Tuesday, 22 July 2014

When did eBay turn into Maplin?

For years we've turned to eBay for cheap, low volume components. Quite often searching for something on Farnell or RS returns three or four of the same thing from a supplier on eBay (unless buying in suitably large volume).

But over the last six-to-eight months, we've been receiving fewer and fewer parcels at Nerd Towers from eBay, and more and more coming from "proper" online retailers. Here's just one example:

We're looking to prototype some simple kits for the up-and-coming Brighton Mini Maker Faire. These kits will be used to create simple motorised drag racers. As ever, habit suggests we hit eBay and see how cheaply we can get hold of the little hobby motors.

any number of variations on 3v motor, miniature motor, 5v motor, 9v motor and so on returned similar results; the cheapest being £1.43 per piece

the cheapest "hobby motors" are £1.59 each

Maybe there are cheaper miniature motors on eBay, but finding them is not easy. Or maybe they're not there. But according to the level of search we used, a miniature hobby motor costs about £1.50

So we were quite amazed to find exactly what we were looking for on the Rapid Electronics website for just 53 pence!


That makes the cost of eBay-purchased products three times the cost of buying them directly from a supplier! But it's not just on electrical items. It seems that sellers are now passing on their high sellers fees and making the exact same products on eBay more expensive than in their own online shops!

modelscenerysupplies.co.uk for example, sell 0.8mm birch ply online. It comes in 9x11 inch sheets, available both in their eBay store, and directly from their website.


In the eBay store, each sheet costs £3.25. But in their own online store, each sheet costs just £2.85


It's long been a running joke that when you buy anything from Maplin, you have to pay the "Maplin Tax". This is the extra you get charged for being able to walk into the store and pick something up off the shelf (if they actually have what you want in stock) instead of waiting for next day delivery from your favourite online retailer.

But there's very little point in an "eBay Tax". There's no benefit buying something at a higher price from one online retailer than from another - better to buy direct from the seller, and let them keep all of the money spent at their online store, surely?

These days, we're finding we use eBay more to browse products, then look to source them elsewhere. Which is quite ironic, given that high-street retailers have been complaining that this is how customers shop in their bricks-and-motar stores - find something they like in-store, then go home and buy the same thing off eBay!

eBay used to be a fantastic world-wide marketplace, where you could reliably go and pick up pretty much anything, easily and cheaply. Yet these days, it's increasingly difficult to find exactly what you want from the eBay search results, meaning it's not easy - and the prices are noticeably more expensive than buying from other sources, so they're certainly not cheaper. 

Maplin is also neither of these things (even in-store it can be difficult to find what you what because of either the surly staff, or the fact that it's not in stock) but at least they have the advantage of being convenient. When you need a 22uF capacitor today, you can pop in and pick one up (albeit paying about 50 times its value). eBay is slowly turning into the online version of Maplin - but without the added benefit of being convenient!

Monday, 21 July 2014

Laser cut planks for Wild West 28mm terrain buildings

Here at Nerd Towers we love 28mm board gaming - and making up and painting the terrain as much as the miniature playing pieces and playing the games themselves.

A quick (but not-so-cheap) way of getting a really impressive looking gaming table up and running is through the use of laser-cut buildings, from companies such as 4ground.co.uk or Sally4th etc. These buildings are, as often as not, lovely detailed, atmospheric pieces which look great when painted up.


The problem is, being familiar with laser cutting, and seeing how these buildings are made, they're a little bit "lacking" for many in the "Nerd Club Gaming Club". It's hard to say what it is, but scratch-built terrain, complete with little imperfections and slight errors always seem to have a little more "character" and (dare we say it) "realism".

I, personally, haven't played and enjoyed a video game since about 1989, when Jon Ritman and Bernie Drummond released Head over Heels on an affordable label. Not long after that came out, when I discovered that ZX Spectrums were not actually coded using a ZX Spectrum, I started writing my own software and simple games - and most computer games become exercises in moving sprites around a screen. I still don't play videogames, even 25 years later on, even after all the advances in technology. At the end of the day, I'd rather be making simple games than playing even the most immersive multi-player dungeon crawler.


Head over Heels - the last decent video game ever made?

And laser cut buildings on a board game terrain leave me cold for the same reason - rather than marvel at the periodic detail, things like finger joints and how the cutting kerf has been disguised catch my attention more than the model; I'm looking more at how it was put together, rather than enjoy the finished product.

And this is mostly, I feel, because most laser-cut buildings have very little construction needed - they're essentially flat-pack, prefabricated miniature houses. They have lots of large, flat surfaces, with some textures laser-engraved onto the surface to make them a little more interesting.

