trying to impose personal entity limits

I’m building a vehicular build-combat server with a coder and a mapper, but am running into difficulties here and there.
First off, We’re trying to impose limits on the number of engine and weapons that are spawned(both are entities). However, the problem lies in that duplicating them with advdupe2 completely bypasses the limit. So while still allowing people to duplicate their contraptions, how can we keep the limit working?

[editline]7th September 2013[/editline]

bump

I still need help with this D:

Assuming these are spawned with a tool, you should look into default gmod tools ( The Make* functions in them ) or post your code here.

Get FPP or URS if you have ULX, block the entities with either.

I believe ULX has a usergroup-based prop limit plugin that you could possibly use.

Shut up about ULX, this isn’t a solution for this situation.

Okay… Not entirely sure where this leaves me. I need it so that a player can’t duplicate a specific entity, so that only x amount can be spawned at any given time.

I told you what to look for in my first post. Assuming you are using duplicator.registerentity, you must put ply:checklimit in your Make function. Look at how default tools do it.