Paul's Flight Thread

[Ken Jackson]

You seem to really be flirting with the ground. Your pyro flips are cool as hell. My last crash was inverted 3" off the ground. It was cool but not! All of it looked good but the whole time I was nervous watching. Enjoy the rebuild and sorry to hear about the goblin. My buddy crashed his TRex 700 yesterday. Link came off the main blade grip just as he went inverted.

Good luck,
Ken

 

[pvolcko]

I'm in pretty good control most of the time. At least around the ground.

Goblin started off a good 50ft up but it was a ways out from me (probably another 50ft out) and when it lost altitude during the piro flip attempt in my weak direction (nose right piro) it crossed into a background of trees and brush that my eyes couldn't adjust to in time. I had to trust it had done what I thought it was in the process of doing. Didn't work out this time.

Normal sources on parts both are out of stock on the tail blades. Going to have to order a size larger than normal (80mm normal, 85/86mm next up) and hope they clear the ground. Or look to some other suppliers... ah, found some rail 80.6mm blades. nice. Glad A Main still has memorial day discounts in place.

 

[Ken Jackson]

Yeah A Main is my main supplier, has been for a while. But I always check EBay with a part number on electronics because I've paid half of A Main price several times buying brand new parts of a motivated seller on Ebay.

If your not flying carbon fiber tail blades you could cut them, but your probably a carbon fiber only guy. I like the bright so I fly KBDD tail blades.

 

[pvolcko]

Yeah. On the 500+ size ones I fly CF only. 300X and lower plastic is fine. The rail 80.6mm blades should be good. Bit more than the 85mm ones I found, but with the memorial day discount they got going it ended up only being a couple bucks more. Plus I got the upgraded lynx main gear instead of the stock replacement (seen too many of them fail due to separation from the hex hub).

 

[pvolcko]

Well I've been fixing... and fixing...

Gob 500: Main shaft, feathering shaft, and tail feathering shafts were all a bit bent. Replaced. Tail hub/shaft looks good. I discovered a crack in the left side frame between the forward and rear motor mount bolt locations. I used some thin CA to seep into that and hopefully reconstitute it. It wasn't completely broken loose, but the CF was pretty seriously compromised. I'll keep an eye on it after a few light flights and if I have to I'll use some flat CF stock to make a patch plate. Not going to buy a whole new frame side just for that break, though. Stripped down and cleaned/lubed the main and tail head assemblies. All good inside. I've spun it up without blades on the bench and I'm feeling a pretty serious high freq vibe throughout the heli. I tried disconnecting the tail belt to see if that fixed it, but it didn't. Drive train feels smooth as silk. Making me think something happened with the motor shaft or perhaps the secondary shaft in the transmission block. I may drop the main drive belt and pully of the motor and see if the vibe continues. If it does then it is the motor. If it doesn't then may be the secondary shaft. Was hoping to have this one in the air today, but not looking like it is going to happen.

550X: Rest of the parts came in, but havent gotten to finishing up yet. Spent this morning on the Gob 500 instead. Hopefully finish off repairs here tonight and then do a maiden tomorrow morning before heading out to work.

 

[pvolcko]

550X: All fixed. Did two test flights today. First with no inverted (forgot to put some velcro on the bottom plate to help hold things in place). Second with inverted and some tame 3Dish moves. Need to tighten the blades and do tracking tomorrow. Also seeing some odd movements. Seems locked in and then the tail will shift a little or it will pick up a cyclic tilt. I doubt this thing has been as free spinning and true since it was first built, so may just need to tweak gains a bit. Put Edge 553 main blades on it this time around. Not barking quite as I expected, but like I said I need to tighten the grips a bit so may just be losing some bite due to the blades being pushed into a lead/lag position on hard stops, instead of holding and beating the air into submission.

Gob 500: Hopefully wrap up the fixes tonight. Doing the pully and belt drop to see where the vibe is coming from. I felt a vibe in the 550X, though, too, on the bench and it seems pretty stable in the air. May not be anything to worry about. Will see.

