experience

	Raptor 60 my experience
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***Glitch problem appears to have been caused by the bearing in the clutch bell.
*Update on my Raptor 60 at the bottom of this web page.
NOTE: I really want to think ACE for their assistance. Unlike some businesses, they really want to help a person through any problems. They have offered me many good suggestions and encouragement through this radio problem. Thanks :)

Ok, I've had several ask me what I think about the Raptor 60. Well.... I wish I knew :) Ok, here's the story.
Construction/design: I like it a lot!
Flying: Not sure yet. I picked up my Raptor 60 kit Thursday 1-4-1. After work that day and the next I built the kit. Construction was easy and parts lined up good. Saturday morning I started installing the radio equipment. I didn't get finished as earlier as I planned on it Saturday. I had several of my friends calling to see how I liked it. A couple of them went to the local hobby shop and bought the other two (one ARF, one kit) that the hobby shop had, then came over to my house. I also had to stop what I was doing and go help one of the new airplane pilots get her engine running. Another delay was when I got the thing completed and found out I couldn't start it because of a defective start coupler. I took off the muffler and dropped the engine to install a coupler from my Raptor 30 spar parts. I put it all back together and got to hover for about 5 minutes before it was too dark outside. The next day, I flew two tanks at the house. The first tank I was mostly adjusting the engine/throttle curves/trims. The second tank I was still tweaking the controls but got to do some forward flight and some very powerful climb outs. It was feeling very good. Then I loaded it in the truck and met the others at the flying field. It was flying great, felt good at the field, but a 1/4 tank through it, I got a fast wobble, the whole helicopter wobbled. I landed, then found one of the bolts that holds the flybar in was loose. I had loctite on it, but maybe I forgot to fully tighten it cause I don't think it would have come back out on it's on. Anyway, I was glad to find this problem, but unfortunately that did not fix the wobble. I spent almost a couple of tanks trying some things to fix it. The other two Raptor 60's at the field Sunday were doing great. Bill Fillman was doing some mild 3D with his. The high wind we had didn't seem to bother these big helicopters. Bill said it was incredibly stable in an inverted hover. He couldn't get over the big power the Raptor 60 had. He was using an engine he had already used on another helicopter. Bruce Hampton got the ARF with the TT70. This seems like it will be a very good engine. Bruce only did some forward flight like me. We both have new engines and believe in taking it easy until the engine breaks in a little more. Neither Bill nor Bruce had the wobble problem I did. I also had a lot of fuel foaming that I was trying to figure out. Wednesday 1-10-1 I found out the fix for that. All I had to do was expand the fuel tank grommet holes from 12mm to 13mm. I got to try it the next day and the fuel foaming problem was fixed, but the wobble problem was still there. I had lubricated the rubber dampners in hope that that would fix it, but it didn't. One thing to note is that the wood blades that come with the kit are not matched. Weight, chordwise cg, and spanwise cg are all off. I did some balancing and got the spanwise cg and weight matched, but the chordwise cg was too far off. I called Nathan (Rick's RC) Monday and ordered some Model Sport 680's with the JR spacers. I talked to him about his Raptor 60 and he did not have any fuel foaming. I decided I needed to take out my engine and check the runout of the crankshaft and fan hub as well as balance. The hub is a little tricky to mount right on the high point balancer. I found that everything was balanced and little to no runout. So my next hope was that the MS blades would fix it. I received them Thursday and tried them out during my lunch break Friday. Unfortunately that did not fix the problem. That night I throughly looked over the rotor head. I found that I had installed the flybar control rod links backwards. Not upside down, but turned around so the link went on the opposite way. Normally this shouldn't cause a problem, but I noticed the link is closer to the arms. I tried it out Saturday morning. I got ten minutes of flight without any drastic wobbles. There toward the end is had a tiny bit, but not anything like what I was experiencing. So this time I filled the tank all the way up. I lifted off the ground and it seemed ok. I was running very rich so I leaned the engine a few clicks then took off again. Just as it was coming up, it did another one of those drastic wobbles. The wobbles have always had some collective movement so I decided to replace the collective servo. One of my friends also suggested that an out of balance head might cause something strange like that, so I took the head with main shaft off and check them on a high point balancer. They were good so I