Raptor 60 Construction Notes
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Raptor 60 Construction Notes |
| Raptor 60 1-2 The biggest problem I ran into during assembly of the lower frame was that the aluminum spacers are approx. 2.440" long. The Engine mount is also 2.440 wide. So it seems that the frames should be spaced at 2.440" throughout to keep the frames parallel. I was building the frames using a granite surface plate so I could build them straight. What I found was that when tightening up the #14 lower bearing subassembly, #15 cooling fan subassembly, and #13 Tail drive unit subassembly within the aluminum frames, the frames would warp and not stay level once everything was attached. What I found was that the plastic "bosses" (where you push the aluminum spacers into were too wide and causing the frames to flex. For example the Lower bearing block width measured 2.455" at one end and 2.454 at the other. The fan shroud has 4 "bosses" for the alum. spacers which measured 2.455", 2.452", 2.449", 2.446". The Tail boom brackets (BK0382 and BK0383) use a total of 5 aluminum spacers. After assembling the halves, the "bosses" varied in width from 2.440" to 2.465. Not only are the "bosses" too wide even taking into consideration the slight "crush" put on the plastic once it is tightened, but the bosses are not even uniform in size to all the other bosses. All the variation causes the frames not to build parallel or straight. I had to use my friends milling machine to re-machine the parts to the correct overall width. Also during the above assembly, I attached the tail drive unit subassembly (#13 on page 8) to the left side of the frame first. Keep in mind that the frames were already aligned using the other aluminum spacers, bearing block, and fan shroud. When I went to install the screws into the right side of the frame, all the holes would not line up and I had to slot all 5 holes. The "bosses" being too long and different lengths causing the frames not to be parallel may in part have caused this. 1-2-2 The 12x18x4 bearings fit too tight in the left and right tail boom brackets (BK0382, BK0383) causing the bearings to get notchy when you joined the halves together. The slots for the bearings were very tight and if you pushed the bearing in by hand, it would pop right back out. I had to open up the slots using a Dremel moto tool until the bearings sat properly in the slots. UPDATE: Received new Tail Boom Brackets (BK0382/0383). These too had the same problem as the previous, the slots were not as tight on the bearings but still tight enough to cause a load on them. I had to open the slots up in the new brackets as well, to get the gear to turn smooth once the bracket halves were put together. Gear mesh was too tight between tail drive bevel gear B (BK0363) and tail drive bevel gear A (BK0362). There is no adjustment here so I had to remove some of the shoulder on the back side of the tail drive bevel gear B (BK0363) using a X-acto knife so it would sit a few thousandths further back against the bearing. This worked well giving me a very good mesh. Make sure no part of the gear touches the bracket halves while turning it, as it may due to having been moved back slightly. If it does, just shave some of the plastic on the bracket halves down with a x-acto knife so the gear does not touch. The below 2 items may be causing some of the gear mesh problems you may be having. Gear #5 (BK0363) tail drive bevel gear B wobbles. Just put the bearings on the end and turn it while holding the bearings between your fingers and observe the gear. You may or may not have this problem. If you do, it's not as big a problem as the next one. Gear #6 (BK0364) also wobbles. The reason for the wobble on my gear is that the hole is not centered in the gear. Look at the front of the gear and you can visually see that the hole is off center. I have measured with calipers to verify this. An easy check would be to just slide the gear onto the #7 tail drive gear shaft (BK0365) and chuck the assembly into a drill and watch the front of the gear while spinning. UPDATE: Received new gears and they too had the same problem. The 12x18x4 bearings fit too tight on tail drive bevel gear B (BK0363). If you got them on, it would be very difficult to get them back off. The bearings which go on the tail input bevel gear (BK0372) fit too tight also. I just cut some of the raised ridges away with an X-acto knife to allow the bearings to go on using hand pressure only, cut one ridge, then cut the ridge that's opposite that one, then cut another ridge 90 degrees to the one you just cut and then cut the opposite ridge (removing a total of 4 ridges worked well). The shaft portion of my gear wobbled so much that I ended up chucking the gear (BK0363) in a lathe between centers and turned the shaft down so it ran true, then I had to make a sleeve to fit over the shaft so it would fit the I.D. of the bearings. 1-2-4 Fuel tank- My fuel tank had plastic spirals on the inside of the tank where the nipples entered, probably caused when the holes were made through the nipples. These plastic "spirals" could cause a blockage of either the vent or fuel lines. 1-6-2 Swashplate- the balls on the inner ring and outer ring do not line up (not in the same path). This could possibly cause some differential throw and possible binding. This is also a problem on the Raptor 30 swashplate. 