This is partly why we recently spent so much time hand-assembling a scratch-built roof for an Old West building from plasticard - to give the final model a little more texture and character. The problem with that approach was that it was really (really) time consuming. So we came up with a compromise of laser-cutting rows of slates and assembling them to create a textured roof, with overlapping tiles, but which took a fraction of the time to put together.

After successfully making our rows of roof tiles, we look the plastic-wooden-planking idea to the laser cutter to see how that would translate too. Instead of carving the card with a knife and then scratching woodgrain into the surface, we drew some slightly wobbly planks (to simulate them being warped and worn in the sun) and drew some free-hand lines over the surface (in Inkscrape) as grain.


(A variety of different worn/weathered planks; to create a straight edge, simply turn the plank upside down - so the wobbly bit is at the top - and overlap with another plank above. The two straight pieces at the bottom are for edging the sides of a "lapped plank" wall)

Our LS3020 laser cutter can etch and cut at the same time (or, rather, one immediately after the other) but the driver isn't as easy to use as the BuildBrighton white laser - you basically need to create a bitmap for etching (the woodgrain) and a vector image for the cut-lines. The NarlyDraw software that our LS3020 uses can only handle engraving from bitmaps, and cutting from vectors.

So this is where the fun starts:
It's easy to import a bitmap followed by a vector image, and line them up by eye. In fact, because our wood grain isn't critically placed, we could have done this. But we wanted to try out (and document) how to go about lining up the cut and etch images. So here goes....

Firstly, create the cut and etch drawing in Inkscape on two separate layers (one for the etching, one for the cutting). Place the etch layer above the cut layer, and make each layer visible and invisible, one at a time, to check that all the lines are on the correct layers!

Now draw a little cross (we used a 2mm x 2mm) and place it in the top left corner of one of the layers. Copy the entire cross and paste-in-place on the other layer. We now have a marker that we can use to align the two images in NarlyDraw. (If you're not confident of important the images to the same scale, you can always put another cross in the opposite, bottom-right corner, and use this as a guide to get both images to scale).

Hide everything except the etch layer, select everything and export the selection as a bitmap (Inkscrape exports to .png so we had to load this into Paint Shop Pro to turn it into a 1-bit bitmap: the one bit thing isn't necessary, but it's handy to do, to keep the file size down!) Now delete everything except the cut lines (or copy the cutlines and the cross to a new document) and save as .dxf.

With a .bmp (for etching) and a .dxf for cutting, simply import the two files into NewlyDraw, zoom in and make sure both layers line up on the same cross.


Lining up the cutting guide on both the etching and cutting layers. When both are perfectly lined up, the final result can be previewed easily in the NewlyDraw application


It was with some trepidation that we hit the "go" button, but shouldn't have worried!
NewlyDraw did a great job of etching the bitmap image first...


...before cutting out each plank from the surrounding wood:


Each set of planks takes only a couple of minutes to complete. They overlap nicely and sit quite flat, to create a realistic, weathered wooden wall for a shack or a shed



After a few of our sample offcut sheets had been fed through the laser cutter we had enough planks for the walls to build a small building


Another couple of goes through the laser cutter and we had plenty of roof tiles too


All that remains is to assemble a building using the bits and paint it up, so see whether the wood holds the grain pattern after a layer of acrylic has been applied and drybrushed  (etching it would be pointless otherwise!) or whether we need to use something more like an ink or a stain, and just keep the grain lines darker.


After all this messing about with laser cutters and trying out different approaches to etching and cutting on the same piece, it was actually quite late when we finished last night; so the build and paint begins in earnest this evening!


Sunday, 20 July 2014

Laser cut slates for 28mm terrain roofs

After getting the laser cutter up and running at the new Nerd Club home in the Boiler Room Studios, we threw some simple designs at it and had it carving out roof shingles from some 1mm birchwood laser-ply at an impressive 32mm/sec, at just 15mA.


After the nightmare that has been the BuildBrighton laser cutter in recent weeks, it was really nice to just load up a file, hit go and have some super-intricate parts drop out of the cutting bed!
We've cut a mixture of "regular" and "irregular" rows of slates and even without the cutting and swapping around we expected to have to do, got some nice-looking roof panels pretty easily


We'll have to design and cut some ridge tiles, but the overall effect is far better than a laser-etched plank of 2mm mdf - and something we're looking forward to putting on our Wild West buildings.

