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DLMACHINE
05-11-2003, 09:54 PM
Any ideas on milling glass at 3000 rpms on a vertical mill?? Could really use a point in the right direction for tooling.

hardmill
05-11-2003, 10:49 PM
PM one of these guys @ this link, i have absolutely no
idea how to cut glass.

http://www.cnczone.com/showthread.php?s=&threadid=357

Let me know how it goes/

PEACE:p :p

cam
04-15-2004, 03:46 PM
we grind glass for a living here and couple of things to do
diamond tooling 80-150 grit roughing/180 and up for finish
our spindle speeds normally run around 6500 rpm(cnc)
we wax the material to "sacraficial"glass for reducing chips cracking or breakage
need more info let me know

jahl69
04-27-2005, 05:45 AM
Then I can put a diamond wheel on my old 4000 rpm hand grinder mounted on a solid frame kicked over at a certian angle to put a spicific sag. in an optic morror??

ImanCarrot
11-08-2005, 11:57 AM
I used to grind glass on a 2VS vertical mill. The tools are actualy sintered diamond on a torus on the outside diameter of a deep shank (picture a coring drill but scaled up with sintered diamond at the cutting torus
. Coolant is important otherwise the glass cracks.

Obviously if you tilt the tool one way it will produce convex surfaces and concave the other way. You will need to "smooth" the glass surface after this roughing using (usualy) 3 grades of Aluminium Oxide or similar. Youcan then polish it using the correct grade of pitch and Cerox or Jewelers rouge with water and a lot of time :eek:

hehe hope this helps. if you need any more info on optical working ive me a shout

jolliesconcept
06-18-2008, 08:10 AM
I am also looking for ways to machine Glass.We are having
CNC 5-axes,vertical milling with 60K RPM.We are trying tp machine our Watch glass crystal using our machine.Pls send me all the precautions and process required.

ALso guide me some diamond tools to get the 3D shape as our watch crystal is not a commonly used flat glass but it consists of a spherical surface with a non symmetric profile.

Also guide me with the tool geometry...

anonymality
08-22-2011, 10:07 PM
I am also looking for ways to machine Glass.We are having
CNC 5-axes,vertical milling with 60K RPM.We are trying tp machine our Watch glass crystal using our machine.Pls send me all the precautions and process required.

ALso guide me some diamond tools to get the 3D shape as our watch crystal is not a commonly used flat glass but it consists of a spherical surface with a non symmetric profile.

Also guide me with the tool geometry...

Maybe I'm missing some details here but if you need to do a big production of these you may consider a tungsten carbide mould for optical quality finished part right out of the mould.
But if your wish to machine these parts you might have to make a lot of experiments or consider having them made by a specialized optical glass shop.
If you REALLY want to machine your parts then you will probably need to make a custom vacuum fixture and get your hands on some metal bonded diamond tooling (80-180 grit for roughing, 220-400 grit for "flat" finishing). For a clear finish seach for "glass buffing disc" on google. These buffing discs wear very quickly and they need to be changed often"0.2mm rad. wear for +/- 1m edje. Cooling your part and tools with lots of freshwater is essential especially when polishing.

Hope this helped you... or anyone else.

mamabrigitte
10-10-2014, 12:50 PM
hello Cam

I went thru your mail looking for information concerning grinding glass or mirror on CNC machine and it seems you are the right person for imformation concerning that topic
I'm at present doing Design mirrors on a CNC 900x15000mm annd designing mirrors from up to 12000x 18000 mm but mostly 1200x900 mm mirrors ( bigger mirrors on my CNC require a specific setting I don't handle yet) the mirrors"s thichness go from 3 to 6 mm ( mostly 4 and 5 mm ) I use 2 , 3, 4 mm diamond rounded cylinder burrs 80--250 grid mostly for contouring using only water for cooling I Because I don"t know better spindle a 3000 rpm and cut federate fed at 25 mm/min in one pass 5 mm and my plunging I never bevel because I don't find cheap 90° burr with a 3 -7 mm shank (ER11) I 'm expecting one from china but it will be a 45 grit one I use double face tape for fixing my mirrors it is a problem the tape thread go around the burr stop the spindle and break the burr and I tried WAx but it didn't work Because by the time I set the mirror on my wood sacraficial the wax is alreay on solid state

so with your long time expertise may be you can hepl me to go futher in my quest especialy concerning you wax technic and the spindle rpm , feed and plunge rate for my cnc do you think mine are ok ?? your answer wiil be apreciate http://www.cnczone.com/forums/images/smilies/banana.gif