Denford Software & Machines

Can anyone suggest why, when I cut a square out of 6mm Acrylic that the opposite sides (when looking on a side view i.e. the 6mm depth) appear to form a Parallelogram shape. i.e. the sides taper in the same direction.

Is there a way I can prevent this or reduce it so that I can get parts to assemble together without having to make modification to the sizes of the pieces ?

Laser cutting will always produce a cut with a slight taper to it.

The material power etc will all affect how large tha angle is.

If you cut a 6" Rule for example then stand it on a 3mm wide edge it will lean slightly where the edge was cut.

If the laser is out of focus then the angle will be more severe.

Try reducing the power to the point where the sides are still cut and the taper should be slightly reduced.

The taper is caused as a result of the laser beam being focused. The beam is at its narowest at the focus point and diverges before and after that point.

You may be able to purchase a different lens that would produce a flatter edge for a set distance but the 2" one is the best for all round operation.

Steve, already answered the question, perfectly.

From my experience I can tell you, that focussing into the material (at 6mm Acrylic about 1 to 2mm) will help to get less angle as if you focus at the top of the surface.

As thicker a material will, as thicker the angle is. Acrylic is melting much more as for example wood, so that is the reason why people see it at first at this material.

best regards from Austria,
Bernhard

I understand why you would get a taper, but why is it cutting a parallelogram? Something is not level or square. The samples left by denford when I bought the machine had a taper not parallelogram.

Are you saying that you get a taper on both edges leaning the same direction rather than both splaying out?

Is the material down flat on the cutting table?

Is the cutting table in flat?

Can you check the focus in the corners of the cutting table to check it is flat?