 

[cml001]

Good luck.. Sometimes tinkering and building is half the fun.. Other times it's like damn! Again! Really!.. Lol

 

[pvolcko]

Gob 500: Oy... So figured out what was causing the vibration I was feeling when I spun it up (no blades) on the bench... secondary shaft bearings are shot. Well at least one of them. I may have been running one of the belts too tight, causing it to have some torque on it and causing pre-mature failure. So I gots to order them up, along with some radius arms (one of the cups got dented and barely grips the swash ball now). So it isn't flying for another week at least.

550X: tighened the blades. Tracking looks okay. I may try putting a round in one of the blades. I think there is a slight mistrack, but it may be too small to fix with non-turnbuckle links. Still getting an odd movement out of the heli during a hover. I'm used to it being fairly locked in. It will drift, of course, but now... it is like it is holding fine for a few seconds and then there will be a subtle, deliberate movement off the tail or cyclic. Almost like a tremor movement. It isn't back and then forth, it just shifts a bit. More than a drift, but not a typical gain under/overshoot type movement either. I also need to redo my min/max pitch settings. It's lacking in climb out and pushout compared to what it was. And the blade barks are not what I expect from Edge blades on hard stops.

Getting there. Slowly. I never want to crash again.

 

[pvolcko]

550X: Finally got a nice day and time to fly. Blade tracking was off a bit so I fixed that. And then adjusted to get a good center 0. Still need to dial in a bit more pitch on max/min positions but looking okay. Also still have the odd "tremor" happening. I've been playing with moving the batteries around on the theory that I have a CG issue that I'm just starting to notice. It helped a bit, but the tremor remains. Now I've swapped out the swash plate. For most of the past year I've been flying on a swash that had a bit of axial play in it which developed after a tip-over crash I had early on with the heli. It was a small amount and so I never really sweated it. But now with everything more or less new on the heli in terms of mechanics, I'm thinking that the play is what is causing the tremor. IT is subtle and favors the backwards right direction. And seems to happen most when heading into a wind. All of that tracks with a swash that is a little loose and perhaps has more play at one point on it. Hoping this is it. Going to test fly it tomorrow. Last option is new dampers. Really last option, pull the motor apart and give it a cleaning and lube and bearing check.

Gob 500: So I had to rip the transmission block out and pull it apart. Bake the two plates and get the bearings out. While I had it out I checked the main shaft bearing in the bottom plate and there was a little notch in it too. Damn... Replaced the two secondary shaft bearings and was going to put it back together with the notch in the main shaft bearing since it was a single notch and subtle. Then I thought, "Well, I have this pack of 550X main shaft bearings here, might as well check if they are the right size." Didn't think it would be close. 550X (basically a 600) vs a 500 setup in the Goblin. Can't be right, could it. Well, guess what, Goblin 500 uses the same size bearings as the 550X main shaft bearings! (and same as a TRex 600, incidentally). So I pulled one from the package and have it in the freezer now. Will try popping it in after this post. Amazing luck. So I should be able to get this back together tomorrow. Hopefully vibe free.

Side note: My RC club (STARS in Phoenix, NY) has been replacing walls in the club house this past week. I took a day off on Tuesday and helped out for pretty much the whole day. Lot of work. Hottest day of the week, too. I caused a bit of delay mismeasuring on the last frame but luckily caught it before we were too far into it. Then screwed up a measurement again. BReak it back apart again and redo. There was a third screw up too, but that one wasn't so much my fault since there was a bit of a miscommunication on how we wanted to handle the discrepency between top and bottom board length and spacing of windows and stuff inside that trapezoid. So fourth time through we got it. The people who knew what they were doing had quit by then. So I'm happy to say we got that fourth wall insert up and sheathed in T111 and it looks good. This week, we finish the wall replacements and will be moving onto wiring upgrades. And we have our annual helijam coming up this weekend so got to get it finished up pretty quickly.

 

[Graham Lawrie]

Cool Paul

I was thrown twice this year so far looking for a fault that looked like gyro issue Both turned out to be bad bearings and play in the tail causing vibration transfer.

I work with bearings daily and would of said they were fine as the play was miniscule On my 550 the tail was so smooth I did not strip it first time round. When I stripped it there was play, and again I would have said acceptable. Changed tail shaft and bearings and it was brand new.

