Long boring of end grain.

[EchoSevenNine]

Morning chaps,

Currently making a few straight stemmed tobacco pipes as a request from a friend but having trouble getting a straight hole bored down the middle.

I'm using 20mm x 20mm Walnut about 200mm long. Start boring a 2mm hole, but end up breaking through the side after 4 or 5 inches.

I tried hand boring one with the drill and after 5 or 6 attempts i made it from one end to the other and then fixed the holes between centres and turned it down. Wasted a lot of timber in the process though.

Ant tips anyone? I realise that the grain is throwing me off with such a small diameter bit, but surely there must be some way round this?

Cheers,
Eddie.

 

[J-G]

Are you turning the work or the drill?

 

[woodfarmer]

If you can, spin both the workpiece and the drill so they are contra rotating, not going the same way. It may be possible using a hollow centre and an electric drill.

 

[graduate_owner]

I wonder whether the use of a chuck in the tailstock plus a drill bit would be allowing too much flexing. Could you perhaps get a morse taper drill bit, so avoiding the extra length of the chuck and arbor and making the drill more rigid? Another possibility might be to use a short drill bit to start with so as to flex and wander less, then increase the bit length as you go deeper. Anything really that will improve rigidity might be worth trying. If you use slightly oversize timber then mount between centres using the holes each end ( which may not be completely central) you might get a satisfactory result.

K

 

[gregmcateer]

Eddie

Go Slow, slow, slow and withdraw often to clear the shavings.
(I may be teaching the old egg-sucking, but always worth mentioning what may seem obvious - I didn't know until I was told)
Some folk recommend a bit of wax on the shank of the drill bit. I've never tried it, but would imagine it could help.

Best of luck and let us know how you get on.

Greg

 

[Paul Hannaby]

Yes it's probably the grain in the wood pulling the drill off centre.

The best way to drill long straight holes is to use a gun drill. They are hollow and can be attached to an airline to blow the shavings clear as they drill. However, they aren't cheap!

 

[Xim]

or chop the stem into differing sections of wood maple - ebony - maple - ebony
etc

 

[J-G]

The best way to drill long straight holes is to use a gun drill. They are hollow and can be attached to an airline to blow the shavings clear as they drill. However, they aren't cheap!

All due respect Paul but I think you missed the size of hole that EchoSevenNine is trying to drill - Getting a 200mm long 2mmØ drill at all is a tall order.

I've asked if he's turning the work or the drill but without response so I'll try to explain how I would approach the problem. It is important to drive the work-piece and to keep the length of drill out of the chuck as short as possible - ie. start with a normal 'jobbers' length drill with only (say) 5mm protruding. Once that length is drilled, extend the protrusion by a further small amount and repeat as necessary, changing drill-bits as required.

Whether or not it would be possible to drill a 2mm hole through 200mm I cannot say but that's the way I'd try.

 

[duncanh]

J-G beat me to it. I would suggest having a series of 2mm drill bits. Start with the shortest and work your way up.
Also start with the timber more oversize - more wastage during the turning but if you're having to scrap attempts due to wandering drill it's worth a try.
Also look for the straightest grain you can find.

 

[EchoSevenNine]

Thanks for all your replies guys.

Sorry for the late reply, i'm only getting back to my computer now after a busy evening.

I've tried spinning the work and boring fron the tailstock with no success. I have also tried hand drilling with the cordless and the work in a vice, with SOME success.

As suggested, i think the combo of heavy grain and a long flexible bit are against me, but with taking some of the above advice on board and a nice bit of straight grained birch i managed to make it all the way through with the cordless and vice option. Spun it up between centres afterwards and came out great.

Advice much appreciated gents, thanks.

 

[chipmunk]

How are you starting the drill in the blank?
My suggestion is to use either a machinist's centre-drill to create a small dimple or create a small one with a spindle gouge so that the drill enters dead on centre.
The other thing is how well aligned are your tailstock and headstock centres?
Did you check them with a kiss test with and without the drill bit?
If they are not bang-on then contrary to intuition you can use a handheld drill chuck and high speed on the lathe. As before keep pecking and withdrawing concentrating on keeping the flutes clear and the drill straight. Do not force the drill in.
HTH
Jon

 

[gregmcateer]

As suggested, i think the combo of heavy grain and a long flexible bit are against me, but with taking some of the above advice on board and a nice bit of straight grained birch i managed to make it all the way through with the cordless and vice option. Spun it up between centres afterwards and came out great.

Advice much appreciated gents, thanks.

Photos, Eddie, Photos!!

 

[Paul Hannaby]

You can get gun drills smaller than 2mm and yes, they are still hollow!

 

[J-G]

You can get gun drills smaller than 2mm and yes, they are still hollow!

Thanks for that correction Paul. I was aware that there are hollow drills down below 2mm but hadn't had need to research them at 100 : 1 ratio.

I do have 2mm Ø long series drills but only just over 80mm long with 55mm flutes.

 

[Walney Col]

If the grain is pulling the drill I would have thought the logical thing to do would be to start with an oversized dia blank, drill your hole through, it THEN put it between centres to turn the OD. Doing that would mean thay the OD would be aligned with the grain too which probably makes for a stronger stem.

Col.

 

[EchoSevenNine]

The simple fruits of my labour... haven't been turning long.

Both stems are Birch, one dyed black. The bowls are an unidentified species that is VERY nice imo.

Really enjoyed making these so more in the pipeline (pun intended)

 

[CHJ]

.......The bowls are an unidentified species that is VERY nice imo.

...

Neatly turned and pierced, but please be careful of using woods that you have not positively identified, some can be very toxic and/or severe sensitizers to some people.

See here taken from the turning Help and Safety links Wood hazard Links page.

 

[EchoSevenNine]

Thats a hell of a list and tbh i cant really think of many more that aren't on it.

i turned Cocobolo a while back and it was crazy irritating... never again. Well, small pieces only.