Thursday, December 31, 2009

Metal Wagon

I really like the wagon vise hardware that Benchcrafted makes, and at $350 it might be worth it, but I decided I would attempt to build my own. I mean, I gotta do something with that milling machine!

I bought a 1-1/4" screw and nut from the local fastener place (uncreatively named 'Nut & Bolt') and a handle from Busy Bee Tools in Edmonton. One of the things that struck me immediately about benchcrafted's wagon vise is the lack of a big ugly wooden handle - cool! One thing that really drove the price up was the fact that the screw and nut have to be left hand thread if you want the vise to work in the traditional 'righty tighty, lefty loosey' fashion. It takes a bit to visualize, but in almost every vise configuration the nut is stationary and the screw moves, whereas in this style of wagon vise the nut is on the carrier and the screw is stationary. Therefore the threads must be reversed to make it work properly. So anyways, a screw and nut alone cost $200, more than half of the benchcrafted vise. Darn...

I turned a shoulder onto the screw to accept a 'garter', and an appropriate sized shaft to mount the wheel. For the carrier I had initially planned on building something similar to the Benchcrafted vise, where the two perpendicular pieces are machined & bolted together, but decided it would be quicker to machine the whole assembly out of a piece of 4" angle iron. It took some torch/press work to get the angle iron square, but once it was close I used my milling machine to true up the 'runners' and drill all the necessary holes. I used hot forged angle iron, because it's all I had kicking around, but for accuracy's sake it would've been better to use cold forged, which is usually much more flat and square, and doesn't have all the ugly heat scale that should be sand blasted off.

Again, my original intention was to machine three 1/4" bolts to hold the nut to the angle iron but decided instead to weld it. It's not as nice looking but it's soooo much faster and stronger. I would've liked to sandblast it once it was done but the only sandblaster I have access to is used to blast entire buildings, so it seemed overkill to fire it up for this!

To hold the screw to the end of the bench a garter is used. It's just two half moon disks that sit inside the shoulder I machined into the end of the screw. I had thought that maybe I would use brass but finally decided that Wenge would look cooler, and I have a bunch of scraps from a previous project.

First I cut a 2-1/2" circle with a holesaw, then used a forstner to drill a 1/2" hole in the center. The screw holes were drilled next. Once all the appropriate holes were drilled I shaved off the garter with the tablesaw, making sure to stick a piece of scrap to the face to keep the offcut from falling into the blade.

And then I split it in half with a zona saw and countersunk the holes. Done, and it only took about 10 minutes.

I decided to use maple for the runners rather than metal, and I attached them with lag screws in oversized holes so I could make a bit of adjustment if necessary.

I drilled the hole through the end cap of the bench a bit oversized to allow some adjustment with the garter placement, and unfortunately getting the vise to operate smoothly through the whole range of movement is a bit tricky. With the vise fully closed the nut is 8" away from the garter, and so the bit of backlash in the system is enough play that everything doesn't need to be perfectly aligned to work smoothly. As the nut approaches the garter however, there gets to be less and less play, and if the garter is not exactly centered it will bind the screw up. It took lots of messing around, but I eventually got it positioned correctly. There has to be a better way to get everything accurately lined up though. Hmmmm...

Monday, December 28, 2009


I have 3 weeks off school for xmas, so between all the sitting on the couch and eating 8-10 meals a day I've been rebuilding the top of my workbench. I built my bench while I was working at a timberframing shop in Invermere BC in 2004. It originally had a tailvise that I purchased from Atlas Machine in Toronto (if you have 'The Workbench Book" it's the tailvise that Michael Fortune designed for his bench) but no front vise because I never made my mind up about what to use. Unfortunately the benchtop warped very badly when I brought it back here to Alberta and despite my repeated attempts to flatten it I eventually admitted defeat. The warpage caused the tailvise to become inoperable and I had planed the top down so much I had almost reached the 'shoulder' of the dog holes on one corner.

After doing some research before starting my new benchtop I decided to forgo the tailvise and instead incorporate a wagon vise. The first wagon vise I saw was the one used on the Roubo bench on Khalaf Oud Luthiery's blog: (which is where the image below is from).

I have since seen a couple other versions, none as pretty as the one shown above however. The thing I like about the wagon vise is how rigid it is. When I was at the IP it seemed like I was constantly having to tweak my tailvise to get it flat to the benchtop, which isn't a concern with a wagon vise. The obvious disadvantage is the lack of ability to clamp pieces on-edge perpendicular to the front apron.

I've mentioned in recent posts how much maple costs in these parts, so in order to reduce costs I only made the top 1-1/2" thick, which is a bit scant. Realistically though, I don't forsee myself working on huge heavy pieces where a bench's rigidity may be called to question, and if I do see some deflection in the top I can always stiffen it up somehow.

After using a few different benches there were definitely a few things I wanted to incorporate into this bench, like lots of dog holes. It's frustrating when dog holes are spaced 3-4 inches apart because sometimes the piece you're planing ends up being 'between holes' and you have to either open your vise up super far or add a piece of scrap between your work and the dog. I also added a row of round dog holes because there's so many good workholding gizmos out there designed for them. Cutting all the dog holes was by far the single most labor intensive step, but I prefer using square dogs for planing.

Man, you sure need lots of clamps to build a benchtop. Even though I don't really like them I bought 5 pipe clamps just for this glue up. I clamped aluminum extrusions on either end to help keep the whole assembly flat - it worked well.

Next step - build the vise.