Seem to have to do this a lot these days. I'm hinking 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

N_Cook wrote:

Seem to have to do this a lot these days. I'm hinking 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


Try asking on the right newsgroup: news:rec.crafts.metalworking


--
And another motherboard bites the dust!

Michael A. Terrell wrote in message
m...

N_Cook wrote:

Seem to have to do this a lot these days. I'm hinking 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


Try asking on the right newsgroup: news:rec.crafts.metalworking


--
And another motherboard bites the dust!

The last time I was there it took ages before someone came up with the name
of the machining process for the step and repeat chiselling for forming
those large aluminium heatsinks, found on domestic amps of the 80s, with
those distinctive curved fins, - its called skyving.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N_Cook wrote:

Michael A. Terrell wrote:

Try asking on the right newsgroup: news:rec.crafts.metalworking

The last time I was there it took ages before someone came up with the name
of the machining process for the step and repeat chiselling for forming
those large aluminium heatsinks, found on domestic amps of the 80s, with
those distinctive curved fins, - its called skyving.


So? Its not something done in a home metalworking shop, but knurling
is. Of course you would have to actually do something right, for a
change. Some of the guys on there make things that would blow your
mind, when it comes to custom tools.


--
And another motherboard bites the dust!

I've returned to the pipe cutter idea.
I've opened out the slot from 3.5mm to just over 5mm and it will now hold
neatly and freely rotating, a 16mm diameter x 5 mm ball race.
I know I can grind into the outer race with a Dremmel and thin disc
(freehand) and cutting 1mm spaced teeth is possible as proved by cutting
,freehand so rough, some 1mm spaced teeth around a steel washer. Running a
24 TPI hacksaw tightly around a pot shaft produced a ring of about 19 small
indents, so 1mm is about right for 16. Next a bit of trig to find a whole
number of rotations into 16 mm diameter to give about 1mm spacing. Set the
Dremmel on the compound/cross slide of a basic lathe (no dividing plate),
and ballrace tightened to some part threaded stud held in the chuck.
Then with lathe motor isolated find a set of gear ratios and pulley marks,
to give the required steps, by turning the first motor pulley by hand, and
maybe lightly clamping per step.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On Apr 2, 10:13*am, "N_Cook" wrote:
I've returned to the pipe cutter idea.
I've opened out the slot from 3.5mm to just over 5mm and it will now hold
neatly and freely rotating, a 16mm diameter x 5 mm ball race.
I know I can grind into the outer race with a Dremmel and thin disc
(freehand) and cutting 1mm spaced teeth is possible as proved by cutting
,freehand so rough, some 1mm spaced teeth around a steel washer. Running a
24 TPI hacksaw tightly around a pot shaft produced a ring of about 19 small
indents, so 1mm is about right for 16. Next a bit of trig to find a whole
number of rotations into 16 mm diameter to give about 1mm spacing. Set the
Dremmel on the compound/cross slide of a basic lathe (no dividing plate),
and ballrace tightened to some part threaded stud held in the chuck.
Then with lathe motor isolated find a set of gear ratios and pulley marks,
to give the required steps, by turning the first motor pulley by hand, and
maybe lightly clamping per step.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list onhttp://home.graffiti.net/diverse:graffiti.net/

Norm:

You obviously have too much spare time. I have a bunch of things
needing help. Do you make house calls on the west side of the big
pond. G

Bob Hofmann

hr(bob) wrote in message
...
On Apr 2, 10:13 am, "N_Cook" wrote:
I've returned to the pipe cutter idea.
I've opened out the slot from 3.5mm to just over 5mm and it will now hold
neatly and freely rotating, a 16mm diameter x 5 mm ball race.
I know I can grind into the outer race with a Dremmel and thin disc
(freehand) and cutting 1mm spaced teeth is possible as proved by cutting
,freehand so rough, some 1mm spaced teeth around a steel washer. Running a
24 TPI hacksaw tightly around a pot shaft produced a ring of about 19
small
indents, so 1mm is about right for 16. Next a bit of trig to find a whole
number of rotations into 16 mm diameter to give about 1mm spacing. Set the
Dremmel on the compound/cross slide of a basic lathe (no dividing plate),
and ballrace tightened to some part threaded stud held in the chuck.
Then with lathe motor isolated find a set of gear ratios and pulley marks,
to give the required steps, by turning the first motor pulley by hand, and
maybe lightly clamping per step.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list
onhttp://home.graffiti.net/diverse:graffiti.net/

Norm:

You obviously have too much spare time. I have a bunch of things
needing help. Do you make house calls on the west side of the big
pond. G

Bob Hofmann


I like a challenge and may learn something along the way. A week ago , if
someone asked me - can you cut a 0.5mm wide slot in the steel of a ball
race, using mundane equipment, I would have said no.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

Too many belts in the lathe drive train. Settled on a doubled large cable
tie around the chuck, clamped to the lathe bed, as a brake and
anti-backlash. And marking around the chuck 50 divisions covered with a
needle, as indicator, on an arm to a magnetic base. Pulling at the motor V
belt to step round. Mounted the Dremmel on 3 short pieces of Dexion to set
on the tool post with a 45 degree set. 3 rounds of cuts to get to final
profile.
Next time I will spend more time fiddling around DTI setting in the 4-jaw
before starting as there was eccentricity.
http://home.graffiti.net/diverse:gra...et/spliner.jpg
There is a lunate form to the cutting edges maybe due to flexing of the
0.6mm thick grinding disc or I did not pay attention to changing direction
of cuts on "odd" and "even" teeth on each pass. Perhaps I should have done
another round of cuts but at the previous depth setting to cut into the
lunate form more. Perhaps it was due to axial play on the Dremmel. Anyway it
works well enough for this purpose. No more than 5mm splining or the
tightening force would be more than finger force on the knurled head bolt
and the aluminium of the holding frame would snap with anything more than
finger force. It is possible to re-engage the spliner further along, synched
with the first cut to form extended splines.
In use leave the pot spindle full length so the 2 round rollers of the
existing pipe cutter can react against the extended shaft. Afterwards cut to
length and the diametrical cut. 16 evenly spaced cuts around the pot shaft
in the bottom view. If not deep enough then at least a good accurate guide
for starting some deeper cuts done freehand with a Dremmel. Didn't think to
measure the diameter of the cutting disc before starting and the others vary
in diameter, but by comparing to them, somwhere between 0 and 0.2mm erosion
of diameter in use

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N_Cook wrote:

I've returned to the pipe cutter idea.
I've opened out the slot from 3.5mm to just over 5mm and it will now
hold neatly and freely rotating, a 16mm diameter x 5 mm ball race.
I know I can grind into the outer race with a Dremmel and thin disc
(freehand) and cutting 1mm spaced teeth is possible as proved by
cutting ,freehand so rough, some 1mm spaced teeth around a steel
washer. Running a 24 TPI hacksaw tightly around a pot shaft produced a
ring of about 19 small indents, so 1mm is about right for 16. Next a
bit of trig to find a whole number of rotations into 16 mm diameter to
give about 1mm spacing. Set the Dremmel on the compound/cross slide of
a basic lathe (no dividing plate), and ballrace tightened to some part
threaded stud held in the chuck. Then with lathe motor isolated find a
set of gear ratios and pulley marks, to give the required steps, by
turning the first motor pulley by hand, and maybe lightly clamping per
step.

These people have what you want !
http://www.rpmechatronics.co.uk

--
Best Regards:
Baron.