Roban AH-1W Cobra 700 Size Scale Helicopter

[PawPaw]

Now it’s right...took out the “2 ball lengths” Demon wanted & can see the offset Roban built in.

[PawPaw]

Well, looking at my pics again I see one of them makes it look like more pitch than it really is. The blade end view is the best one. Glad I brought this up because I’ve now learned I set the tail up wrong to begin with. I set the tail pitch to zero to match the main & didn’t pay attention at all to the slider position so wouldn’t know if Roban builds in offset pitch or not. It’s on the test stand & ready but my yard could breed ducks right now so good time to start over on the tail. Thanks for the info, y’all!

[DCORSAIR]

*Although I know heli rudder 101 says you should have some loaded in for rate mode... Just wanna throw that out there lol... I just never fly in rate mode...

Yes your right about that, I used to be a rate mode flyer, didn't like headiing hold, now I only fly in HH mode, but its when your gyro first initializes, its good to have it set with the proper tail pitch, makes scale take offs look nice, I hate when I see a scale heli go left or right all of a sudden on lift off and the poor pilots nerves are shot already because he has thousands of dollars into it, lol. If you have the tail pitch set right from the start and not rely on HH mode to straghten it out, it just makes it so much smoother transitioning into a hover, just the way I do it, we all have our quirks......

[sfcfury]

*Although I know heli rudder 101 says you should have some loaded in for rate mode... Just wanna throw that out there lol... I just never fly in rate mode...

[sfcfury]

I guess what kinda making me scratch my head in the first place is that, if you're heading lock mode, the tail should adjust to wherever it needs to hold the nose steady anyways... so where it starts seems irrelevant, unless of course it's staying pegged one direction or the other to maintain a straight nose.

[sfcfury]

I don't think I've ever put a pitch gauge on my tail ... Looks good... When it comes time to test it, if it feels like too much, maybe just back one turn out... But something tells me that it will be okay!

[DCORSAIR]

That does look a bit much for a two blade, my pic is my 4 blade tail rotor, my camera angle makes it look like I have more than it is, now my Magnum PI has the 2 blade and I will get a pic of that today and see the difference, got to thinking about your Demon instructions, maybe on certain helis they don't have the thrust angle built into the pitch slider and want you to offset the tail rotor yourself, yours should have the built in pitch needed when the pitch slider is lined up with the tail rotor shaft, not sure now that I see how much they are asking, I guess you will find out soon, just becareful when you first get it up to speed I guess, I also do something a little different than most guys do, I do my first spool ups on a piece of plywood using zero pitch on the main blades and a linear throttle curve which is a little less headspeed than normal flight so I can't get an accidental lift off, then I monitor the tail and see what is it going to do, so basically I turn everything on and let my gyro initialize and do not input any tail movement, spool it up and focus on the tail, the plywood will let it spin if things are way out of adjustment, I still don't touch the tail input and make your adjustment until you get it close, this is only if you get a bad spin or something like that, if your confident that everthing is good, then skip all my jabber, lol. This is my way of doing the first hover and flight setups and it will not work for everyone I understand that but just wanted to share a couple of things, of course blade tracking is a must do as well at the same time your watching the tail and getting it right.

[PawPaw]

Sorry for pic quality but maybe good enough to see....gauge shows 8.9* but didn’t have a target value to shoot for so that’s what 2 full turns on the link rod ends up being. Really doesn’t look as extreme as I first thought when comparing to DCCORSAIR’s pic so gonna call it good. Thanks again!

[PawPaw]

Thanks, guys....Yes, I just got it mounted to the test bed (copied yours sfcfury, of course) and will get it outside when the rain quits. I read good reviews of the Demon so don’t question it overall just think the “two ball length” instruction to be kinda vague. I see the benefit of a little offsetting tail pitch & will keep it set. I’ll measure it & send a pic later after wife frees me up a minute.

[DCORSAIR]

Sorry I can't help you out either, not familiar with the Demon FBL gyro, I just got into FBL and the Microbeast is my first gyro I have ever tried to set up, I don't see it in my instructions but I did add in a little left pitch as well and it seems to be perfect, I have no trouble lifting off nice and straight, I think they want you to put that left pitch in there, like sfcfury is saying, can you post a pic of how much pitch they are asking for and maybe we can see, here is my AH-6 tail rotor with the left pitch for take off, also where my pitch slider is.

