reflection biplane priory models

[crispin church]

i got second hand reflection biplane from priory models

put a emax 2628 on front as advert said 45 - 61

for cog needs 800 grams with using a 4 cell takes it over 3.2 kilos

a webra 91 would still need weight added can this be right?

[Biggles' Elder Brother - Moderator]

Wow! That's awfully heavy!

Where are you getting the CoG info from - off the plan? And where is it located.

BEB

[crispin church]

there a thread on different forum and they say its 3 and half " on plan but use 3"

on top wing which i agree with you the cog calc i use say 4" ?

[Bob Cotsford]

I would expect the C of G to be somewhere nearer the rear cabane mount, maybe an inch or two forward of that but not at 3" from the LE. That's just from past experience with biplanes, not with this specific model though.

3" sounds very nose heavy, what's the chord, around 9 or 10"? I'd go with the 3 1/2" as a starting point if that's what the plan says. 3.2 Kg, what's that in real weight, just on 7lb or so? Heavy but flyable. My 48" Jungmeister weighs in at 7 1/2lb with a 61 up front, that's fine but would be better with a lb less auw

It looks to have a swept top wing and straight lower, I'll look where the recommended C of G is on the Skybolt I'm building as that has a similar planform so should give a good guide.

[crispin church]

cog is very flyable at 100mm just shy 4"

thats with webra 91 up front no extra lead and just added 3 stage flaps on lower wing

really good sports bipe