I’ve been building jaws for some time now, and have been asked to build a couple pairs of Chas Parker jaws by various people. Well, it took me a year before I decided to try my luck. I was sent two different 8″ jaws from two different 978 Parker vises. I own the Parker 956 (6″ jaws) vise, and my neighbor has a 973 (3″ jaws) in excellent shape. Then another customer sent me a 4-3/4 set to reproduce.
So, I had three to fit, and one extra size to build. Hopefully I could do this. Being a retired Mold Maker, I knew they were not impossible to make, but selling them would probably be the hard part because they wouldn’t be cheap. Building these particular jaws would be very time consuming and require many setups. I don’t own a Wire EDM, a Horizontal Milling machine (which was used to build them) or a 4th axis VMC machine. I do have a CNC and a surface grinder. My 3-d software that I used building Injection Molds would also be a big help.
First I had to figure out the geometry. I used a microscope in my CNC and found points that I could create in my CAD program like a dot-to-dot puzzle. The A-2 tool steel I use is expensive, so I really didn’t want to make any mistakes. After I created the geometry, I double checked the angle on the surface plate just to be sure. The top and face angle on the vise must be nails on or the jaw faces will not meet flush when you close the vise. I was trying to figure out why Chas Parker used this design, and the only answer I came up with had to do with the jaw support. If a hammer blow was missed, the Static and Dynamic jaw supports would not break like you sometimes see on simpler jaw designs found in Wilton’s.
My evaluation was that all four jaws were built with different angle. This creates more work, so instead of creating this angle on a Staggered Tooth type cutter, I would have to create the angle on my surface grinder wheel instead. I didn’t want to make different angled cutters and have to re-sharpen them to the right angle. It was easier to dress the correct angle on the grinding wheel, but first the jaws had to be roughed out before going to the surface grinder.
After I cut the serrations, I set the blocks up in a vise bolted to a large sine plate made for heavy cutting on a CNC or a Bridgeport type machine. The jaw block had to be located precisely on the correct angle; the 8″ was set at 12.54 degrees and the others were up to 18 degrees like the 3″ set. I used the CAD program to calculate location but it could also be done with trig. I also set the tools to the top of the pin because I found this was the easiest for setting all my cutters.
After roughing out most of the material, I programed cutting a finishing cut with a ball end mill. I did a step over with 3 dimensional cutting of .015 per scallop. It took time to cut that way, but it was the simplest way I could do it with the machines I have.
I’m excited to write about finishing and fitting the incredible Chas Parker jaws, but I have to end this blog until I can get caught up on my Wilton orders. So stay tuned. You’ll be able to find them on my other site benchvisejaws.com as soon as they’re ready.