 

[pvolcko]

I changed out the tail shaft after the crash, but not the bearings back there. I checked them and felt no notching or other oddness. I'll check again if things aren't improved when I do my test flight in a little bit.

Also wondering if I screwed up gluing the torque tube bearings on the tube. Might not have been squared to the tube so they are wobbling in there leading to some highly dampened vibrations (through the rubbed grommets between them and the boom). May also explain jello like movement/tremors.

 

[pvolcko]

Well, the test flight hasn't happened yet. Weather got cruddy here. Should be able to get it out tomorrow (Thurs) though.

Gob 500: Putting it back together after replacing the main and secondary shaft bearings. I'm a bit miffed. Somehow one of the small posts that hold up the FBL mounting plate got stripped out. I have no idea how it happened since it was plenty tight when I took it apart and I barely got any torque on it putting it back together before the bolt started spinning. Tried a different bolt with the same result. I ended up putting a ton of blue loctite on it and got it so it at least had a bit of bite. Then I let it set up and zip tied that side down to the bottom plate. Seems sturdy enough for now. Can't believe I need to order a flipping standoff/post for this thing now. Anyway, got the head back on and together after replacing the radius arm link that was bad. Lubed up the OWB since I had that gear off. Got the servos remounted, etc. I haven't zip tied any wires down yet in case I need to take it apart again. Going to do a bench spin up tomorrow. I'm guessing I'll still feel the vibrations in it that I did before. I'll just put it back together and give it a try. The new main gear may simply have to wear in.

 

[pvolcko]

The saga continues...

Gob 500: Did bench test spin up. Still gots the vibes. I'm going to do another crack check on the frames tomorrow. I checked them over for over flex when I had the transmission off and didn't see anything bad. That or else it is just the new main gear needing to wear in. Also discovered that the main blade holder arms got bent a bit in the crash while I was setting up the head. I'm going to fly with them as is. I believe I have it setup so that the bend will not impact flight performance. And that looked fine from a rigidity/safety perspective. I'll do a nice long hover test when I remaiden it tomorrow. Some pitch pumps at distance in case something goes sideways. Should be fine though.

550X: got two flights in today. New swash helped a bit, but still getting some odd drifts. Will check the torque tube and redo the bearing glue if need be. Also, my 5300mah 6S glacier pack is dying. Can't make it 5min before it starts sagging badly (to the point of going into LVC protect mode and nearly crashing me a couple of times). On the bright side the EcoPower 60C 5000mah 6S pack I started using (replacement for the nanotech pack that died) is doing very well.

Got vid of the 550X flights. Will do a comp and post it later this weekend. Busy couple of days coming up with the annual HeliJam at STARS coming up on Saturday!

 

[EyeStation]

Careful with that Gobby tomorrow. And good luck!

 

[pvolcko]

I'm not worried about injuries or anything flying off of it. At least no more than normal. My concern is the vibe I'm feeling in bench spin up. Hoping I'm just misremembering it being smoother running on the bench. Or hoping the blades will help add some mass to the rotating bits and help smooth it all out.

Blade grip arms have me a little concerned about how it will behave in the air. But bent or not, so long as I have the links dialed in for 0 on both and matching min/max pitch then I should be okay I think. I'll get new ones ordered (along with the short posts for the FBL plate, which required buying a whole new plate assembly! argh!) after the maiden and making sure I don't need something else.

 

[pvolcko]

Okay. Gob 500 remaiden when perfect. Noticed some tail bobble at normal headspeed setting. BUt in IU1 and 2 it is not present. Blade tracking is spot on. Min/max pitch was perfection. Flys like a dream. So I'll order up the replacement grip arms for install later, but if it is flying this good with the bent arms I see no reason to replace. I'll keep an eye on them after each flight, along witht he rest. To make sure I didn't forget to LT anything.

550X: flew it today in very low wind conditions. Held very well. THinking I may need to up my cyclic gain a bit now that everything is so free and precise.

