mitering program by Giles Puckett produced Dec 1998. And the text file to accompany it.
program in Excel for use with Autocad - http://members.austarmetro.com.au/~cesnur/
- Stephanie Monfrey's
- See the JD Squared Inc Commercial Holesaws
100 Tubing Notcher
- From: Jeff
Subject: Cutting large diameter tubing
The usual way is with a hole saw. It will take a drill
press, and a good vise. PEI and others make a neat
centering gadget to go in a drill chuck. (its a pivoting
V). To get the angle, I would just tilt the table.
You can come surprisingly close without the tilt by
offset drilling. The tube miter template program (on the
web site) will be helpful in positioning. (I modified the
one that came as source to print a center mark) I would
use a slightly smaller hole saw, and finish up with files/grinder,
as the offset method doesn't produce quite the right
If you don't have a drill press, I would make a wooden
guide block (as solid wood will cut less erratically than
partial engagement of a metal tube. I would consider this
hole a good excuse to spend the $150 or so that a medium
size hobby grade machine would cost. (for hole saw work,
look for one with slow speeds. 200 rpm or less preferred)
- From: Don Ferris - Anvil
Lots of folks use lathes for mitering. It has it's
limitations but works well and offers a very rigid
structure. Myself, of all the different methods, I prefer
a horizontal mill.
Using end mills for mitering tubing works - the thicker
the tube wall, the better. The down side is cost and the
fact that even multi-flute end mills can crush a tube in
a blink of an eye if your feed rate is not perfect. End
mills of proper size for bike tubing are also expensive -
sometimes very expensive. If you decided to pursue using
end mills, then I suggest you use multi-flute roughing
end mills. Roughing mills do not impart the torque loads
on the tubing that a standard end mill does and they
still make a fine, smooth, miter. The thing to keep in
mind is that with thin wall bike tubing, the greater the
TPI (tooth per inch), the better cut you're going to get
and the less tooth load you have on the cutter (which
means a lesser loads on an easily deformed or crushed
tube). David Bohm is developing a cutter that sounds very
promising and I look forward to using one. If you want a
easy/safe way to miter tubes, then use a vertical spindle
belt sander with interchangeable mandrels for miter size
and flood coolant. I'm in the process of developing a
reasonably priced version for resale to hobbyist and pros
and the testing is very promising.
- Date: Tue, 27 Jun 2000
From: Tom &
Subject: [Frame] quiet mitering
I just discovered something useful. You know how tubes
sometimes make that horrendous screeching noise when
you're filing and sawing on them? I HATE that noise. I
want peace and quiet when I work. And after all, bike are
supposed to be peaceful, quiet machines, right? Of course
often you can get rid of the noise by clamping the tube
closer to where you are working (or wearing ear plugs).
But sometimes that is not practical (and ear plugs are a
So today I found that you can use a spring clamp (the
type they sell in hardware stores that look kind of like
giant clothespins) to eliminate much of that noise. Just
clamp the thing onto the tube somewhere between where you
are working and where the tube is chocked in your vise.
With a little experimentation you will be able to find
just the right location to deaden the unwanted vibrations.
And the clamps that have vinyl coated jaws seem to work
better than ones with just bare metal.
- Date: Sat, 19 Aug 2000
From: tubus_nl, import
Subject: Mitering small tubes
List-Id: Amateur and professional bicycle frame building
You can get some pretty small holesaws, but not in the
welded variety. And allthough you can miter tubes with a
hacksaw and a file, it can be a pain with small flexible
tubing and shallow angles, as the clamping blocks get in
the way. So you increase the unsupported lenght of the
tubing and the file starts to chatter. Machining with a
holesaw is then the way to go, as you won't need a clear
exit as with a file. If you use the time honoured hacksaw
and file method, don't make the beginners mistake of
cutting out V-nothes with your saw. Turn the tube 90
degrees, and cut off the top and bottom of the fishmouth.
You now start with a nice round bottom, instead of a
sharp V. With thinwall tubing you can do most of your
filing with a large flat file. Machining thinwall tubing
with a 2 or 4 fluted mill is risky. The unsupported
leading jaw of your fishmouth stands a fair chance of
getting caught in the flutes of the cutter. Bad for the
tube, the mill and your nerves. A holesaw with a
smooth cylinder will support the tube.
-- Marten Gerritsen
- From: Dave Bohm - Dave Bohm Bohemian
Subject: hole saws
Date: Thu, 31 Aug 2000
List-Id: Amateur and professional bicycle frame building
If you need to make a cut deeper than the maximum depth
of you hole saw, go through about half way, snip off the
waste piece with some dikes and proceed. everything
should be fine.
Concerning hole saws. Good miters can be made using
standard higher quality hole saws like Morse or Starret.
It really depends on the level of quality you are looking
for and the welding/brazing processes you are using.
The ground high speed steel hole saws have many
advantages and make absolute perfect miters without tube
chatter, catching tubes etc. If treated well they
will also outlast (with resharpening) dozens of standard
holesaws and give you better results throughout. An
example of this is tight tube miters for TIG welding.
Ever wonder how some people seem to be able to get super
tiny tig welds? Its mainly tight tube miters.
Also tight tube miters help alignment tremendously.
One reason for many builders not having good results with
ground hole saws is a lack of education as to there use
and the incorrect tooling and featuring to use them.
To get good results with any machine tool you must have
as much rigidity as possible (the main reason harbor
freight tool don't work). If you are using a small
drill press, handfeeding, or have a drill press vise or
jig-a-notcher thingy the good hole saws won't work for
One small off the subject rant. I know that many
framebuilders don't have enough money to just go out and
buy all sorts of expensive stuff. It's kind of fun
to know you made something or figured out a way to do
something just as good for cheaper than normal. But....In
general I have been disappointed in my cheap tools over
the long run. Either they don't last or they do a
poor job. A quality tool prevents lost down time in
trying to repair it or replace it and is a joy to work
with compared to the harbor freight specials.
Thursday, 29 January 2009