Couple of notes about moving weight around.<ul>[*]For 40 / 60 size planes, as a rule of thumb only, to move the CG point 1/8" add 1/4 oz. of weight at the tail or add 1 oz. at the firewall.[*]Different props have very different weights (e.g. Zinger 12x8 = .7 oz. and APC12x10 = 1.8 oz.)[*]Don't permanently mount weight until after the plane is trimmed for your style of flying[/list]I initially mount weight using some temporary means (not epoxied). The screw-in approach and double-sided tape are perfect. I use foam to wrap weight and insert it into a nook or cranny that so that it is firmly mounted for trimming. I learned from experience when I forgot that it was temporary and flew it hard UNTIL3.5 oz of weight loosened up and moved from the firewall to "somewhere"in the fuse. Can you say really, really tail heavy. That way you can trim you plane by adding / (re)moving weight as needed until you get it where you like the flying characteristics.

For the battery Iuse a block of foam (see pics) that has been cut to match the fuse and the battery pack. If I use 3 pieces I can mount the battery rear / mid / forward by rearranging the foam blocks. Guess that using 1/2" foam sheet (like SIG's)and rubber bands would work for the battery then use denser foam blocks to position it within the fuse.

Good flying ...

Btw - the big block on the left of pic 1 weight 2.5 oz. and the big block on the right weighs 4.0 oz. That's an 8 1/2 x 11 sheet of paper on the left.

Oh yea - don't forget to ballance the plane laterally as well. With a finished plane you have 3 options: use double sided tape at the tip (fliers in the know will appreciate that you balance your plane latterally); if you have dual aileron servos - add the weight inside the servo mounts; and if you have matching covering, cut hole near the tip on the bottom, add the weight to a rib, spar, inside tip or sheeting then re-cover with a neat patch.