Saturday, 4 April 2015

New Toy. 50W laser cutter.

Visit Tagbits to see the full range of tagger products described in this blog.

I've had one of these in my sights for a while now. And I came into enough cash to allow me to buy one. I ordered from AliExpress rather than ebay, as the price seemed better.

It arrived last week via DHL. Well packed but delivered by Mr. Grumpy himself:

It's slightly bigger than the cheapest that can be bought with a cutting area of 400x300mm. As a 2015 model, it comes with accessories that would previously have to be purchased separately:

An air assist laser head and air pump. This helps to extinguish flames and generally blow unwanted smoke away from the laser head:

A digital control panel, thoughtfully worded in Chinese and English:

A Z adjustable cutting bed.

A honeycomb bed. This reduces the amount of heat transferred away from the underside of the work piece during cutting, and also allows the extractor fan to draw down any smoke:

In typical cheapo Chinese fashion, the honeycomb was not flat, with about an 8mm delta from corner to corner. I solved this by drilling M4 holes in the corners that were raised, and drilled a 9mm holes on the upper side of the frame to allow screw heads to pass inside the frame. I then drilled and tapped the Z bed to M4. This allows me to screw the corners onto the Z bed, forcing it to be flat.

It's also supplied with a water pump to cool the laser tube. I got a 32L box from Wilkinsons and drilled two holes in the top and filled it up with 25L of distilled water from Halfords.

Distilled water is required to stop any impurities in tap water from depositing inside the laser tube. This could cause hot spots. I also added some propylene glycol to act as an anti bio/freeze agent.

Included with the package was a rotary axis to allow the engraving of cylindrical pieces:

Most impressive is the laser tube itself, glass with a helix! Covered in cautions written in Chinese. No doubt recommending not staring into beam with remaining eye.

The software was supplied on a DVDR with a USB dongle. Not entirely sure if this is legitimate or not. However, once installed, it works as expected. There is a plugin for CorelDraw included on the disk which seems to be the most useful of the bunch, providing direct access to the laser cutter from CorelDraw.

The main issue with these budget laser cutters is the alignment of the mirrors. This image from LensDigital shows the laser beam path:

At assembly, they only seem to centre the laser tube on mirror 1. The user is expected to align everything else. I followed this video, and got everything aligned in about 40 minutes.

So with a day of tinkering behind me, I've managed to create a gear with the excellent, free Gear Generator and import a SVG file of a gear and cut it from 6mm acrylic. This has some random lines on it due to my inability to set the feed rate correctly, but still impressive:

A really nice feature of the cut is that it leaves no blemishes on the edges. A cut with a jigsaw would require treatment with a solvent to get this clean:

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