MSRaynsford

One of the EMF projects that didn't make it to completion were these edge lit badges. It uses a similar technique to my own EMF badge  (black spray paint over fluorescent perspex) except this time the UV led and coin cell is built into the badge. The reason it didn't get to completion is because the led needs a hole all the way through the badge but the LED has to be covered otherwise the eye can't see the subtle fluorescing (the LED is too bright). The prototype used a piece of black tape but it's not exactly an elegant solution. I also tried to cut the whole first, then engraved through a black label over placed over the whole thing but I couldn't get it to cut clean enough.

I think the title just about sums it up, I was looking at some of the Cotton Clara designs and I was inspired to make my own embroidery designs based upon dinosaur shapes. I think they'd make fun little kits for kids.

Engraving can be tediously slow, especially when you want to do the edge of a large area but not fill in the middle. It's something I covered before when I carved the cupboard door shields . I previously drew a dozen different lines to simulate the engraving effect, it was faster than the engrave but still a little bit slow. This time I thought I would try defocusing the laser beam to get a nice wide engrave, then the groove can be cut in a single pass which would be a lot faster.  I ran these test pieces at differing heights under the laser (the mm distance is height below the focal point. The results were quite effective and with a bit of tweaking it will do the job nicely. The first thing to note is that the corners cut a lot deeper than the straight sections. This is a known issue and Lasercut specifically has a setting for it. I found that reducing the corner power to around half of the main power solved most of these issues.  The other issue is the s...

A few weeks back I investigated various latching box mechanisms with minimal success, mostly it felt like they were trying to flex the material in the wrong direction which lead to snapping. I tried to make a sliding lid on this box to test a latching mechanism. The lid is a basic sliding lid but when it is fully closed, protrusions on the lid push the side walls out and latch it into the closed position. The walls flex with with the grain of the material so it is pretty sturdy and should last a long time. It's not the best box in the world because the lid is very tight anyway and it doesn't need to be locked into place but it's a successful test nonetheless. ( svg here ) 

The third and final project from this years maker faire was a webcam capture program that would easily digitise children's drawings and then send them down to the laser cutter for engraving. The webcam holder  with led lighting to illuminate the drawing. I used a c# wrapper for the open CV library to capture images from the webcam, a little bit of filtering to remove pixels that weren't black enough. The image was then converted to G Code, and transferred to a GRBL controller that was wired into the Greyfin laser cutter . The G Code simply drives the laser to the next black pixel and burns a single dot for each pixel, repeat for each black pixel in the image. The program ended up being a bit of a mess as it evolved throughout the course of the weekend. It's got some nice features though such as the ability to capture or load an image for engraving, automatic detection of GRBL devices on the serial ports and free text sending to control GRBL directly. I'v...

I've been writing some of my own greyscale engraving code recently. I have written both ends before (in a project that didn't make it to the blog) but this one is a PC sender program connected to a GRBL controller in my Whitetooth laser . The fun part is that the image was captured from a drawing my wife did for me via my webcam. Yes, I know it's only on/off and not real greyscale. Yes, I know the image is mirrored. Yes, I know it is titchy compared to the original. It's a really cute picture of a kitty though, now move along.

I designed this piano hinge a long time ago but I was holding it back for a special occassion. Since then I've been distracted and the occasion never came so I'm releasing it today. The hinge is made from 2 sheets of material a groove is engraved along the middle and a piece of piano wire inserted along the groove. It's a strong sturdy hinge that can be created to any length you require, the only minor issue is that it leaves the burnt side out, but that can be cleaned. ( svg here )

I used up my laser engraved eggs by having scrambled eggs for breakfast, but I noticed that in the places I'd engraved upon the surfaces the eggs had actually started to cook on the inside. This got me thinking, if I engraved the whole surface of the eggs then I would have a lovely boiled egg instead. I drew up a simple spiral pattern for maximum area coverage and set the laser slow and powerful (2mm/s, maximum power), I turned the egg at the end of every cut to cook the next part. It's not enough to cut through the egg but it certainly did a good job of heating up the innards. Like all laser cut foodstuffs it's a pretty stinky process but it did leave me with a yummy egg afterwards.

It's still Easter and I've seen a few laser cut eggs in various places online so I thought I would give ti a try too. I put the egg on a plate under the laser and held it down with some blue tack. Engraving is not so good, it's hard to mark it the right amount so the rest of these images were done with low power cut lines.  Kim wanted a Good/Bad Egg and while I'm marking up tomorrows breakfast I should probably give Kim what she wanted :) They look pretty in the egg bowl and I'm sure the kids will love them in the morning.

0.8mm ply I saw this  instructable  a while back on how to cut a flexible ply sheet, the idea is that it can flex in multiple planes at once. I was a bit sceptical and when it came up in conversation again this week I took the opportunity to cut some samples for someone else. The result is a relatively flexible sheet, I wouldn't really call it a super flexible sheet.  I tested it by pressing it down over an object and seeing how well it deformed. I started using 2.7mm poplar plywood, my favourite material that is already lightweight and flexible. It took about 12 minutes to cut a 200x200mm section. It flexes quite well in one plane and with encouragement in the second. I still wanted more so I cut it again in 1.5mm ply and 0.8mm ply. The thinner the ply, the more flexible the sheet. It helps that the 0.8mm stuff is already called flexible ply and can be wrapped around without any cutting.  Given the amount of time it takes to do this kind of cutting i...

I had a very spur of the moment visit today by Paul from Rideworks . He wanted to know if our machines were capable of engraving his anodised aluminium parts so the best way to find out was to try it. We played around with a few different speeds and settings and we even cut an impromptu jig to align the parts perfectly. The test results are great, in fact the hardest part of the process was the moving of files between our aging laptops.

I've known about this effect for quite some time but since I had the lid off my laser cutter and I could video easily I thought now was a good time to share. When you're testing the alignment of the laser you cover the mirror with some masking tape and shoot the beam at it. The first shot burns a dot on the tape but subsequent shots increase the dot size, in essence burning a ring around the centre. This ring of burning turns into a ring of smoke which gently rolls upwards from the masking tape. Repeatedly shooting the tape eventually burns through it which may cause damage to your mirror but I did at least manage to capture a few on video.

I've been toying around for a while with the idea of laser cutting through the material at an angle to create a mitred edge. Cut enough of these edges and you can still all the shapes together to create special boxes of polyhedra. I finally got round to testing it and it works really well. You can see all the cutting details over on the JustAddSharks blog here , but for now I'm just sharing pictures of the polyhedra I made using this technique.

Since I've been playing with foam again I took the opportunity to conduct some tests on thicker sections of foam.  The 12mm foam cut in a single pass, 25m/s and 30% power so super fast. The trouble is that the middle of the material gets really hot and starts to melt, drawing back from the beam, this causes the curve you can see on the edge of the cut. The 30mm foam was cut in multiple passes, 25mm/s and 15% power. As you can see the laser caused ripples down the edge of the material for each pass. Both of these are pretty much unacceptable for the majority of things. The second problem is caused by the way the laser works. As the beam passes through the final lens it takes on an hour glass shape. The neck of this hourglass should be focused onto the surface of the material. As the beam passes through the material it gets wider again at the bottom of the cut the beam is noticeably wider than the top. These two issues can actually be used to counteract each other. If ...