I spent a fair amount of time shaping a crochet in walnut that looks like ones I have seen, more or less resembling the profile of a human hand. Held it up to the bench and decided I didn't like it aesthetically or functionally, so decided to start over.
As I thought about it, the crochet is nothing more than the vertical analogy of the planing stop. On the Nicholson bench, that is simply a square block of wood. It doesn't hold the workpiece down to the bench; gravity does that. When you plane the edge of a piece held vertically against the sideboard, holdfasts hold it up and against the sideboard. As far as I can see, all that is needed from the crochet is to function as a planing stop, nothing more. If you make it wrap around the workpiece, it sticks out too much for my taste, limits the thickness of the piece you can hold and doesn't seem to serve any purpose. Anybody know why crochets are the way they are?
I spent a few minutes creating a basic planing stop as an experiment, bolting it to the bench in case I end up not liking it and want to remove it. I think it fits the look of a Nicholson bench very well and functions perfectly. The picture below shows my first effort and what I ended up with. It works great. It obviously doesn't need to be 2" thick and I may make a thinner version 2.
Once you edge plain on the front of a Nicholson bench you'll wonder how you ever did without it. It's a horizontal workbench. Tremendous.
A crochet holds the wood against the front apron as well if it is shaped like the one on the top of your bench. As you push the board toward the crochet it gets pushed toward the apron. You can plane the edge in a crochet with just pegs in the apron, or just resting on holdfast shafts.
ReplyDelete(You may want the opening of the crochet a bit longer, with a more gradual slope to encourage this behaviour.)
I use the vise on my Nicholson as a crochet all the time, the work resting on pegs/shafts and the vise open just enough to keep it from slipping.
What Dean said :).
ReplyDeleteWhat Dean said, indeed :). In my opinion, holding the the top of the board against the apron is key, especially when edge jointing a wide board. There's enough spring in my holdfasts that they won't hold work tight against the apron, if you have enough of a lever pulling against them (unless you really bash them in). I typically rest the workpiece on two holdfast shafts, and only set the one furthest from the crochet with a mallet (lightly).
ReplyDeleteNot sure what a “proper” crochet looks like, but I think I made mine to hold work ranging from 1/4 to 1-1/2" thick against the apron. It's also poplar, so it's not going to harm the stuff that I work with. Let me know if you want a photo with dimensions or anything...I'd be interested in seeing what others have come up with, or especially old benches.
(apologies if this somehow shows up twice; it timed out the first time)