Hello,
I am interested to hear from owners of Axiome GP (Oxai)
what is the recomanded CG?
Regards
Amram Leshed
F3A Israel

I have two Axiome's and all that I did was put the gear in the planes where they suggested. I know they don't come with instructions but it is pretty self explanatory, I mean the plane is 99.8% built for you.  I am not unning CDI, I am running straight glow.  The planes balance perfect.  I did not have to move anything around inside the fuse.  Now if you are running CDI you will probably have to push some equipment behind the CG.  I do not have the exact CG of the plane because I don't measure it just because I fly my planes where I can get them to perform best and fell best to my likings.

Matt Kimbro</p>

thank you for your commant.
My Axiome is almost finished and YS170 CDI is installed.
Still it will be intersting to know extect CG location from wings LE or TE
Thank you
Amram

Hi Amram

I'm flying my Axiome with the CDI, an two separate batteries, here is hoy the setup ended, (pictures later)

CDI unit is about 2 inches from the firewall, CDI regulator ( duralite ) and CDI Switch, about the same place, receiver battery (duralite 2.150mah) in ons side of the rudder servo, CDI Battery, (lipo 950mah) on the CG

I started with the CG where Oxai recomends, but I had to move it back

weigth of the plane is 4.950g

Regards

TUNY

Hello Tuny,
thank you your reply. I am interested to see the pictures...
thanks
amram

hello Amram!

here are the pictures, hope they help.

according to Oxai, the cg is 190mm from the leading edge, mine ended up behind that

best regards.

TUNY

Hi Tuny,
thank you very much for the pictures.
I see on your model PowerBox Sensor double Digiswitch which is two independents switches and regulators ( I am planning to use same)
However, I see another small switch on the other side. Make I ask why do you need 3 switches?
Regards
Amram

Hi Amran,

I have been flying mine at 225mm from LE. Over the weekend I put enough weight in the nose (280g) to bring it forward to 190mm. The model felt more nose heavy but tracked better, locked into lines better and was more resiliant to wind. Snaps were the same spins were better. Unfortunately the model is right on the 5kg limit and the only way I can get the Cof G forward without extra weight is to get rid of the tailplane servos and extension lead and look at either a MK bellcrank / closed loop or just double closed loop. The elevator servos (Futaba 9650) weigh 30g each and removing them at that distance should be nearly as good as adding weight at the firewall. Problem is how to fit it with the built in formers at the rear fuselage. It does fly well at 225mm but I will aspire to try to bring it forward somehow.

Keith

Keith,

Add a small header tank near the firewall. It allows you to carry the extra weight when the plane is full of fuel, but it comes back out when you drain the plane for weighing. An empty header tank will weigh much less than the weight you are carrying, and accomplish the same thing without hurting before weighing.

Arch

This would have to be the sneakiest thing I have ever heard of Absolutely brilliant !!!!

Just another thing to get up the electric flyer's noses.......

Hi Arch,

Thanks for the great idea, I'll see about giving it a go?

Best

Keith

Dear Arch
The Header tank is a brilliant Idea....
Regards
Amram

Arch,
Can you post pictures of the header tank and pluming scheme?
Amram

Switching to Electric..... I tried..... :-)

Hi Amram

I use the powerbox switch for the receiver, I like redundancy, one battery with two plugs and the energy goes to the receiver from two independent systems, the smaller switch is for the CDI with a separate voltage regulator. I know is not necesary but it gives me peace of mind...

Best regards.

TUNY

pd: that header tank idea is brilliant!!!!

Well,
It came out with all accessories at place exactly 190mm of the Wings LE.
This with PowerBox Double sensor switch and 2 x LiPO 1320MAH Bat
Located under the Canalize (Can be changed by removing the Canalize)
APC 19X11 prop, and CDI unit just behind the Firewall.

This will allow me to work 190mm of the LE and move it backwards by moving
The CDI unit backwards if needed. The total weight ready for lift-off is 4920.
I hope this will work fine.

Thank to all helpers….

Amram

Nothing sneaky with this, a lot of peoply been doing this for a long time.
But it is a little sneaky when one of us 'E' guys installs a fuel tank to sort our CG ,which we can.[sm=punching.gif]

here 2 photos of the new machine...

Amram,

Sorry for the delay. Was moving into a new house all weekend. I'll see if I have some old pictures. Now that I'm flying the CDI, I don't run the header tank as the ignition unit weighs enough to accomplish what I want. Basically here is how it is done.

From the engine a line goes into the header tank. If you can find really flexible fuel tubing you can use a clunk line. You don't need one as the tank will be full when flying, but its the only way to get the fuel out later. Out of the vent line on the header tank, run a line back to to the pickup line of the main tank. Then the vent line is open to the atmosphere as normal. Make sure you fuel / drain line is between the engine and header tank as you want the header tank to fill, then the overflow will fill the main tank. Works great and also means the engine doesn't have to draw fuel as far (not a problem with a pumped engine).

Really simple setup,

Arch

Are you saying the SEcond vent line off the main tank vents to the atmosphere??

There is only one vent off of the main tank. Basically you are just inserting a header tank between the engine and the main tank. On the main tank, the vent is open (or a check valve, whichever way you want). The clunk line from the main tank goes to the vent of the header, then the clunk line of the header tank goes to the engine. There are no more open lines with this system than there would be with just a main tank.

Arch

lHi,

I've now changed my elevator setup and installed a closed loop onto an MK bellcrank. Removing the servo cable saved 30g and two Fut 9650 servos 30g each. I say saved, actually its just redistributing the weight forward as I've used a 9151 servo that I had handy to drive the bellcrank, which weighs 50g. So I've not saved weight but the combined effect moved the C of G forward by 15mm. The model is much improved, sits better in the air, doesn't lose heading as easily and transitions between the reverse spin better as well. Definitely worth the headache to fit the bellcrank.

Keith

Keith, thank you for Sharing. My ship CG is now 190mm exactly (as suggested by Oxai).
Next week I will take the test flight this way. If needed can move the CG forward by moving the Throttle servo from the inner tray forwards to the Muffler tray or by moving the Batteries which are now placed on a tray under the Canalize opening.
Moving CG backwards can be done by moving the CDI unit backwards. (Now it is placed right behind the Firewall).
I will report after the test flight.
Regards
Amram Leshed
F3A Israel