this is not easy

[cob]

check this out I got this stainless steel part that I have to do a groove that looks like a dove tail but I have not the slightess idea how to go about doing it that is because if the entry of the opening is only .710 but the inside of the groove is .750 how do you go about machining this groove .
can this be done on a mill or do you have to use a lathe.
here is how it looks

[Geof]

Your sketch is a bit awkward to interpret because it is sideways and not to scale, but I think given that the bottom of the dovetail is only .040" wider than the opening it is quite feasible.

To do it on a mill you would need to be able to get a cutter with the correct angle for the 'dovetail'; on a lathe it would be possible with a simple grooving tool. Unless I am totally mis-interpreting your sketch.

[cob]

Originally Posted by Geof Your sketch is a bit awkward to interpret because it is sideways and not to scale, but I think given that the bottom of the dovetail is only .040" wider than the opening it is quite feasible. To do it on a mill you would need to be able to get a cutter with the correct angle for the 'dovetail'; on a lathe it would be possible with a simple grooving tool. Unless I am totally mis-interpreting your sketch.

forgive my lack of knowledge but where can I get a cutter that would do this on a mill I dont even know how the cutter would look.
for doing it on the lathe I kind of thought of a grooving tool just like you mention I am just trying to get a picture of how this cutter would look to do it on the mill. is someone has any web site I can look at I would greatly apreciated.

[Geof]

Just Google dovetail cutter. I will try to attach a picture but it may not work.

Dovetail cutters are available for 45 and 30 degrees so if your part needs a different angle on the sides you may be out of luck.

EDIT:

The comment below from One of Many is very pertinent; with stainless steel you probably would need many cutters. If I was faced with this part I would probably do it on a lathe.

[One of Many]

Since it is .04 different on the diameter and .02 different on the depth, I'd say it was a 45deg under cut with the .750 bore .08 below the dovetail undercut runout. If milled, you'd need a custom ground 45deg dovetail cutter to achieve the .08 undercut efficiently. Honestly since it is SS you might need several depending on quantity of order.

I'd lean toward a lathe operation and single point it after boring to the .710 full depth.

Is the equipment manual or CNC?

Keep it cutting and do not let it dwell. Stainless can take out a cutter tip once it work hardens.

DC

[DJPLAST]

You need to recheck some numbers from that sketch. 10" - 9.290 = .710 . You have a "groove" on either side of center that are shown as .710" . The math is not correct somewhere. Probably the 9.290" dim is incorrect since the cross section shows the .710 dim. of the "groove" opening.

[Superman]

Depends on how many you have to do

I would face turn the 0.71" wide grove to 1.0 deep finish size

then a http://www.iscar.com/Ecat/item.asp/a...801041/lang/EN in imperial format or similar tool
R/H tool to do the undercut ( tool pointing to centre )
L/H tool to do outer undercut ( tool pointing away from centre )

DOC is only 0.040" ( 1 rough passs, 1 fiinish pass on each side )

milling time will be about 4X longer or more, + cutters and you will have problems
m/c the 0.71" x 1" deep slot to finish size
then a solid CBD endmill form tool, OD 5/8" to the form of the profile on one side of the 0.71" groove, drop it in on the centreline of the groove and run around each side of the groove

[One of Many]

I gotta say the reason it is not easy is, I tried drawing this up in cad to apply some sense out of the sketch....which makes me wonder if these are mixed units. As in the use of inches and decimal foot? Which makes the .25 thru hole 3" if the OD is 14"? The 9.29" across the hole shouldn't be there, it should be out near the 10.00" and the .71 is the difference in the 2 diameters of the features not the bore diameters. The cross section sketch would lead one to think something else is amok!

DC

[Matt Berube]

Dude, you gotta get the engineer more ashtrays & cups (for tracing) so he can achieve something that is somewhat close to scale... I am guessing all he has now is one plate and one ashtray. ROFLOL

[cob]

Originally Posted by Matt Berube Dude, you gotta get the engineer more ashtrays & cups (for tracing) so he can achieve something that is somewhat close to scale... I am guessing all he has now is one plate and one ashtray. ROFLOL

actually the way I traced it was with a cd and some quarters. LOL
also yes the 10.00 inches was suppose to be 10.710
I wish I could show the print but it is just not possible I might get in trouble.
but on another note thanks for all the info by the was it looks it is going to be done on the lathe. just got to get me those right and left boring bars.
but if any one has a bet idea please let me know I am open for all and any sudggestion