Sunday, 13 July 2014

UV exposure unit ready for fitting

About six weeks or so ago we pulled apart some UV acrylic nail art lamps with a view to creating an exposure unit for fixing images onto silkscreens (and for fixing solder mask to etched pcbs).

The project stalled for a while due to a number of things, but having recently got the laser cutter working, and successfully getting the CNC router to move about (albeit not exactly drawing shapes yet) we've been inspired to spend a bit more time kitting the unit out with stuff that "just works" so it's on hand, ready to be used, as the need arises.

With this in mind, we spent some time last night getting the UV exposure unit finished - well, the electrics for it, anyway


The controls are all wired up and at the minute we're running the whole thing straight off the mains. All that remains now is to line the bottom of the tray with reflective foil (to hopefully reduce any chance of "striping" as the unit won't actually sit very low down on the underside of the desktop). Once it's installed in our large desk we'll put a relay switch inline with the power supply, so we can control the exposure time using a homebrew digital timer (of course, made from a PIC and a max7219 and some 7 segment LEDs!)

Just to make sure nothing had got damaged during the rewiring, we powered it up to see that it all still worked. Amazingly, it did.


It was only afterwards we realised that had it gone horribly wrong, none of us actually knew were the fuse box is, in the Boiler Room Studios - we could have been left in the pitch dark, feeling pretty stupid. Thankfully it just worked; but we'll make sure we know where the fuses are before we do anything else with mains wiring - just in case......

Friday, 11 July 2014

HPC LS3020 laser cutter up and running again!

A while back we secured a unit in a shared studio in Hove, for making messy things and generally doing the kind of things that are likely to either upset the family home or the neighbours (laser cutting, CNC routing, screen printing etc.)

Our LS3020 laser cutter from HPC has been in storage for a long time -maybe about 12 months or so - and it was to great delight that we got it connected up and working again last night.


Given the amount of hassle the laser cutter at BuildBrighton has caused in recent months, we were terrified that the mirrors might need realigning, the cutting lens could be damaged... any number of things that could have gone wrong with it, as it's been dragged around a few different places and never actually tried out, for a long time.

Amazingly, we switched on the old PC that was driving it last time, plugged everything in and hit "go". It cut our 3mm acrylic sheet at 15mA and at 16mm/sec, straight through, first time!


Because Nick, Charlie and Paul were also at the unit during the first test, they each got a yellow nameplate. The cuts are spot on - no beam spreading or half-cut lines; the cuts are nice and "tight" and well focussed. Some of the pieces needed pushing from the sheet - not because they were badly cut, but because the cutting was so precise, the parts had to be lifted exactly vertically to get them to come away.

Sometimes, on the BuildBrighton laser, everything falls away from the sheet as it's lifted off the cutting bed. While this is encouraging (at least the laser manages to get all the way through the material) sometimes it's only after two or three passes. And that means that sometimes the cuts are wider than they would normally be. Not only were all our cuts cleanly through the entire material, the cuts were so tight that the pieces were a little bit "squeaky" as they were removed from the sheet. At 16mm/sec we erred on the side of caution - there's a chance that we might even get away with cutting at a faster rate.

But for now, we're just thrilled that we have a working laser cutter once more. Admittedly, the extractor wasn't connected up properly during the test cut, and the studio did smell a bit like pear drops for a while, but as soon as that's all plumbed in, we'll be super-productive, laser cutting night and day, no doubt (for a while, at least!)

Thursday, 10 July 2014

The internet continues to amaze

For years the internet has been amazing, and continues to amaze.
When I was first introduced to Compuserve over a hacked retail till modem running at 14.4kbs I struggled to comprehend what I was seeing. When, back in 1994, I was told "just type in whatever you're looking for", in my naivete, I didn't think to enter "tits" or "porn" - I just put "carrot soup". From memory there were about 36,000 results. My brain hurt. In 1994 the internet was amazing.

Years later, as I wrote entire DMS systems in HTML and Javascript (long before it was cool to call Activex objects AJAX) I was blown away by how anyone could not only contribute to the internet (not just the world wide web), but build massive, complex systems on it. In 1999 the internet was amazing.

Seeing those fantastic, simple animations and tiny file sizes when Flash hit the 'net was pretty amazing too - then it became a fully-fledged web publishing platform, for games, apps and even music and video online. It was all pretty amazing stuff -as was watching it all disappear again, as Web 2.0 rebooted the 'web - and almost every application became a browser-hosted application.

