7x12MiniLathe@groups.io

#538

Greetings,

My 13 year old son built Junior Solar Sprint car.  The wheels were machined
from black Delrin on the Homier 7x12.  We made a new set of lighter wheels
tonight, since he's competing in the Northeast Championship on Sunday. (see
)

The Delrin is wonderful material to machine, except for one annoyance: the
chip comes off as a single, long string.  It becomes a big, soft, fuzzy mess
that gets tangled up on the work, the tooling, the live center, the chuck,
etc.  It reminds me of poodle fur.  We had to stop often to clean off the
fuzz.  It's especially annoying when parting off.

Is there anyway to get the chip to break into pieces?  Or is it something we
have to live with?

BTW, projects like this are a good way to justify the purchase of machine
tools - "But, dear, it's for the children!"

-Ron

Richard Albers

#546

--- In 7x12minilathe@..., "Ron DeBlock" <rdeblock@a...> 
wrote:
  <Snip>
The Delrin is wonderful material to machine, except for one annoyance: the
chip comes off as a single, long string.  It becomes a big, soft, fuzzy mess
that gets tangled up on the work, the tooling, the live center, the chuck,
etc.  It reminds me of poodle fur.  We had to stop often to clean off the
fuzz.  It's especially annoying when parting off.

Is there anyway to get the chip to break into pieces?  Or is it something we
have to live with?  We just live with it.  I don't think it is possible to break such
a soft material into smaller chips.  It *may* be possible to grab the
string with pliers and break it (or just hold it away from the cut),
but I do not recommend this for most HSMs - it would be too easy to
get into trouble.  Like watching the chip,and forgetting to stop the
cut before the bit hits the chuck (lots of us have done that :-o).

BTW, projects like this are a good way to justify the purchase of machine
tools - "But, dear, it's for the children!"  Sounds like that one should fly!

  RA

V Sathe

#555

I am a newbie to the group.  I know that many plastics
become brittle at (very) low temperatures.  Some of
them need to be treated with liquid nitrogen to make
them brittle.

One experiment someone can try is to keep the piece in
a freezer for a couple of hours and then try to
machine it.

Liquid nitrogen is dangerous in some ways (don't try
to dip your body parts in it - they will break off
too) but something else that can be sprayed to cool
the work piece (The newer Freon?) may do the job. 
Don't know how it will affect the cutting tool though.

I don't have a lathe yet.  I joined the group to hang
around & read various discussions to get a feel of
what I should buy.  May be in a few months ...

Chip_User
----------------------------------------------
--- Richard Albers <rralbers@...> wrote:
Snipped

  We just live with it.  I don't think it is
possible to break such
a soft material into smaller chips.  It *may* be
possible to grab the
string with pliers and break it (or just hold it
away from the cut),
but I do not recommend this for most HSMs - it would
be too easy to
get into trouble.  Like watching the chip,and
forgetting to stop the
cut before the bit hits the chuck (lots of us have
done that :-o).Snipped

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Jerry Smith

#557

I haven't tried the new replacement for Freon. What I have done is used CO2 for my spray coolant for larger projects. It works well for my things. I have a 10 pound ( I think) and a 80 pounder in the hot shop. I use CO2 for carbon steel with MIG welding, so I do have it on hand.

Jerry

Show quoted text

At 06:03 PM 6/20/2003, you wrote:
I am a newbie to the group.  I know that many plastics
become brittle at (very) low temperatures.  Some of
them need to be treated with liquid nitrogen to make
them brittle.

One experiment someone can try is to keep the piece in
a freezer for a couple of hours and then try to
machine it.

Liquid nitrogen is dangerous in some ways (don't try
to dip your body parts in it - they will break off
too) but something else that can be sprayed to cool
the work piece (The newer Freon?) may do the job.
Don't know how it will affect the cutting tool though.

I don't have a lathe yet.  I joined the group to hang
around & read various discussions to get a feel of
what I should buy.  May be in a few months ...

Chip_User
----------------------------------------------
--- Richard Albers <rralbers@...> wrote:
Snipped

  We just live with it.  I don't think it is
possible to break such
a soft material into smaller chips.  It *may* be
possible to grab the
string with pliers and break it (or just hold it
away from the cut),
but I do not recommend this for most HSMs - it would
be too easy to
get into trouble.  Like watching the chip,and
forgetting to stop the
cut before the bit hits the chuck (lots of us have
done that :-o).Snipped

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Delrin