Read this group all the time, but wow, haven't posted here in years. Now I
have a question concerning the use of a router bit to round off the edges of
a piece of acrlyic. Good idea or bad? Will the acrlyic piece tend to shatter
or get hot and just kinda melt and gum up the router bit? It's a piece of
1/8" thick and I won't be taking much material off. Thanks.

--
Paul O.

On 10/15/10 3:27 PM, Paul wrote:
Read this group all the time, but wow, haven't posted here in years. Now
I have a question concerning the use of a router bit to round off the
edges of a piece of acrlyic. Good idea or bad? Will the acrlyic piece
tend to shatter or get hot and just kinda melt and gum up the router
bit? It's a piece of 1/8" thick and I won't be taking much material off.
Thanks.


No experience at all doing it, but I've used a router a lot and I have
to think that, even on it's slowest speed, it's just going to melt it.

Off the top of my head.....
I've seen guys bend that stuff using a torch to soften it. What if you
softened it with a torch and followed behind with something that had the
profile you want? Sort of like a concrete worker forming an expansion
joint.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On Oct 15, 4:27*pm, "Paul" wrote:
Read this group all the time, but wow, haven't posted here in years. Now I
have a question concerning the use of a router bit to round off the edges of
a piece of acrlyic. Good idea or bad? Will the acrlyic piece tend to shatter
or get hot and just kinda melt and gum up the router bit? It's a piece of
1/8" thick and I won't be taking much material off. Thanks.

--
Paul O.

If the bit is fresh, sharp and no seized bearing, it will cut the
acrylic just fine. I do that all the time, even with router bits way
bigget than what you're planning on. But at that little roundover,
flaming will do it too, but that takes practise.
A sanding block works, with 220 grit, but it will be a matte/dull
finish.
A flame IS the way to go once you get the hang of it.

On Oct 15, 4:34*pm, -MIKE- wrote:
On 10/15/10 3:27 PM, Paul wrote:

Read this group all the time, but wow, haven't posted here in years. Now
I have a question concerning the use of a router bit to round off the
edges of a piece of acrlyic. Good idea or bad? Will the acrlyic piece
tend to shatter or get hot and just kinda melt and gum up the router
bit? It's a piece of 1/8" thick and I won't be taking much material off..
Thanks.

No experience at all doing it, but I've used a router a lot and I have
to think that, even on it's slowest speed, it's just going to melt it.

Off the top of my head.....
I've seen guys bend that stuff using a torch to soften it. *What if you
softened it with a torch and followed behind with something that had the
profile you want? *Sort of like a concrete worker forming an expansion
joint.

--

* -MIKE-

* "Playing is not something I do at night, it's my function in life"
* * *--Elvin Jones *(1927-2004)
* --
*http://mikedrums.com
*
* ---remove "DOT" ^^^^ to reply

The flame, with a steady, but quick hand, will melt the edge to it's
own, clean natural edge.
Cast acrylic will behave a bit differently than extruded acrylic.

On Oct 15, 1:27*pm, "Paul" wrote:
Read this group all the time, but wow, haven't posted here in years. Now I
have a question concerning the use of a router bit to round off the edges of
a piece of acrlyic. Good idea or bad? Will the acrlyic piece tend to shatter
or get hot and just kinda melt and gum up the router bit? It's a piece of
1/8" thick and I won't be taking much material off. Thanks.

Lots of woodworking tools work OK in acrylic, but the combination
of router speed and 'not taking much material off' leads to disaster.
You'll have better finish if you just build a wood-and-hacksawblade
scraper plane for this job.

Impact from a router cutting edge can fracture and flake bits of
acrylic.
If you make a shallow cut, the acrylic will slightly bend and flex,
which
causes friction and melting.

On 10/15/10 3:44 PM, Robatoy wrote:
If the bit is fresh, sharp and no seized bearing, it will cut the
acrylic just fine. I do that all the time, even with router bits way
bigget than what you're planning on.

