Chattering countersink

[WKevinD]

I'm almost embarrassed to ask this but then again there are other things worth being embarrassed  about that I can admit to.

Lately my countersinks are all chattering. I am using an 82degree multi fluted 1/4" and 3/8" countersinks
years ago I had some countersinks that had a circular cutting edge made mainly for aluminum that worked well for brass.
What are you guys using? Do you freehand with a hand drill, use a drill press?
Tools or technique?
Kevin

[JBJ]

I use fluteless Weldon countersinks both in the drill pres and in the handdrill. Do not buy the knockoff fluteless countersinks from China as they do not run true!
J.B.

[cunninmp]

Kevin,
Normally the multi flute countersinks will chatter when using too high
an RPM.
I generally run mine around 40 to 50 rpm.
Try it on a test piece and you might be surprised.
Mike

[Chris Evrard]

Like Mike said, slow is the key. I like to use the drill press to keep everything square and it is easier to apply pressure.

Many of the Sears and Ryobi cheapies don't have a slow enough setting. In that case a variable speed hand drill would be the best. Use lubricant of some sort and go slow and almost any style will work well.

CE

[Acer Saccharum]

some members have recommended putting a piece of cardstock, like business card, under the six fluters, and that stops the chatter.

[Acer Saccharum]

these don't chatter so much:

with any countersink, the work must not move, and the cutter be run slowly.

[WKevinD]

I think my speed is to high,  I'll also look for a single flute like the one Acer showed and play with some brass stock.
Thanks
Kevin

[gunmaker]

You can get a reostat from elec. suppliers that is like a light dimmer on your home.  Dial it down so slow you can see the flute turn.   Tom

[greybeard]

A couple of layers of t shirt over the tip of the countersink will help reduce chatter. Also slow speed.    Bob

[Acer Saccharum]

For brass, a slight flat stoned on the leading edge of the cutter will make the countersink(or drill) run smooth as silk. Ruins it for cutting steel, tho'.

[okawbow]

I use a hand crank drill and the countersink never chatters.

[FDR]

I think my speed is to high,  I'll also look for a single flute like the one Acer showed and play with some brass stock.
Thanks
Kevin

You should be able to find one here
http://www.use-enco.com/CGI/INPDFF?PMPAGE=54&PARTPG=INLMK32

Fred

[WadePatton]

For any given material, chatter is going to be a function of Feed and Speed and Sharpness/Angle of tool.  Sometimes more pressure is the answer (higher feed rate).

This is something i recently worked through on the cold-saw at work.  Other guys get chatter.  I don't.  I vary the pressure 3 times going through the work.  Increasing the pressure through the thick part of the stock (round stock) is critical to chatter killing.  Then easing off in order to avoid burr.  Easy to work through this with thousands of cuts to be made. 

Rheostat for the drill press eh?  I'm going to look into that.  Electric hand drills now all have wonderfully variable speeds.  Remember the old ones that didn't?

[Bob Roller]

I have used drill presses with a foot switch that was a rheostat and that is on hand gadget.
'Bob Roller

[WadePatton]

I have used drill presses with a foot switch that was a rheostat and that is on hand gadget.
'Bob Roller

Like a sewing machine...excellent!

I love footy controls.  Going to put foot valves on my kitchen sink, but saving up for TIG machine now, with footfeed of course!

[kaintuck]

Home Depot sells a reasonably price 5 fluted ones......go slow.

Then when all else has failed, chuck the screw head into the drill, thru the piece, and coat the parts with valve lapping compound......turn on the drill and lap the head into the piece........then wipe off the goop from your shirt and face...

Marc n tomtom

[okieboy]

 I find that a brace can produce low enough RPM.

[WKevinD]

Just finished a set of countersinks- butt plate, trigger bar, and white lightning vent and a few scrap brass practice runs. I also swapped drills, I use battery operated hand drills and found my compact right angle Milwaukee easier to control speed and pressure than the Dewalt. I don't have the confidence that I am drilling a clean hole for tapping with a hand crank so unless I am using the drill press I'll use the batteries.
I have to get more of the countersinks (with the circular flutes) from CR Lawrence and try those again as well.
Amazing how one little task can become a technical puzzle that demands attention.
All of today's contersinks were smooth and clean.
Kevin

[B.Habermehl]

A little late for this thread.. I generally drill a small pilot hole, about 5/64 dia and counter sink this hole to the finish dia desired. I seldom have trouble with chatter. This method is the One I use for installing white lightning liners. The tap drill will center in the countersink and follow it down nicely. By using a pilot drill this small you can easily double check your touch hole position before final tap drilling. You can fudge the final position by making a chisel mark on the side you need to draw counter sink towards. The tap drill will center on the countersink regardless of the small pilot hole. BJH

[ironwolf]

  I use the method that Acer described above except with a small patch of one of those microfiber paper wiper thingys since I've got plenty around.  A doubled paper towel might work just as well.

   Kevin W.

[eddillon]

I use 3 layers of paper towel and run my cordless drill at low RPM.  No problems.

[Ray Barbarow]

Low RPM on any power tool. I use an old hand Brace for most of my countersinks.  I use pieces of denim from worn out jeans to dampen or remove the chatter. Sometimes dry and sometimes with lubrication.