I had original used some plastic drinking cups cut out and glued into place. But since then I put mine in kind of hard and had to do some wing repair. I did not replace the cups. But flying you will not know the difference. Mine is powered by a .91 TT FS and uses a 15X4W APC prop and the plane is also recovered. I have not flown it in a while but it is definitely time to put it back in the air. My plane requires no weight to balance in the nose. I have an onboard glow and batteries shoved up there so that is probably why.