Right on. That was totally counter to what I speculated.
I'll tuck that away in the ol' brain for future use.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

"-MIKE-" wrote in message
...
On 10/15/10 3:44 PM, Robatoy wrote:
If the bit is fresh, sharp and no seized bearing, it will cut the
acrylic just fine. I do that all the time, even with router bits way
bigget than what you're planning on.

Right on. That was totally counter to what I speculated.
I'll tuck that away in the ol' brain for future use.

I do not know if you know how to modify a drill bit for acrylic, but if
not, you change the cutting edge from positive rake like most drill bits, to
a 0 degree rake or a 1 or 2 degree negative rake, so it scrapes the
material, instead of grabbing off more than you want and chipping or
cracking it.

It would follow that such a mod on a HHS router bit would be necessary if
you were to ever want to use a router on acrylic.
--
Jim in NC

On 2010-10-15, Morgans wrote:

I do not know if you know how to modify a drill bit for acrylic, but if
not, you change the cutting edge from positive rake like most drill bits, to
a 0 degree rake or a 1 or 2 degree negative rake, so it scrapes the
material, instead of grabbing off more than you want and chipping or
cracking it.

It would follow that such a mod on a HHS router bit would be necessary if
you were to ever want to use a router on acrylic.

We used to knock off the sharp edge on a new drill bit, jes touching
it to the wheel at a 45 deg angle to the apex. We'd use these for
both plexi and brass. I was thinking the same for a router bit, but
have never used a router on plexi.

Call a TAP plastic outlet. They do plexi/lucite by the ship load.

http://www.tapplastics.com/

nb

Robatoy wrote on 16/10/2010 :
On Oct 15, 4:34*pm, -MIKE- wrote:
On 10/15/10 3:27 PM, Paul wrote:

Read this group all the time, but wow, haven't posted here in years. Now
I have a question concerning the use of a router bit to round off the
edges of a piece of acrlyic. Good idea or bad? Will the acrlyic piece
tend to shatter or get hot and just kinda melt and gum up the router
bit? It's a piece of 1/8" thick and I won't be taking much material off.
Thanks.

No experience at all doing it, but I've used a router a lot and I have
to think that, even on it's slowest speed, it's just going to melt it.

Off the top of my head.....
I've seen guys bend that stuff using a torch to soften it. *What if you
softened it with a torch and followed behind with something that had the
profile you want? *Sort of like a concrete worker forming an expansion
joint.

--

* -MIKE-

* "Playing is not something I do at night, it's my function in life"
* * *--Elvin Jones *(1927-2004)
* --
*http://mikedrums.com
*
* ---remove "DOT" ^^^^ to reply

The flame, with a steady, but quick hand, will melt the edge to it's
own, clean natural edge.
Cast acrylic will behave a bit differently than extruded acrylic.

And just in case.
Polycarbonate is near immpossible to flame smooth. It bubbles and looks
terrible.
Polycarbonate looks much like acrylic but with a blue tinge and is
stronger and more expensive..

--
John G

Thanks everybody. Think I'll try the torch method and see if I can get the
hang of it, if not, I'll get out the ole sanding block.

--
Paul O.


"Paul" wrote in message
...
Read this group all the time, but wow, haven't posted here in years. Now I
have a question concerning the use of a router bit to round off the edges
of a piece of acrlyic. Good idea or bad? Will the acrlyic piece tend to
shatter or get hot and just kinda melt and gum up the router bit? It's a
piece of 1/8" thick and I won't be taking much material off. Thanks.

--
Paul O.

"Paul" wrote in
:

Read this group all the time, but wow, haven't posted here
in years. Now I have a question concerning the use of a
router bit to round off the edges of a piece of acrlyic.
Good idea or bad? Will the acrlyic piece tend to shatter
or get hot and just kinda melt and gum up the router bit?
It's a piece of 1/8" thick and I won't be taking much
material off. Thanks.


