21 turns. This gets the threads of the flybar deep into the paddle preventing the stresses from acting on the end of the threads, causing a breakage.

If installing other paddles such as V-Paddles, I turn them on far enough to install the setscrew in clean metal, past the threads.

Measure them, ensuring they are on the same distance, then level them to each other AND the flybar arms.

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We do offer a specific place to mount the gyro, no guessing or trying to make room somewhere!!

We also HIGHLY suggest the use of Zeal Tape to mount the gyro, even in an electric. I have had the stock tape fail, leaving sticky parts on both the gyro and mounting plate, but nothing in between!!

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Nows the time to hook up power to the servos.

We want to center EVERYTHING. Zero out any subtrims, put all ATV's at 100%, and start your pitch and throttle curve at 0, 50, and 100.

Center the collective stick, using the pitch curve page as a guide to ACCURATELY set half stick.

We do this to facilitate centering the servo wheel ACCURATELY at half stick. If the holes in the servo wheel aren't straight up and down, rotate the wheel 180 degrees and try again.

If it STILL won't line up, try another wheel. You'll notice on the back of JR servo wheels, a small number. I have found a 1, 2, 3, 4, and M. Each one has a slightly different offset of the splines.

Is all of this REALLY necessary? That depends on you. How accurately do you want your heli to fly? For general Sunday sport flying, well you can fudge a little, use a little subtrim to straighten out the servo wheels.

If you're using high end servos, a high end Gyro, High voltage battery packs for the extreme in servo power and accuracy, then spend the time here to mechanically set up the heli properly.

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We're now using the BIG JR wheel on the aileron servo to decrease the ATV to 100%, and speed up the roll cyclic.

The first pic shows the wheel slightly off center, the second one is EXACTLY on center.

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The elevator servo wheel is centered a little differently.

The wheel is centered to the angle between the servo and the "X" arm.

Use a straightedge, over the bolt in the "X" arm and over the servo wheel screw, aligning the outer holes in the wheel.

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With the power still on, all sticks centered, mark the holes where we want to install the servo wheel balls.

The Tail servo gets a ball in the bottom most hole.

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The servo wheel balls that come in the kit are chromed and the right size, no need for aftermarket searching for something that will work...

Install a nut under the ball AND on the other side of the wheel. This sets the ball link up off of the servo wheel, and secures the ball properly to the wheel.

With power still on, reinstall the servo wheels on to the servos, centering them as before. When using servos with metal output shafts, use loctite on the servo wheel screws.....

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The collection of pushrods and ball links.

We use what use to be referred to as "Rocket City Links" standard in our kits. Mr. Chambers retired and sold the molds, but we know where they are....

The trick here is to make each set of pushrods IDENTICAL. This prevents any binding in a TRUE fully push pull system.

Each function (collective, elevator, and aileron) is a closed loop system from the servo to the swashplate. This adds redundancy, allows the elimination of slop in each function, and gives each servo tremendous power. It's not only pulling, it's pushing too!

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For setup purposes it is nice to have a flybar lock, this locks the flybar 90 degrees to the mainshaft and rotorhead.

When all linkages are setup properly, all arms are level or straight up and down, all bellcranks at 90 degrees, then you should be looking at 0 degrees of pitch at half stick on the collective.

This also sets up a perfect +- 12 degrees with NO binding, no grinding away at bellcranks or arms or rotorheads.

With a perfect mechanical setup, now you can electronically adjust for different setups such as 5 degrees for hover at 1/2 stick if so desired, and still have a bind free system.

That is one absolutely worn out MA pitch gauge. Works great!!

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We do have head buttons, but if you have an older head without the threaded holes, you will have to JB weld it in place. With the newer heads, simply bolt it in place.

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The tail servo connection should be secured in some fashion. I like to use shrinkwrap, 3/8" available from McMaster Carr works great.

It seals the connection, secures it, and is easy to cut off when needed.

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It's also necessary to secure the wire to the frame work in some way. We do provide for this in the kit with these neat little tye-wraps that slip onto the head of a bolt.

A piece of double sided tape under the shrunkwrap connection secures it to the frames under the gyro.

We suggest running the wire above the main gear to keep it as far away as possible from any rf interference, such as a gas engine ignition or a rubber belt running between 2 metal pulleys....