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View Full Version : Single flute counter sink sharpening



IOWOLF
07-01-2007, 09:03 AM
Is there an easy way to sharpen these things?

A fixture bought or made maybe?

oldtiffie
07-01-2007, 09:29 AM
Deleted/erased-out

IOWOLF
07-01-2007, 09:55 AM
Tiffie,You have never seen a single flute countersink? :)

I know You grind on the cutting edge, I guess I should have said a way to repair someone Else's attempt to regrind the outside eccentric taper.

oldtiffie
07-01-2007, 10:35 AM
Deleted/edited-out

DR
07-01-2007, 11:44 AM
Single flute countersinks need a special fixture to sharpen.

MA Ford makes the least expensive one I'm aware of.

http://www.nolansupply.com/bysubcategory.asp?category=Cutting+Tools&supercategory=Countersinks&subcategory=M+A+Ford+Uniflute+Countersinks+%2D+Uni cam+Resharpening+Fixture%26nbsp%3B&type=False&specs=True

Weldon, Harig and KO Lee also make fixtures. They all make the Ford style look cheap.

tattoomike68
07-01-2007, 11:58 AM
Take a belt sander to it IOWOLF, its not rocket science. :rolleyes:

If you cant do that then you better stick to buying new tools.

oldtiffie
07-01-2007, 12:24 PM
Deleted/edited-out

Norman Atkinson
07-01-2007, 12:38 PM
Iowolf,
I confess to never having to use anything but a Centre drill or slocombe drill but the easiest countersinks are made following the old D bit technique but grinding the point and then grinding a flat which is half the diameter plus .005 " The latter works extremely well with no arris or raised edge. Sharpening a D bit is simply grinding a bit off the front. It cuts on one face only! I have made lots from what we call silver steel or you 'key steel' and tempering them with a potato. Yea, we all have funny ways.

Looking at these posh versions( I never knew you had such aspirations), these are no more than a half a twist drill end. You either go down the road to sharpen twist drills or you get with it and use the four facet system which does away with all this clap trap. I simply haven't the room for such things as drill grinders.

Having said all this, the Quorn is supposed to repoint centre drills.
My copies of the Quorn instructions are somewhat tired but Chaddock gave instructions in Model Engineer 3rd December 1976. Following on, the Quorn has much the same as any other T&C and the cam assembly seems suitable to other designs.

There, me old friend, you sort of have it.

Cheers

Norm

Alistair Hosie
07-01-2007, 01:08 PM
My very dear friend Norman how are you keeping these days hope you are well kindest regards Alistair

IOWOLF
07-01-2007, 01:38 PM
Tiffie, if you follow the link Dr put up ,That is the exact countersink in question.
Thanx Dr. that is what I thought, a cam type device.

Mike, I am just a poor country boy in a " .005" is close enough" world.
But even I wouldn't be dumb enought to try to do this on a sander,no matter how fugged up the last guy got it.


Norm, Nice to hear from you again,I got a bunch of these cheap but they are 82* I need 100*. and yes a drill bit is a good way but by the time you get a 1" bit then grind it to 100* well that is $25 +.
But if I had a few laying around it would be great.

Norman Atkinson
07-01-2007, 01:50 PM
Alistair,
I wrote a reply. It was a rant. A friend was up there near Paisley and Glasgow Airport.

That was you- you hairy old goat! So there!

Cheers

Norm

Here goes that memory- Jay- goes in and out like the tide!

I'm a Quorn man and all that sort of jazz but Guy Lautard made a Norman Tinker jig available on the US side of the Pond.
I am going through a haze because I never made one. I do recall- I think- that he could do countersinks on it.

It is worth a google and I know that there are two sizes and it is well documented. May solve a problem or three.

N

John Stevenson
07-01-2007, 03:23 PM
One point I'd like to note over these M A Ford single flute countersinks is that in my book they are the best.

And in this case it took a lot of work, trial and expense to come to this conclusion, so hopefuly I can save someone else the bother.

