Another Roban 700 AH-64D Apache

[AtomicFrawg]

It looks stellar to me, AtomicFrawg ! ! By the time you're reading this, how did it go?

I just hovered it a few times to get the tunning started. It's going to be real nice once it is tuned properly. Just was chased off by some very big thunderstorms in south Louisiana.

I have a few more photos our local professional photographer shot that I'll be posting soon.

It seems I also need to run 95% throttle to get it in a hover. Using a scorpion hk-4530-450kv not sure if that sounds right.

Also anyone know when motion rc will be getting main shafts in for the Apache or know where I can get one? Its 45 bucks to get one shipped from Germany.

[Gravythe clown]

95%? God I hope something was not configured right. I’m using a 450 also. I think RcJetdude use a 525 or something close.
what was your AUW?
looks really good though.

i just finished building my test bed. So the mechanics are ready to test flight.

Gravy

[sfcfury]

I don't think a 450KV motor will be enough... RPM = 450 x 44.4 x 0.9 / 13.8 = 1303 rpm. At 95% power that's 1237rpm. Even with four blades that's just a lil too slow for anything more than a hover. RCJetdude is running a Tengu 4525-515KV (I went and got one myself lol) That will put you at 515 x 44.4 x .9 / 13.8= 1491rpm (1416 @ 95% pwr). From all of the different forums I have read and videos I have watched, I think 470kv is about as low as you can go with comfortably....

[Gravythe clown]

Lol and yet 450kv is the motor Motion recommends.
sounds like they need to update their recommendations for this bird.

Gravy

[AtomicFrawg]

I don't think a 450KV motor will be enough... RPM = 450 x 44.4 x 0.9 / 13.8 = 1303 rpm. At 95% power that's 1237rpm. Even with four blades that's just a lil too slow for anything more than a hover. RCJetdude is running a Tengu 4525-515KV (I went and got one myself lol) That will put you at 515 x 44.4 x .9 / 13.8= 1491rpm (1416 @ 95% pwr). From all of the different forums I have read and videos I have watched, I think 470kv is about as low as you can go with comfortably....

The problem I have with that is, the 450kv is the recommended motor. You are supposed to be able to run a head speed around 1000 to 1200rpm. I'm checking my pitch right now to make sure I'm at 0 pitch at half stick and 11 at full.
I'm using the new spektrum flb controller so I have some tuning to do tomorrow. I need to adjust my PIDs.

[sfcfury]

It seems like Roban lists 450kv as the recommended motor on most of their models... not that I have seen them all. I know that's the same thing listed on my cobra... at least on the paperwork when i got it. The manual I downloaded says this now: *Electric Motor:
10S-12S – 400-600Kv

[DCORSAIR]

So you guys are saying the 450kv is not enough to fly the Apache? I have the 800 Hughes 500 and in the parts selection my main pulley and motor pulley are the same as the Apache parts, just curious though, is the gearing changed in the secondary gear and causing your headspeed to be lower or is it because I have an extra blade, I'm using the Kontronik 700-45L and I have plenty of power to lift my big AH-6 and my Magnum PI version, these things are heavy to and it does it effortless almost, my Magnum PI is set to 70% and my AH-6 is set to 80% on my Kontronik 160, and I only use 1/2 throttle most of the flight, you guys have 4 blades, so why won't the 450kv work for the Apache? Now I'm not to smart on this stuff but was just curious why that is.

[sfcfury]

I honestly can't say. Just seems like it would be on the low end trying to maintain the headspeed... But then I've only dealt with the the AH1... with a target of 1350rpm with two blades. The AH6/500D... how much do they way? Even as a 800 size, it's still not an overall heavy bird huh?

[Gravythe clown]

I’ve lifted his AH-6, it’s around 20lbs. I was actually surprised how heavy it was.

gravy

[AtomicFrawg]

I flew it today a few times. It flies really good and smooth.

[Gravythe clown]

So what was the issue? Pitch not set right?

Gravy

[DCORSAIR]

Well, my digital scale only goes to 12 lbs, so I had to use our bathroom dial scale as well, batteries are 3 lbs, blades are 2 lbs, and the heli only on the dial scale is around 13 lbs, so not as heavy as I thought but still heavy enough, now I didn't count the ounces on the batteries and blades but they are over 5 lbs together, so I would say, just under 20lbs. I will be making me a way to transport them, I have a not so good back and believe me, these get heavy and are awkward to carry as well.

[AtomicFrawg]

So what was the issue? Pitch not set right?

Gravy

I'm using the new spektrum flight controller and the PIDs were way off and it was sloppy. It still needs 95% but is still smooth.

[Gravythe clown]

I changed my motor out to a 510kv. I’ll see how it flys this Sunday. I too had to be a 95% with the 450kv. Not much head room for the governor to work with.

also I did a test I think the ratio is 13:1. I simply spun the motor by hand and counted the rotations until the main rotor made one full rotation. It was right at 13.

ill let you know how the 510 feels after this weekend.

Gravy

[AtomicFrawg]

Soooooo. I found out the motor that came with the heli I bought was not the correct motor. It was a 450kv motor but a 14s motor. I switched to a 4035 560kv and what a difference. It flys so damn smooth on the new motor and the demon 3x. Very very very happy now!

[sfcfury]

[Gravythe clown]

Yeah I forgot to come back and post but the 510kv feels real good. I ended up with 30% headroom. I was at 20% but could hear the blades free spinning at times while the governor was backing off. So I backed off a bit in the head speed and that went away.

alao I’ve been working on a plarfoarn that will added in transport, assembly and tear down. I still have some things to mod on it I.e. couple carrying handles, Foam riser and strap down for the back and couple wheels so I can roll it around a little. But iron board is a great start.
Gravy

[Gravythe clown]

Well I still got that damn tail vibration, but I flew her today. She is impressive in the air.

https://youtu.be/cub8uj6MQ8E

Gravy

[PawPaw]

Nice flight Gravy! Looks awesome. I like your ironing board idea, too. Reminds me of the old Ferno EMS stretchers that would fold their legs backwards as you pushed them into the ambulance.

[Gravythe clown]

Thanks. Yep that’s why I picked that ironing board. It makes loading and unloading out of my van really easy.

best $45 I spent in this helicopter.

Gravy