Setup fail!

[TucsonFlyer]

I was looking forward to getting my P380 evo together as a bit of a spare parts special and it's turned out to be a bit of a disaster. I'm a bit obsessive about my helis and so i'm going to redo this thing and make it right.

As I mentioned this was a bunch of parts I had laying around or traded for:
CC Edge 75 lite (Re-used from an old 500)
BK 3001HV x3 (traded from a buddy)
BK 5005HV (traded from a buddy)
Xnova 890kv (new)
Pulse 6S1800 (traded from a buddy)

I'm pretty unhappy with the outcome. First off it's dreadfully nose heavy. With everything as far back as it'll go and still fit the canopy it takes 30g on the end of the boom to balance. That's crap. I don't really like 30g of lead strapped to the outside of the heli. Second, the servos are "well used" with two having lots of play in the output shaft bearing. They were free but are a bit crap.

So I want to get the dang thing to balance. The edge 75 needs to go, that's clear. Will 60A work? I can get a hold of a YGE 60 cheap which should be about half the weight of the edge.

Suggestions on replacing the BK's? I'm actually not concerned so much with weight on these. If they were heavier it might even help the CG. I was thinking a set of KST's? The 5005hv seems fine so I think I'll leave it alone.

Thoughts? Is it even possible to get a 380 evo to balance with the 890kv and 1800's?

[tshelby73]

Mine is slightly nose heavy with 1800mah and hobbywing 60a but don't notice it in flight.


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[mulchi]

Is the EVO boom heavier or lighter than the standard?

I have a standard and run it with 890 motor, MKS servos and HW 60a v4 ESC. GC is spot on with 1800 SLS packs.

[gilligansc]

How are you getting COG? 30g?

[mulchi]

Originally Posted by gilligansc

How are you getting COG? 30g?

Me? I think the reason might be that the SLS X-Cube are 293g vs. Pulse 333g

[TucsonFlyer]

Evo boom is supposed to be heavier than the regular tube which is why I wasn't expecting CG issues.

I'm getting CG by the turn it on the side and hold the head method. I know it's not 100% accurate but it's worked well for every other heli I own. It's clear that the CG is off significantly.

One note, I can get the CG much closer if I push the pack waaaay back but then the canopy is not remotely close to fitting.

I was initially really happy with the space under the canopy in the nose for something so streamlined looking but it seems like the restriction is really in how far aft the pack will go. Also the ESC box is a great idea but having something as heavy as the CC 75 lite (95g) that far forward really makes correct CG difficult.

[OnTheSnap]

I run the very light HW60 in my setups. Never has skipped a beat.

[gilligansc]

I'm getting CG by the turn it on the side and hold the head method. I know it's not 100% accurate but it's worked well for every other heli I own. It's clear that the CG is off significantly.

OK That is the most accurate way I know of. I am just surprised it is that far off...

[OnTheSnap]

Originally Posted by gilligansc

I'm getting CG by the turn it on the side and hold the head method. I know it's not 100% accurate but it's worked well for every other heli I own. It's clear that the CG is off significantly.

OK That is the most accurate way I know of. I am just surprised it is that far off...

It's a very very light heli. Very heavy pack, + heavy ESC will require some weight to be added in the rear (mini tail servo, etc).

It flies forever on an 1800mah pack, so going to a smaller LiPo is a real option as well.

[TucsonFlyer]

Originally Posted by OnTheSnap

It's a very very light heli. Very heavy pack, + heavy ESC will require some weight to be added in the rear (mini tail servo, etc).

It flies forever on an 1800mah pack, so going to a smaller LiPo is a real option as well.

Yep, I did end up with a mini tail servo. Ironically I might have gotten it closer with the regular boom by boom mounting the tail servo.

I'd really like to stick with the 1800's. I like as much flight time as I can get, especially with the big 890kv motor in there. Plus I took the time and effort to change over all the connectors on them

[Only Fine Helis]

I run the HW60 as well with Xpert micro servos all around with no issues.

