Another Roban 700 AH-64D Apache

[sfcfury]

Hey I like the ironing board idea! lol... Somebody actually posted this musical keyboard holder as their plane stand...

https://www.thomann.de/gb/millenium_ks1010_keyboardstaender_economy.htm

For the price you can't beat it... I picked up two of them lol... I like the straight bars... and it feels really sturdy.

OAN, about your vibration... So I started getting back to my cobra build this weekend (I had been procrastinating b/c I needed to install the helical upgrades etc, and work, and hurricanes etc lol), and when I got it back on the test bed, I had a pretty wicked vibration in the tail. I went thru all kinda hell previously trying to get it (the tail) to calm down, which resulted in some over the top blade balancing etc. So, I was just back tracking... checking everything etc. I take the Mains off and do a run up (tail blades still on), and the tail boom is pretty much smooth as silk. Put the main blades back on, and its like Michael J Fox is holding the tail boom... I recently ordered a set of RotorTech 760 main blades, and although not as bad, the same result. To be honest getting pretty pissed... b/c I really can't determine the cause...
So I am running the CC Talon HV 120. I have set rpm governor running, and I have three head speeds set on my idle up switch. 1050 (just to get it spooled up), 1300, and 1400. B/c I kept getting so much vibration at 1300, never pushed up to 1400. After the 3rd time yesterday of talking things off looking, double checking etc... I just tried the 1400, and oddly enough most of the vibration went away.
So perhaps try some different head speeds? It does seem to be a lot of vibration you're having though... like to make me think something mechanical is out of whack... could be just one blade out of track.. or something like that. Perhaps start with no blades, see if there's any noticeable vibration in the tail, b/c if there is, the blades will just amplify that I would think.
I did one more check of things last night, changed my tail grips out (I had been planning to do that), and reset my governor to 1350 and 1410. Today when I get home I'm going to try it and see how it looks.

[Gravythe clown]

Well pulled it all out today. Everything was tight and gears didn’t look worn. I had put some lithium grease on the metal gears originally, but since have bought some Bezz grease. So I took the whole tail drive section out all the way to the plastic gear on the main frame. Cleaned everything up and did visual inspection.
at this point I made some adjustments and modifications.
first I switch the first umbrella gear from top drive to bottom drive. This as most know will correct the tail rotation.
I then had excessive slop in the main torque tube so I sanded about 3mm off the boom. The slop is now gone. I did have to rotate the rear boom support 180 and drill a hole in bottom of boom for the set screw. I really don’t think the 3mm will effect its fit in the body. I did check to see if it had room to move forward before I did this mod.
next I need to pin both sides of the torque tube.
I added bearing in the tail riser boom for the short torque tube.
I have a cascading tail coming next week I ordered from Michael Brown.
oiled all bearings with scorpion bearing oil. And greased all metal gears with bezz grease.

I put everything back on my test bed and ordered another castle bec pro and receiver for the test bed. That way I don’t have to pull all that out of the Apache body.

next I want to start working on a removable replacement for the two pitot tubes. I’m tired of breaking them off while either moving or during transport of the Apache.

Hopefully next weekend I can start test flying her again.
I’ll post again after I’ve gotten read of the vibrations.

Gravy

[AtomicFrawg]

Teaser from today's AOA fun fly

[AtomicFrawg]

[DCORSAIR]

Looks awesome, between you and Gravy showing his off, I might have to build me one............

[AtomicFrawg]

Looks awesome, between you and Gravy showing his off, I might have to build me one............

You wont be disappointed. If you do, make sure you beef up the landing gear mounting points.

[Gravythe clown]

Looks great. Man I do love how she looks in the air.

so I now have the torque tube pined. I actually tapped and threaded a 2mm machine screw in both sides. Then added some epoxy to the screw as I screwed them in. Finished them off with a little grinding and sanding. Need to now do the short torque tube.

