Intro: Downdraft Moxon Vise
What good are your tools if you can't hold your workpiece? I've often struggled to really perform any detail work on pieces before because I'm trying to drill with my right hand while holding a wobbly piece of wood in my left.
While my bench (instructable) is fantastic for general garage activities, I've often longed for a woodworking specific bench that's designed to help securely hold your workpiece. As nice as that would be, the wife still says the car needs to sleep in the garage, so a freestanding bench isn't an option. Just don't have the space
My solution is to build a "bench on a bench", or really a vise on bench. This will serve several purposes:
- Gives me a secure place to clamp down my workpieces
- Raises my benchtop up to a height ideal for more detailed hand work.
- Space saving design means no need for a dedicated floor bench. If I need the full 8' of my assembly bench, I just unclamp and move it out of the way.
I based my design off many others, specifically Jay Bates's version and this American Woodworker's article. The finished product is sort of a combination of a moxon and twin screw vise. My own twist is to add dog holes and use the body as a downdraft table, which I haven't seen anyone else do. Maybe there's a reason. Guess I'll find out!
Like others I used 1/2" pipe clamps as an affordable mechanical screw, only because I can't afford the Porsche of bench hardware.
This project roughly cost me $50 to make, with a breakdown as follows:
- 2 1/2" pipe clamps: $22
- 1/2"x36" galvanized pipe: $10
- 1/2" half sheet of BB ply: $19 (didn't use the whole half sheet)
- Tabletop / Screws / Vac attachment: Scrap / what I had on hand
Enough talking, let's build!
Step 1: Tabletop
Starting with the table top I grabbed some scrap 3/4" ply and MDF to create a sturdy box. 20" wide by 16" deep seemed large enough for detail work, without being too big to move. The base piece is 30" wide to match the length of the jaws.
I calculated the height by measuring from my assembly benchtop to my elbow when bent at 90 degrees. This gives an overall height of 5". This means I need 4.25" of table height (plus a 3/4" base) but your height will be specific to your measurements.
Take care to keep all front edges flush, and the tabletop 1.5" back from the base's front
Pocket screws and drywall screws make the assembly easy to put together, but also give me the option to disassemble if I ever need to replace a component.
Step 2: Laminating Vise Jaws
Next come the vise jaws, which are 4 laminated strips of Baltic Birch ply to make a dimensionaly stable and hefty block. To make it easy to square the edges, I always overhang one strip by just a little bit and use that as a reference edge against the table saw fence. This technique is exaggerated in the last two pictures.
My front jaw strips are 5.75" tall and 30" long, mostly because it's an efficient use of a half sheet of BB ply (60" x 30").
The rear jaw is designed to overhang beneath by 3/4", so for me that means three strips are 5" tall, and one is the full 5.75". If you remember I actually only need a height of 4.25", but I wanted to make sure I could trim the jaw and not risk running undersized.
After the glue finishes drying, square up each jaw so they have nice parallel faces. We'll fit the lower jaw in a later step.
Step 3: Create Dog Holes
While the glue is drying on your jaws, we'll create the dog holes.
With a 20" wide by 16" deep top, I can space 3/4" dog holes on a 4" grid. This gives lots of holding options and provides the holes for the downdraft table. I started each hole with a forstner bit for a nice clean entry, and then finished with a spade bit.
I slightly rounded over the tops of the dog holes with my router, you could easily sand this, but where's the fun of having a router and not using it?
Step 4: Finish Vise Jaws
To fit the rear jaw we need to trim the 3 shorter plys to the same height as the benchtop. I for me this is 4.25". Set the blade height to just kiss the outer layer and the fence to your desired height. Run the top edge against the fence and you'll have nice parallel faces to make sure the jaw sits flat. Clean up any glue residue with a chisel.
To fit the pipe clamps, we'll drill a 7/8" hole for the pipe to pass through on both pieces. I put mine 2.5" from the top and 3" from the sides. Using a fence with a stop block makes the holes repeatable without having to measure (as long as your jaws are the same length!).
Screw on the back jaw from beneath and on either end of the table. Make sure to countersink the screws on the face of jaw.
Drill the final dog holes in the front jaw, but not through holes this time. I made them 1.5" deep and only aligned with the outside rows, but I can easily disassemble and make the inner rows anytime if I decide I need them.
Step 5: Install Pipe Clamps
I used 1/2" galvanized pipe instead of black iron pipe because the former has a lot of oils and paint that tend to stain wood. Galvanized was actually slightly cheaper too. One 36" pipe cut in half gives plenty of room for jaw expansion.
Optional but it's a good idea to drill a hole through the tail stop to allow it to be screwed to the rear jaw. Just one screw will do, all we're doing is making it easier to adjust the pipe length.
The pipe clamp's head has a tendency to spin as it attached to the threads of the pipe. This is annoying so I drilled and tapped a small 10-32 screw in both parts to keep them pinned together. You could probably lay teflon tape on thick to keep the head still with friction if you don't have a tap set.
Step 6: Vacuum Attachment
Now with the jaws attached, we seal the rear opening and attach a vacuum port to complete the downdraft table. I used a car cleaning attachment that I had leftover to save some cost on an specific dust collection port.
Scrap wood with a few screws made this quick work. No need to get fancy.
Step 7: Vise in Action and Downdraft Testing
I made simple bench dogs by screwing on 1.5" squares of mdf onto short lengths of 3/4" oak rods. For the front jaw cut a shoulder in a dowel to create a driving side.
I tested the downdraft table shown in the second picture. Particle board was the most dust creating thing I had, and I used a fresh face for each test to keep things even. Even with my small shop vac the difference is noticeable. It's not as good as a specific downdraft table obviously, but considering it's a no cost add on, I will definitely be using it.
I'm super pleased with the vise's performance, and the downdraft functionality makes it really earn it's keep on my benchtop. Without moving the tail stop I have ~2.5" of motion from only the screw, which is enough to handle 90% of my clamping needs. It hardly takes any pressure to really lock down on workpieces, and between the bench dogs and vise jaws themselves, you'll struggle to come up with a workpiece you can't hold down.
Feel free to ask any questions, and if you make your own I'd love to see it!
Don't forget to vote for me if you liked this instructable, thanks and Happy Woodworking!