Sorry for the sad picture but here is my setup.
From left to right. 54mm,3",4" nosecones.
Same idea as from John's video.
On the 4" a wood ring with t-nuts. Easy to do.
On the 54mm & the 3" I machined some metal rings, drilled and tapped them for the attaching screws for the bulk head. Not as easy to do.
As per Greg bubble wrap the BRB900 and install.
It is a tight fit going into the ring on my 54mm nosecone but it can be done.
Enjoy the BRB900. Greg puts out a good product.
If anyone is wondering why the odd cut out section in the wood ring on the 4".
Answer is.
That nosecone has some age on it. It is back from the days when I was using an Ozark Aerospace GPS unit. Large unit using a large battery pack. Needed the cut out to get the unit into the 4" nosecone. Also needed the use of a laptop. Not to my liking.
I do remember flying that unit in a 3" Wildman drag race on a CTI L935 motor.
To do so I had to extend the nosecone and it added about three pounds of weight.
Needless to say I did not win the drag race.