York Hackspace

The Space will be open to the public on Saturday 27th August from 12:30 to 15:00.

Feel free to drop by and say hello and see what we are all about.

https://www.ccc.de/en/updates/2022/offenehackerspaces

I wanted a cover for my kindle and had been pondering it for a while drawing up some ideas of more and more elaborate cases with various pockets. Then I decided to try and focus a bit and reduce the case to the bare basics. I like to have a notepad with me when I read as I tend to get in a thinking mood quite often when I have been reading so it’s nice to have somewhere to get those thoughts out of my head. I had a few of these little notebooks that seemed to be just a little bit bigger than the kindle and so I thought they could be used to protect the screen of the kindle as well.

So I had a basic layout idea now it was to the scraps bin to find something to make it out of. I brought a load of leather offcuts for another project and had a load left. You can buy them by the Kg on ebay and get a random selection of small bits which are all quite useful. I found one that was almost big enough and folded it into a rough shape. I say almost big enough as it did not quite fit but looked like I could botch it a little so ploughed on.  I got a rough idea of the layout then used a rotary cutter to trim off some the excess till I had a rough shape.

Next up was working out how to hold it in pace ready for stitching. CA or superglue was the chosen solution it had two key properties, it sticks leather quickly and I have some to hand. So I ran a few beads of glue on the leather around the kindle and folded over one side. Held it down for a few seconds then breathed a sigh of relief as I manged to pull out the kindle and thus proving I had not glued it in place.

Repeating this for the note and pen and then adding a couple of extra tabs at the bottom of the notebook where the scrap did not quite fit it was starting to come together nicely. I grabbed one of the cut offs from earlier and made a little strap, again gluing it in place. Then left it to set for a while and when I came back was pretty pleased and impressed by the strength of the bond. I left if like that for a few weeks and it seemed to be holding up fine. In the end I decided to run a row of stitching along some of the glue joints just to be sure; using the Hackspace’s trusty Singer 413. The strap on the front is still just glued on and seems to be holding up fine though.

When I started to build this I just wanted to get started so this quick build method of superglue and rotary cutter seems like a really easy way to get a prototype made but in fact it looks like I’m sticking with this one for a while longer. There is something to be said for just getting started with what you have at hand rather than thinking things through and not making something. I would probably change some things if I make another one but I only know that now because I have been using this one for a while. Get out there and make something today!

For some time now I have wanted to make a roller top desk. These are normally made by cutting a plank of wood intro strips and sticking them to a piece of cloth backing to allow it to flex. This wobbly sheet is then held in a captive groove at either side allowing it to roll when pushed from one side. This creates a curved cover that rolls away in a satisfying manner. My first thought was to cut a single sheet of A4 ply into strips using the laser cutter and then follow the classic design but then I was shown a curved laser cut panel where somebody had just cut slots in a board and weakened it enough to bend it round a curve.

My first attempt did not go well, the lines where just too close together and I ended up with a smoldering square of charcoal. But it’s quite a quick feedback loop with the laser so a quick trip back to Inkscape, which was the tool I was using to do the drawing. With the line spacing just a little further apart it suddenly worked and I had something that looked like it might get me there. It took me a little while to get to grips with Inkscape but there are some good tutorials online for most things you want to do.

Next up was to build the box. I decided to go for a pretty simple design with top and bottom being the same. Laying out the overall bottom shape, then a second panel that was the same outside dimensions but had cutouts for the doors to run in. There where also some cut outs for the sides and back to fit. Then gluing these two panels together gave me a top and bottom. Then adding in some sides and back and squeezing it all into a single sheet of A4.

You can see in the photo that my door lines overran the doors. These looked okay in Inksape but something in the way K40 Whisperer laser cutter driver renders the SVG that does not quite seem to work.

After sticking it together with some superglue and a little light sanding of the tracks and the bottoms of the doors I put some candle wax on the edges of the doors and it pushed it all together. Getting the doors in place is tricky but not impossible and I found the best way was to have them about half open and fettle them into place with a thin screwdriver and a bit of wiggling.

If you want to make one for yourself then they are up on my gitlab page: Laser cutter source files.

I’m pretty happy with the overall design and have refined the first version to round some of the corners and generally fit together better. It’s great to be able to go from an idea to a working device.

3D printing is a familiar activity at York Hackspace but John Robinson, one of our members, has in particular done a lot of modelling work with OpenSCAD. Amongst other things, he prints small animals, decorations, accessories, buildings, and geometric designs on his (rather well-calibrated) delta 3D printer.

Recently, John and his prints have featured on the St John’s College, Cambridge Alumni blog, after his work on an intricate model of New Court came to their attention.

You can check out their full article, presented as an interview with John, here – a few pictures of his prints are reproduced below.

The next hackSaturday will be from 10:00 until 16:00 on Saturday the 26th of May

Wednesdays have been Open Nights since version 1.0 of York Hackspace, way back when we used to meet in the Black Swan. However, we understand that weeknights aren’t the best time for everyone to visit the space.