A little more info: [http://www.plasticsmag.com/routing.asp?
fIssue=Mar/Apr-03&aid=3751]
Also, Google: acrylic router bit

Ken

On Oct 15, 5:03*pm, -MIKE- wrote:
On 10/15/10 3:44 PM, Robatoy wrote:

If the bit is fresh, sharp and no seized bearing, it will cut the
acrylic just fine. I do that all the time, even with router bits way
bigget than what you're planning on.

Right on. *That was totally counter to what I speculated.
I'll tuck that away in the ol' brain for future use.

--

* -MIKE-

* "Playing is not something I do at night, it's my function in life"
* * *--Elvin Jones *(1927-2004)
* --
*http://mikedrums.com
*
* ---remove "DOT" ^^^^ to reply

Considering that I rout out large letters out of 1/4" acrylic all the
time, the one common denominator is that the 'special' acrylic bits
are highly polished as to not to give the acrylic much to grab on to
when a 22K PRM spinning bit loiters somewhere during the toolpath.
This is cut from the back with a regular bullnose bit and lit from the
edge. (Not mine)
http://www.vectric.com/forum/downloa...7159&mode=view

On Oct 15, 5:03*pm, -MIKE- wrote:
On 10/15/10 3:44 PM, Robatoy wrote:

If the bit is fresh, sharp and no seized bearing, it will cut the
acrylic just fine. I do that all the time, even with router bits way
bigget than what you're planning on.

Right on. *That was totally counter to what I speculated.
I'll tuck that away in the ol' brain for future use.

--

* -MIKE-

* "Playing is not something I do at night, it's my function in life"
* * *--Elvin Jones *(1927-2004)
* --
*http://mikedrums.com
*
* ---remove "DOT" ^^^^ to reply

Done with a V shaped router bit
http://www.vectric.com/forum/downloa...7187&mode=view

On 10/16/10 11:16 AM, Robatoy wrote:
On Oct 15, 5:03 pm, wrote:
On 10/15/10 3:44 PM, Robatoy wrote:

If the bit is fresh, sharp and no seized bearing, it will cut the
acrylic just fine. I do that all the time, even with router bits way
bigget than what you're planning on.

Right on. That was totally counter to what I speculated.
I'll tuck that away in the ol' brain for future use.

-MIKE-

Done with a V shaped router bit
http://www.vectric.com/forum/downloa...7187&mode=view

Guess I won't shy away from routing acrylic should the need arise.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

"notbob" wrote in message
...
On 2010-10-15, Morgans wrote:

I do not know if you know how to modify a drill bit for acrylic, but if
not, you change the cutting edge from positive rake like most drill bits,
to
a 0 degree rake or a 1 or 2 degree negative rake, so it scrapes the
material, instead of grabbing off more than you want and chipping or
cracking it.

It would follow that such a mod on a HHS router bit would be necessary if
you were to ever want to use a router on acrylic.

We used to knock off the sharp edge on a new drill bit, jes touching
it to the wheel at a 45 deg angle to the apex. We'd use these for
both plexi and brass. I was thinking the same for a router bit, but
have never used a router on plexi.

I "usually" go for a little more precise modification, by using a dremmel
cutoff wheel, and turn it sideways to the leading edge of the bit, grinding
a small amount of the leading edge back a bit to produce a 0 degree face. I
then paint the bit with a bit of orange spray paint. The paint wears off
the outside of the bit, but enough remains down in the flutes to make quick
work of identifying it as a modified bit.

Call a TAP plastic outlet. They do plexi/lucite by the ship load.

http://www.tapplastics.com/

A safe bet, but where is the adventure, in that? ggg
--
Jim in NC

"Robatoy" wrote

Done with a V shaped router bit
http://www.vectric.com/forum/downloa...7187&mode=view


Cool. Done with a CNC setup?
--
Jim in NC