This is a portable worktop I originally built for building ARs on my dining room table. It's easy to build, inexpensive ($75-$85, including the vise), and works great for its intended purpose. In the time since I built it though, I've found it works well for a lot more than just building ARs. The entire project is available for free on instructables.com here.

Nice project, do you have a Canopy that hangs from the ceiling to capture wayward detent springs?

LOL! No. I lay a cardboard box on its side next to the lower, open end towards the lower. I haven't lost pivot pin detent or spring yet! Though maybe saying that is tempting fate.

It's nice.  And clean.

Haven't been using it long have you?  Or do you not lube till after you get it built?

Neat...

Curious.. What is the drill for?

Thanks. Actually, those pictures are from the very first time I used it. Several builds and other miscellaneous projects later, and t's not nearly as pristine looking. Don't get me wrong: it's held up great, but it's gathered a few scars and stains. As far lubing, that's right, I don't lube the parts (other than the threads on the barrel nut) until the build is done.

I like to chamfer the ends of roll pins before I install them, so I chuck them in the drill and run them at an angle against a piece of wet/dry sandpaper.

I have a couple of drills and drill presses in my AR build setup, as well as a trim router.

Tell me about the vise. Source, cost, are you happy with it?

I will check out the instructions, as I may need to build something like this.

The vise in the pictures is a Yost LV-4 (~$28 on Amazon). However I upgraded to a Bessey BV-HW45 late last year (~$37 at Home Depot). The Yost was great, and I would have kept it if all I worked on were AR15s, but I needed the larger capacity of the Bessey to hold an Aero M5 upper in a set of PlastiXrevolution AR10 upper receiver vise blocks. Complete details, including links, etc., are in the instructable I linked to in the original post.

I like this a lot. I had been trying to figure out how to set up a portable vise. I don't have a place to mount something permanent at the moment. I was planning on going over to my dad's house, to use the vise in the garage, when I start my first build. Something like this would be more convenient. Still waiting on a couple of parts on backorder, so I may build this in the meantime.

Do you have to clamp the worktop to the table, does it tip up when torquing the barrel nut?

If you like doing DIY stuff, even beyond AR building, I think you'd be very happy with this worktop. Since I built it it's opened up a world of possibilities as far as other projects I'm able to tackle.
No, you don't. Look at the picture I posted where the upper's in the vise. With the upper in that position, tightening the barrel nut actually presses the worktop down onto the surface of the table; i.e. there's no possibility of tipping it. Conversely, if you were trying to loosen a stuck barrel nut in that position, you could potentially have to apply enough force to start to tip the worktop, but you have two things going for you: one is that the vise swivels, so you can turn it such that you're again pressing the worktop onto the table, and the other is that the worktop is heavy, meaning that in most circumstances it's unlikely you'll have to resort to swiveling the vise. When I install a barrel nut it's a process of tightening and loosening, tightening and loosening, etc., slowly ramping up the torque to get the barrel nut timed, and I can tell you that with the four ARs I've built I've never had the worktop tip, or had to reposition the vise.