We are therefore pleased to announce that we are starting up hackSaturdays: different day, different time, but the same original recipe as the Wednesday Open Evenings.

Want to know how to find us? Click here

For more details about our open nights, see the wiki.

Curious about what to bring?

All you need is yourself, enthusiasm and curiosity. Feel free to bring a project, things to make, things to do, things you want help with, or things you just can’t find time to do elsewhere.

What does the hackspace have to offer?

You’ll be free to use whatever tools and facilities you want, subject to the necessary training and/or supervision. Non-members will be expected to contribute towards hardware, electronic components etc (members get all this stuff for free!) if it’s more than a few bits and pieces. We have a fast Internet connection sponsored by Andrews & Arnold which you’re welcome to use. And a tuckshop!

 

Questions?

Please contact us using any of the methods below!

Twitter •  Facebook •  Instagram •  Google+ •  Mailing List •  GitHub •  Telegram

 

The next hackSaturday will be from 10:00 until 16:00 on Saturday the 14th of April

So why not pop down and say hello. There will be members there to show you around or chat about the space and what people do here.

Want to know how to find us? Click here

For more details about our open nights, see the wiki.

Curious about what to bring?

All you need is yourself, enthusiasm and curiosity. Feel free to bring a project, things to make, things to do, things you want help with, or things you just can’t find time to do elsewhere.

What does the hackspace have to offer?

You’ll be free to use whatever tools and facilities you want, subject to the necessary training and/or supervision. Non-members will be expected to contribute towards hardware, electronic components etc (members get all this stuff for free!) if it’s more than a few bits and pieces. We have a fast Internet connection sponsored by Andrews & Arnold which you’re welcome to use. And a tuckshop!

 

Questions?

Please contact us using any of the methods below!

Twitter • Facebook • Instagram • Google+ • Mailing List • GitHub • Telegram

 

 

 

The next hackSaturday will be from 10:00 until 16:00 on Saturday the 24th of February

Wednesdays have been Open Nights since version 1.0 of York Hackspace, way back when we used to meet in the Black Swan. However, we understand that weeknights aren’t the best time for everyone to visit the space.

We are therefore pleased to announce that we are starting up hackSaturdays: different day, different time, but the same original recipe as the Wednesday Open Evenings.

Want to know how to find us? Click here

For more details about our open nights, see the wiki.

Curious about what to bring?

All you need is yourself, enthusiasm and curiosity. Feel free to bring a project, things to make, things to do, things you want help with, or things you just can’t find time to do elsewhere.

What does the hackspace have to offer?

You’ll be free to use whatever tools and facilities you want, subject to the necessary training and/or supervision. Non-members will be expected to contribute towards hardware, electronic components etc (members get all this stuff for free!) if it’s more than a few bits and pieces. We have a fast Internet connection sponsored by Andrews & Arnold which you’re welcome to use. And a tuckshop!

 

Questions?

Please contact us using any of the methods below!

Twitter •  Facebook •  Instagram •  Google+ •  Mailing List •  GitHub •  Telegram

Please note: The date for this workshop has changed to the 22nd of March (1830 to 2200)

We’re kicking off our Workshop series with an evening workshop: Hackspace First Aid.

Hackspaces can be a bit hazardous, depending what you’re doing: sharp things, spinny things, hot things, cold things, laser-y things, poisonous things…

Whilst unlikely, all of these things can hurt you. The aim of this workshop is to share some knowledge on how to respond to accidents that you might see at a Hackspace.

We’re aiming to cover:

• CPR
• Cuts/bleeding/trauma
• Burns
• Eye injuries
• Falls
• Electrocution

Be aware: this is not a First Aid course! It is not ratified by anyone, and you will get no qualifications at the end of it.

Tickets are free, but there will be a suggested donation (TBC) that we would greatly appreciate if you attend, especially if you aren’t a member of York Hackspace.

Register for a free ticket at https://www.eventbrite.co.uk/e/hackspace-first-aid-tickets-42955741780

 

It is probably a bit late in the month for New Years resolutions, but York Hackspace never does things by the books, so why start now…? 

An inkjet printer cartridge looking genuinely shocked that a new blog post has appeared

It’s been a while since our last blog post: Since October, in fact. Despite the radio silence, lots has been going on: the laser cutter has some shiny new modifications and upgrades (watch this space for an update!), plans hatched, wood carpenter-ed, mallets crafted, lasers cut, many chocolate bars munched and cans of Coke drunk. We just need to tell people about it!

 

So, York Hackspace has a New Year’s Resolution: BE MORE SOCIAL!

