Sorta Woodworking - New Sight Glasses for My Table Saw

[Bob La Londe]

I don't CNC cut a lot of polycarbonate, but I thought folks might like
seeing that with sharp cutters it cuts very nicely. This piece was from a
piece of scrap left over from building the table top enclosure on my big
mill. The math said I could have taken a much deeper depth of cut and made
these sight glasses faster, but I don't CNC cut a lot of polycarbonate so I
wanted to take it easy on my cutter without slowing down the feedrate and
risking melting the edges. It came out perfect. The edges look as good as
the edges on uncut sheets. A razor knife cleaned up the holding tabs.

Video
https://www.youtube.com/watch?v=YqF56m31TYo

Picture
http://yumabassman.com/forums-new/gallery/2_22_05_16_5_24_01.jpeg


--
--
Bob La Londe
CNC Molds N Stuff
http://www.cncmolds.com

[Bob La Londe]

"Bob La Londe" <no...@none.com99> wrote in message
news:nhtj1h$tfo$1...@dont-email.me...

As soon as I hit send I knew I said that wrong. The stock was just held to
the backing with packing tape, and I didn't want it to come loose and go
flying.

[Leon]

Pretty cool!

[Electric Comet]

On Sun, 22 May 2016 17:35:15 -0700
"Bob La Londe" <no...@none.com99> wrote:

> I don't CNC cut a lot of polycarbonate, but I thought folks might
> like seeing that with sharp cutters it cuts very nicely. This piece

what about magnification

mine has a magnifier bulge on it

seems like cnc is the way to go these days

the right setup can be very versatile and replace a lot of conventional
machinery


a while ago i saw a video where a guy moved out some of his old stuff
and built a new platform for a cnc rig

he had provisions for handling vertically or horizontally placed
materials for maximum flexibility

[Bob La Londe]

"Electric Comet" <electri...@mail.invalid> wrote in message
news:ni1t3v$khn$1...@dont-email.me...

> On Sun, 22 May 2016 17:35:15 -0700
> "Bob La Londe" <no...@none.com99> wrote:
>
>> I don't CNC cut a lot of polycarbonate, but I thought folks might
>> like seeing that with sharp cutters it cuts very nicely. This piece
>
> what about magnification
>
> mine has a magnifier bulge on it

That would be nice, but the old ones are totally 100% unuesable.

>
> seems like cnc is the way to go these days
>
> the right setup can be very versatile and replace a lot of conventional
> machinery
>
>
> a while ago i saw a video where a guy moved out some of his old stuff
> and built a new platform for a cnc rig
>
> he had provisions for handling vertically or horizontally placed
> materials for maximum flexibility

A flatbed CNC router large enough to handle sheet good will eliminate the
need for a lot of things. It might not be as fast as a panel saw for
ripping shelves out of plywood, but once you have it programmed you can do
an entire sheet while you are on the other side of the shop sweeping up from
your last project. I want one, but the metal woring is what is paying the
bills. It will be a year probably before I like at large format CNC routers
again.

[OFWW]

On Sun, 22 May 2016 17:35:15 -0700, "Bob La Londe" <no...@none.com99>
wrote:

I love what you did. Looks great.

[Electric Comet]

On Tue, 24 May 2016 12:37:50 -0700
"Bob La Londe" <no...@none.com99> wrote:

> That would be nice, but the old ones are totally 100% unuesable.

wonder if a small magnifying lens could be glued onto one

not sure of there are any adhesives that dry clear and stay clear

there are hemispherical lenses

i guess the trick would be getting the proper magnification

> A flatbed CNC router large enough to handle sheet good will eliminate
> the need for a lot of things. It might not be as fast as a panel saw
> for ripping shelves out of plywood, but once you have it programmed

plus it is probably safer

> you can do an entire sheet while you are on the other side of the
> shop sweeping up from your last project. I want one, but the metal

one thing i wonder about is the depth of cut

how to make sure the cut is clean through

you would not want to cut into the table and how do you keep the
material flat for large sheets

[krw]

On Tue, 24 May 2016 16:44:24 -0700, Electric Comet
<electri...@mail.invalid> wrote:

>On Tue, 24 May 2016 12:37:50 -0700
>"Bob La Londe" <no...@none.com99> wrote:
>
>> That would be nice, but the old ones are totally 100% unuesable.
>
>wonder if a small magnifying lens could be glued onto one
>
>not sure of there are any adhesives that dry clear and stay clear

Sure there are. They're used in photography and in making touch
screens (the "touch" part is a separate piece from the "screen" part).
They're also used for cell phone protective glass sheets.

>there are hemispherical lenses

I'd think you'd want a cylindrical lens.

>
>i guess the trick would be getting the proper magnification
>
>> A flatbed CNC router large enough to handle sheet good will eliminate
>> the need for a lot of things. It might not be as fast as a panel saw
>> for ripping shelves out of plywood, but once you have it programmed
>
>plus it is probably safer
>
>> you can do an entire sheet while you are on the other side of the
>> shop sweeping up from your last project. I want one, but the metal
>
>one thing i wonder about is the depth of cut
>
>how to make sure the cut is clean through

The same way you do it with a saw.

>
>you would not want to cut into the table and how do you keep the
>material flat for large sheets

Sacrificial backer (someone here, I think it was Swingman, uses foam
insulation sheets. A CNC machine should be able to cut precisely, so
the backer will last a while.


>
>
>
>
>
>

[Bob La Londe]

"krw" <k...@nowhere.com> wrote in message
news:atr9kbducb5g48unn...@4ax.com...