About three years ago I had a job to do some bases for bar stools, laser cut circle in 10mm thick steel and needed three 10mm mounting holes and countersinking.
Drawing spec'd 30mm diameter [ 1-1/4" ] far bigger than 10mm screw so I queried it but was told 30mm was what was needed.

OK start doing these and having problems with chatter on a Csk this big. The drill I use, a twin spindle drill, is ideal for countersinking as it only has one speed on one spindle, 70 rpm driven by a geared motor and toothed belt so no slip.

Next step was to find a tool to do the job, looked in the J&L book and ordered one of each of 7 different types, single flute, multi flute, inserted tip type and solid carbide amongst them. Nearly $200 spent on sample tooling.

The multi flute chattered too much, the carbide one $70, chipped after only a few holes :eek:, the inserted one isn't suitable for a drill press as it want to throw the work around, may be OK in a vise ?

Result was the single flute TiN coated cutters from M A Ford came out the best at around 250 CSK's before changing, bear in mind this is a far more server test than most people have to come across and the tooling was built into the price.

.

IOWOLF
07-01-2007, 05:58 PM
That's good to know , John.

Thank you.

oldtiffie
07-01-2007, 06:28 PM
Deleted/edited-out

japcas
07-01-2007, 07:34 PM
IOWOLF, I have used the fixture that DR posted the link to at work. I thought it did a very good job. As close to factory new as I've seen. We have even sent some out to our drill sharpening guys and it seems they never cut like new but the fixture does a good job of getting them touched up. In my experience, I believe the single flute cutters work the best also and we use M.A Ford all the time at work. We also cut stainless and hastelloy on a daily basis so they earn their keep in the shop.

The problem with grinding the face is that it only cleans up the face. If you chamfer much stainless or hastelloy usually the profile of the cutter will get scarred and that gets transfered back to the work. The fixture takes care of this problem by dressing the profile of the cutter. Essentially making it like new.

Back to the fixture. We use it on one of our own drill grinders and mount it in the chuck that holds the drill. Then put the countersink in the fixture and set it. The cutter is set in relation to the cam to get the proper relief, and then turn the cutter by hand and feed the head of the grinder into the wheel. This tool grinder is supposed to be able to do countersinks but the fixture does a better job than using the machine by itself.

Like John said, M.A. Ford has done a lot of research to get the relief angle on these countersinks just right. Not enought relief on them and they won't cut and to much and they want to grab. So resharpening them is not an easy task. But with the right equipment it can be done. As far as trying to change the angle on the cutter, I'm not sure you would be able to do that. Your fingers would be very tired anyway if you did. If you have any more questions feel free to ask IOWOLF.

IOWOLF
07-01-2007, 07:39 PM
Tiffie,Have you been drinking ,or on drugs?

It clearly says "UNIFLUTE" ,IIRC uni means one.

I saw nothing in the links that shows an Eccentric toolholder to grind relief 3/4 the way around.

Thanx all for your help I know what to do now.
Make a special holder.

A.K. Boomer
07-02-2007, 09:57 AM
One point I'd like to note over these M A Ford single flute countersinks is that in my book they are the best.


The multi flute chattered too much,
.


In so many ways it all depends on the application and material and speeds and pressure and there is probably no one better qualified to make a judgement call than Sir John so please do not confuse this with a dispute towards what he said as its more of a reason as "to why" than the comparison itself,,, weve all used both ---and if I can get away with using my multi-flute without chatter I like it better and feel it does a better job because it does not "push" off to one side and leave a lip if taken away from the material to soon without a few good cleanup passes, A multi is also easier on the workpiece as far as keeping it centered where-as the single will have a tendency to move a piece even in a vise occasionally causing one to have to re-indicate the workpeice, still --- the multi's chatter like hell --- so what if we could have all the bennie's of the muti without the chatter ----- WE CAN -------- they just dont make them:(

