On 2010-04-28, Jon Danniken wrote:
DoN. Nichols wrote:
Jon Danniken wrote:
My concern is that the bit will wander, but perhaps the size of the
bit (3/4") means it is stiff enough to resist skating. Also,
perhaps the top hole will serve as a drill bushing and keep the bit
aligned all the way through.
The "bushing effect" from the top hole will make up for a lot
with a bit that size.
[ ... ]
I would say that you can get away with it, because the drill is
being supported less than 2-1/2" from the drill point. Even if the
quill has a lot of slop in the casting the first hole will serve as a
one-shot bushing while you start the second side hole.
Thanks Don, I appreciate it. I found a suitably-sized MT2-shanked bit on
ebay, so we'll have to see how it's going to work out. Fortunately the
application isn't _too_ demanding of precision, so I'll know after a few
test pokes if it's going to work.
O.K. And you should still try the UniBit step drill in the
material. I think that you'll like how it behaves. (And your work
won't be trying to climb the spiral when it breaks through.)
Others have mentioned vises. I didn't because your original
fixture would prevent it being spun. And with that long a workpiece,
[ ... ]
For a nice lever-operating vise, take a look at MSC # 09145566.
[ ... ]
The price, however, is perhaps enough to send you elsewhe
$283.94
Aye, as much as I'd like to furnish my new tool with some well-needed
accessories, I'm relegated to cobbling up jigs for the time being, at least
as far as it is reasonably practical. Along those lines, I'm thinking of
using two sections of tubing (or very sturdy angle stock) bolted securely to
the table, leaving a channel between them to slide the long tubing to be
drilled through.
The long section to be drilled will already be scribed and punched, and I'll
tap it with a hammer from either end as required to encourage it into the
correct position. I'll come up with some means to secure it from rising up
off of the table in order to prevent a surprise when the bit pushes out of
it's hole.
O.K. For that, make an extra bolt through one of the guide
pipes, and a strap of steel to pivot over the workpiece to keep it from
lifting. Better if you have two about equidistant on either side of the
drill bit. And remember the sacrificial length of 2x4 under the
workpiece -- unless you carefully position the table so the center hole
will pass the drill bit. It would be a shame to drill dings into a
drill press table which has lasted unscarred this many years (based on
its appearance and its similarity to my 1975/76 one). :-)
Good Luck,
DoN.
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