Brian C
Heliman
Location: Houston, TX
| My notes as I assembled a Knight 50 Plastic version as sold in the USA. I started flying RC helicopters in 1980, a GMP Cricket and then a Horizon 60 (no flybar), before gyro’s were out. I remember opening the magazine and seeing the add for the first Futaba Gyro, my flying certainly improved by an order of magnitude, and sold the rest of the group I was flying with on buying one too! Sold all my Heli stuff in 1984 and picked them back up again 5 years ago with a Raptor 30 V1, then moved on to a Freya 90. The following is my viewpoint based on assembling the one kit, as they say, your mileage may vary.
Problem Items:
My kit came with an improved alum. T/R drive gear, after changing it out, the new alum. gear rubbed the bottom of the main gear to the point you could barely turn the main rotor by hand. I trimmed .030 off the bottom of the new alum. gear to provide clearance and filed a flat spot on the shaft for the set screw, the original plastic gear used a roll pin. I also added shims between the lower bearing and E-clip at the bottom of the shaft to eliminate verticle play in the assembly.
Center swashplate servo hits servo tray on bottom, I added a servo plate under the grommets to raise the servo up enough to clear. Using Futaba S9252.
Good Job:
Swashplate is all alum. and the bearing has no play.
Main gear mesh is great, although the main gear is molded, the teeth are cut. My main gear has very little wobble.
Assembly by factory looks good, locktite as needed and the screws are not overly tight.
I only found one screw on a mixing arm that was loose.
Clutch/Fan Hub runout was less than .001
Main Blade Hub made from Alum, and also clamps on main shaft.
Inner air baffle to help direct airflow over cylinder head.
Thrust Bearings in T/R blade grips.
90 degree setup on linkages.
One piece Engine Mount.
Socket Head bolts, only a few Phillips head.
Main Frame design, largely a scaled down Freya, looks strong.
Parts Prices
Manuals and Parts List are posted online.
Items I would like to see improved:
No magnet spot molded into fan for governor.
Tail Pitch Lever screws are milled smaller in diameter than slot in the Tail Pitch Plate is wide, replaced with Hirobo part.
T/R shaft had side play between bearings, I added a shim to correct.
Clutch rubs top of fan hub, no relief cut in hub or spacer shim provided.
Fuel tank clunk hit back of tank. I was going to replace that line anyway with the black Hayes tubing, trimmed shorter to provide some clearance.
Servo screws do not have built in washer and will not fit through eyelets. I ended up leaving the grommets and washers off, and using Thunder Tiger servo plates. Some say this works well, I have never used this method before. I like servo screws with the built in washer.
Canopy grommets provided have too large of an ID, I replaced mine with some from the hardware store that fit.
Canopy is rough on the outside, smooth on the inside, should be other way around.
Blade bolts have too much thread, should be all shank thru the blade and grip.
Fuel tank fitting hole is too small; I opened mine up with a drill to 5/64.
Short one ball and screw. Came with a small bag of 5 each, 3 went on cyclic, 2 went on throttle, nothing provided to connect the T/R pushrod to the servo.
Servo Frame looks to be just plastic without any fiber content, I expected it to be fiber filled.
Tail Rotor servo mount flexes some, adding a couple of webs on the back would help.
Outer bearing in T/R grips do not have any shields, just a plain open bearing. I will eventually replace them with a shielded set.
Rigging:
There are two holes in the mixing arms, comes with blade links in the outer holes, you need to move them to the inner holes. With this setup you get the following:
+ or – 12 degrees collective with 6 degrees cyclic movement of the blades.
You also have a 1 to 1 flybar ratio.
However, at full pitch/cyclic you can twist the main blades and the mixing arm goes over center, not sure this would ever happen in flight.
If you drill a new hole on the mixing arms 3mm inboard of the existing inner hole, the setup changes to this:
+ or – 14 degrees collective with 6 ½ degrees cyclic.
You also get a 88 % flybar ratio, flybar moves 15 degrees and the blade moves 13.
Link from swashplate to mixing arm needs a small bend near top just below threads to make rod end clear set screw in paddle pitch arm.
Misc:
Balls links and T/R pitch links a little tight, I resized mine with the special tool. Depending on how fast they loosen up/wear out, I may not the next time.
My Paddles have a very sharp leading edge, I rounded mine off some with sand paper. Weighed 22 and 21.8 grams.
T/R blades are very flexible and short, weight 5.1 grams each. I am trying the Hirobo 92mm blue blades like the Freya uses, 7 grams each.
Came with red dampeners installed, I bought the clear ones, going to try the red first and then replace with the clear.
Auto bearing covers had a lot of drag on the Auto-Rotation Drive Shaft, I sanded I.D. of mine to loosen them up some.
I plan on adding a strap behind the fuel tank.
Spindle is 6mm.
Radix Blades both weight 136.4 grams.
Total dry weight of my heli with OS50 Hyper, MP II, GV1, GY601, 1700ma Nicad, 9252’s, 8 lbs exactly.
Assembly Manual and Parts List:
If you have assembled a Heli or two, all the info you need is there. Both of them have a few errors: Assembly Manual shows assembling items that already are; Parts List is missing some parts on the machine and shows others that are not. They need to add sizing to the parts manual, the bearings just say “bearing”, no dimensions.
Final Thoughts:
I am sure I have forgotten or missed a few items. Most issues I would like to see corrected or improved are not exclusive to this model. Many of the items I would like to see changed may in fact not improve the performance or longevity of the model, it is just my version of correct. I was hoping it was going to weigh a little less. They got the big items right, like the gear mesh, thrust bearings, clutch runout, and metal hub, ok the T/R shaft needs a little work. I like the overall design, and the price is right too! |