[vtown nick]

I think people tend to get too worked up over perfect cg on smaller helis. Even if it's a little nose heavy you're not going to see it in high speed piro moves with the brain on this lil guy.

[flint723]

YGE 60 would be ok since it was fine in the P500. Not sure how many are using it though but it is still about the lightest 60a. But HW 60 v4 is only about 15g more. Both are quite a bit lighter than Edge lite 75. Plus Edge bec isn't the greatest, hit or miss on this size.

Talon 35 should really be ok in this heli if geared properly and not running crazy high head speed. Although no one is going to recommend it (not sure if anyone has even tried it).

[nickthenorse]

I've got:

Standard alu boom
HW v4 60a
Mini tail servo (MKS HV9780)
1800mAh GensAce packs (330g)

Heli is perfectly balanced with the canopy on

[Michaelinpr]

HW60 is plenty for this heli even at high head speeds and putting the sticks in the corners.

Why would you replace the BK's????? If the slop is just the bearing then get bearings. I use AVID RC for most all my bearings. Everything is usually $1 each. Or you can just get a gear set for each which will include the bearings plus your gears will be nice and solid. Basically you will end up with very close to new servos.

30g on the tail will likely mean you have around 100g extra upfront. Is the EDGE 75 that much heavier?

[TucsonFlyer]

Originally Posted by Michaelinpr

HW60 is plenty for this heli even at high head speeds and putting the sticks in the corners.

Why would you replace the BK's????? If the slop is just the bearing then get bearings. I use AVID RC for most all my bearings. Everything is usually $1 each. Or you can just get a gear set for each which will include the bearings plus your gears will be nice and solid. Basically you will end up with very close to new servos.

30g on the tail will likely mean you have around 100g extra upfront. Is the EDGE 75 that much heavier?

Yep, I already ordered new gear sets for all three BK's. Now I just need to find the time to rebuild them, but I certainly wasn't going to waste them! I'm considering moving them to the OXY3 I have under construction to replace the old old set of aligns I was going to use... so many choices!

Edge 75 is around 90g whereas the HW60 or YGE 60 is around 35g. Plus they're physically smaller so I can cram them further aft. 60g saved is a good start towards getting the thing balanced. I might also be able to move the ESC out of the ESC box onto the side or something.

I've had 5 helis on brain now and honestly I don't feel like the brain plays well with the CG out. It really seems to like the CG to be very close.

[OnTheSnap]

IMO it's not a Brain thing. If the CG is very bad, on a very light model, the heavy side has to dip on a hard collective input. Likewise, fast moving piro will have to have a slight wobble. Or if you bang collective while doing a piro it's going to dip.

Physics is physics. Depends on your dampeners, and how bad the CG is.

[TucsonFlyer]

Originally Posted by OnTheSnap

IMO it's not a Brain thing. If the CG is very bad, on a very light model, the heavy side has to dip on a hard collective input. Likewise, fast moving piro will have to have a slight wobble. Or if you bang collective while doing a piro it's going to dip.

Physics is physics. Depends on your dampeners, and how bad the CG is.

Yep, I wasn't meaning to ding the Brain, you guys do a fantastic job with it. Part of correct mechanical setup is setting the CG. A pilot shouldn't rely on the FBL unit to cover for poor mechanical setup.

[quinn]

that brick 75a esc is WAY overkill and probably the main cause for the cg issue. ive been running a hw50a for a long time, including speed runs at 3500 headspeed and 14.5 pitch, no issues at all. definately get a smaller esc. absolutely no need for anything larger than a 60a, which is still more than needed. 60a escs were standard for 500 size helis for a long time so 75a is double overkill. with a proper size esc, i think youll be pretty close to balanced.

[tacomaster]

HW 60 ,tareq 930kv 15 pitch @ 3600 rpm no issues at all. Mine is slightly nose heavy with a 60c gensace 1800 but I don't feel it in flight.