Problem cutting dovetails.

[miker]

Now that I have a Z axis DRO on the mill I started back into
the Tripod Mount that Marv detailed here...

http://www.homemodelenginemachinist.com/index.php?topic=8815.0

Made the foot first and after purchasing a Dovetail cutter (15mm diameter)
I tried cutting the dovetail. I think the cutter may be too small as I can't
see how I can make the dovetail in the block any deeper so it will fit the foot.

I really can't find any info on how to size a dovetail cutter to achieve a particular result!!

This is as deep as the cutter will go and is tearing into the top lip.

Here is the foot sitting ontop of the block. Somehow have to make that fit!! ???

Do simply need a larger diameter cutter so tha I can go deeper before hitting the sides?
If that makes sense?

HELP!!

 

[tel]

Cut this bit away

 

[miker]

Thanks Tel. I had thought of that but want to retain the thickness.

I would really like to know how to increase the depth of the cut out to
fit the foot as is. In other words if the foot had to be as it is, how should
I have made the cut out in the first place? Bigger cutter? If so, how do
you determine the size of a dovetail cutter for a particular job?

There must be some relationship that shows what size cutter is needed to
be used. I don't mind buying a couple more cutters.

 

[tel]

OK, I see you problem. Not that I'm by any means an expert on dovetails but what you needed to do is start with a slot in your lower part the with of 'a' or a bit less. Then you could deepen the slot to whatever you wanted, cut the dovetail sides as you have and then nibble away underneath them with a woodruff cutter or something.

 

[chillybilly]

Hi tel,

I just had to do a dovetail for a ball turning tool i am knocking up .

I first madt the female ,then inverted the male part and used the same cutter to cut the mail doves milled the base off to fit the slide .Did take an extra .100 " of one male dove to allow for the fitting of the jib strip ,bit of a clean up and a spot of oil ,runs a treat .I cut my doves to pretty much full cutter height ,then got it cock on fit by milling the base of the male .

Incidently ,after all this i realised i had made it back to front and now will have to start over :

 

[Peter.]

Hi Miker.

Looks like the dovetail you have cut is already too wide for the foot. You need to either re-make the foot to fit your dovetail or mill the top off that block and start again.

Pete.