In the above video we see opposition fighters using what is becoming a popular DIY weapon, pipe bombs, simple metal tubes filled with explosives ignited by a simple fuse. In the following video we see how unexploded bombs (in this case an OFAB) are used as the source of the explosives for this weapon
There's also been several example of the pipe bombs being used in conjunction with slingshots to send them even further
How effect and accurate this is seems pretty questionable, but the use of slingshots like this has been spotted in a number of locations, so it seems a popular combination.
CJ Chivers covers the production of rockets in great detail in his previously mentioned article, but what I'd like to highlight is how these are becoming an increasingly common sight in Syria, in particular Aleppo, such as these rockets recently used to attack the infantry school
Or this attack on a checkpoint in Aleppo
In the above video the Salman Al Farisi brigade show off a BMP turret they've attached to a trailer, something some of you might remember being done in the Libyan Civil War, as shown below
This video demonstrates the more sophisticated end of Syrian opposition weapon manufacturing, showing rifle grenades being manufactured in a machine shop, then demonstrated.
Again, another example of a machine shop being used to manufacture a weapon and ammo, this time a DIY recoilless rifle. Judging by the amount the barrel jumps when it's fired it's questionable how accurate this is, but it's certainly got a hell of a kick to it.