Can someone build a glass scoring head for me?

[Perry Holbrook]

I cut a lot of small odd shape glass in my studio. In February I stumbled upon a bench top CNC machine designed to score glass exclusively. It was offered by an individual who made them probably in his basement (nothing wrong with that). After speaking with him, I felt a little uneasy, but placed an order anyway since I really need this capability and its very low price.

Very long story short, I finally cancelled the order yesterday due to his repeated failures to meet any of the numerous shipping dates he gave me.

But I still need such a machine. I had hoped to be able to justify a mid size Shop Bot later this year to speed up wood production. So now I'm wondering if I could attach a glass scoring head to the Shop Bot.

The other guy has a web site that shows his machine, but I would rather not list it here ( I have a real problem bashing any company in public no matter how much they deserve it). I would really appreciate it if you guys would take a look and tell me if such a head could be built. If you are interested in this project please PM me and I will give you the link to his site and other details required to score glass.

Thanks, Perry

[Kenneth Hertzog]

PM sent
hope I can help
ken

[Steve knight]

I have a diamond drag tip I use in my shopbot. that would do it. though the spring loaded holder was 350.00 the bits are only about 25.00 I have not done much with glass yet but it sure works on everything else including tile.
http://www.2linc.com/engraving_products.htm

[Perry Holbrook]

Ken, I sent you more info, thanks for the interest.

Steve, I saw your drag tip attachment when you posted it. I think you are correct that it will score the glass, I think the problem is the tip will wear pretty quickly. Standard glass scoring heads use a diamond tip wheel that rotates as it travels to keep the wear factor low.

The challenge is that as you score a curve you must rotate the scoring head so that it stays in perfect tangent with the arc as it changes. I'll PM you a link to his video.

Thanks, Perry

[Kenneth Hertzog]

Perry

the link you sent me come up to a Realistate person
not a web site for glass cutting.

did the link work for you?

ken

[Perry Holbrook]

Ken and Steve, I send you another link, not sure what the other problem was.

Perry

[Joe Chritz]

Any reason you can't just fab up a bracket to attach a scoring pencil onto the head?

I have used one to do some engraving with a vibrating pencil with a CNC router and it works very good.

Joe

[Rob Wright]

How about something like this?

http://solsylva.com/cnc/cut_glass.shtml

- R

[Perry Holbrook]

Rob, I have seen that before and it appears to work for circles. However, for my purposes it won't to the job. One of the problems is cutting glass with corners like squares, triangles, octagons, etc. You have to be able to index the scoring head mechanically. Another problem is when you are scoring irregular shapes, the head must swivel perfectly, if you let it swivel freely it tends to lack and dig in, especially in tight curves.

Thanks, Perry

[Lewis Cobb]

Hello Gents -

I seldom wander outside the power tool forum but for some reason I took a look in here today and saw your posts.

I am aware of the fellow that makes the glass scoring CNC machine spoken about and although I never had any dealings with him, I have seen his site and the machine he crafted up to do the scoring. It looked very promising as a way to reduce the production time of making glass pieces. A waterjet machine would be a more complete soution as you still have to break the glass pieces by hand with the scoring machine, but at about 100k for a waterjet and an industrial building, I'll happily break the pieces out by hand

My wife does stained glass as a hobby and is getting some requests for jobs for people from time to time. As an electronics fellow, I am always keen on the "automation" of tasks and starting looking into the job of stained glass scoring with a tabletop CNC machine about 2 years ago.

The tangential control of the cutterhead is key, as has been mentioned, the drive software that controls the stepper or servo motors has to be able to have a "4th" axis to control this rotational movement. x, y for the table, z for up/down and then the rotation. In the case of the scoring machine mentioned, I believe the z axis is a simple spring loaded up/down movement so there's a constant pressure that's applied to the scoring head as it travels across the glass (probably tweaked by the loading spring in a similar fashion as a bandsaw).

I never got too far with this research, but did come across a fellow that makes a very cost effective software package that might be a piece of the puzzle - the software is called MACH 3 and if you go into the "CNC Zone" forums I think it's called, you will find machinists all over the globe using it. The website is machsupport.com

I'd like to stay in this "loop" to see what you fellows come up with so if there's any chatter "off line" - please PM me as I might be able to offier up some snippets of info that would assist the process as I learn more.

Incidently, the CNC zone place (cnczone.com) has plans for a do it yourself x/y/z table set up that's based on MDF boards and the like. For woodworkers it's an easy project, but there could be some machining bits and pieces that would have to be jobb'd out if you are not into metalworking. One of the keys to the glass scoring CNC approach is that you can do it with fairly sloppy leadscrews on the table movement etc. as compared to some precision operation like machining metal. In fact, the leadscrews used in the home brew plans are based on threaded rod from the hardware store !

Anyway, nice to make everyone's acquaintance and look forward to reading more about this development.

Cheers,
Lewis

[Kenneth Hertzog]

Perry

did you have any success cutting glass
had to do some work on my machine
can run a test if you still need it done.

ken

[Joe Doherty]

We apparently have a CNC glass scoring machine on a truck that should arrive this Friday. Hopefully it will work as advertised we have to cut 250 or 300 circles, offset hoops really, and we are hoping this machine will get the job done.

Mr Hertzog, What type of machine do you use? I would be interested to speak with you to get up to speed with our cutter as we are up against a deadline and the delivery date has been delayed time after time.

Thanks,

Joe in New Orleans

[Angus Hines]

Here's a tangent cutter someone built for their Bot.

http://www.youtube.com/watch?v=8nYQaLgvvKI

[Kenneth Hertzog]

Joe
I"ll be happy to try it
I've got a spring loaded diamond cutter
what size circle are you looking for
or was it a hoop
I have a cnc router and a cnc milling machine
both can use the diamond cutter
router is 24 x 30
mill is 7 x 15
ken

[Joe Doherty]

Ken,

It's a hoop with a 12" outside circle and a 10" circle. The edge of 10" circle is 1" from the edge of the 12" circle at the closest point. Does that make sense? We will be cutting these circles out of 3mm bullseye glass. We can do it with our manual circle cutter but it's a little slow.

Thanks,

Joe in New Orleans