Milling Dovetails

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Chucketn

Toxic Lunatic & Psychotic
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Hey all,
I should soon receive my first dovetail cutter. As I have never used one before, can someone with experience lead me through cutting a dovetail, please?
I am building Howard Hall’s Deluxe Grinding Table. I have cut the channel in the parts with the internal dovetail and machined to size the parts with the dovetail on the outside. All that remains is to cut the dovetails themselves.
I have an X2 mill. Do I use cutting oil?

Chuck in E. TN
 
Also, cut out most of the dovetail area with a straight endmill and use the dove tail cutter for the sloped portion only.

Rick
 
Watchout for the cutter to be pulled down into the work by the forces while cutting. If using collet make sure it is clean and oil free. It helps, I know from having this exact problem the first time I cut a dovetail.
 
Here's pictures of what I'm cutting dovetails in.
I have already milled the waste away where I could:

DSCF1095.jpg

group3.jpg


Chuck in E. TN
 
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Take a moment to think on the cutter, the very tips of those many teeth are VERY fragile, theres very little metal there in those last few thou and will turn blue in the blink of an eye - and of course there goes the ability to cut (guess why I know this!!) Keep your rpm way down and take is slow, as you move along in the process you should get a feel for the way the cutter is doing its job and do okay - Im on my 3rd cutter, having fried 2 :(
 
I agree, fine job Kevin.
DaveH, I think I have enough to go on. HHS dovetail cutter has not arrived yet, but a contact on another forum sent me a couple of inserts to try, that arrived today. I am going to finish the indexable dovetail cutter and try that on a scrap piece first. If that works, I'll be trying to rough out the dovetail with it.
Thanks for all the info and help.
I have a couple hours to work today but I'm out on a job tomorrow. I'll post more when I have tried some cutting!

Chuck in E. TN
 
I had turned a blank for an indexable dovetail cutter, but ran into a quandry as to what insert to use. The cutter blank, and the inserts are here:

http://s571.photobucket.com/albums/ss157/chucketn/Machining/dovetail%20cutter/


I had marked a couple of reference lines on the face for milling the pocket. I'm going out to the shop now to set up to mill the pocket for the inserts. Hope it's o.k. to include this on this thread...

Chuck in E. TN
 
Someone from another forum noticed I had the back edge of the insert on the center line instead of the cutting edge. So, back to the mill to correct that. I used the cutter yesterday to rough out 2 of the 4 pieces needing dovetails. I managed to chip 4 of the 6 cutting edges, but I did get them cut. On the last pass, the holding screw stripped out of the tool, and it's now toast. First order today will be to make another tool!
It was quite the learning process. There are several variables involved in using inserts. Verry little change in speed and feed makes very big change in quality of cut. I had enough vibration going with the interupted cut that axis locks loosened, the part was pulled up in the vise a couple of times.
I also noticed the back edge of the insert got chipped. That I don't understand.
I had ordered a HHS dovetail cutter from CTC tools at a reasonable price, but did not notice it was metric 12 mm. It came in yesterday, and I discovered I didn't have a 12 mm collet. Ordered that this morning.

Chuck in E. TN
 
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