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...


thewoodshopbug said...

Very cool!

Makes me wish I had a milling machine.

Cody said...

Thanks! Yup, a milling machine is awful handy. Unfortunately though, I've found the learning curve pretty steep - lots of broken endmills! Turns out I'm a pretty crappy machinist...

jbreau said...

jesus, leave you alone for a little while and this is what happens. wow. so did it end up cheaper? or was the experience worth it?
too bad your south bend isn't up and runing, you could have cut the thread and saved a bundle on the screw.
can i have one?
how's the mortiser coming along?
do you have your phases converter up and runing?

Cody said...

What the? First you chastise me for overdoing my vice then ask about several unfinished projects? :)

My dad actually has a huge 24" metal lathe but I don't feel I'm at the skill level to cut 1-1/4" acme threads yet, unfortunately. I definitely considered it though...

My bench is actually complete, I just haven't posted it all. I'm building a tool board + cubbies to hang above the bench. And when that's done I'm going to get back to work on the mortiser. And when that's done, I'm going to get to work on a reproduction of a Finn Juhl chair I've been compiling drawings & pictures of.

The phase converter has stalled due to a lack of a slave motor. I have all the components except a 10hp 3ph motor, which aren't cheap! It's just a slave so it doesn't need to be in good shape, so I'm keeping my eye open for a good used one. Lots on ebay, but they're so damned heavy shipping counteracts the cheap price.

jbreau said...

go check at the scrapyards. i was looking for a smaller single phase, and all they had were bigger 3 phase motors. or just the plain old motor shops. i got a single phases two horse for my bandsaw for 60$. good shape too.

didn't mean to chastise, you probably work faster then me.