STARS (Syracuse Thunderbirds Aero Radio Society) HeliJam 6 tomorrow! First funfly I'm registered to fly in. Helped on setup of the field and facilities today. Weather is looking to be georg. Bought a pop-up canopy and a folding table. Will pack up some tools to have on hand (for others, I'd never need them <snicker>). I'm actually most concerned about charging up. I have a case. May try to slap together a charging case tonight with some zipties.

 

[pvolcko]

So the HeliJam is done. What a great day. Kyle Stacy and Chris Reibert were on hand (they're from the Rochester area, about 70 miles away), as well as a number of other local and regional pilots that have some mad skills. And then there were us wannabe pilots taking up some flight light time too.

I only took one video. I wasn't even planning to do that, but Kyle Stacy started off a late flight with a ripping big air maneuver: straight up off of takeoff about 500 feet or so, long FFF field right, maybe another 500-1000 ft, then put it into a steep inverted dive and level out about 2-3ft off the deck. BRing it all the way back in at high speed like that and around 10-20ft out do... something... didn't catch it exactly as I was now fumbling for my phone to start video. Small blade fart... speed it still going and the heli is now drifting, still inverted, perhaps tail is 180 from the level flight in, drifting to the ground. About 2-3 inches off, hard collective wall maneuver, climb to 10 ft. Sounded and looked amazing.

My video starts right after that.


[video=youtube_share;4I4ENNSX-XA]http://youtu.be/4I4ENNSX-XA[/video]


You'll note that 30s into it he does a tail left push out all the way back to the far far away trees. He actually clips a bit of limb off the top of a tree if you look close. It was insane. IF he screwed that up it would have been a long long walk through swamp land to get that heli back. The tree cutting maneuver was him upping the ante from some earlier fun:



That was Chris Reibert piloting with Kyle videoing.

Chris let Kyle fly his beautiful "Blue Eyes" custom paint Gob 570:

[video=youtube_share;AFrK79b48JQ]http://youtu.be/AFrK79b48JQ[/video]

In total we had 21 or 22 Gobling helis at the event. There's some group pics floating around, I'll see if I can find a few. I got a few of just the goblins lined up. Will post up a couple later on.


My flight report:

Gob 500: Flew great. Only put one flight on it, but it is locked in pretty well. Like the crash never happened.

550X: Getting better. I'm seeing some ail interaction on elevator tictocs. I'm going to play with the cyclic gain setting on the 7200BX to see if I can tighten things up. I'm pretty sure it isn't me sticking in some ail on the cyclic during them. I didn't see the same movement/creep when I do them with other helis. I also see the same kind of ail kick when I do inverted (tail up, skids in) rainbows.

TRex 700: Put in two flight on this one. I really am starting to like the 700 size. Flew great and since these were my last two flights of the day they were some of my best. Nerves had started to calm down and I was getting more in control of my collective (left thumb is always the jittery one when I'm nervous flying). Thats one thing about this 700 heli, use too much collective and it will jump all around the sky. Same with the Gob 500. 550X is more forgiving in this regard.

 

[pvolcko]

Just did the 550X cyclic gain adjustment and put a flight on it. Awesome. Tightened up the cyclic wonderfully. Half the time when I bail out of a tic toc it is because I get out of step on the stick movements (too close to the ground) and need to reset. The other half was because I was getting ail creep after a couple back and forths. Now, it is holding ail perfectly, to the point I was able to use rudder to successfully steer the tic toc left and right to keep it where I wanted it. Frikin awesome. Fast and slow piro flips were very nice too. Inverted rainbows were good when I didn't put any unwanted stick input in and got the heli lined up right before starting the front flip. Also started playing with ail input during the rainbow to correct for direction during the inverted phase. skids out tail down rainbow phase I've been correcting for a while now.

PRactice practice... Starting to get some improvement again after plateauing for a while.

 

[pvolcko]

So someone finally posted a picture of the Goblin crew at our HeliJam (thanks Jim!). Not bad for a small regional gathering, 21 Gobs! I only brought my Gob 500, or else there would have been 22! Mine's second from the right end. And I am the rotund happy guy on the right side. The guy in the white shirt in the middle (didn't catch his name) had two Goblin gassers there.

 

[stokke]

Cool!