If we make one hole perform both functions, we reduce the tolerance and repeatability with which we can perform the Location function. Imagine dropping a dowel pin down two bores. One is half or even 1/3 as long as the other. Remember, we’re talking 1/2″ diameters in bores that are 3/4 to maybe 0.8″ deep. There’s a chamfer at the top and bottom so we have even less length available. Which bore is going to hold the pin more accurately vertical and in position? Bob is responsible for the development and implementation of the popular G-Wizard CNC Software. Bob is also the founder of CNCCookbook, the largest CNC-related blog on the Internet. Let’s go a little more in-depth with a particular feature plate. I received a plate from Dan Bye of Tosa Tool for review purposes and installed it on my Tormach PCNC 1100 CNC Mill. Yes, journalists get free product a lot of time, but I’ll tell you the straight 411 about a product anyway. My CNCCookbook business is far more important to me than any review, so I’m not afraid to be critical if need be. Works equally well with soft, green or hard woods. The curved blade is relatively easy to sharpen. Available in three sizes only: 3/8 inch (9.5 mm), 7/16 inch (11.1 mm) and 1/2 inch (12.7 mm). These cutters made by Veritas can be used two ways. Using them like a hand-held pencil sharpener, you can put accurate tenons on the tips of turnings or on rustic furniture components. The cutters can also be used with a power feed to make accurate dowelling.

With G10, you can set the values for any work offset. Let’s say the coordinates of the fixed rear jaw, left front corner, on the left vise in the picture above are X20.0 Y11.733 Z0.0 on that left jaw when you drop it into the proper grid position on the fixture plate. You’ve also got a set of fixed coordinates for the right vise. Run your short g-code program with a couple of G10’s in it, and Bob’s your uncle (not really), the work offsets are set and you’re ready to start running parts. Now, having made sure the Fixture Plate is in the right place, you can see where the T-Slot Nuts are. Use a tool such as a drift to reach through the Fixture Plate holes and align the T-Slot Nuts with the proper holes. Suddenly our Fixture Plate is a lot less convenient to use. The alternative is we loosen up tolerances and make bigger holes in the sub-plate. Of course that means it will be positioned less accurately. With T-Slots, the T-Slot nuts slide. A fixture can thus be located anywhere. That sounds great except that the fixtures can be anywhere. With a Fixture Plate, your fixtures can’t be located anywhere. They have to go into the grid of available holes. In other words, with a Fixture Plate, fixtures are always at a well-defined location.If you want to make exact-sized dowels from any wood you choose, a Lie-Nielsen Dowel Plate is the best tool. Some vendors tap every single hole on the plate, but having both smooth bore and threaded holes is a better design. When using a Fixture Plate, the holes perform 2 functions:

I’m using some dowel pins that are part of Tosa’s modular fixturing kit. It comes with a variety of gizmos. Here are just a few of the locating pin variety: Simpler maintenance: Full access to subgrade enables re-levelling in the event of rutting from vehicles With a fixture plate, bolt fixtures on using the threaded holes in the plate. Why use a Fixture Plate? Minimises common issues: Controls the natural characteristics of concrete. Less joint restraint, faulting, spalling, curling, and shrinking.Once clamped in place, the dowel pin holes are drilled undersized them reamed to size. Their position is not super-critical, but we should still spot drill and use screw machine-length twist drills.