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Help with deep face groove tool selection

Bill in PA

Hot Rolled
Joined
Jan 25, 2011
Location
Fairfield, PA
Greetings,

See attached drawing.

There is a face groove on the back of the part, .110" wide, 1.550" deep, on a 6.780" diameter.

I have looked at Iscar, Sandvik, Tool-Flo, and Kyocera. I don't see any off-the-shelf tool holders that will go this deep. Has anyone had a custom tool holder made for a similar situation? The insert would need to be no more than about 3/32" wide to allow for finishing.

I may no-quote this job. I am not looking forward to holding the diameter tolerance on the groove.

Quantity is 1 of this part and 1 of a very similar part.

Thanks,

Bill

D01637035_A Crop.jpg
 
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I'd walk away from that one Bill ………..you so realise that's 14 x W deep - in 300 stainless, …...get a hammer and a few lbs of 4'' nails and practice nailing your own gonads to 8x2's - it'll be less painful
 
I'd walk away from that one Bill ………..you so realise that's 14 x W deep - in 300 stainless, …...get a hammer and a few lbs of 4'' nails and practice nailing your own gonads to 8x2's - it'll be less painful

303 will turn fine, but yeah, it's narrow and deep. This is for a good customer and this would be the first time I would no-quote a job for them. Any other customer and I would not consider it.

Thanks,

Bill
 
I would tell your good customer to shoot his engineer. Can you turn a wider groove and shrink a ring into the part to maintain the width for them or some such?
 
I would tell your good customer to shoot his engineer. Can you turn a wider groove and shrink a ring into the part to maintain the width for them or some such?

My customer is quoting a job for a DoD contractor. Having design changes made can be very difficult. A recent job that I helped them with took five months to have a simple correction made to a drawing. By the time the OK came through, the job was already late.

I will suggest that a two-piece design would be more sensible when I no-quote it next week. I don't want to say "no" to work from them, but I imagine other shops won't be eager to make these parts either.

There are some other parts in this quote package. The drawings require that the engraved part numbers be .005" to .008" deep. :nutter: These parts are in-house use gauges and fixtures.

Thanks,

Bill
 
If I absolutely had to, I'd probably try roughing it with a Hougen rotabroach or similar, then finish with a face groover.

It'd still be awful but maybe less awful ?

Not sure if it would be less awful or not. This method then would require two custom tools. Not much to work with on such a narrow groove.

I don't think the aggravation would be worth whatever price I quote. I think a part redesign is in order.

There is a second similar part with a wider groove that would require custom tooling also.

Thanks,

Bill
 
I’d want to know more about the piece, what it’s used for and the like. To shoot the engineer is a good start but an interchange theorists-practitioners seems to lead further. My first reaction to the drawing was: make two parts and fit them.
 
I’d want to know more about the piece, what it’s used for and the like. To shoot the engineer is a good start but an interchange theorists-practitioners seems to lead further. My first reaction to the drawing was: make two parts and fit them.

I cannot say what this gauge is used for (other than it is a go, no-go). Neither I nor my customer can make a change to the drawing. It is either make as is or no-quote. My customer can pass along suggestions, but that is all.

Thanks,

Bill
 
I agree with "shoot the engineer", but have you tried PH Horn or Thinbit?

Face Grooving Products

These say up to 1" deep, but they might have a reasonable special they could make?

As an aside, it really sucks when you get something near impossible and it is for aero or gmvt so you know it is a no-go on a design change.... Eventaully someone will do it for 100x what it should cost, but hey "didn't have to change the print" so they win. :(
 
Talking out of my arse here but:- Making a trepanning tool for that groove would cost far more than the part and still not guarantee a good finish. Is it at all possible that it could be EDM'd?
 
One other thing I was thinking, and I am *sure* it is not worth it for a one off piece (unless you reeealllyyy want to not no-quote this for your good customer) is you don't really need 1.550 of total length, you just need that on the side nearest the boss. Obvious maybe, but I (personally) was thinking "ouch 1.55" loc on a 3/32" groove!", but you only need that on one side, so the other side could have more meat.

OK, no laughing as I don't have any cad software at home just ms paint! :D Could you makebad sketch.jpg something like this?
 
A section of 6" pipe perhaps 1" or 1 1/2 turned to clear the groove by .010 on a side and then a carbide insert silver brazed ti the mid point of part spec width. The pipe arc to become the heal of the cutter to give it strength below the cutting edge. I don't have much experience in SS cutter so don’t know what rake attitude might be best. Likely an 8* back rake made with a 1/8 radius scalp at the top end cutting edge with 10* side clearance with 2* side clearance (back taper) going back about 5/8 inch.

Or just a 1 x 1" bar stock and turn it to be the 6.70/6.50 radius below the tip pocket.. then braze and sharpen a tip..

Likely a $300 special cutter, or a couple hours to make one.... for a one-up part.

Custom size hole saw:
Stock Sizes : Custom Holesaw Technologies, Hole Saws made to your size.

A 1" square brazed carbide tool bit.. cut away all but the width of the groove and the heal(below the cutting portion) ground/turned at the radius of the groove(about 6.70-6.50 with having back taper on both sides.
American Carbide Tool Carbide-Tipped Tool Bit for Straight Turning, Right Hand, C5 Grade, 1" Square Shank, AR 16 Size General General

* A straight heal tool/cutter would not have enough strength to make such a cut.
like this would not work because to make the groove radius there would be nothing/little under the cutting portion.
American Carbide Tool Carbide-Tipped Tool Bit for Cutoff, Neutral, C5 Grade, 0.5" Square Shank, CT 111 Size General General
 
I see a drawing like that, and just have to wonder what sort of experience the designer has that makes him/her think this is doable in the real world. In 303. Madness.
 
I'm not saying it can't be done, more trying to get across my take on the job.

To those suggesting special tools, yes some of them will work and cut, but working that deep and with such a narrow slot, ………... in 300 series stainless - including 303! chip breaking and evacuation will be the big bugbears.

RG - The tool would have to be made as wide as possible in order to get maximum strength, while at the same time, leaving enough material for finishing cuts, AND the tip would have to be shaped to ''narrow'' the chip in order to have any chance of success.

Due to the fragility of the tool, running at ''normal'' cutting speeds will be out the window so it's granny gear which by it's nature won't help with chip breaking, ……..and those who've done such jobs will know 99 times / 100 it's jammed chips that break tools, ( I can hear and feel that tool graunching now - can you? :eek:) ……...and usually damage the workpiece in the process! ...and as there's very little left for clean up - you get my drift.


As has been said - throw enough $ at it and someone will succeed, us mere mortals call for a redesign.
 
Perhaps the offer of a 3D-printed part would work. I'm sure ABS will be almost as good as 303.
 








 
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