I've been thinking of making a dry log maker for some time (I have 'wet' log maker see -
http://chat.allotment-garden.org/index.php?topic=24733.15) but drying wet logs on radiators drains energy from your central heating and creates condensation (OH has City & Guilds in Energy Advice).
So this is my
first prototype which should make mini logs from stuffed bog roll tubes and only cost about £1 to make:
Simply insert bog roll tube then tap down scrap paper inside using a length of dowel and a hammer, then open then catch to release 'mini log'. When yours run out (and those of neighbour's, etc.), create an alternative tube out of newspaper - rather like when making a 'newspaper pot', twisting both ends to seal it.
If successful, I don't see why it couldn't be increased in size (which would probably necessitate using a jig/fret saw to form the hole - and definitely making in laminated layers - rather than a 50mm tank cutter) and maybe a club hammer to compress the paper.