# Drilling problems with a 9a



## brandon428 (Sep 19, 2021)

Have a South Bend 9a that I mainly use for turning work from the headstock.  I have no problem turning 1/16"+ steel per pass -- so plenty strong.  However, I went to drill some holes in the end of a 3/4" rod to turn a piece on center, and I'm having a heck of a time getting holes that don't require a lot of force and end up breaking my bits.  I have Keo's, so I'm not working with cheap bits.

If I put a dead center in my headstock and tailstock, and use a magnifying glass, they look in alignment.  So even if I'm slightly out, it shouldn't be enough to cause any issues.

I've tried both using my Jacobs 14N chuck and countersunk collet holders.  When I use the chuck, it moves slightly up and away when I hit the bar with the bit, but the collet stays steady. I can't get any play by hand.  My tailstock does seem worn, but again, can't imagine that could be causing such a problem.

Any idea what could be going on?


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## woodchucker (Sep 19, 2021)

how big a hole?
if you are drilling a large hole, are you pilot drilling it first.
the center of the bit really doesn't bite in.
What kind of material?
Stainless 304 is a ***** to drill if you work harden it. So if you are rubbing,  you can forget about it.


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## brandon428 (Sep 19, 2021)

I'm just talking about a #2 or #3 center drill.  I have trouble getting up to the countersink.

12L14 and 1018 steel.


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## woodchucker (Sep 19, 2021)

bad center drills?   turning the wrong way?

those are easy metals to machine..  Hard to believe a 2 or 3 would give you that much of a problem.  
is your rpm high enough? those little guys require speed to cut.


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## brandon428 (Sep 19, 2021)

Exactly my thought on the metal.

I only have 6 speeds, so I'm limited to 680 RPM, though I've been drilling at 392 (middle in normal gear).  You think that's fast enough?


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## pineyfolks (Sep 19, 2021)

Is your tailstock aligned?  Or are the adjustment screws loose? Is your tailstock worn and below center? That's what I'd check first.


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## brandon428 (Sep 19, 2021)

pineyfolks said:


> Is your tailstock aligned?  Or are the adjustment screws loose? Is your tailstock worn and below center? That's what I'd check first.


It's aligned by eye with a magnifying glass as I said, but I'm having trouble drilling a hole for a test bar to get it any better.  Unless you have suggestions for how I could check alignment without one.


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## Nutfarmer (Sep 19, 2021)

Maybe the center drill is dull


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## projectnut (Sep 19, 2021)

brandon428 said:


> Exactly my thought on the metal.
> 
> I only have 6 speeds, so I'm limited to 680 RPM, though I've been drilling at 392 (middle in normal gear).  You think that's fast enough?


That should be more than enough speed for a #2 or #3 center drill.  That's about the top speed for my Seneca Falls lathe, and I use it for drilling all the time.
My bet is a dull drill.  Use the same drill in the drill press or mill on a piece of flat stock to see how it performs there.  If you get the same results you know it's the problem.

Are you facing the part in the lathe before trying to center drill it?  If the surface isn't flat the drill will try to skate to the side.  That will make the drill hard to start and eventually break it.

As an FYI my bench style drill press has 5 speeds.  The lowest is 380 and the highest is 2250.  I drill anything from 1/16" to 1/2" at the lowest speed and it always works fine..  For the bigger stuff I go to the floor model.  It can go down to 60 rpm.  It's supposed to be capable of drilling a 1 1/4" hole in mild steel, but I've never gone over 1"


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## woodchucker (Sep 19, 2021)

I agree on the dull bit, if you have a drill press or mill try the bit there.
my SB9 is 750.. but 650 is good enough.
I don't believe the facing, or off center is your issue. you said you are already getting a hole, just can't go deep.

BTW instead of visually seeing if the points line up, try a ruler between points. it will quickly tell you if it's off. My eyes just can't seem to get those points easily lined up... I find it hard.


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## brandon428 (Sep 19, 2021)

Not dull, I tried more than one _brand new _bit.

I'll try 680 and a ruler to see how the points line up and will report back.


