Folding sack truck 15L cylinder cradle

I haven't tried yet but i'm sure most size cylinders will sit nicely in the cradle.

no supports required

use 3 x 12mm cap head screws and m3 threaded inserts.

I used 12 but I don't see why you can't get away less! 

designed for this style of inexpensive folding sack truck

https://www.amazon.co.uk/DURATOOL-Lightweight-Folding-Sack-Truck/dp/B07D7FTJB6/ref=sr_1_3?adgrpid=1181975898820169&hvadid=73873694271559&hvbmt=bp&hvdev=c&hvlocphy=132032&hvnetw=s&hvqmt=p&hvtargid=kwd-73873630953740%3Aloc-188&hydadcr=19918_1851292&keywords=duratool&qid=1686826295&sr=8-3

i also designed a hole through the model for upto a 6mm bungee cord with a thumb pull to help hold the cylinder in place. 

for extra security i attach a luggage strap

these are perfect

https://www.amazon.co.uk/dp/B08LP68K93?ref_=cm_sw_r_apan_dp_DFWQ8RKE2GPXC4FCQW66