About a week ago, Ralph Boumenot asked if I could make a gauge for him. He'd been hunting for about 2 years for someone to make it for him.
Normally, I would have posted this as I made it. However, I wanted Ralph to receive his gauge before I posted anything. You can read about it from him
here.
Basically, what Ralph wanted was a solid brass dovetail marking gauge, based loosely on an older Hayward design. Instead of the double angle on the gauge that most of us are accustomed to, he wanted a 1:7 slope on one side and square on the other. Sure, you have to mark and flip as you lay out your dovetails, but you also have a built in square on your gauge. I think Ralph is onto something.
Following is about how I made it. Just highlights, really. Sometimes I forget to take pictures when I get going.
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| Before starting, I wanted to make a 1:7 gauge of my own. This will get used later to mill the final angle into the finished product. It will replace the parallels that are usually used while milling a part. |
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| This was a good chance to test out my 2" indexable face mill. What makes this one different is that it uses round inserts. I wanted to see what kind of surface finish it could lay down. |
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| Yup...I dig it! |
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| Once the dimensioning was done, it was time to form the cut aways that make up the shoulders. |
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| Sometimes you need to get real close to the vise. But hey, .001" of clearance is still clearance in my book! This was more like .015". |
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| Now we get to use the angle gauge from earlier. |
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| Finished product. |
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| Another view. |
I'm thankful to Ralph for putting his trust into me to make this tool for him. Making parts like this is what I enjoy most. At work, or at home, I love to sit on the milling machine and play (um...I mean work).
I'm so glad that he is happy with the finished product. I get a little nervous when I make stuff. I try to hold myself to a high standard, which means I always feel like I may fall short.
Thank you, Ralph!
I've been watching Keith Rucker and Tom's Techniques for a few years or so to familiarize myself with machining. I had heard about a trade school in Massachusetts that did night schools (3 hour round trip). That would have been my next step because I couldn't justify buying a milling machine for a one off tool.
ReplyDeleteHow I think I would have done it: 4 square the blank - cut the bottom tongue - put the gauge in a pivoting vise set at a 1 in 7 slope and mill that. I hadn't thought of using a 1 in 7 parallel(s). I think I'm learning something about machine work but I'll stick with wood.
Ralph- The reason for using the angle gauge is that it makes it repeatable. The actual angle of a 1:7 slope is a little more than 8 degrees. It's an odd measurement that would take some math and figuring every time I set the vise. In making the gauge for my mill, I marked out the slope the old way (blue dye and straight edge) and milled to the line. With the milling gauge made, I never need to figure it out again! A bonus is not having to take my vise out of alignment.
DeleteMaking gauges for other pitches would be just as simple. I was thinking about making a 1:8 and a 1:6 just to have around if someone wanted those angles.
I did take pictures of that process if you are interested in seeing how it was done.
fine work on the gauge, and for a friend....even better!
ReplyDeleteThank you, Rick. Like I said in my write up, making parts like this is something that I enjoy quite a bit.
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