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## woodchucker (Sep 19, 2021)

brand new doesn't mean much, you may have a really bad batch. I've seen it, recently someone reported the same on practical machinist group.

if you have a drill press, give it a try, or even a regular drill.


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## Eddyde (Sep 19, 2021)

When I'm facing a piece of stock to be center drilled. I give the apron wheel a little "tap" towards the headstock just as the tool gets to the center, this gives a slight dimple that centers the drill perfectly.


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## projectnut (Sep 19, 2021)

woodchucker said:


> brand new doesn't mean much, you may have a really bad batch. I've seen it, recently someone reported the same on practical machinist group.
> 
> if you have a drill press, give it a try, or even a regular drill.


I agree.  In a brain dead moment a few years ago I ordered a box of #2 center drills.  I'd been looking at Keo's all day and didn't realize the ones I ordered conveniently lacked the brand name.  I ended up with just what I ordered.  A box of cheapie chinesium ones that wouldn't cut hot butter.  It wasn't just one, the whole box full was rubbish.  I pitched them in the trash and ordered a box of Keo's. 

Like most tooling the prices are going out of sight lately.  2 years ago a #2 Keo 60* center drill was selling for $2.00 when buying singles.  They were as low as $1.25 per unit when buying by the box.  I loaded up at the time buying several boxes of #1s, #2s, and #3s.  I bought 2 boxes each of #4s, #5s, and #6s.  They were all under $5.00 a unit when purchased by the box.. Today #4's are around $5.00 to $6.00 a copy, #5s are around $8.00, and #6s are around $12.00 plus shipping when bought as singles.  Why the #4s remained the same price and the 5s, or 6s are so much more expensive is a mystery to me.


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## pineyfolks (Sep 19, 2021)

brandon428 said:


> It's aligned by eye with a magnifying glass as I said, but I'm having trouble drilling a hole for a test bar to get it any better.  Unless you have suggestions for how I could check alignment without one.



You could sweep the tailstock quill or a dead center with an indicator held in your chuck


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## Technical Ted (Sep 19, 2021)

Center drills like fast speed and light feed.... I've run them slow, but I baby them feed wise with plenty of cutting oil. Unless your tail stock is way out of alignment, I would say you are running too slow for the feed you are using or you aren't using cutting oil which will make things worse. 

For example, when using a center drill in my Bridgeport I'm running over 1000 RPM. If you are running ~500 RPM you will need to be pretty soft on your tail stock feed wheel or you will break that center drill for sure.

Good luck,
Ted


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## Technical Ted (Sep 19, 2021)

For whatever size center drill you are using, measure the drill point diameter. Look that diameter up in the HSS speed charts available on-line. I think you will find that a 1/8" diameter drill should be run probably ~2000 RPM. Don't quote me on that number, because I'm guessing, but it's a lot faster than your lathe runs.

Bottom line.... feed VERY lightly and use plenty of cutting oil to help. 

Ted


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## SLK001 (Sep 20, 2021)

I suspect something else is amiss.  Even a cheap center drill should have no problem with those two steels.


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## neilkingent (Sep 20, 2021)

I only use cheap center drills on my 9b and don't have any problems. And my machine is wore out and I have no idea the spindle rpm

Sent from my SM-N975U using Tapatalk


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## mmcmdl (Sep 20, 2021)

Try a spotting drill . If it drills easily I'd say it's dull center drills .


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## brandon428 (Sep 20, 2021)

Ok, so I ran it on the highest speed today, and I now see that my center drill is mildly shaking vertically, which I suspect is the problem.

So perhaps it is alignment after all...


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## tq60 (Sep 20, 2021)

Tail stock out of alignment.

Make a spool to check it.

Search my posts for a detailed instruction on making and using.

Sent from my SM-G781V using Tapatalk


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## brandon428 (Sep 20, 2021)

Your threads on making a spool require drilling a center. 


tq60 said:


> Tail stock out of alignment.
> 
> Make a spool to check it.
> 
> ...


Your threads on making a spool require drilling a center.  So...


