First shapes off the laser cutter

While waiting for a delivery of acrylic sheets (ok, it was only ordered a few hours ago and it's Sunday evening!) we've been playing about with the few sheets of clear plastic we got with the cutter, to find out which settings work best for us.

We found that cutting at 15mA, 20mm/sec works really well for 3mm acrylic.
Any slower and the beam reflects off the honeycomb bed and pits the reverse of the plastic. Any faster and the beam doesn't always cut all the way through on the tight corners of intricate shapes.



Here are some example logos for a new shop opening soon; it's called NIX and offers an outlet for cottage industries and artisans. The idea is really simple. For a fixed monthly fee, you get a shelf on which you can display and sell your wares.



Obviously these would look much better in coloured and/or opaque acrylic, but they're just test pieces to see what the laser cutter can do. And so far, the results are pretty impressive!

line drawing exported as dxf for importing into NewlyDraw

Here's the original business logo, to compare the results to:

Cutting at last!

After a few false starts, and a nervous first try, we're finally cutting stuff with our new LS3020 laser cutter! The tiny bubbles problem apparently is quite common with new tubes, and a few capfuls of Milton sterilising fluid soon sorted them out (thanks guys on the LaserScript forums for the tip!)

So now we're safely(?!) cutting acrylic with the laser, it's time to get familiar with the NewlyDraw software and find out which power and speed settings work best with which materials.

At the minute, we're trying on clear 3mm acrylic.
The laser cutter is whizzing little 10mm circles out no problem, at about 12mA. Now we just need to find out what all these settings in the software actually do!

After selecting the items to cut out and from the file menu, hitting ENGRAVE, the following dialogue appears. From here you can jog the head around or set it to it's origin (we found that -80,0 put us in a good starting point, at the top left of the sheet of acrylic) and even choose optimum cutting paths (more on that later, we're still trying to walk, let alone sprint off into the distance!)



After hitting "start engrave" a second dialogue appears



This has more of the same - a second chance to jog the head around - and some speed/power settings. We're not quite sure which of these relates to what: whether the speed setting is for jogging the head, or for cutting. To date, changing these values doesn't really make much difference: the laser head goes off on it's merry way, making short work of the 3mm acrylic, no matter what speed/power settings we put into this second screen. We're guessing that these need to be changed somewhere else, and we're probably giving it too much juice or not moving as quickly as we could, for the given power level or something.
Either way, it's another visit to the LaserScript forums to double-check we're doing everything right. It's exciting having a laser cutter. And a little bit scary!

Laser cutter from HPC

It's been a busy couple of weeks, with "real life" taking over for a while (always the case, as summer approaches, family holidays are arranged, lots of doubling up at work covering for colleagues who are lucky enough to take their holidays before the schools break up and so on).

As work on the touch-sensitive range of instruments stalled, due to cutting problems, we decided to take the plunge and make a heavy investment. In fact, we're making quite a few BIG investments at the minute, the least of which is taking out a lease on a shop to sell homewares, home-made goods and generally supporting the whole maker/cottage industries that are slowly but surely growing throughout the UK. As well as buying stock in, I've got a crazy idea about selling make-it-yourself kits and pre-assembled "geeky gadgets". And the first range of products? Yup. Miniature instruments.

So making them from MDF seems difficult due to the limitations of the CNC, what's the alternative? Acrylic of course! You can see where this is heading....

...HPC in Halifax supply laser cutters. And we're the proud owners of a shiny new LS3020 machine. We spent the day up there recently and saw one in action. It was amazing - blasting through 6mm acrylic in a single pass with no problems, cutting mdf, laser ply, and even solid maple, all 6mm thick, in a single pass at varying speeds (the slowest at around 8mm/sec cut 4 layers for an entire guitar in just a few minutes). Exciting stuff!

After getting everything set up and following the instructions and advice very closely, we're almost ready to cut. The only thing is, this is an expensive bit of kit, and very easy to get wrong (and break �150 CO2 tubes apparently). So we're a bit nervous of actually firing the thing up on our own!
The thing is, the CO2 tube had some air bubbles in it even after the machine had been switched on (with the water pump running) for about half an hour. We got rid of the big bubbles that had collected at either end, by tipping the machine then pinching the water inlet pipe for a second or two and releasing (returning the machine to horizontal). This worked really well for getting rid of the "air locks" in the tube.
completely air bubble free water jacket around the CO2 tube

The worry thing is that the main part of the tube has a lot of little tiny weeny bubbles along its length.

smaller than the bubbles in a Wispa bar, are these anything to worry about?

We've tried all manner of stopping and starting the water flow, tipping the machine, leaving it to rest, turning it off and going for a walk, switching it on and moving it around. It doesn't matter what we do, those little tiny bubbles don't want to go! The question is - can we run the machine with these little bubbles? Do they matter that much? Not knowing enough about it, we're frightened to fire the machine up fully and try cutting, just in case the tube gets busted. That'd be a real bummer. The machine's only a few days old; we don't want to break it before we get started!