re-installed them and went outside to test fly. Again I got the same results. One of the other things I noticed Friday at lunch was that the Gem 2000 would go solid sometimes. I remembered that I had some 60 size head loaders so I installed them to check for an RF problem. I had figured that if I were getting glitches that it would have acted different, but I could not find anything else wrong. I'm really glad I had those head loaders, they allowed me to get right beside the helicopter and watch the servos. I found that all servos are twitching 1/8" to 1/4" just before lift off speed. The 60 size head loaders sure did come in handy. Next I will change out the receiver and see if that solves it. 1-14-1 This morning I changed out the receiver. I installed the one from Raptor #2. With the head loaders still on, I tested it out. At about half throttle the Gem 2000 goes solid, just like with Hitec receiver. One thing I noticed is that the rudder servo was moving back and forth so fast that it appeared to be a blur. The Airtronics 94357 is a fast servo. I wondered if it was the cause, so I replaced it with the Futaba 9202 I had taken off the collective earlier. I know this is too slow for the rudder, but all I needed it for was testing to see if the RF problem was gone. I ran it up on the head loaders again and it did fine. I headed out to the field to meet the others. I ran it there on the head loaders for several minutes and all seemed fine. I put the blades on and hovered for about ten minutes. At times it still would wobble a very tiny amount. I later went to hover again and just after take off, I had no control for a little over a second. As soon as I got control I sit it on the ground and killed the engine. I was tired of working on this problem so I just flew Raptor #2 the rest of the day. Next step is to take the servos and receiver and gyro out of Raptor #1 and install into Raptor #3.
1-17-1 I may have found the problem. I won't know until I get some non-rainy weather so I can check it out. If this works then I can't believe I missed such an easy problem. In my defense I want to state that I was not the one the installed the engine, a friend that was helping me worked on that part while I was building the head. Also when looking for loose bolts earlier, these are half way hidden by the pitch arm. I have tightened the pg 6 part (2) bolts that go into the top start shaft bearing block. The problems I was having was worse with higher engine rpm, so with these bolts being loose, that makes sense. I just wish I would have found them earlier, but they are kinda hidden behind the pitch arm...
1-18-1 I ran the helicopter with the head loaders this morning for about ten minutes before I had to go to work. All servos did fine. I would have put the blades on and hovered it at lunch, but it's raining outstide...
1-19-1 Ran 3/4 tank this morning before work. No problems. BC6 did not detect any glitches. Never wobbled or did anything unusual. At lunch I put the 3 9202 servos back on the aileron, elevator, and collective. After work I flew for ten minutes with no problems. Things are looking up :) Just wish I would have discovered the bolts much earlier hahaha
1-20-1 Still have the RF glitch problem. Shows up more when the right side of the helicopter is facing me. Collective goes up and the cyclics are causing a wobble :-(
1-20-1 I found the start coupler had backed off about a 1/16". And I ground the fan hub down so the clutch shoes would not drag. I had one person tell me this fixed a glitch problem in his wife's Raptor 30. I also moved the rubber band holding the antenna to the left side of the horizontal fin. This puts the wire at more of an offset angle to any other metal components.
1-21-1 Got to try it out between the rain for a few minutes. Still has the problem :-( I've done everything I can think of, I think I might have to get a PCM receiver. So far, everyone I know with a Raptor 60 has a PCM receiver. One person I talked to had a FM-PPM receiver and after getting one glitch on the collective, he switched to PCM.
1-24-1 I got to fly my Raptor 60 after I got home for work for almost 20 minutes. It got too dark outside to see very well. I took the receiver out of Raptor #2 (Airtronics 92777) and it flew fine at all angles. I have had it fly 1-2 tanks without showing up, so I just need to get more flights. I did change the receiver out before, but another problem confused the situation. I have an Airtronics 94357 on the tail and had the gain set at 100%. This servo is very fast and has high torque. At 100% gain, I later discovered the gyro was so sensitive to vibration, that the servo arm was moving faster then my eye could see. It was just a blur. I'm thinking the current drain was so much that it lowered the voltage enough to cause the Gem 2000 to go solid just as I would lift off the ground. I didn't realize this was the cause before putting the original receiver back in. At this point, with the Airtronics 92777 receiver in, it is doing fine. Weather permitting, I will try to get more flight time on it to see if the problem shows up again. Hopefully it won't.
