Thread: Build Log Sig 4*20 EP Build
View Single Post
Old Oct 10, 2012, 02:13 PM
Dereck is offline
Find More Posts by Dereck
Visitor from Reality
United States, VA, Arlington
Joined Dec 1996
12,788 Posts
Originally Posted by pigcop2 View Post

Other than that, I have the battery tray in. I chose to build it to plan as opposed to cutting hatch in the top. I just didn't feel comfortable doing that at this stage of my experience. Speaking of the battery, It appears that my big 3200mAh battery will fit in the designed bay. Just not sure if its going to be too heavy though. It feels like a ton. I was thinking of putting a former in the middle of the plane to act as a stop for the battery, as I was thinking of trying to put it as far back towards the CG as possible. The current set up doesn't seem like its very secure to me.

Some more pics.
Doing well, keep on going, it'll be fine. Sig kits are great. Seldom anything exciting about them, but rock solid and well engineered.

Watch that battery size for balance. The builders manual recomends 1800 - 2400 mA 3S packs, which for convenience these days settles nicely on the very common 3S 2200mA pack. That size will fit in the battery bay as per the kit, but puts the pack well ahead of the CG.

I must confess that my battery experience goes back into the dim mists of time, when the aim was to get a hefty pack over the CG and moving it a half-inch made the CG pack up and move real quick. Hence my 'slight alteration' to the kit's battery bay - which is a development of what I used on the Four Star 40 electrocution I did back around 1998.

With the kit battery bay, the easy way out would be to buy two or three identical packs, so you could swap packs and fly without having to worry over a shifting CG.

You could, with little extra effort, move the rudder and elevator servos to somewhere aft of the wing to help balance a forward battery pack. Early indications are that my model will balance with the battery as per my photos, so I've put the rudder and elevator servos in pretty much the kit position. In other models, I've put them aft of the wing with access through a bottom hatch in the fuselage - I have a serious allergy to servos hanging out in the breeze for some odd reason.

Dereck is offline Find More Posts by Dereck
Reply With Quote