Gyro gain on MCPXv2

[sarpilot]

Hi guys....
Are you guys messing with tail gain on this sled? I notice nothing in the manual about it and so far tail holds fine with no gain channel selected or adjusted.... thx

[65L88]

The gain is fixed on the mCPX. No way to adjust it without modding the 3 in 1.

[Epoweredrc]

Originally Posted by 65L88

The gain is fixed on the mCPX. No way to adjust it without modding the 3 in 1.

+1 no adjustments

[Elmosaurus]

The closest thing we have to adjusting gain is to change the tail boom length; increased length has an effective positive gain adjustment effect.

E.

[Ric66]

Originally Posted by Elmosaurus

The closest thing we have to adjusting gain is to change the tail boom length; increased length has an effective positive gain adjustment effect.

E.

Probably why some people have reported a slight tail wobble with longer booms.

[Elmosaurus]

Yup. I went to the +1" length about a week ago, and I noticed the slight wobble crop up too. "It's all about leverage..."

I think I'm going to go to a +.5" boom. I wasn't having horrible authority issues to begin with on the stock length boom, especially after going to a skeletonized tail fin. I 'think' that the combination of +.5", the skeletonized fin, and the cat5 wiring upgrade for higher current flow will be plenty for tail authority improvement over stock.

(plus, I haven't liked having such a rearward C.o.G. due to the much longer solid boom...knocking half an inch back off should help with that)


E.

[Liduno]

Originally Posted by Elmosaurus

Yup. I went to the +1" length about a week ago, and I noticed the slight wobble crop up too. "It's all about leverage..."

I think I'm going to go to a +.5" boom. I wasn't having horrible authority issues to begin with on the stock length boom, especially after going to a skeletonized tail fin. I 'think' that the combination of +.5", the skeletonized fin, and the cat5 wiring upgrade for higher current flow will be plenty for tail authority improvement over stock.

(plus, I haven't liked having such a rearward C.o.G. due to the much longer solid boom...knocking half an inch back off should help with that)


E.

You can fix the COG by trimming the plastic tabs on the side of the batteries so the battery will slide further forward.

I suspect your tail wag isn't from extending the boom, have you checked for a bent feathering shaft? lubing the bearings can help with tail wag too.

[sarpilot]

Ok thx for the replies guys…

Sent from my DROID3 using Tapatalk 2

[Elmosaurus]

Originally Posted by Liduno

You can fix the COG by trimming the plastic tabs on the side of the batteries so the battery will slide further forward.

I suspect your tail wag isn't from extending the boom, have you checked for a bent feathering shaft? lubing the bearings can help with tail wag too.

I thought about the battery tabs, but I tested what it would take to properly balance the CoG, and it required me inserting the battery from the front side of the skids, with the ends of the tabs still a full cm away from the front side of the battery holder in the skids. (way too far forward for my comfort if I crash; instant Pack Taco) What makes my bird so tail heavy beyond the solid, extended tail boom, is the fact that I went to a paper canopy; great for crash resilience and costs, but throws off the CoG since even when I double up the paper thickness, it's lighter than stock. (I may try tripling up the paper next time though; see if that extra layer of 20# paper makes a difference)

As for bent shaft or such, nah, I go over this thing religiously. I lithium grease my bearings every week or so, and I check the shafts (feathering and main) on glass each time. Old habits from my nitro days...

It's not so much a wobble, as a tiny slight wag of 'over-correction' whenever I make anything more than a corrective tail input. I'd call it a single tail 'bounce' more than anything. I'm probably being my usual OCD self trying to get it more dailed in than is actually possible... This bird flies ultra smooth and stable in all other regards; no vibes, no shakes or twitches, etc. I shouldn't really even be complaining....

E.

[ltburch2000]

I am glad I am not the only one seeing a little tail wag on an extended boom.

Given the choice of a little tail wag or massive TBO, I am gonna have to say I will take a little tail wag.

