Ron wrote in message
...
N_Cook wrote:
Allodoxaphobia wrote in message
...
On Tue, 31 Mar 2009 17:12:27 +0100, Baron wrote:
N_Cook Inscribed thus:
Baron wrote:
N_Cook Inscribed thus:
Seem to have to do this a lot these days. I'm thinking of
converting one of these neat little pipe/tube cutters to roll on a
spline form.
http://image.bizrate.co.uk/resize?sq...5102&mid=82383 the
only pic I could find , a smaller version of these
http://www.choiceful.com/prod_image/66677_l.jpg by changing the
sliding-in cutting wheel to a toothed cog. Currently I do this
spline conversion by thin grind wheel and cutting splines freehand
, so rough and ready, does the job, but not very elegant and wary
of breaking the thin Dremmel type grind wheel. I cannot even find a
brass gear to fit in there for proof of concept, let alone a steel
cog. Anyone know where to look for a steel cog with about 1mm pitch
of teeth , between 10 and 24 mm diameter and between 3.5 and 5 mm
wide. I don't mind sawing and grinding out the slot that takes the
roller on one of these pipe cutters. Where would I find such brass
or steel cogs in some application that could be robbed out. Not
much of the shaft needs to be splined and remainder of shaft could
be undercut to clear knob and still engage well enough for finger
pressure. Or any other ideas ? I have a ball race that would fit in
there neatly , after widening the slot but would havre to grind
teeth to the outer ring of the race. I'm aware of engineering slit
saws and may even be able to justify the cost of one, but would
rather try a proof of concept first
There is one major problem to overcome ! For any given spline pitch
there are fixed diameters where the spline won't over ride ! You
basically want a fixed size forming tool for a particular diameter.
In which case there are companies that manufacture gears and I'm
quite sure that for the right fee they would supply a steel gear
that
could be case hardened to do what you want.
Yes as in knurling, the pattern repeats for only one diameter and a
certain degree of intrusion.
Actually it would be any diameter where the distance could be divided
exactly by the pitch.
Fiddle-faddle. :-)
If all you need is a force-fit of a knob on a shiney/slick shaft, use
large Vise-Grips (tm) ("locking pliers") to bunger up the shaft with
the
pliers' teeth in the section the knob will slip on to.
No long division required. :-)
WFM,
Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
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Thats an option I'd not thought of.
Find some 1mm spaced ridged steel and stick to some "mole grip" jaws.
Squash
and turn a few times, plastic knobs usually so no great precision
needed.
Actually, there`s probably the germ of a good idea there, if you could
find or make a suitable hydraulic press, and make up some half round
'jaws' with the correct tooth pattern, you could probably form the
aluminium of the shaft quite easily, band sawing in the slot after
cleaning up.
Ron
Find some fine pitched , BSF ,UNF or metric ordinary steel, non-hardened ,
bolts, but as large a diameter as possible. Hacksaw some "chord" sections
off and braze to some vice jaws sounds plausible.
--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/