2-1 The spindle caused the rotor head to be out of balance on the high-point balancer once assembled. The reason I found was that it was drilled and tapped deeper in one end than the other. #28 Flybar control rod (BK0344) split at the bottom when I installed it on the ball, even though I was careful about putting it on, and yes , I did install it using the correct side as they are uni-directional. Only one of them split, the other went on okay. Both of mine had the #1 stamped on them. Different batches or molds have different #'s on them. UPDATE: Got a new set of flybar control rods (BK0344), as I was trying to size them with my JR ball link sizing tool, another one of them split immediately. I managed to size the remaining one without it breaking. Both replacements also had the #1 stamped on them. 3-1 Tail Drive Shaft (BK0367) would not pass through the drive shaft bearing (BV0423). The I.D of the Bearing is .315" or 8mm. The O.D. of the torque tube varied anywhere between .314" and .3155". There was also some swelling of the steel tube around the area where the aluminum inserts were pressed in. The O.D. in those areas was as high as .318. There was no way the bearing could have even been pressed on without damaging the tube. The tube also had a slight bend to it, roll it on a flat surface such as a glass table and watch. Be careful if you try to straighten it, it bends very easily. UPDATE: Received a new torque tube. This one measured .313" O.D. The bearing fit over it very nicely, just as it should. The new torque tube also had a bend to it. The original torque tube measured 810mm in length, the new torque tube measured 815mm in length, this is not a major problem as you have the ability to adjust the boom out to compensate for the added length. 3-1-1 The pitch slider bushing (BK0345) had a good fit on the tail shaft, but once the tail pitch fork (BK0025) was threaded on, the pitch slider would no longer slide on the tail shaft, it was very tight due to the pitch fork compressing the brass pitch slider. It appears the O.D. of the brass pitch slider needs to be reduced slightly allowing the tail pitch fork (BK0025) to thread on more easily. While I was threading the pitch fork onto the brass slider, it was so tight, I thought the fork might break or crack. GENERAL (BK0082) collars were about .015" - .020" too long which allowed too much play in the tail pitch link (BK0026). I used a Dremel cut off wheel to shorten the collars. (BK0076) collar was also about .015"-.020" too long allowing too much vertical play in the tail pitch control lever (BK0346) The screws, which go through the above collars, are too small in diameter. It would be nice to have a shouldered type screw or bolt to reduce the amount of side play. 98% of the 4x8x3 bearings which are used in much of the bellcranks and mixing arms, etc. would get notchy once installed in the respective arms. The holes are a little tight causing a load on the bearings which results in a notchy feeling bearing. I had to open most of the holes up using my Dremel moto tool to allow the smaller bearings to be slipped in with minimum pressure rather than being pressed in ( you can use a tiny drop of CA to secure them if you want). Although I didn't think the original holes were actually too tight, they still caused a load on the bearings making them feel this way. I don't know if it's the due to the nature of the size of bearing or quality of bearing?? The clutch had a lot of sharp edges on it, which could cause premature liner failure. I removed most by using small needle files. It was also a little out of balance, enough which may cause some vibration when running at 14000 or so RPM. All the screws including set screws need to be cleaned using a solvent prior to assembly to remove the oily residue, especially if you are using locktite, which you should be. I used acetone to clean all the shafts and screws. Both the main gear and spur gear had some wobble. Nothing I could do to fix it. I even tried boiling them to relieve any stesses but with no luck. I thought the clutch to bell clearance was a little excessive. Mine measured .036 clearance. I reduced mine to .025 but I think around .015 to .020 (total clearance) would be good. The outline on the windshield for cutting purposes is not extremely accurate. If you cut on the line it will come out oversize, mine did anyway, and then you will have to take your time and cut further while trial fitting. The dimples in the windshield do not represent good mounting positions. Look it over while holding the windshield in place and make your holes accordingly. In the areas where the bolts attach to the metal frames without any of the supplied washers, I would make sure and use your own 3mm washers under all bolt heads. Looks like you are going to have to file away at the fan hub or have it machined so that the clutch shoes do not come into contact with the top of the fan hub. This is also the procedure on the raptor 30. I do not know if anyone is making shims for this yet or whether the shims will cause a problem since it places the clutch slightly higher. I prefer to file or machine the edges of the fan hub down so that my overall height will not change once the clutch is installed. Make sure and use a tiny drop of CA on the 2x8mm screws that are used to secure all the balls. One of the 3x18mm set screws (HME3-18B) which go into the tail rotor hub were longer than the other, just slightly but enough that it may cause a small imbalance. I just shortened the long one using my Dremel cut off wheel. Make sure and use blue locktite on all shafts that run in bearings. I don't recommend red locktite because of the difficulty in removing shafts in the future. Blue locktite will work fine. No big deal but the Thunder Tiger/ Raptor logo was not printed correctly on the boom. With the boom installed, the logo should be at the 3 and 9 o'clock positions. Mine were at the 1 and 7 o'clock positions. That's all for now. More as I continue! Raj Patel Ponca City, OK |