1-28-1 r60_grounding.htm
2-5-1 Still have RF problem <under construction> will write up some findings I have made later...
3-4-1 It's been a while since I updated this. I tried many experiments and then ran out of ideas about a week before Ron's fun fly. I was hoping to talk to some others about RF troubleshooting. I was lucky to find Curtis' dad was there, Dave Youngblood. I talked to him a long time about how he found the Vigor glitch problem and about troubleshooting in general. He said he has had some helicopters in the past that he never did figure out. One was an Xcell 60 that started glitching bad after 650 flights. He looked over the Raptor 60 to see if there was a potential for an RF loop problem like on the Vigor, but did not see anything that would cause that. One thing that I mentioned to him that I thought about, but then figured that couldn't be it, was intermittent contact of the frame spacers against the clear anodizing of the frames. I told him I had abandoned that idea because if one frame spacer wasn't making contact, that at least one of the many others would. He pointed out that this could still be where the problem is since you don't look at it from the standpoint of electrical conductivity, but instead look at it in the sense of radio frequency absorption. It's a little hard to describe in text, but as the radio wave passes through a section of the frame with an intermittent frame spacer contact, it effects the wave in the way it did on the Vigor. I have been very busy but finally got a chance to work on it yesterday since it was raining and I couldn't fly. I had to take the helicopter apart and file down through the clear anodizing on the frame at each point a frame spacer makes contact. I tried it out today and unforturnately I still have the problem. My friend Bruce wanted me to try wrapping the receiver in metal. He heard about some of the airplane pilots doing this, so I tried it, but that did not change anything. I only know of 3 people (including myself) that are having a problem. Almost everyone that I have talked to or emailed are using PCM and not having a problem. The 3 that are, have FM-PPM. I did meet one person at the Corpus Christi that is running FM-PPM without any problems. He said he got one glitch on the tail on the first tank, but has not had a problem since. I have also heard there are others sucessfully running FM. If I just had one glitch every once in a while I would just go PCM and forget about it. But mine is bad enough that I'm worried a PCM might go into lockout. Dave Youngblood fully agreed that just covering up a problem with a PCM receiver is not the right thing to do. When those with PCM have lockout problems, they put FM receivers in to figure out the problem then put the PCM back in. I wish I had this problem figured out, it's really getting to be a pain. Thankfully I have two Raptor 30's that run good, so I still get to fly whenever I want, it's just that I would really like to have the extra power for practicing certain tricks. Here is a list of things I have tried:
1. Change standard on/off switch with an Ultra Switch
2. Unplugged the Gem2000
3. Changed out all electronics. The electronics came from Raptor #1 which was and still is working great. The electronics include all servos, gyro, battery monitor, and receiver. The on/off switch was not changed as it is an Ultra Switch that was installed earlier while trying to figure out this problem. The receiver that was/is in it is a Hitec SuperSlim FM-PPM on channel 49. I first tried the Airtronics 92777 receiver out of Raptor #2 that is also on channel 49. I also tried a Futaba R148DF receiver on channel 34 that came out of Raptor #1. The Futaba receivers issued in the U.S. use a negative pulse. This receiver was controlled with my Futaba 8UHFS radio. The other two receivers were controlled with my Airtronics RD6000. Out of these combinations, the Airtronics 92777 receiver did much better then the Hitec or Futaba receivers. This was also found to be true with one of the other two that's having the glitch problem. I don't remember what model receiver he had, but it was an Airtronics receiver controlled by an Airtronics Stylus radio. He also tried a Futaba receiver and still had the problem. The gyros were totally different, one was a Telebee and the other was a GY501
4. Tried different antenna positions. With the head loaders on, I took the antenna out of the holders on the skids and laid it forward extending in front of the helicopter. This made no detectable difference.
5. Used a rubberband to keep the start shaft from spinning. This made no detectable difference. The shaft to one way bearing in the clutch was still a possible area of intermittant contact.
6. Tried grounding the start shaft. This is only a semi ground since ground contact is through the bearings on the start shaft.
Notable things:
1.The glitch happens on throttle and collective mostly, aileron a lot, and elevator some. Have not noticed it on the rudder but the gyro could be dampening it.
