Thread: Cutting A 6MM Wide 60 Degree Dovetail - Any Suggestions

Yes and how do you propose dressing it? Please don't suggest holding a single point diamond to the wheel by hand and dressing in the angle!

Originally Posted by Michael G

There are lots of good suggestions for making the dove tail which if it were larger would be great. This thing is small though. Draw it out on a piece of paper - 6mm across the widest part and between 1 to 2mm deep. As far as grinding goes this is really Dremel territory. Toothed cutters whether D, fly or dovetail similarly are going to have to be really small. To make up a cutter for a one off job like this will take more time than can probably be justified. Even grinding the tool and setting up a shaper will take some time.

Based on all that I still think the only way to do it is to straight mill out most of the material (say around 1.2 DOC with a 4 to 4.5mm cutter) and then take out the corners with a needle file.

Michael

It looks like the good old art of filing has been lost. At least the many answers seem to indicate that nobody feels to have the skill set to accurately file such a dovetail. Or the skills have been lost long ago by lack of practice.

The most difficult part is probably to file the dovetail straight and parallel. This can be simplified as above by first straight milling out as much as possible. Another trick would be to initially make the part 2 or 3 times as thick, file it, then mill off at both sides where the filed portions are most likely to be rounded. Or use both tricks combined.

Originally Posted by cba_melbourne

It looks like the good old art of filing has been lost. At least the many answers seem to indicate that nobody feels to have the skill set to accurately file such a dovetail. Or the skills have been lost long ago by lack of practice.

The most difficult part is probably to file the dovetail straight and parallel. This can be simplified as above by first straight milling out as much as possible. Another trick would be to initially make the part 2 or 3 times as thick, file it, then mill off at both sides where the filed portions are most likely to be rounded. Or use both tricks combined.

Hey Chris,

As hard to believe as it may be, there was a time when I wielded a file or two. Don't ask what this is but the thing below was hand filed back when I was a student at WAIT. I still use my needle files. The orange boxed set of Favorites was purchased new in 1982 but my new favourite is the little No.6 cut barrette, still sporting its plastic overcoat. The die sinkers rifflers have also proven very handy over the years.

Bob

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I took the easiest option. Ground the teeth off a small file. I will spend a few minutes tomorrow in the corners of the dovetail with a needle file before it bathes in Blackfast.

BT


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Originally Posted by Pete F

Yes and how do you propose dressing it? Please don't suggest holding a single point diamond to the wheel by hand and dressing in the angle!

The bulk of the dressing would be done by using a round Crystolon dressing stick and the finishing would be accomplished with a Norbide stick.

Gene

Nice work Bob, as usual!

Simon

Originally Posted by easymike29

The bulk of the dressing would be done by using a round Crystolon dressing stick and the finishing would be accomplished with a Norbide stick.

Gene

Gene with due respect, everything you've said makes perfect theoretical sense. In practice however I have serious doubt that it will work as you suggest for all manner of reasons there's no point in enumerating here. I have just spent a very unpleasant hour or so going through various grinding wheels trying to find one that will hold a crisp edge, and even my hardest broke down rapidly. If you've successfully ground accurate dovetails in solid steel using the method you propose I'd say good luck to you.

Sometimes having too much stuff leads to forgetting about some of the stuff you might have. Advanced years probably contribute.

About ten years ago I bought a Baty DTI on eBay UK and it came with the attachments pictured below. I did not know what they were intended to fit or their country of origin. I presumed they were Baty accessories but strangely the main column clamp didn't fit any of my stands and the dovetail clamp didn't really fit on any arms. It was too big to fit on the little magnetic base featured in this thread. I had the dovetail clamp poorly mounted ( too sloppy a fit ) on an Eclipse base. I had long forgotten that these components were originally together.

This morning I looked at an image in an online Tesa catalogue and it sunk in. It doesn't feature the fine adjustment but it allows the mounting of the Interapid and Mitutoyos by their 4mm shanks. The Mitutoyo DTIs are usually supplied with both 3/8" and 4mm shanks so by interchanging the arms on the little stand, I have even more flexibility.

BT

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