I found some NOS idler gears for my Rockwell 11's quick change on ebay.
One fits pretty sweet, the bore on the other's a little small. Dave
Gingery describes a way of making reamers that sounds doable - make an
acute bevel cut across a piece of drill rod or crs.

I only need it for one bronze bushing - think it'll work? Anybody
made/used such a tool?

On 25 Nov 2005 06:37:37 -0800, wrote:

I found some NOS idler gears for my Rockwell 11's quick change on ebay.
One fits pretty sweet, the bore on the other's a little small. Dave
Gingery describes a way of making reamers that sounds doable - make an
acute bevel cut across a piece of drill rod or crs.

A "whistle reamer" as they used to be known.

They give a good finish, but they need a reasonable lead in and have a
minimum hole length of a couple of diameters, if they're not to make the
hole bell-mouthed.

wrote in message
ups.com...
I found some NOS idler gears for my Rockwell 11's quick change on ebay.
One fits pretty sweet, the bore on the other's a little small. Dave
Gingery describes a way of making reamers that sounds doable - make an
acute bevel cut across a piece of drill rod or crs.

I only need it for one bronze bushing - think it'll work? Anybody
made/used such a tool?

Lose the reamer idea. That's what boring bars are made for. A bushing
should be dead concentric with the OD, which you would insure by boring and
turning in the same setup. No real reason to go to the trouble to make a
reamer that would be used for one purpose, with less then perfect results,
when you can make the bushing in less time by my suggestion. If, by
chance, the entire gear has to be turned, the same thing still applies.
You can make the necessary setup by various means, then bore the bushing
after it's pressed in the gear. A reamer would be a poor choice, for
various reasons.

Harold

wrote in message
ups.com...
I found some NOS idler gears for my Rockwell 11's quick change on ebay.
One fits pretty sweet, the bore on the other's a little small. Dave
Gingery describes a way of making reamers that sounds doable - make an
acute bevel cut across a piece of drill rod or crs.

I only need it for one bronze bushing - think it'll work? Anybody
made/used such a tool?

Yes, they work. They were used a century ago for reaming the holes in master
watch plates and so on -- then the highest-quality toolmaking work done
anywhere.

I used to make them a lot, when I was doing a lot of hobby machining. I also
made plain D-bit reamers and drills; they work, too. Worn-out or broken
drill bits make good stock for these things, but be aware that the butt-ends
of drill bits aren't hardened much, if at all. And the butt-ends are
undersize.

--
Ed Huntress

Do it the easy way.

Assuming you don't have a sunnen hone, see if your brake cylinder
hone will go small enough. If not cut a slot in a steel rod that
will go in the bore and but a strip of emory paper in the slot.
Hold the rod in the drill press and work the gear up and down.
Easy to take out a few thousandths and/or slick up/debur the bore
by using correct grit paper.

Uncle George

On 25 Nov 2005 06:37:37 -0800, wrote:

I found some NOS idler gears for my Rockwell 11's quick change on ebay.
One fits pretty sweet, the bore on the other's a little small. Dave
Gingery describes a way of making reamers that sounds doable - make an
acute bevel cut across a piece of drill rod or crs.

I only need it for one bronze bushing - think it'll work? Anybody
made/used such a tool?

"F. George McDuffee" wrote in message
...
Do it the easy way.

Assuming you don't have a sunnen hone, see if your brake cylinder
hone will go small enough. If not cut a slot in a steel rod that
will go in the bore and but a strip of emory paper in the slot.
Hold the rod in the drill press and work the gear up and down.
Easy to take out a few thousandths and/or slick up/debur the bore
by using correct grit paper.

Uncle George


No doubt it works, but it's a bitch to avoid bell mouth, or to control size.
I do not support a brake cylinder hone when size or configuration is
critical. They have the potential to destroy an accurate bore.