In short, the internet is pretty impressive. It was when it first came to public consciousness, and it still is today. More than anything, as well as being a massive repository of data and information, the internet has made interaction not just possible, but essential. Not stupid social media, and tw@tter updates, people showing photos of their morning breakfast toast-and-jam-(nom-nom), but being able to speak with people, literally from all over the world. Talking about anything. For any reason - sometimes for business, sometimes to buy, sometimes to sell, and sometimes just over a shared interest.

What amazes me more than anything about the internet are the people who use it. People who give up their time, expertise and experience - all for free. For no reward other than seeing a job well done. Lots of people use the internet to give things away: whether it's open source software, designs for the latest 3d printer, or - sometimes - something a little more personal.

I had one of my "isn't-the-internet-brilliant" moments last night, when I received an email from Martin (who runs JustAddSharks.co.uk). He'd been reading this blog, seen we'd had problems laser cutting some design ideas, and rather than wait for the next painful installment of disappointment and broken laser tubes, he downloaded the designs and cut out some of our projects, so we could see the results straight away!


Without prompting, and for no reward (we had no idea he was doing it) Martin tried out one of our ideas and sent the results straight back. He even sent some comments and suggestions for possible improvement (yes, the tiles do look a little to far apart in the final cut!) and used different materials to demonstrate the different effects. And all because something had piqued his interest enough to want to contribute.


Our favourite has to be the (left-most) 0.8mm birch ply version: the tiles look about the right thickness (though the left-most 2mm mdf looks pretty good too, for a rough-built log cabin, say).

What was really amazing was that someone, somewhere, saw what we were doing and wanted to get involved. And just did.

Some days I really hate the internet.
I work with it every day. I build websites. I write complex software and use a mix of web- and non-web languages. I love the underlying technology, but some days I hate how it's abused. I hate adverts on just about every YouTube video. I hate that people allow them to be put on their videos (the person posting the videos can decide to turn them off if they want). I hate viruses and pirated software. And stupid in-jokes about cats, and massive video attachments in pointless emails, asking me to "share this".

And porn. Maybe it's considered weird - but I don't want porn on "my" internet. I want it to be a place of learning, shared interests, marvellous inventions and a community of people making everything better, one stepper-motor-driven device at a time!

But some days I really love the internet.
Thanks to Martin's email, today is one of those days.

Wednesday, 9 July 2014

Laser cut roofing shingles for 28mm terrain

After the dismal failure of silicone mould making, but the tedious task of scratch building roof sections for our board game terrain, we decided to try laser cutting lengths of roofing tiles (rather than etching the entire, flat panel) to make our 3d models looks a bit more, well, 3d.

Using our scratch-built roof as a guide, we made each tile 3.7mm wide, 6mm high and spaced them 4.233mm apart. This means that a 4" strip of tiles can easily and cleanly be cut into 1, 2, 3 or 4 inch strips, to match any width of building.

Making the image didn't take very long at all using Inkscrape.
Our first roof section was just three inches wide, and we're unlikely to make any buildings more than 4" wide (they would take up too much room on our relatively limited 6x8" board sections) so 4" strips just seemed sensible. If ever longer runs are needed, it's no trouble to join two strips end-to-end to make longer runs of tiles/slates for a roof.

For a regular (modern, well-built, slate) roof the tiles work well when placed in a row and by simply overlapping (and offsetting) one row above the previous one. The red lines in the image below show where they can be cut to create a 4" wide section.


For a slightly more old-fashioned roof, just a single strip of repeating tiles gives quite a nice effect. We nudged a few up and a few down, and rotated some by just a few degrees. The tiles are all still roughly the same size (on our scratch-built roof, the tiles were all different sizes and fitted like  jigsaw to get them to overlap properly) but the end result is still a pretty rough-looking surface.


To avoid repetitive patterns, the higgledy-piggledy row of tiles can be cut off at different places, so the pattern starts on a different tile at different places throughout the roof section. The tiles can, of course, be flipped over, to make them lean in different directions. And then, there's always the possibility of mixing shorter sections of straight and wobbly tiles on the same roof to create an old slate roof - generally regular, but with the old slate slipped or out of place:


The designs appear to work pretty well onscreen.
All we need now is access to a working laser cutter to give them a try!
Here's a pdf of the roof strips - load into Inkscrape and copy/paste whichever parts you need:


The top two rows are ready for laser cutting. The bottom two rows allow you to ungroup each individual tile (and the connecting strip) to rotate/resize/respace as necessary. When done simply select the entire row of individual tiles as well as the connecting strip and select "path -> union" from the menu, or hit Ctrl & + to join all the shapes into one single shape.