model(entity) solid help !!

i first post in Help & Support
but i felt this post not fit Help & Support
so that, Here again post

I’m so sorry…

i extract tank model in other game to make tank which is drivable

and i perfect extraction and make entity
but… i face problem when entity set solid

Speaking ahead, in ragdoll did not occurs this problem ( ragdoll work that i want to result )
this problem occurs when entity set solid ( Entity:SetSolid(SOLID_VPHYSICS) )

i wanted solid model :

collisionmodel is combined three part ( gun, turret, hull )

however in game solid :

(not same entity in solid which model have collisionmodel ( collisionmodel is first picture ) )

and, i thinking this problem and arriving cause

this proble cause ( i forecast ) SOLID_VPHYSICS is use part of one solid model ( this model have part of three solid model (gun,hull,turret) )
if more than one solid model, engine make temporary solid box

whether true or false, Anyway

and Finally i realize this method (SOLID_VPHYSICS) not good because if this do, it is same to ragdoll

so i use other method, SOLID_OBB but it is not change angle( only change model angle, not change soild angle, it is drivalbe vehicle, so that need to currect soild )

help me
how to do solved this problem, set soild vehicle fit perfectly for tank!!