The photo series is on my Flickr page, with some helpful descriptions and mouse-over-notes on the photos: http://www.flickr.com …n/sets/72157619327939335/
Basically, I wanted to have a Domke style insert for a bag I had laying around, without spending a bundle. I looked around the net and some local stores for foam, and it seemed that if I actually bought all the supplies I needed new I may as well just buy the Domke insert(s), because the cost savings wouldn't be significant.
Ultimately I decided to scrounge what I could. I found an old camping pad, about 3/8" thick. This seemed just right to me. I knew I wanted to reinforce the bottom with a second layer of foam, as well as a thin sheet of plastic for stiffness and extra protection. I found a cheapo poster frame from my wife's college days. The front cover was about 1/32" thick--exactly what I was looking for. I took it out and cut out the piece I needed.
As for design, I measured the inner dimensions of the bag and figured out how much space I would have left after the foam sections were in place. I decided on two large sections for lenses and camera, and a smaller one that would hold my flash. I designed the dividers about 2" shorter so that the camera back would be flush with the top of the insert when mounted lens-down.
I cut out two fabric pieces for each insert. My mother in law helped me sew the fabric into pockets for the inserts. Each pocket had generous amounts of extra fabric on the sides and bottom to allow them to be sewn to each other. One side was left open to insert the foam later. Since it would have been impossible to sew the completed panels together, I sewed the pockets together with the foam removed. I started with one outside corner and worked my way around in a circle, sewing only the vertical seams. It was a bit trickier to do the seams including the dividers. The dividers had to be lined up so that they were recessed a bit, plus those seams included three flaps of fabric, rather than two. Once this stage was complete, I filled all the panels with foam. I was able to sew the bottom of all exterior panels shut with the sewing maching, but the recessed dividers had to be done by hand.
For the bottom panel I sandwiched the thin sheet of plastic between two layers of foam and stuffed it in a fabric pocket with 4 wide flaps to attach to the bottom of the assembly. The main section was designed so the bottom panel would be recessed inside. I didn't want it to meet the main section corner-to-corner, because then the edge would be unpadded. I hand sewed the bottom panel in place. This took a long time.
Finally, I hand sewed all the rough edges so the cloth would stop fraying. The synthetic stuff I used frayed horribly and got all over everything, so leaving it rough was not a smart option.
If I had to do it again, I would make it slightly smaller so it didn't look quite so square when loaded into the bag. Also, I would make the fabric pockets differently. I would sew an oversized three-sided pocket. I would then turn it inside out. I would then sew seams about 1/2" in from the edges to create the flaps used to attach to the other panels. This would result in nice finished edges without me having to go back and do it by hand.