Kera foehunter:
i like my old style earth shaker cannon
but i want to make it more modern.
or more chaos looking
with all you madd engineers at this site it should be easy
thanks kera
minty:
get the skulls from the hell canon and put it on the barrel. it’s the same size so it works
then add some spikes and stuff, and jobs a good un
Hashut’s Blessing:
Add a couple of lightning bolt motifs to it. big hat? 
Have some slaves tied to it or holding it down. Have an ogre or two as loaders. Have a bunch of slaves holding a platform of ammo, so they don’t need draft beasts, etc etc.
furrie:
use slaves infused with deamons as ammo
Ghrask Dragh:
Do Games Workshop still do the Chaos Vehicle conversion sprue?
If they do it is a must buy, spikes, spikes and then more spikes 
Kera foehunter:
sweet keep them comming
Couchmonster:
I made mine like this: http://i178.photobucket.com/albums/w250/killerofsmallchildren/P0001630.jpg
Fell free to yoink the idea should you feel so inclined.
wallacer:
Well, if you want to make it look more like the Hell Cannon, you could get some chain and tie the cannon to the ground. Along with the suggestion above of using the skulls on the barrel that should make it look fairly convincing.
Kera foehunter:
must get some cd engineers to cast a new barrow since gw don’t sell bits
Hashut’s Blessing:
GW has begun to reintroduce some of their bits for sale, so you may be able to. Just keep checking unless you can find it elsewhere.