Fat Binary

Hi Chaps, I thought I'd just weigh my binary and it comes in at AUW 161gm which is 6gm over the recomended weight but i'm surprised it's so light considering how much glue and glass I used! So all in all I'm quite pleased but the C of G is 2mm in front of where it should be.
Do you guys think that will be a problem?
Marty

it really needs to be 0mm in front of where it should be

Yeah I know but if it is a bit nose heavy is it going to affect the flying charicteristics drastically? I can ballance it perfeck if I put a 4mm x 20mm bold on the tail or a 3mm x 20mm bolt in the end of the boom but thats adding weight, or am I being paranoid?

If it's nose heavy you might not have enough elevator authority or run out of elevator on the landing, can't you arrange the battery a bit further back.

there's only a 2mm range between the CoG anyway 55mm-57mm, if you are 2mm in front of 57mm then it's 4mm out.

Yes you are paranoid

Thanks Rich. I was a bit of a job to shoehorn the Batt', rx & servo in the pod but I might be able to move the Batt back a little, I'll give it a go.
As for being paranoid, well that comes from inexperience. The more I do the more I will (should) learn! lol

Sorry I thought the paranoia was just a general question not whether you were paranoid about the glider.

mine was at 57mm for the vid that everyone said looked nose heavy so im now at 60mm

Go figure

M

What's the all up weight, to put Marty's mind at rest

Oh phaff! I just did some jiggery pokery and moved the battery back and got the C of G bang on 55mm and now you say it aint enough! pants! I'll see how it goes, my incedence may be different to yours! If it is nose heave it'll be a bolt up the boom now.
Well I have flaps mixed on the throttle os as I throttle down (towards me LOL) at about half throttle the flaps come progressivly down .... smart eh?

proportional flaps Eh, full flap down throttle, no flap up throttle

Don't forget to roll out of the throttle Marty

A forward CG is better than one that is too far back

Try it with the CG where it is. Start off with some firm (but gentle) javelin type launches, or test glides, to get the elevator trim right. You'll find that as you home in on the right trim for a firm push of a launch, then it requires less up trim if you give it a much harder launch. If you then progress to a full on discus launch, a nose heavy model will try to climb very aggresively on the launch (or you will have the launch trim right, but as you are gliding around, it will be nose diving).

Running out of elevator on the landing could be an issue, but if you drop the flaps by 45° when you are on your landing approach, you will find that you need a bootful of down trim to compensate anyway.

You really need to fly it to decide where the best CG position is. Everyone has there own preferences, I like mine to be slighty more forward compared to Barnes/Rich. You'll know when it isn't to your liking though!

Andy

23 mins

Thanks for the input Chaps!
I'm going to the rock tomorrow and the ship on Sunday so the maiden for the Binary will have to wait till I get back! Oh well.
If your not up the rock tomorrow I'll see ya in a month
Cheers
marty