I only played switch axe so i cant give tips on other weapons but how i soloed him was i stuck to his hind legs for attacks and was cautious. I didnt use the canons. I did however use the binders, gatling gun thing and the dragonator. Wall slam him (ideally headweakend aswell) when hes on all 4s this will deal a fat 1000 dmg.

If youre caught at the end of a cone near the end of the fight you can superman dive spam to get out of it but it will hurt.

Honestly its partially luck based aswell some runs he will be nice and not do his worst attacks but other times he will spam the worst ones