One of the neatest tricks I've seen is to surface your sacrificial backer,
and then use your tool height setter to set that as negative the nominal
thickness of your sheet goods. Then you throw your stock on the table align
it, and lock it down. This way you just scuff the back, regardless of the
varying thickness of the sheet goods. If you are good at setup your
sacrifical backer should last for hundreds of jobs.

[Electric Comet]

here is the problem that i imagine could be encountered

you lay a 4x8 sheet down let us say it is 1/4 or 5/16
it does not lay perfectly flat so you get a different depth of cut
over the area


it seems to me you would need to have wheels on the cutter head that
applied consistent downward force while cutting to provide even
depth of cut and not cut into the sacrificial backer

with thicker sheet goods i would not expect much warping over the
4x8 area but with thinner i would expect a problem


maybe i misunderstand what you mean by lock down

[Bob La Londe]

"Electric Comet" <electri...@mail.invalid> wrote in message

news:ni4oj7$amf$1...@dont-email.me...

Ok, first off if you are cutting through, which was the question then you
don't give a flying rip about varying thickness of the sheet goods. You cut
based on the surface of the table. Second if you don't lock it down in some
fashion its not going to stay on the table. Third, if it was me I would
"lock it down" with a vacuum table if I was doing a lot of sheet goods.
Only small parts will go flying. Larger ones will remain in place just
fine.

[krw]

On Wed, 25 May 2016 10:51:57 -0700, Electric Comet
<electri...@mail.invalid> wrote:

>On Tue, 24 May 2016 18:21:17 -0700
>"Bob La Londe" <no...@none.com99> wrote:
>
>> One of the neatest tricks I've seen is to surface your sacrificial
>> backer, and then use your tool height setter to set that as negative
>> the nominal thickness of your sheet goods. Then you throw your stock
>> on the table align it, and lock it down. This way you just scuff the
>> back, regardless of the varying thickness of the sheet goods. If you
>> are good at setup your sacrifical backer should last for hundreds of
>> jobs.
>
>here is the problem that i imagine could be encountered
>
>you lay a 4x8 sheet down let us say it is 1/4 or 5/16
>it does not lay perfectly flat so you get a different depth of cut
>over the area

You lay it on a table that is flat. If you're not cutting on a flat
table, you're screwed before you start.

>
>it seems to me you would need to have wheels on the cutter head that
>applied consistent downward force while cutting to provide even
>depth of cut and not cut into the sacrificial backer

See above.

>with thicker sheet goods i would not expect much warping over the
>4x8 area but with thinner i would expect a problem

Exactly the opposite.

[Electric Comet]

yes i understand the material has to be secured
but that has to be at the perimeter of the material

the vacuum table would do it for sheet material as you said
so there is the answer

have you done any research on the most bang for the buck for a cnc
setup for wood

being budget conscious i am interested in looking at solution

[Sonny]

On Sunday, May 22, 2016 at 7:35:25 PM UTC-5, Bob La Londe wrote:

> Video
> https://www.youtube.com/watch?v=YqF56m31TYo
>
> Picture
> http://yumabassman.com/forums-new/gallery/2_22_05_16_5_24_01.jpeg

> Bob

Pretty neat, Bob.

When making/replacing my sight glass, I used a small plastic rectangle box, that fish hooks came in. I trimmed 3 sides of the box off, leaving the bottom and one perpendicular side (the attaching portion). Back then, Delta wanted $9 for a replacement glass. Today, my fabricated glass has dulled, become scratched, etc., again.

Sonny

[Bob La Londe]

"Electric Comet" <electri...@mail.invalid> wrote in message

news:ni766b$edk$1...@dont-email.me...

If you are up for builiding your own you can invest a little at a time by
starting with one of Ahren Johnson's kits from www.cncrouterparts.com , but
by the time you get done building the cost will be the same to build a solid
heavy machine of decent quality, plus a lot of your time. There are noname
Chinese Imports for around $4800 to $6800, but I have yet to talk to
somebody who owns one. The most basic machine I would consider as decent
will run from about $12.8K to $15K nearly complete. (may still need
computer and control software) The really nice sheet goods size machines
start at around $16k and go up. I'll probably go with the $12-13k range
machine and build my own vacuum table when I am ready to add that machine to
my arsenal.

[bnw...@gmail.com]

I'm not positive, but I think I just heard EC hit the floor somewhere :)

[Electric Comet]

On Thu, 26 May 2016 10:45:46 -0700
"Bob La Londe" <no...@none.com99> wrote:

> If you are up for builiding your own you can invest a little at a
> time by starting with one of Ahren Johnson's kits from
> www.cncrouterparts.com , but by the time you get done building the
> cost will be the same to build a solid heavy machine of decent
> quality, plus a lot of your time. There are noname Chinese Imports

i will probably do it myself but just wanted a starting point for
inspiration

there is a lot of opensource cnc stuff out there
my big concern is getting caught up in putting one together and
enjoying this fiddling around stage too much

fwiw i would probably do 4x5 or something like that or some other
optimal size that is less than 4x8

i have noticed some equipment sellers/makers have fewer conventional
machine offerings and more cnc stuff

[Sonny]

On Thursday, May 26, 2016 at 2:21:51 PM UTC-5, Electric Comet wrote:

> i will probably do it myself but just wanted a starting point for
> inspiration
>

Maybe search the IRS (Industrial Recovery Service) auctions for a used pin router, to start with, if you want to play, first.

Example: In York, Pa, the bidding for a few are $200-$500 at the moment. Lots 417, 422, 435: http://www.irsauctions.com/index_lots.asp?pg=details&tot=&id=20325

Check the other listings for an auction near you.

Sonny