There is a wide selection of drywall dust separators on the market from $50 or so on up to several hundred dollars for a nice Festool extractor. Being a DIY homeowner, taping drywall is not a full time job and doesn't warrant spending the money, so I decided to make my own with about $20 at the local hardware store, This price can be more or less depending on how you make it and what items you might have lying around, I could have used an old bucket but opted to buy a new one for this project, about $5 for bucket and lid at Lowes.
Step 1: Shopping List
1 - Bucket and Lid
1 - 1" schedule 40 PVC pipe, cut in several sections: 1 x 12" and 4 x 1 1/2"
4 - 1" PVC female slip to male threaded
1 - 1" PVC threaded coupling
1 - 1" PVC slip to threaded coupling
2 - 1" PVC slip 90 degree elbows
1 - 1" PVC female slip to male threader 90 degree elbow
PVC primer and glue
All purpose PVC glue
Hacksaw to cut PVC pipe
1 1/8" spade bit or hole saw (I used a 1" spade bit and widened the hole with a box cutter)
Step 2: Prep and Assembly
Cut the PVC pieces, 1 x 12" piece and 4 x 1 1/2" pieces. I used a hacksaw, but a sawzall might make faster work of this. Sand the ends to remove any burrs.
Dry fit all of your PVC pipe and fittings to ensure you have everything in order. I failed to take a picture of the fittings laid out, so please see the sketch.
PVC primer all of your slip ends. WEAR GLOVES, PVC primer and glue is nasty stuff and does not come off easily, so unless you want sticky purple hands, wear gloves.
PVC glue all of your slip ends and push together your fittings, If you never done this before, you may want to glue them one by one, PVC glue has very little working time, precious few seconds.
Use the general purpose glue on the PVC threads that will go through the bucket lid, screw the threads through the lid and then screw your threaded ends together, till the lid is firmly between the two ends.
Step 3: Done
Attached completed lid assembly.
Attach sander hose to intake pipe and vacuum hose to exhaust pipe.
You might need a hose clamp if your vacuum hose does not fit snugly, my sander hose fit very tightly, but the vacuum hose was a bit loose.