2. It glitchs even at idle while on the bench. So this eliminates bearings in the tail and on the rotor shaft since none of this was moving.
3. Distance of transmitter doesn't seem to matter. This tells me the problem is local to the helicopter.
4. Radio channel doesn't matter, nor positive or negative pulses
5. Engine rpm seems to have a lot to do with it. I can get it to mess up at a certain idle speed, but if I go below or above that it won't mess up. Have also noticed this at hover also.
6. The problem does not seem to be with a certain type of engine, I have an OS 61LX and one of the others that is have the glitch problem is using a TT70.
Things I'm going to try next:
1. One thing that Dave Youngblood suggested was to run the helicopter without the start shaft. I will try that next, but if it does not mess up, this won't help me much because the start shaft maybe carrying the vibration over to another area. If I still get the glitchs then at least that will tell me it's not an intermittant contact problem with the one way bearing in the clutch. I have removed the E-clip from the bottom of the start shaft so next time I get a chance to try it out, I will crank up the engine then remove the shaft.
3-7-1 In discussing this problem with Curtis' dad, I let him know that from some of the experiments (that I have not mentioned yet on my website) that I really believed the interference was originating from the start shaft area. Dave suggested that I remove the shaft after I got it cranked up to see if that would stop the glitchs. So late last night I removed the e-clip that holds the shaft in. I cranked it up today after work and wanted to confirm the glitch was still there before I pulled out the shaft while it was running. I tried many different rpms but found no glitch. So now I'm wondering if the loose e-clip on the start shaft was the cause. It is metal to metal and the shaft might act like an antenna. I made a washer to place between the e-clip and the clutch bell bearing. I also filled the start shaft e-clip groove with epoxy and put the clip on with the washer up against it. This should keep the e-clip from vibrating around. The test today was with the head loaders on. I will test fly it tomorrow if the weather is okay. I sure hope this does it. I really want to get my 60 flying.
3-11-1 The e-clip thing didn't work, the helicopter still did it's little dance and got a collective hit while hovering. I'll report more after I try something different.
3-11-1 A couple of suggestions I have received are to re-grease the bearings on the start shaft and to change ou the engine and muffler. I can't get the clutch bell bearing out without damaging it, but I did grease the other two. I have been suspecting the engine, but don't have another one to change out. My flying buddy Bruce said he would let me try his next time we fly. That will eliminate the engine and muffler both.
3-12-1 If...when I get this problem fixed, I'm going to write a long web page on RF troubleshooting. I know radio problems are tough, but it shouldn't be THIS hard. I did find something yesterday. One person suggested relubing the bearings on the start shaft. He said a friend of his was trying to track down a RF problem on a GPH helicopter and eventually found that regreasing the bearings and locktiting them to the shaft fixed it. The bearings seemed to have enough grease in them when I was assembling the helicopter, but I figured I would take the bearing block and clutch bell out and re-grease them anyway. I felt of each bearing, just as I did when building the helicopter, and they all felt fine. I relubed the start shaft and pinion bearings. I could not get the clutch bell bearing out without risking damaging it, so I put the assembly together and then noticed it was rough turning. I took the two top bearing out and it still was rough so the bearing in the bell was the problem. While turning it some more it freed up. I suspect there is a loose piece of metal inside the bearing. It does not have a c-clip like other bearing I have had so I could not figure out how to open it up. I went to the local bearing shop and got them to order one. It should be here in a couple of days then I will try again and see if that solved the problem.
3-16-1 The bearing in the clutch bell seems to have done it (so far). I now have two tanks through it without the 'wobbles' I was getting before :) If I can get a third tank without the wobble, I will feel like that problem is fixed. It seems to me that the place in the bell that the bearing fits is too tight. I wonder if this damaged the bearing internally. It was too tight for me to put the new bearing in so I expanded it just a little.
3-16-1 2nd update: I got to fly one tank after work today and I did not see any glitchs. I hope it is fixed <knock on wood> :)
3-17-1 I got in 3 flights today so that makes 6 tanks without the wobble. It appears the clutch bell bearing was the problem. It feels soooo good to just go fly instead of working on it!
3-18-1 1 more glitch free flight.
3-20-1 2 more fun flights, I did the a bunch of inverted hover, forward flips, and tail slides. It performed very good, very stable, I just have to get used to the power the collective has.