I suddenly have to learn all there is to know about abrasive fiber. I have
a huge opportunity to make quantities of assorted sizes and grits of wheel
brushes. The stuff it really cool in all kinds of application. I make a
few things now and know some of the characteristics. The stuff if slippery,
hard to handle and eats machinery but the margins are substantial. My main
concerns will be bearings in cutting and trimming machines, the dust gets
everywhere and seems to migrate into anything. I can start with better
seals, evac systems and sacrificial parts. On other parts I'll try TiN type
coatings or ion implantation.

What strategies are used in grinding applications to protect machine guts?
I can't flood with liquid. The media is typically Silicon Carbide. Has
anybody used any of these materials?

Tom Gardner wrote:


What strategies are used in grinding applications to protect machine guts?
I can't flood with liquid. The media is typically Silicon Carbide. Has
anybody used any of these materials?

Have you considered trying to pressurize bearings to keep stuff out? I
built a semiautomatic bead blasting machine for a former employer. The
part to be cleaned was mounted on a mandrel and inserted into a tube
that ran in a Teflon block. Flanges top and bottom had felt seals and
the block was under about 5psi pressure. A small gear motor rotated the
tube. Abrasive nozzles were mounted to the end of shafts passing through
polymer sleeve bearings. I used mountain bike fork boots to seal the
shafts inside the chamber, and the boots were also lightly pressurized.
There were two chambers, one side runs aluminum oxide, the other runs
glass beads. This machine has cleaned several hundred parts a week for
some 6 years now with no maintenance to the moving parts.

Depending upon the design of the machines you build, it might prove
challenging to design everything so it can be pressurized, but the idea
certainly works.

Jon

Jon Anderson wrote:

Abrasive nozzles were mounted to the end of shafts passing through
polymer sleeve bearings. I used mountain bike fork boots to seal the
shafts inside the chamber, and the boots were also lightly pressurized.

These shafts were reciprocated as the part was turning, to provide full
coverage. That's why the pressurized boots on the shafts...

Jon

Tom Gardner wrote:
I suddenly have to learn all there is to know about abrasive fiber. I have
a huge opportunity to make quantities of assorted sizes and grits of wheel
brushes. The stuff it really cool in all kinds of application. I make a
few things now and know some of the characteristics. The stuff if slippery,
hard to handle and eats machinery but the margins are substantial. My main
concerns will be bearings in cutting and trimming machines, the dust gets
everywhere and seems to migrate into anything. I can start with better
seals, evac systems and sacrificial parts. On other parts I'll try TiN type
coatings or ion implantation.

What strategies are used in grinding applications to protect machine guts?
I can't flood with liquid. The media is typically Silicon Carbide. Has
anybody used any of these materials?




Jon has some mighty good thoughts, I was thinking about going low-tech
and using babbit bearings that were easy to get to so you could melt 'em
out and repour quick. If you can keep the bearings at the ends of the
shafts you could also make the shaft's bearing surface replaceable.

John

On Sat, 13 Aug 2005 03:08:28 GMT, "Tom Gardner"
wrote:

I suddenly have to learn all there is to know about abrasive fiber. I have
a huge opportunity to make quantities of assorted sizes and grits of wheel
brushes. The stuff it really cool in all kinds of application. I make a
few things now and know some of the characteristics. The stuff if slippery,
hard to handle and eats machinery but the margins are substantial. My main
concerns will be bearings in cutting and trimming machines, the dust gets
everywhere and seems to migrate into anything. I can start with better
seals, evac systems and sacrificial parts. On other parts I'll try TiN type
coatings or ion implantation.

What strategies are used in grinding applications to protect machine guts?
I can't flood with liquid. The media is typically Silicon Carbide. Has
anybody used any of these materials?


I have a half hundred 1/2" ones and some 1.5" nylon cup brushes. I can
send you a couple for investigation.

Gunner

In article ,
Jon Anderson wrote:

Tom Gardner wrote:


What strategies are used in grinding applications to protect machine guts?
I can't flood with liquid. The media is typically Silicon Carbide. Has
anybody used any of these materials?

Have you considered trying to pressurize bearings to keep stuff out? I
built a semiautomatic bead blasting machine for a former employer. The
part to be cleaned was mounted on a mandrel and inserted into a tube
that ran in a Teflon block. Flanges top and bottom had felt seals and
the block was under about 5psi pressure. ...

This gives me an idea - hydrostatic bearings. If pressurized fluid is
fed to the center of a plain plastic bearing running on a stainless
steel shaft, the pressure will keep the shaft floating, and the outward
flow will prevent the entry of grit into the bearing space, especially
if simple shaft seals are provided. It's best to have a groove in the
bearing to carry the fluid all around the shaft, to ensure even flow and
pressure. Hydrostatic bearings work at any speed, right down to zero.
But you have to remember to turn the pressure on before starting the
machine.