The reason Multi's chatter so much is because they set up a pattern --- plain and simple, If one cutter goes through a "bump" then the rest of the cutters create a reverberation "bump" of thier own, then the next time around it gets worse and so on and so forth,,, if they offset the cutter flutes just slightly then they would be the smoothest running countersinks available, so why dont they do this? I think its production, try grinding three flutes at 0 - 110 - and 250 degree's, (instead of 0-120-240) now indexing either gets complicated or the grinding machinery has too ----
I learned this lesson years ago when my older brother (who's built stuff thats sitting on the moon many decades ago) bought some "new way" valve seat cutters, when I went to use them I noticed thier was three carbide cutters yet they were offset, I said outloud --- "these things are stupid --- thier not even centered" My bro said --- "your stupid because you dont know how things work --- thier offset so they dont set up a pattern doofus"
Spankings from older brothers sink in --- the new-way cutters proved to be the bomb, he bought them to take the meat of the seat down instead of having to use stones, then his plan was to do the finishing touch with stones, what we ended finding out is after prussian blueing it was very rare indeed that we ever had to final stone at all, and they never chattered...

Peter N
07-02-2007, 11:47 AM
Sorry Wolfie, I can't offer advice on sharpening these, but wanted to comment on another countersink.

FWIW, I have a set of the Keo 'zero flute' c/sinks and find them very, very smooth in the cut, with no chatter whatsoever.
Apparently easy to re-sharpen too (haven't tried it yet) with just a small grinding wheel through the hole.

I haven't tried the MA Ford c/sinks, but I'm happy to take Johns and others word on them.

Peter

tattoomike68
07-02-2007, 12:09 PM
Mike, I am just a poor country boy in a " .005" is close enough" world.
But even I wouldn't be dumb enought to try to do this on a sander,no matter how fugged up the last guy got it.


By all means you should spend 20+ hours building a fixture to sharpen a ruined countersink.

DR
07-02-2007, 01:32 PM
........
the multi's chatter like hell --- so what if we could have all the bennie's of the muti without the chatter ----- WE CAN -------- they just dont make them:(



Try a Severance multi flute. They don't chatter.

The flute design is a little different than common multi-flute styles, almost looks like a negative rake on the cutting edge. Price is up there too, but you get what you pay for.

The Severance are tricky to sharpen.


Speaking of sharpening single flute style......it ain't so easy to do free hand, especially if the some one has messed up the original geometry.

A.K. Boomer
07-03-2007, 01:16 AM
I went into the severance website and checked them out, I dont think its just because of a negative rake and it appears that I stand corrected also--- somebody is building multi fluted countersinks with offset flute's --- they are calling them "chatterless" and the flutes "staggerd" and it explains as how they avoid the pitfalls of setting up a pattern, I tried to copy and paste the info but its that acrobat reader crap and It wont let me and i dont know how:o anyways, when mine wear out I will spend the extra money and hunt these down as i know how well my bro's valve seat cutters worked...

J Tiers
07-03-2007, 01:25 AM
I have seen single flute countersinks, and multi-flute, and the ones that are basically a hole thru a cone.......

Which one are we talking about? The hole thru the cone type? I have no idea how they are supposed to be sharpened.


BYW, every one of the above chatters like a tickled monkey, with the EXCEPTION of the "hole through cone" type.

Those suckers peel off metal without complaint or noise. The worst thing about them is that they are done before you expect them to be done.

If you apply any pressure, better have a stop, because they will cut too deep just as fast.

J.Ramsey
07-03-2007, 02:21 AM
The "hole through the cone" type are sharpened by enlarging the hole till it cleans up, but before you do that spin it reverse and get twice the life out of it.

BadDog
07-03-2007, 04:00 AM
I've got a set of MA Ford multi-flute CSs that have staggered flutes. They seem to have no problem with chatter than I've seen, and they leave a very nice finish.

IOWOLF
07-03-2007, 05:54 AM
By all means you should spend 20+ hours building a fixture to sharpen a ruined countersink.

No mike, I guess you don't get it. If I make one I can reshapen as many as I want, and in time it will save me money , as with any tool the more you use it the less it cost per use.