 

This is what we have planned:

 

• Expect more posts about what we’ve been up to on the blog, Facebook, Instagram, Twitter… you name it, you’ll see it.
• More open events! Wednesday evenings at 8pm will remain Open Nights, but we will be having regular open days on weekends (to be announced later this week!) so more people can make it down to the space.
• Workshops: we want to share skills and help people teach themselves about making cool stuff, so expect workshops about laser cutting, PCB making… watch this space!
• Hackathons: 24 hours of hackery goodness!

Want to keep up to date with whats going on? Follow us at any of the links below, and see ya at the ‘space!

 Twitter •  Facebook •  Instagram •  Google+ •  Mailing List •  GitHub •  Telegram

 

 

We were going to write a post a few weeks ago about our new laser cutter. Unfortunately, after a relatively short time, it stopped cutting. This post is about how we’ve gone about diagnosing the problem, since it’s hard to find this sort of information online.

Before I get into things, please be warned: Lasers used for cutting are extremely hazardous – the diffuse radiation from the laser can blind you without staring into the beam, and the carbon dioxide lasers commonly used produce a beam which is mostly invisible! Additionally, the power supplies produce extremely high voltages (on the order of 25kV – that’s enough to cross a significant air gap), and can supply enough current to produce a lethal shock (it only takes 27mA). Don’t do this unless you know what you are doing – and even then, please have someone working with you.

That being said, let me get on with the article!

Firstly – some basics. I’m not a laser expert by any means, but I’ll attempt to describe the requirements around the operation of one. A carbon dioxide laser relies on electrical excitation of the gas molecules to produce radiation, which leads to laser operation. To excite the gas, a high voltage must be applied to the tube, which ionises the gas and “strikes” the tube. Once ionised, the gas begins to pass electrical current, which then sustains the laser operation. For our tube, around 25kV is required to strike it, after which the voltage reduces to around 2kV. The power supply regulates the current supplied, to stabilise the power output of the tube.

The aim of our diagnosis was to determine which of these components was most likely the cause of the fault:

• The laser tube
• The high voltage power supply
• The laser controls

We’d already eliminated the basics – mains power issues, fuses, etc. The next thing we checked was whether there was any sign of laser power. Once we’d determined there was no sign of laser activity, we flipped open the laser cover to observe the tube. We could see some faint glowing around the electrodes, which suggested that there was some ionisation of the gas, but not enough to strike the tube.

The first thing we attempted to rule out was the panel controls. We found the data sheet for the laser supply. The power supply has a regulation input of 0-5V, which controls the current to the laser. On our cutter, this is directly wired to a potentiometer on the front panel. We checked this using a multimeter, and verified that the output varied smoothly, with no jumps or dirty spots. We also checked that the test button was able to drive the input terminal on the power supply, that the panel ammeter was able to pass current, and that the wiring was sound.

Since we had no guarantee that our laser tube was OK, we needed to create a test circuit that “looked” like a laser tube to the power supply. This would then provide a means to check whether the power supply was able to produce the high voltage required to strike the tube, and whether it was capable of supplying the current to sustain operation.

Since testing the supply’s sustain current was the simplest thing to do, we calculated an appropriate resistor value to load the supply. As we knew our tube was a 40W model, and worked at about 20mA current, we chose a 100kOhm resistor (20mA into 100k produces 2kV, 2kV x 20mA = 40W). We purchased a large, high wattage ceramic coated resistor for this, both to ensure sufficient power dissipation, and to be certain the high voltage wouldn’t arc over the resistor. The resistor was wired in instead of the laser, and we used the earth terminal on the cutter’s chassis as the return path, after verifying that this connected to the power supply’s return terminal. We also connected a 100 ohm resistor in series, at the earth side of the power resistor – this provided a 1000:1 resistance ratio, which was suitable for connecting a voltmeter to, so we could see the voltage produced by the supply.

We began testing with our control potentiometer turned all the way down, and tested for a few seconds at increasing levels. The result showed a gradual increase in current with no sign of a problem. We then held the supply at its maximum current (which was about 18.5mA) for 10 seconds to check it produced a steady current.

To test the striking voltage, we used a simple spark-gap setup in series with the resistor. Dry air has a breakdown voltage of about 3kV/mm. We used some bare copper wire to assemble a simple gap which could be varied by bending the wires. While this didn’t provide a way to directly measure the striking voltage, the gap would provide an approximation – with the rest of the circuit acting as a realistic dummy load and providing a means to check the current and running voltage.

Starting with a gap of about 1mm, we tested the supply. At 1mm, we got a nice clean purple arc. Increasing the gap, we got to around 3mm before we hit trouble. At this point, the breakdown voltage was about 9kV, but the supply would only strike with the control potentiometer in a particular position, and wouldn’t sustain operation. Increasing the gap further resulted in no striking at all.

As the laser required around 25kV to strike, this setup should have worked up to a gap of about 8-9mm, so we were quite far off.

This seemed to indicate a problem with the power supply – most likely, some form of insulation breakdown in the flyback transformer.

We’ve since ordered and installed a new power supply, and I’m pleased to report that the laser cutter is now back in working order!