Use water so it doesn't make a mess and contaminate the product.

The required pressure will be in the hundreds to maybe a thousand psi,
depending on bearing area and needed forces. Plain old tap water will
do. One could adapt a pressure washer to be the pump.

Joe

"Gunner" wrote in message
...
On Sat, 13 Aug 2005 03:08:28 GMT, "Tom Gardner"
wrote:

I suddenly have to learn all there is to know about abrasive fiber. I
have
a huge opportunity to make quantities of assorted sizes and grits of wheel
brushes. The stuff it really cool in all kinds of application. I make a
few things now and know some of the characteristics. The stuff if
slippery,
hard to handle and eats machinery but the margins are substantial. My
main
concerns will be bearings in cutting and trimming machines, the dust gets
everywhere and seems to migrate into anything. I can start with better
seals, evac systems and sacrificial parts. On other parts I'll try TiN
type
coatings or ion implantation.

What strategies are used in grinding applications to protect machine guts?
I can't flood with liquid. The media is typically Silicon Carbide. Has
anybody used any of these materials?


I have a half hundred 1/2" ones and some 1.5" nylon cup brushes. I can
send you a couple for investigation.

Gunner

Thanks Gunner but I make end brushes and 3" to 6" wheels so I have stuff to
play with, but tell me about using them...the god and the bad, what
applications do they shine. (pun intended)

Yep! That's what I'm talkin' about!

"Jon Anderson" wrote in message
...
Tom Gardner wrote:


What strategies are used in grinding applications to protect machine
guts? I can't flood with liquid. The media is typically Silicon Carbide.
Has anybody used any of these materials?

Have you considered trying to pressurize bearings to keep stuff out? I
built a semiautomatic bead blasting machine for a former employer. The
part to be cleaned was mounted on a mandrel and inserted into a tube that
ran in a Teflon block. Flanges top and bottom had felt seals and the block
was under about 5psi pressure. A small gear motor rotated the tube.
Abrasive nozzles were mounted to the end of shafts passing through polymer
sleeve bearings. I used mountain bike fork boots to seal the shafts inside
the chamber, and the boots were also lightly pressurized. There were two
chambers, one side runs aluminum oxide, the other runs glass beads. This
machine has cleaned several hundred parts a week for some 6 years now with
no maintenance to the moving parts.

Depending upon the design of the machines you build, it might prove
challenging to design everything so it can be pressurized, but the idea
certainly works.

Jon

On Sat, 13 Aug 2005 16:29:16 GMT, "Tom Gardner"
wrote:


"Gunner" wrote in message
.. .
On Sat, 13 Aug 2005 03:08:28 GMT, "Tom Gardner"
wrote:

I suddenly have to learn all there is to know about abrasive fiber. I
have
a huge opportunity to make quantities of assorted sizes and grits of wheel
brushes. The stuff it really cool in all kinds of application. I make a
few things now and know some of the characteristics. The stuff if
slippery,
hard to handle and eats machinery but the margins are substantial. My
main
concerns will be bearings in cutting and trimming machines, the dust gets
everywhere and seems to migrate into anything. I can start with better
seals, evac systems and sacrificial parts. On other parts I'll try TiN
type
coatings or ion implantation.

What strategies are used in grinding applications to protect machine guts?
I can't flood with liquid. The media is typically Silicon Carbide. Has
anybody used any of these materials?


I have a half hundred 1/2" ones and some 1.5" nylon cup brushes. I can
send you a couple for investigation.

Gunner

Thanks Gunner but I make end brushes and 3" to 6" wheels so I have stuff to
play with, but tell me about using them...the god and the bad, what
applications do they shine. (pun intended)

Ive only seen them used for surface finishing (polishing) and very
light deburring. They are not particularly common in machine shops
that Ive visited, shrug. Seem to work pretty good on Stainless steel
for fine polishing, which is about all Ive done with mine, in a drill
press. I did use one of the small ones to jewel a piece of steel, but
it was pretty unimpressive compared to a dowel and fine polishing
compound. They are reputed to do a decent job of deburring without
making dimensional changes to the parent features.

perhaps these might help?

http://www.weilercorp.com/tpart.htm
http://www.osborn.de/english/product...sh/korfile.htm
http://www.progressivedistributor.co...es/brushes.htm
G


Gunner

On Sat, 13 Aug 2005 16:29:16 GMT, "Tom Gardner"
wrote:


Thanks Gunner but I make end brushes and 3" to 6" wheels so I have stuff to
play with, but tell me about using them...the god and the bad, what
applications do they shine. (pun intended)

In addition to Gunner's response:

I recently used one of these in the form of a small dia pad, probably
3M "Roll-Lock", in a die grinder to pretty up some aluminum boatlift
parts after welding.

I'd first tried wire brush (too slow), and rotary wire brush (too
aggressive). The Skotchbrite pad worked beautifully, and right now!