|
|
|
Plug cutting |
|---|
| message from N. Thornton on 15 May 2004 |
Hi
Have drilled holes with a 13mm auger, and have cut wooden plugs for
them with a 13mm plug cutter. Needless to say the 2 dont match, the
plugs are rather too small.
1. Why?
2. Solution?
The plug cutter is absolute crap. It is extremely slow to cut, and
reaches smoking point before producing even a shallow wood plug.
Thanks Toolstation.
Regards, NT
|
| Dave Plowman replied to N. Thornton on 15 May 2004 |
I've always used twist drills since it usually covers a screw and they
give the correct taper at the hole bottom. So I usually start with a
slightly smaller one.
I've got two different types - one a set from Screwfix with four cutters,
and others bought singly from my local toolshop with two. I've not found a
problem, although I do use them in a drill press.
|
| Dave Liquorice replied to Dave Plowman on 15 May 2004 |
Er no they don't a twist drill is normally(*) 118 deg at the tip a
counter sunk screw head is 90 deg...
(*) For general purpose use.
|
| Dave Plowman replied to Dave Liquorice on 16 May 2004 |
Something like that - I should just have said taper. I just think it would
be better than that made by most wood bits.
|
| Peter Taylor replied to Dave Plowman on 16 May 2004 |
I did some trials on Beech skirtings last year with an American plug cutter from
Isaac Lord (about £13.00) and using a drill press. The neatest holes I could
drill were using a Forstner bit http://www.axminster.co.uk/default.asp?sub=303,
and they came out really fine. No matter how gently I did it, the twist drill
(without a vertical blade) tore the grain slightly. Sorry that advice comes too
late for you now.
Peter
|
| Dave Plowman replied to Peter Taylor on 16 May 2004 |
Unfortunately, they don't appear to do a 1/2" size, which is the most
common one I use.
I agree a twist drill isn't ideal, but if it's a choice of getting a plug
to fit correctly or not, it's a decent compromise, given that most will
have a set going up to 1/2".
|
| Tony Williams replied to Dave Plowman on 16 May 2004 |
My lathe book shows how to grind a twist drill
for wood drilling without 'rags'.
It has a small central point, two outer points,
and slightly sunk cutting faces with a large
backing off.
The author says "In spite of their somewhat
complicated appearance these drills are quite
simple to grind up". But I've only ever been
able to do a bodged version.
|
| Dave Plowman replied to Tony Williams on 17 May 2004 |
You can buy them in any decent tool shop. The sheds also have them, but
usually in limited sets.
|
| Pete C replied to N. Thornton on 16 May 2004 |
Hi,
A plug cutter from a woodworking site would probably be better. Can
you sharpen it in any way? Maybe there needs to be more rake behind
the cutting edge.
cheers,
Pete.
|
| N. Thornton replied to Pete C on 16 May 2004 |
Yeah, the angles on it are hopeless. I was just afraid to put any
angle on it as the unsupported metal would then be subject to
substantial downward forces and may bend. But maybe its whats needed.
The cutting edge is almost 90 deg, and the bottom edge of the cutter
is all level, that could be shaved back as well.
Meanwhile I'm stuck for a plug solution for my 13mm+ holes. :(
Regards, NT
|
| Pete C replied to N. Thornton on 16 May 2004 |
Hi,
Thinking about it some more it may be better to remove some material
before the leading edge rather than from behind it, to create a slight
step between the two.
If you have a router and a straight bit, a jig with the right sized
circle in it would allow a circular slot to be routed out.
Or if the holes are just over 13mm then perhaps a machine shop could
drill or turn the inside of the plug cutter to make it big enough.
cheers,
Pete.
|
| Dave Liquorice replied to N. Thornton on 17 May 2004 |
Have you a chisel? Preferably sharp sharp. Cut you own from the wood
you where going to use the plug cutter on.
|
| Dave Plowman replied to Dave Liquorice on 17 May 2004 |
Proper plug cutters that work are available from the bigger sheds and work
fine even in hardwood.
|
| N. Thornton replied to N. Thornton on 15 May 2004 |
I measured the plug cutter, it is exactly 13mm inside dia. I guess the
drill bit cut bigger than 13mm as it wandered, the cutter did
smaller... result a hopeless failure to fit. But what to do now? I
guess I need a 14mm or 15mm plug cutter!
Thanks, NT
|
| RichardS replied to N. Thornton on 18 May 2004 |
how many plugs do you need to cut (will have a bearing on how practical this
solution is...)?
I recently needed to plug a hole left by (incorrectly positioned) 5mm wood
bit.
you can't get 5mm plug cutters (well, at least not in our local tool shop,
nor Axminster) so I got a 6mm one, cut the plug, held it in the chuck of my
mains drill and sanded it down against some 80 grit paper taped to the
workmate. Keep checking until it just fits, then flip the plug around and
sand down the remainder of it.
this would work if you bought an over-sized 14mm or 15mm plug cutter.
I used the mains drill as the cordless couldn't match the speed, and it
would have taken forever.
Of course you realise that the solution to the problem in the future is to
buy something like one of Axminster's tapered plug cutter & tct bit sets....
|
| Dave Plowman replied to RichardS on 18 May 2004 |
Wouldn't it have been easier to enlarge the hole to 6mm? If it's a
mistake, it would hardly make a difference.
|
| RichardS replied to Dave Plowman on 18 May 2004 |
Sadly not, I did consider it though.
Having drilled the hole incorrectly in the face frame of my prized hard work
(I know, measure once, cut twice...!!! but in my defence the hole was
precisely where I had carefully measured it to be, just failed to take
account of the clearance required for screw-in hinges mounted side-by-side
so hole correct, measurement correct, calculation wrong) I really didn't
want to risk a cock-up on the enlargement front and wanted to keep any
visual impact minimal.
So, 5mm plug it had to be...
Fortunately it was finished in danish oil & wax, so the finish touch up was
a doddle and it really is barely visible.
|
| Jerry. replied to N. Thornton on 15 May 2004 |
Outside dia' of the hole cutter is 13mm, the resultant plug will be that
LESS TWICE the thickness of the metal used to make the cutter - think about
it...
Find a hole / plug cutter with the correct INSIDE dia' !
|
| Dave Plowman replied to Jerry. on 15 May 2004 |
I've got two different types, and they both cut a plug of the size they
say - anything else would be a nonsense.
|
| Jerry. replied to Dave Plowman on 15 May 2004 |
I quite agree, but I was just trying to point out what probably went
wrong....
|
| Dave Plowman replied to Jerry. on 15 May 2004 |
Nice theory, but I'd guess NT would be wise to that - after all they'd
look miles out. My 1/4" plug cutter has an O/D of approx 1/2" which is
near as dammit 13mm. You'd have to be near blind to think it would fit a
1/2" hole.
|
| Dave Liquorice replied to N. Thornton on 15 May 2004 |
Auger bit is 13mm across the metal. It will have wandered a bit during
drilling and unless the point and lead screw is absolutely dead center
won't rotate about it's true center either.
Buy matched pair of plug cutter and drill? Use 12mm auger bit and
sand/par down the plug to fit?
|
|
