Glass cutting

[ChrisG]

On the Excalibur I sometimes find that although the sheet is scored right the way down it doesn't break cleanly, typically at the start ie top of the score the glass breaks at a slight angle away from the clamp. The result is a small nib preventing the sheet from fitting into its intended frame.

[Graysalchemy]

Try using a more even pressure across the score line so it snaps more uniformly on the machine. You can also take of the nibs with pliers.

[Abacus]

I don't think you are supposed to use the clamp with glass (the fletcher I use has "do not use for glass" on the clamp).

If i've misunderstood, please accept my apologies.

[Graysalchemy]

I agree I wouldn't clamp it

[Graysalchemy]

I agree I wouldn't clamp it

[Roboframer]

I always have - (on the keencut) it still scores unclamped but there is a chance of movement.

You may need a new wheel or a drop of oil on the one you have or to adjust the tension, maybe in addition to one of those. Put a piece of mount board behind the glass, that will effectively increase the tension, see what happens, if it improves things increase the tension.

[IFGL]

what roboframer said is exactly right, the clamp on the Excalibur is designed for glass clampage
in addition to his very good advice, you may need to adjust the baring screws if there is play in the head, correctly adjusted the glass should only need very slight pressure to snap it cleanly.

[hyperfocal]

I had the same problem for a while and an older framer suggested just to run the score a couple of times at the top for about 5cm then the full length as you would do normally. (hope that makes sense) it works a treat.

[GeoSpectrum]

I found that happened but at the bottom, I found I was pressing on the glass a bit too high, I just moved my hand down a bit and the problem went away.

[Not your average framer]

This problem happens from time to time on my system 4000, but I have found that the problem goes away when I lubricate the cutting wheel and axle with a quick squirt of GT85.

I think this must have something to do with how freely the wheel is able to revolve.

(GT85 does not contain oil, so it does not ruin the nylon cutting wheel housing).