[jimmy2020]

I'm considering entering a new market with lasers, in particular the cutting of CR39 (the plastic used to make most spectacle lenses).

Given the high cost of lens production for rimless specs I thought about giving a laser a go, does anyone know if there are any issues using a laser to cut CR39 I should be aware of such as the fumes, or should it be okay to use a laser for this application.

I'm also planning to use the laser for engraving the lenses with custom logos, I can sense a high value niche market here.

[bennett71]

A general rule for cutting anything with a laser is if you can smell it, exaust it. Most plastic is poisonous to some degree when burned. Thin plastic is not to bad but when you get 1/4" & above it gets nasty unless properly exausted. A small vac table with some 4" thick aluminum honeycomb would work great. The honeycomb will scatter the beam & protect the bottom of the box as well as providing a flat surface for cutting. Back burn is minimal also. What is CR39? Lexan is difficult to get a good edge finish but in acrylic you can get a perfect polished edge.

[jimmy2020]

Oops, new to forum and repeated reply

[jimmy2020]

What is CR39? Lexan is difficult to get a good edge finish but in acrylic you can get a perfect polished edge.

CR39 is short for allyl diglycol carbonate.

see http://en.wikipedia.org/wiki/CR-39 for the full description

Well the good news, it cuts, I needed the full 40w of my little redsail RS3040A, at medium speed, took 20 seconds to cut the lens. using a PLT file from corel draw.

This is exceptional, as lenses normally require tracing, cutting, pollishing, then the tricky part of getting the drill holes in. The normal process has a high break rate, and a high machinery cost (10k for the tracer, 30k for the edger, 2k for the polisher, and 4k for the CNC drill, + expensive consumables)...,, Expect to see some unique shaped lenses on the market soon as no conventional setup will cut the shapes i'm looking at making.

[Neil Pritchett]

Hi Jimmy,

Just thought I'd let you know that we are the UK distributors of Redsail lasers.
We hold spares etc and can offer on-site repairs.
Have a look at ctrlasers.co.uk for info.

Best regards.
Neil

[jimmy2020]

Hi Neil,

I'm glad to see that someone has taken the effort to distribute these machines in the UK.

I had some issues getting my laser to work at first and would have appreciated some UK support during the setup phase, I had to remove the existing brass screws and upgrade the earth for the whole chasis. I'm fairly confident on the operation and design of the RS3040A now having to make some of my own modifications to get it going.

We where considering importing the redsail units ourselves, but in the end decided just to be an end user given the cost of the CE test, and the fact it still might of failed to meet the CE test after all our modifications. I look forward to working with you in the future, I would like to know will you keep these machines in stock and what level of support will you offer, as I'm sure we will need support from time to time. PM me, and i'll give you my contact details, I'm interested in getting a cutting machine over the next 3 months.