Setting up a boring head

[MetalMarvels]

I have not had much call to use a boring head on my mill, but the time had come.... In the past, I set the boring head up as close as I could "eyeball" it, but undersize. Then positioned over the hole and slowly incremented the head until I got touch-down in the roughed hole. After that came the tedious process of bore, measure, adjust, bore, measure, adjust, ....... etc. My question is how do some of you folks set up your boring heads for a particular hole size? Is there a "quick" was to set the offset and "know" what size it will cut? I have not figured out how to "directly" measure the size the boring bar will cut.

[Keith Graydon]

quote:

---

My question is how do some of you folks set up your boring heads for a particular hole size?

---

I have succeded in distilling the essence of that procedure and I save it in small, precious, Crytaline Flasks. From time to time I sell one or two Flasks to those searching for a solution. I am very wealthy.../end fantasy

 

Er, Ah, no. I just do "touch and go" Then break an insert......

[MetalMarvels]

yeah, so far it really BITES when everything is dialed in to a gnat's eyebrow and then you chip the insert.

[Harryman]

Cool fantasy.

 

Let's say you want to cut a 2" bore, you can position the spindle 1" away from a known edge and touch off on it.

[Thad]

Harry, you beat me to it.

 

Thad

[Rekd™]

What boring head? Criterion? Or a good one?

 

I'll dial them in using calapeters to with +.002 then measure with a bore guage. Then I'll get out the mag-base and put an indicator on the boring bar, in the direction of the cutting surface. Having measured the hole with a guage, I'll offset the boring bar 1/2 the amount of difference in diameter, and away you go. I can generally get to with a couple tenths the first try using this method.

 

On the criterions, they have 3 set screws for the adjustment. Use these for fine adjusting, (you can fine adjust under .0005" just by loosening and tightening the set screws (in no particular order) and it will change the dia. Use the indicator to see which way it's going.)

 

'Rekd

[Scott Bond]

I use the criterions for short runs, I use the set screws to create a constant dragg that will allow me to almost trust the dial, and will also stay put when the required demention is achived.

 

Scott teh' did you guys hear about the guy who drank six cokes but burped 7 up .

 

[ 10-02-2003, 02:49 PM: Message edited by: Scott Bond ]

[Müřlıń®]

quote:

---

I save it in small, precious, Crytaline Flasks.

---

LOL .....

 

 

Murlin

[crazy^millman]

Well Metal you can alway like at a boring system if the job has the money for it. otherwsie besides that flask idea pretty much the fun way we all do it point and shoot.

 

Crazy Millman

[iowajim62]

Hi all,

 

quote:

---

pretty much the fun way we all do it

---

Unless of course you are fortunate enough to have and use an Optical Presetter. Parlec is my preferred toy to play with for this task.

[Marty A]

i used to bring my bar until i touched the side

of the hole. i would then take a skim cut and check the size. if your used to boring alot this only takes a few seconds of your time.

 

 

marty

[MetalMarvels]

I have a couple of nice Ramsey heads and a POS Criterion head. The Ramsey's allow me to bore open holes (i.e. nothing in the middle - like a spigot or other center feature that you have to reach past and bore around). Unfortunately, they have a limitation in travel (what head doesn't). On this job, I will have to use the Criterion since there is a "tube" feature in the center of the bore...

 

Harryman.. that just might work - I do have a mag-base tool setter (the LED type, 2.000 inches tall) that I could set on a vertical surface that I have "measured" for the X (or Y) position. At least that would get me very close.

 

I never have figured out how to use calipers to accurately measure a single-point boring head - I can see how it would be doable with a double-insert head.

[Müřlıń®]

quote:

---

i would then take a skim cut and check the size

---

+1

 

Only way to be sure if you are using a dial out head.

 

I usually take two cuts the same depth to make sure I have all the spring dealt with and measure in 4 places with telescoping guages and mic to make sure the cut is repeating.

Then take your finish.

 

One can get fairely close...+ or - .0002 or so.....depending on the finish you are getting.

 

quote:

---

I never have figured out how to use calipers to accurately measure

---

You can't use pert-neers for anything close...

 

Murlin teh old school boring on a wore out machine.....

 

[ 10-02-2003, 05:56 PM: Message edited by: Murlin ]

[skeetboy25]

my prefered (slacker) way is to place a small piece of sheet stock under the head, coat with steel ink (dychem) and barly tap with the bar, you can then remove this and measure your arc at your leisure (as in not hanging over the bedway) with calipers. from there you should be able to dial in/out as needed. I rarely have to reajust as this is surprisingly accurate (+/- .0005). I only do this on manuals though, much prefering contour operations on cnc's.

[Brendan P]

I alway just cut the part at any damn dia.then junked the 1st. pc. and told the boss it was a "set up" piece anyway!

J/K

[Keith Graydon]

Part of the tool set to our old, but perfect, SIP Jig Borer.

 

[Jack K]

kaiser boring head & a kaiser presetter works a ok for me. on the dime all the time.

 

 

Jack

[CAM-mando]

When doing lots of boring I sometimes use an indicator to get close. It sometimes pays to have some scrap material prebored for this also when dealing with expensive workpieces.

 

We has a composite part that our customer supplied material for. Very expensive Rotor blate parts. We sawcut the rough shape then profiled and bored a close tolerance hole. 90% of the rejections were o/s bored hole. The kicker was that each part had a big hunk of drop that had been sawcut off and the parts were pre drilled and reamed off the machine in a jig. So we made it part of the process to drill and ream a couple of scraps with each lot. Anytime the an inser was change they adjusted the boring head on the scraps. TOTAL job time went DOWN.

[MetalMarvels]

Thanks guys! Nice tool set there Keith!

 

When (if ever) I can afford it - it looks like I should check out the Kaiser boring heads - sounds like it is a favorite out there.

[MetalMarvels]

If you hear a VERY loud BANG!!! And a boring head setup magically appears stuck through the machine shop wall.... Not to worry, just me throwing this POS Criterion boring head out of the shop... tried shorter bars, tried longer bars, tried faster and slower speed and feeds, tried monkey snot on the bar to dampen it, tried carbide, tried two styles of insert, tried different DOC.... Freaking thing is BORN to sing!!!! IF I HAD WANTED TO HEAR A SONG I WOULD HAVE TURNED ON THE RADIO!!!!!

 

One day I hope to own a REAL boring head setup... but not today....

 

[gcode]

I've had pretty good luck with them when mounted

directly to a Cat 40 toolholder. They didn't work very well for me as a straight shank in an endmill or collet holder.

[crazy^millman]

Ok now you got to pull the rabbit out of the hat. Frist trick make sure you have alot of the part clamped into soemthing. If you have apart sticking as little as 1 inch out of vise the part is what is acuttllay causing the virbation. I was alo get me a box of rubber bands and wrap the bar alomst to the point of my favorite way crazy. Next thing take your insert and hand grind relif is such a way you are almost creating a scoop. I have even take clamp to the top of a part to create down force and has seemed to elimate the probelm. The last trick and I promise will give you the best results get a circle carbide boring bar and use it for the bar. The bar is expensive but I found this the cure all for all my tricky boring operation goes lath or mill included.

 

Crazy Millman

[Allan]

MetalMarvels, have you tried a regular old piece of momax or HSS, A good sharp edge will get rid of that song.

 

Allan

[cadcam]

Keith,SIP Jig Borer. Have one at my work. Nice precision machine we us it for tenths and millionths holding.

[robk]

As Jim mentioned earlier-- an optical pre-setter works nice but expensive. If you get a chance check out Command Urma Digiset 2. It's still not that cheap, but works beautiful.

 

Rob