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## pineyfolks (Sep 21, 2021)

It's possible that the base of your tailstock is worn from years of use. If so placing the correct size shim stock between the upper and lower half of the tailstock will take care of it.


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## SLK001 (Sep 21, 2021)

brandon428 said:


> Ok, so I ran it on the highest speed today, and I now see that my center drill is mildly shaking vertically, which I suspect is the problem.
> 
> So perhaps it is alignment after all...


A drill will try to self center - even with it being out of alignment.  This doesn't explain why it isn't drilling into mild steel (it does explain why you are breaking small bits).


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## tq60 (Sep 21, 2021)

brandon428 said:


> Your threads on making a spool require drilling a center.
> 
> Your threads on making a spool require drilling a center. So...


In the old bays you marked the center with a square and drilled it on your bench.

If a center drill does not work it is baaaaad.

One could try extending the quill fully with leaving the tail stock loose and pushing by hand.

It will self center maybe.

Or...

Just face the stock and notice the bump in the middle.

Place a center in the tail stock and adjust until it aligns.

Not perfect but close enough to possible work.

Sent from my SM-G781V using Tapatalk


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## mmcmdl (Sep 21, 2021)

They sell offset bolts . Perhaps you could find an offset chuck ? ! 









						BOLTS COD COD for Holes Counfot for Roles Drillad Too Deep Crooked Then for Misnatched for Holes Too Near the Edge Holes Straight for Holes Counter for Holes Drilled Binocular Bolt for for Holes Not Double Drilled Holes Dried Straight Sunk on Wrong S
					

BOLTS.  COD COD  For Holes Counfot  For Roles Drillad  Too Deep  crooked Then  For Misnatched  For Holes Too  Near The Edge  Holes  straight  For Holes Counter For Holes Drilled  Binocular Bolt for  For Holes Not  Double Drilled Holes  Dried straight  sunk on wrong side.  Too Big Then  Right...




					me.me


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## stupoty (Sep 21, 2021)

SLK001 said:


> A drill will try to self center - even with it being out of alignment.  This doesn't explain why it isn't drilling into mild steel (it does explain why you are breaking small bits).





brandon428 said:


> When I use the chuck, it moves slightly up and away



The chuck is "probably" pulling towards the rotation center which might help with the shimming of the tail stock.

Stu


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## brandon428 (Sep 27, 2021)

I ordered an Edge Tailstock Alignment Bar and found I was off .003 vertically and .015 horizontally.  I shimmed the tailstock by .004 (assuming the bed is more worn closer to the headstock) and corrected the horizontal.  Drills now stay centered (don't move/shake) and drill clean.  Not like butter, but they go.

Surprised that being offset by such a small amount makes so much of a difference, but I guess I shouldn't be.


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## Technical Ted (Sep 27, 2021)

I doubt very much that being a few thousandths off would cause a center drill to break. Without seeing how hard you are feeding that center drill and not knowing your experience level I'm just guessing, but all the guys who broke center drills where I used to work were feeding them too hard for the speed of that the spindle was running, both in lathes and mills. They are fairly delicate and break easily. You need to baby them and use plenty of oil.

Ted


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## brandon428 (Sep 27, 2021)

I do baby them with oil and a minor advance every few seconds, pulling out occasionally to clear the chips.  Regardless of your doubt, my method didn't change and I was clearly breaking them before and am not breaking them now. 

That said, I did use new bits (since my old ones broke), so it could arguably also be a bad batch, though they were shaking before and they aren't anymore.


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## brandon428 (Sep 27, 2021)

On that note Ted, if the goal is to drill centers for turning on centers, is there a "faster" method than center bits?  I know some people prefer spotting bits.


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## Technical Ted (Sep 27, 2021)

I use center drill for both centers for turning on centers and for starting a drill. I know lots of guys use spotting drills for starting holes for drilling and that might be better for that, but I don't have any so I use center drills.

Like I said, without seeing what you are doing and not knowing your experience level I was just sharing what I've seen/learned in the past. Didn't mean to say or imply you didn't know how to run a center drill. Just throwing things out in an attempt to help.

Ted


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