[sfcfury]

To revisit an earlier post, I’m still trying to figure out this part of the Demon 3X FBL programming. When main is set to 0 pitch at 50%, Demon is wanting a “2 ball length” positive link adjustment, which I’ve done. I haven’t measured it yet, but 2 turns on the rod looks like a lot of positive pitch. I’m inclined to reset the tail to 0 to match the main, but thinking this FBL needs that mechanical offset for the gyro? Just seems like that much more travel to 0 & negative with a fixed positive dialed in but Demon’s wanting it. Opinions?

PPaw... I'm sorry I can't offer much input... just haven't dealt with the demon. Perhaps its just them loading in some pre compensation? B/c following the directions, cobra is a CCW rotor, so you would give two ball link rotations to left. Are you working on a test bed? Worse case is give it a hover test, if you don't like it, go two ball links back right.

[PawPaw]

To revisit an earlier post, I’m still trying to figure out this part of the Demon 3X FBL programming. When main is set to 0 pitch at 50%, Demon is wanting a “2 ball length” positive link adjustment, which I’ve done. I haven’t measured it yet, but 2 turns on the rod looks like a lot of positive pitch. I’m inclined to reset the tail to 0 to match the main, but thinking this FBL needs that mechanical offset for the gyro? Just seems like that much more travel to 0 & negative with a fixed positive dialed in but Demon’s wanting it. Opinions?

[PawPaw]

I really like this RC Logger so far. It displays pitch & roll at the same time & is easy to calibrate & zero. It’s shortcoming is the swash plate adapter & I discovered that’s what was kicking my butt. It’s robust & solid but not a really good fit on the AH-1W swash plate allowing a mm or two slop on the bottom. Easy to fix with a piece of aluminum tape but a proper solution would be to Dremel more clearance around the swash plate shaft bearing on the adapter plate. My original head settings were spot on to begin with but I changed everything in the Demon FBL before I discovered the adapter issue. It’s all reset to normal & time to switch gears to another challenge.

[sfcfury]

I am curious to see your data logger device you talking about. Some where along the way I came across the soko pitch gauge kit. It's a lil pricey to say its just a pitch gauge... but I really like it.

[PawPaw]

Oh, it’s just me I think. This Data Logger is precise like I want but probably more than is required when all said and done. The Demon just makes the process difficult because it’s software isn’t the friendliest but then again Futaba menus take time to master as well. We’ll get there.

[sfcfury]

I gotta take a break. I just thought I had the head setup really close....until I put this newly purchased Data Logger pitch/roll instrument on it. I’ve always 90’d servo arms, verified exact equal length on paired pushrods, and mechanically set their lengths to give a “perfect eyeball” level from swashplate to rotor shaft & grip screw parallel to shaft (with blades off). Always seemed to work before on smaller helis & kept me happy. Until today, that is. I been chasing digital zeros on this €£@#* thing all morning, which is made much worse by having to plug my Demon 3X FBL into my laptop to make subtrim changes because it won’t allow them in the Tx. I’m getting close to accepting -0.8* as perfect!

Yea Paw... you definitely gotta step away sometimes! What's crazy is that I have the Demon FBL as well (I got it b/c it was suggested as well), and long before I got around to tinkering with this cobra, I got to liking the spektrum FBL's. Sooo I have never even hooked it up... I think I had looked at a video, and downloaded the interface etc, and was just like bump that... so unfortunately I can't give any advice on what to do with it. I know I do zero subtrim adjustments with the 7210... not that helps you any...

[sfcfury]

F106.... man that looks awesome... got me all envious lol!! I really would like to do the traverse part at least on sync the flir and gun.... need to look at what you did closer on that... my problem is that I really don't want to add a different receiver... I think what really draws me to the AR7210BX is that it's all in one... taking care of all the normal heli stuff and you still end up with two AUX channels.

[PawPaw]

I gotta take a break. I just thought I had the head setup really close....until I put this newly purchased Data Logger pitch/roll instrument on it. I’ve always 90’d servo arms, verified exact equal length on paired pushrods, and mechanically set their lengths to give a “perfect eyeball” level from swashplate to rotor shaft & grip screw parallel to shaft (with blades off). Always seemed to work before on smaller helis & kept me happy. Until today, that is. I been chasing digital zeros on this €£@#* thing all morning, which is made much worse by having to plug my Demon 3X FBL into my laptop to make subtrim changes because it won’t allow them in the Tx. I’m getting close to accepting -0.8* as perfect!

[PawPaw]

Great job, F106. Turned out better than I had imagined!

[Beta_Grumm]

Exactly what Spinny said.