Harold

On Fri, 25 Nov 2005 18:07:07 -0800, "Harold and Susan Vordos"
wrote:


"F. George McDuffee" wrote in message
.. .
Do it the easy way.

Assuming you don't have a sunnen hone, see if your brake cylinder
hone will go small enough. If not cut a slot in a steel rod that
will go in the bore and but a strip of emory paper in the slot.
Hold the rod in the drill press and work the gear up and down.
Easy to take out a few thousandths and/or slick up/debur the bore
by using correct grit paper.

Uncle George


No doubt it works, but it's a bitch to avoid bell mouth, or to control size.
I do not support a brake cylinder hone when size or configuration is
critical. They have the potential to destroy an accurate bore.

Harold

And how is this a problem with idler gears? For grins measure up
some well used but still functional change or idler gears and see
how the bores measure. It all depends if you want to machine
perfection or cut metal .... i.e. when is 'good enough' good
enough.

Uncle George

"F. George McDuffee" wrote in message
news
On Fri, 25 Nov 2005 18:07:07 -0800, "Harold and Susan Vordos"
wrote:


"F. George McDuffee" wrote in message
.. .
Do it the easy way.

Assuming you don't have a sunnen hone, see if your brake cylinder
hone will go small enough. If not cut a slot in a steel rod that
will go in the bore and but a strip of emory paper in the slot.
Hold the rod in the drill press and work the gear up and down.
Easy to take out a few thousandths and/or slick up/debur the bore
by using correct grit paper.

Uncle George


No doubt it works, but it's a bitch to avoid bell mouth, or to control
size.
I do not support a brake cylinder hone when size or configuration is
critical. They have the potential to destroy an accurate bore.

Harold

And how is this a problem with idler gears? For grins measure up
some well used but still functional change or idler gears and see
how the bores measure. It all depends if you want to machine
perfection or cut metal .... i.e. when is 'good enough' good
enough.

Uncle George

It also depends on if you'd like to establish concentricity and
perpindicularity, or can live with runout. Not a great idea with gears.
The point is there's better ways to do a job like that, with less effort and
better results. There's no such thing as "good enough" when it gets down
to gears meshing. They're right, or they aren't. Well used gears that have
excessive wear, idlers, or not, are called "worn out".

Harold

In article , Harold and Susan Vordos says...

It also depends on if you'd like to establish concentricity and
perpindicularity, or can live with runout. Not a great idea with gears.
The point is there's better ways to do a job like that, with less effort and
better results. There's no such thing as "good enough" when it gets down
to gears meshing. They're right, or they aren't. Well used gears that have
excessive wear, idlers, or not, are called "worn out".

I could imagine one time a reamer might be appropriate for a job
like this - if a) the original bore of the gear were only
several thou undersized, and also not bored concentric with the
OD. And the person involved did not have a four jaw chuck.

But for any other case, simply indicating the bore of the gear
in, and using a boring bar to skim a few thou seems like a real
cheap shot to do the job fast and right. Nothing to make,
nothing to heat treat, etc.

Jim


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"jim rozen" wrote in message
...
In article , Harold and Susan Vordos says...

It also depends on if you'd like to establish concentricity and
perpindicularity, or can live with runout. Not a great idea with gears.
The point is there's better ways to do a job like that, with less effort
and
better results. There's no such thing as "good enough" when it gets
down
to gears meshing. They're right, or they aren't. Well used gears that
have
excessive wear, idlers, or not, are called "worn out".

I could imagine one time a reamer might be appropriate for a job
like this - if a) the original bore of the gear were only
several thou undersized, and also not bored concentric with the
OD. And the person involved did not have a four jaw chuck.

But for any other case, simply indicating the bore of the gear
in, and using a boring bar to skim a few thou seems like a real
cheap shot to do the job fast and right. Nothing to make,
nothing to heat treat, etc.

Jim


Funny, that's how I see it, too. *Especially* if there's a keyway
involved.

Harold