[sarpilot]

Ya I am liking it pretty much so far haven't tried any aerobatics yet. Had nasty crash into the wall couple days ago only damage was an ejected grip link and main gear moved down out of position. Pressed gear back on put link back on and good as new… 450 all I have to do is look at it funny and $100 in damage…


Sent from my DROID3 using Tapatalk 2

[Ric66]

Originally Posted by ltburch2000

I am glad I am not the only one seeing a little tail wag on an extended boom.

Given the choice of a little tail wag or massive TBO, I am gonna have to say I will take a little tail wag.

Yep, my reward for a little tail wag is finally being able to loop and fly inverted without TBO and the inevitable crash. Well worth it!

[Drivinfast247]

Originally Posted by ltburch2000

I am glad I am not the only one seeing a little tail wag on an extended boom.

Given the choice of a little tail wag or massive TBO, I am gonna have to say I will take a little tail wag.

Exactly. I only see tail wag when I hover. If you want to fix wag, dont hover.

[sarpilot]

Another devestating indoor crash..... dodging chandeliers and ceiling fans is not for the faint of heart. I keep hitting the damn Phoenix throttle hold instead of the redneck toothpick.....

Finally broke something. It seems like the main gear wants to move down every power on crash but pressing it back for 0 thrust corrects. Flung both FBL pitch links off this time with 1 snapped; wonder how many hits the swash and grips can take?

So far total damage is around 25 cents......

[Liduno]

The gear has a flat spot so make sure you line that up with the flat spot on the shaft, If you take the ink cartridge out of a bic pen it makes a great tool for pushing the gear back up.

For the links popping off you can put a little hot glue between the fingers on the head to keep the links from flying off.

As far as the chandelier and the ceiling fan go, fly outside..lol [I always tell myself that but I don't listen either..lol]

[sarpilot]

Originally Posted by Liduno

The gear has a flat spot so make sure you line that up with the flat spot on the shaft, If you take the ink cartridge out of a bic pen it makes a great tool for pushing the gear back up.

For the links popping off you can put a little hot glue between the fingers on the head to keep the links from flying off.

As far as the chandelier and the ceiling fan go, fly outside..lol [I always tell myself that but I don't listen either..lol]

Glue the FBL links???? One of my nut drivers works well for pushing the gear back on sort of like your idea....

Being as how the FBL links take all the damage so far in 2 hard crashes I am all about letting them destroy themselves.... securing them is the last thing I want to do.....

[sarpilot]

Also remember ball links must float for proper geometry in any helicopter. Gluing is a no-no. Maybe can get away with setup like that for hovering and stuff unsure but for maneuvers they must float on the balls.....

[65L88]

Originally Posted by sarpilot

Also remember ball links must float for proper geometry in any helicopter. Gluing is a no-no. Maybe can get away with setup like that for hovering and stuff unsure but for maneuvers they must float on the balls.....

The idea is to bridge across the ends of the antirotation pins on the rotor hub with a drop of hot glue. This holds the links in much like the Microheli hub does. Look up a pic of the MH hub and you'll get the idea. DON'T put any glue on the links themselves...

[sarpilot]

Originally Posted by 65L88

The idea is to bridge across the ends of the antirotation pins on the rotor hub with a drop of hot glue. This holds the links in much like the Microheli hub does. Look up a pic of the MH hub and you'll get the idea. DON'T put any glue on the links themselves...

You guys are still losing me.... If the FBL links fly off and prevent damage to other components why strive to protect them? Mine is a V2 and looking at it there is only 1 anti rotation device on L swash and it must float as well...

[wulfrun]

Originally Posted by sarpilot

You guys are still losing me.... If the FBL links fly off and prevent damage to other components why strive to protect them? Mine is a V2 and looking at it there is only 1 anti rotation device on L swash and it must float as well...

Calling them anti-rotation pins is a bit misleading. By rights they're pro-rotation pins, they force the links and swash-inner to turn. Take a look at the hub, the links pass between two "forks", one for each. The forks are open-ended, allowing the links to fly away. Putting a dab of hot-glue across the open ends of the forks stops the links flying off altogether, it doesn't stop them popping off the balls.

The other way (as I've done) is to tie them together with a loose piece of thread, looped over the top of the head. Nothing gets tangled but it's harder for them to fly off and get lost. This has paid for itself quite a few times over for me!