Bec and cascading tail should be here this week. Hopefully I can start testing the mechanics again.
I hope that vibration is gone. I’ve done everything I can think of.
blades rebalanced (weren’t bad, but did it again anyways)
checked every screw. Got read of any slop I could. Check torque tube bearings and locations reset. Added bearing to short torque shaft. I think I’ve gone through it all. All gears looked good and not overly worn. So I hope this does it.

Gravy

[PawPaw]

Just curious....if you slowly rotate your tail rotor with a finger, do you feel a “snag” (don’t know a better word) at some point in the rotation, or is it completely smooth 360*?

[PawPaw]

Forgot to add: I didn’t know my Gartt 1220kv’s PWM rate so had it set to “Outrunner” in my CC Talon 120. Had a wicked vibration I couldn’t track down. Completely by accident and after I located the Garett’s PWM (8), I reset the CC & vibrations were gone. Had no idea the PWM rate could affect motor vibes like that, or even suspected the motor was the culprit to begin with. Oh, well....I’ve always learned the hard way so too late to change now.

[AtomicFrawg]

Looks great. Man I do love how she looks in the air.

so I now have the torque tube pined. I actually tapped and threaded a 2mm machine screw in both sides. Then added some epoxy to the screw as I screwed them in. Finished them off with a little grinding and sanding. Need to now do the short torque tube.

Bec and cascading tail should be here this week. Hopefully I can start testing the mechanics again.
I hope that vibration is gone. I’ve done everything I can think of.
blades rebalanced (weren’t bad, but did it again anyways)
checked every screw. Got read of any slop I could. Check torque tube bearings and locations reset. Added bearing to short torque shaft. I think I’ve gone through it all. All gears looked good and not overly worn. So I hope this does it.

Gravy

I did both torque tubes using red Loctite and drilling / tapping 2/56 pan head bolt with a lock nut on each end. Long and short shaft.

[Gravythe clown]

Just curious....if you slowly rotate your tail rotor with a finger, do you feel a “snag” (don’t know a better word) at some point in the rotation, or is it completely smooth 360*?

completely smooth. Also Turing the tail rotor blades pitch by hand on one blade is smooth too.

I’ll double check my CC settings but I’m sure I have it set for the right frequency the Align motor wants.

gravy

[RCjetdude]

Such an iconic look. Excellent job!

[Gravythe clown]

Got my cascading tail today from Michael Brown. It’s a thing of beauty. All I need is my 20Amp bec for my test setup and I can start testing it out again to see if the tail vibration is gone.

Gravy

[AtomicFrawg]

Michael Brown is the man.
Recieved my cascading tail. Now off to paint and fly this weekend.

[PawPaw]

This thread is therapeutic: I’m almost cured of my AH-64 anger. For many years the Texas National Guard has flown a daily training route from Ellington field to parts unknown...directly over my house. AH-64s. At 500’. Sometimes 2 in formation. Never faster than 80kts or so, which I’m certain is intentional just to spite me. Always at 6pm in the summer & 4pm in the winter months so I can’t see their nav/formation lights, which is also intentional. Always approach from Tabbs Bay so nothing can mute the sound. I swear the FCO shot me the finger last month. Yes, that was intentional too. So.... keep posting updates & pics of your Apaches to force me to buy one, which, of course, is intentional.

[DCORSAIR]

This thread is therapeutic: I’m almost cured of my AH-64 anger. For many years the Texas National Guard has flown a daily training route from Ellington field to parts unknown...directly over my house. AH-64s. At 500’. Sometimes 2 in formation. Never faster than 80kts or so, which I’m certain is intentional just to spite me. Always at 6pm in the summer & 4pm in the winter months so I can’t see their nav/formation lights, which is also intentional. Always approach from Tabbs Bay so nothing can mute the sound. I swear the FCO shot me the finger last month. Yes, that was intentional too. So.... keep posting updates & pics of your Apaches to force me to buy one, which, of course, is intentional.

MRC has only one left and whos knows when the next shipment will be........

[Gravythe clown]

I think it has your name on it DCORSAIR

Gravy

[DCORSAIR]

Oh so tempting.....

[PawPaw]

How much a decent kidney fetching these days?

[sfcfury]

Well you can always sell a testicle for 35K lol...