But hey ,you throw away all the dull tools you want, better yet ship them to me.:p

DR
07-03-2007, 09:35 AM
The "hole through the cone" type are sharpened by enlarging the hole till it cleans up, but before you do that spin it reverse and get twice the life out of it.


Nope on both counts.......

Yes, you can sharpen them by enlarging the hole, but that's not the manufacturer's recommended method. Enlarging the hole has drawbacks, it weakens an already fragile cutting edge. I believe Weldon company was th originator of the "fish eye" style. Their sharpening method is to use an expensive radial relieving fixture to grind the OD. The MA Ford fixture meant for their Uniflute style will do the fish eye style at a much lesser expense for fixture.

Reversing the rotation of a fish eye countersink will not do anything except rub. The trailing edge is relieved substantially so it can't contact the work.

DR
07-03-2007, 09:46 AM
I have seen single flute countersinks, and multi-flute, and the ones that are basically a hole thru a cone.......

Which one are we talking about? The hole thru the cone type? I have no idea how they are supposed to be sharpened.


BYW, every one of the above chatters like a tickled monkey, with the EXCEPTION of the "hole through cone" type.

Those suckers peel off metal without complaint or noise. The worst thing about them is that they are done before you expect them to be done.

If you apply any pressure, better have a stop, because they will cut too deep just as fast.


The original poster was asking about an MA Ford Uniflute. It's a single flute style, not the fish eye style. And no, if properly sharpened they do not chatter. They "peel" material just like the fish eyes.

Notice I said "properly" sharpened. That's the key. The trick is to get the proper amount of radial relief, the relief also has to be positioned accurately with respect to the cutting edge. If either of those are off a bit the countersink mysteriously won't work well.

I've had enough experience sharpening and "re-angling" single flute countersinks to know it's not something easily done without a fixture. You may be able to lightly touch one up freehand, but if it needs any amount of cleanup use a fixture.

Scishopguy
07-03-2007, 01:25 PM
I have seen single flute countersinks, and multi-flute, and the ones that are basically a hole thru a cone.......

Which one are we talking about? The hole thru the cone type? I have no idea how they are supposed to be sharpened.


BYW, every one of the above chatters like a tickled monkey, with the EXCEPTION of the "hole through cone" type.

Those suckers peel off metal without complaint or noise. The worst thing about them is that they are done before you expect them to be done.

If you apply any pressure, better have a stop, because they will cut too deep just as fast.

When I worked in tool and die the Weldon "hole through the cone" type countersinks were all they used. Tough as nails and never chattered. I scrounged some of these out of the trash, ones that had been chipped, and decided the best way for me to sharpen them was to use a hand grinder and enlarge the hole enough to eliminate the chip. Worked fine. I am still using them and they still work flawlessly. That was 30 years ago. Those things last forever!!! By the way, they were refered to as "sheet metal countersinks" back then, although they would cut anything you could put under them.

DR
07-03-2007, 01:59 PM
they were refered to as "sheet metal countersinks" back then, although they would cut anything you could put under them.

We use them on practically everything, hard metals, soft metals, plastics, whatever.

Just recently I was made aware they're only recommended for aluminum and other equally soft materials. Oh well, we'll still go after stainless, etc with them, I have a sharpening fixture.

IOWOLF
07-04-2007, 10:39 AM
I did it, I got the eccentrics correct and the offset close enough.

I tried the 82* first, to get the angles right, then the Eccentrics.

The final product rolls thin sheets up like a shave tool (A screw machine reference).

The 100* version works just as well.

It feels good to do something to SAVE money for once.

For those Doubting Thomas', It is done to my liking, and I have about 8 hours of free time in it.

japcas
07-04-2007, 11:32 AM
Glad to hear you got it worked out IOWOLF. I guess that means you won't need me to get the specs off of the one at work now. Let me know if you still want them.

IOWOLF
07-04-2007, 05:08 PM
If it is not too much trouble, Jonathan.

Mine isn't perfect, just useable.

japcas
07-04-2007, 08:05 PM
No problem Jay. I'll see what I can come up with.