IMAC Double Build, Carden Pro 124" Extra 300 40%

[orthobird]

Well, my balance point is somewhere between 3.75" and 4"

at 4", it looks great. at 3.75", as in the video, just a tad tail heavy.

 

[capthis]

Cam you need to build one of these:

http://home.mindspring.com/~the-plumber/Vanessa CG Machine.htm

 

[rarcdon]

Cam,

I have a couple of suggestions on your balancing rig:

1. Make the plywood pieces significantly smaller and lighter. I think the size and weight of your plywood pieces may have an impact on the CG.
2. Make a spreader bar that is the same width as the fuselage in order to keep the plywood from "pinching" the fuselage as you pick up the airframe.

I've attached a picture of a similar setup where I used much smaller plywood pieces that were attached to a spreader bar with wire. This is a 30% Pilot Extra with a DA 70 in it which makes it a little easier to handle.

Don

 

[capthis]

That Vanessa Rig is so much simpler and can then be used on any airplane. and is accurate down to the 1/16th of an inch. After seeing one work, and seeing tha article that's how I'll do it on big airplanes that are hard to balance.

 

[Rusty 73]

Been out of town for past few days. Went to the National Judging School in Fort Worth. Here Russell, I met some Canadians while I was there, including Gordon, whom has helped me in the past with the build threads. It was nice to finally put a face on the names.

When I arrived yesterday afternoon, I saw a box by the front door. Not a huge box, but was too tired to open it. This morning, I was able to do so, and was excited to install them.

These are the lightest pilots. 1.1 ounces. I have installed both into each Carden. Both of the airplanes, right now, are tail heavy, so time to go to work, and see what happens.

View attachment 93228 View attachment 93229

The National judging school i bet was well worth attending, glad you met Gordon he is our past president of our club , very clam and cool as you expect from his profession. Was Brent Bullen there as well , he probably was .We only have one contest close to our city this year and most are in Washington, Oregon with one in Idaho.

I do like your pilot great choice to keep the CG in check.

 

[Bunky.F.Knuckle]

Well, my balance point is somewhere between 3.75" and 4"

at 4", it looks great. at 3.75", as in the video, just a tad tail heavy.

Nice T Shirt, Cam!

 

[orthobird]

Don, thank you so much, i will definitely make those mods. easy to do.

RUSTY, YES, Brent was there as well. Nice guys.

OK, success, I am very happy, the airplane is ready for the maiden.

I have it balanced at 3.75" aft of the wing tip.

I will maiden it some time. But 1st, I need to crank the motor on and tune the motor.

Soon, time to install all the radio into fuselage #2.


I think I will maiden both of them at same time.

Best regards,


Cam

 

[Rusty 73]

Thats good to hear about the CG issue and wasn't that a Taildragger t-shirt....

How far ahead did you have to move the batteries for balancing.

 

[orthobird]

Hi Rusty, yes, that was a taildragger shirt.

I did have to move batteries forward, and I made a tray that will allow me to move the batteries forward or back to make adjustments of the balance point. The batteries are now rear to the wing tube. When they were forward of the wing tube, the airplane was nose heavy. I will take a picture so you can see what I have done.

 

[orthobird]

This tray weighs 3.25 ounces, with all the wood used to mount it, and the velcro. the tray itself is made of G10 material sheet, that weighed 6 ounces. I then drilled out multiple holes in it, and got the weight down to 2.8 ounces. I weighed everything!! LOL, being OCD.