C of G with forward facing motor

[CustomPC]

Hi,

I finished the final setup of my Spectra-G with the motor in the forward facing config and i found that my CofG is very nose heavy.

I'm using Fromeco Arizona Reg and 4800mAh Peerless on the radio tray and the Hatori #957 pipe. Fuel tank is a Dubro 14oz.

I've tried moving the battery back to the right side of the frame but it's still nose heavy.

The #957 is designated for rearward facing motors and has a lot more pipe in front of the exhaust port.

Would the #956 pipe (which has less pipe in front of the port) move the CofG significantly rearwards?

I'm contemplating going back to rearward facing if i can't get the heli balanced.

Anyone else have the forward facing setup with correct CofG?

[ClayK]

Mine is rearward facing. :dontknow

[bigrcr]

I have the motor facing forward and the equivelent of the #957 pipe installed and the model is only slightly nose heavy. I have a 4000 Mah Duralite pack, regulator and switch up front and a 14 ounce tank on the tray behind the motor (the model balances slighly nose down with NO fuel.

-Are you using a 33" inch aluminum boom?

Later,

[CustomPC]

Hi John.

Define slightly nose heavy. ei if you pick it up by the flybar, how much does the rear of the skid lift before the front?

I have kit serial number 244 and using the boom that came with it. I'm assuming it's the 33" boom.

Without the canopy and with the Arizona reg and 4800 LiIon pack on the radio tray and a Dubro 14oz tank, the rear of the skids lifts between 1/2" and 3/4" sooner than the front.

If i hold the heli by the blade grips with heli on it's side and blades vertical with boom horizontal the nose drops pretty quickly taking maybe 1-2 seconds to rotate 90 deg downwards.

I tried the same checks with tank empty, half full, and full and it made little difference.

I removed the LiIon pack and the CofG is perfect. I could move the RX to the radio tray and put the LiIon pack it the RX pocket or the right side of the frames but my preliminary check indicates that it won't have much of an effect.

All this is without the canopy installed (i have not trimmed it yet until i decide which config to go for).

I'm wondering how much of a difference the #957 Vs #956 makes. They're the same pipe but the proportion of how much pipe is in front and behind the header differs by 3/4" which is only about 7% length difference. I have no idea how much of an effect on weight balance it has.

[bigrcr]

The difference/effect on weight is nearly zip, it just won't make much difference. I have one of each of those pipes and have seen no appreciable difference between them.

When I lift the model by the fly-bar, the rear of the skids will rise around 1/2" inch before the front does with an empty tank and closer to 3/8" inch when full (14 ounce tank).

Is your 14 ounce tank in the nose on the tray?? If so, get it off and put it behind the motor.

Later,

[CustomPC]

No, it's behind the motor.

Our setups are nearly identical. I don't understand why mine is much more nose heavy. Do you have a Hatori fitted now or the TRM?

I'm guessing the TRM pipe is lighter than the Hatori's and will move the CofG rearwards. Eagerly awaiting it's release.

[carey shurley]

I set this up so that with the engine forward, if you lift by the flybar, when the front of the skids just touch the ground, the rear of the skids are about 1" off the ground. In this config, it will fly very fast forward hands off, and track through loops and rolls very nicely.

[CustomPC]

Oh, so 1" is ok?

I was under the impression that it would be too much.

Thanks