Hole drilling advice please

[Lightweeder]

I can't seem to drill a hole of any kind, in any work piece, without it waggling about and making the entrance hole too big. Always seems to settle down eventually, but ruins the entry point. Not only on a deep piece, it also seems to happen on a piece as shallow as a couple of inches. I've also got some quite (relatively) expensive drill bits like the Colt pen drill and Colt forstner bit. I'm not using it for pens, but it's just as well really :? Is this a common problem please :?:

 

[loz]

Using a jacobs chuck LW ? - your taper clean where the chuck is held ? - drills straight ? the wood holding chuck running true ? are your centres lined up ?

 

[Lightweeder]

Not using a Jacobs Loz, though I have one. Yes to everything else.

 

[loz]

Drilling by hand then into stock ?

You could make a guide to mount in the banjo that could be used on both face and side of stock i suppose to help.

 

[Bodrighy]

I stick my Jacobs chuck into the tailstock and wind it in to drill in a piece. Most times it works fine though there have been the odd occasion when I have ended up with an oval hole, usually if I haven't centered the headstock properly after having it turned off the bed.

pete

 

[Paul.J]

Also make a little recess for the drill to locate the center better when using the JC.

 

[tekno.mage]

I wouldn't expect oval holes with small drills (6mm - 10mm) if held by hand, providing you make a little centre recess in the work for them to start in with a skew chisel or similar before trying to drill the hole. I often use an 8mm drill mounted permanently in a nice to hold oak handle for this very purpose. I find it can also help to slide the banjo down the bed a bit, swing the toolrest around 90 degrees and use it to rest my arm on during the drilling.

With larger bits the problems can really start and I wouldn't attempt to hand hold larger forstner or flat bits. Even when securely held in the tailstock using either a jacobs chuck or a collet and drawbar system I've seen the "waggle" apparent on forstener bits when drilling into end grain - and the quality of the bits doesn't seem to make much difference to this - my expensive forstners waggle as much as my cheap ones!

As I can hollow out a box to a depth of a couple of inches pretty accurately (and more importantly not oval!) using a gouge and scrapers in under 2 minutes, I now keep my forstners for use with the pillar drill rather than the lathe! The gouge & scrapers stay sharp rather longer than the forstner bits, and are actually easier to sharpen as I have jigs set up for them.

Kym

 

[paulm]

That reminds me, I got a few of these for the same problem, drilling with smaller drill bits in end grain on the lathe (or pillar drill).

Haven't tried them yet but in theory the short length of small diameter drill at the end, supported by much larger diameter behind, I'm hoping will give a decent starter hole to locate the end of a normal bit into.

Same principle I guess as using a skew point or similar to start a hole which may be sufficient and an alternative.

Cheers, Paul

 

[tekno.mage]

Centre drills will work just fine.

Kym

 

[Lightweeder]

Not sure if I've been misleading. I'm not doing this by hand. I take the revolving centre out of the tailstock and put my bit direct in its place. All bits wobble for a bit, before settling down and making the correct sized hold.

 

[paul-c]

hi lightweeder
have you checked that the tailstock is lined up with the headstock correctly :?:

 

[CHJ]

LW are you sure your Headstock Spindle and Tailstock Quill are aligned?

Point to point contact of centres is not a guarantee that they are.

I have seen machines that have point to point contact but the Tailstock Quill out of alignment, fitting something like a Jacobs Chuck in the tailstock or a long drill takes the leading drill point off centre.

If you have a hollow spindle try shining a bright light through from the left end and checking from the rear (right end) of the tailstock.

 

[Lightweeder]

I'd assumed it was aligned, Chas, as I would have expected all manner of problems otherwise. I can't understand how it always appears to correct itself half way through. I'll have a further check today and see if I can see anything. If it's not correctly aligned, is there anything I can do about it ?

 

[loz]

Not sure if I've been misleading. I'm not doing this by hand. I take the revolving centre out of the tailstock and put my bit direct in its place. All bits wobble for a bit, before settling down and making the correct sized hold.

I mioght be wrong but im not sure this will work out for you - My quill is a morse taper, and thus tapers, all my drills are straight..... and thus will not seat properly in a quill, and will wobble


Unless you have taper drills ? http://www.handyhardware.ie/cat/A130-Morse-Taper-Shank-Drills/Dormer/278/1410

 

[CHJ]

I'd assumed it was aligned, Chas, as I would have expected all manner of problems otherwise. I can't understand how it always appears to correct itself half way through. I'll have a further check today and see if I can see anything. If it's not correctly aligned, is there anything I can do about it ?

Does it happen regardless of drill diameter or type?

 

[Lightweeder]

Does it happen regardless of drill diameter or type?

Seems to happen with every drill bit. I discarded a brand new pen drill in favour of a shorter wood drill, and it still happened.

I think what was supplied in the tail stock is a type of Jacobs chuck, but please, guys, what's a quill ?

 

[loz]

LW can you take a photo of your drilling config, ?

Might help diagnosis.

Regs

laurence

 

[CHJ]

but please, guys, what's a quill ?

I was using the term to describe the tailstock spindle that you advance with the handle.

 

[Lightweeder]

LW can you take a photo of your drilling config, ?

Might help diagnosis.

Regs

laurence

I'll try and do that tomorrow Loz.

Thanks Chas. Sorry for my ignorance.

 

[Lightweeder]

With larger bits the problems can really start and I wouldn't attempt to hand hold larger forstner or flat bits. Even when securely held in the tailstock using either a jacobs chuck or a collet and drawbar system I've seen the "waggle" apparent on forstener bits when drilling into end grain - and the quality of the bits doesn't seem to make much difference to this - my expensive forstners waggle as much as my cheap ones!

As I can hollow out a box to a depth of a couple of inches pretty accurately (and more importantly not oval!) using a gouge and scrapers in under 2 minutes, I now keep my forstners for use with the pillar drill rather than the lathe! The gouge & scrapers stay sharp rather longer than the forstner bits, and are actually easier to sharpen as I have jigs set up for them.

Kym

What I need to do, from time to time, is to drill a hole 16 mm in diameter and 75 mm deep. The entry point is invariably well over 16 mm.