NortHACKton

    Reducing entropy since April 2010

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    On Monday we visited Martin’s laser cutter, as once he installed it at his house with a water tank for cooling, it’s not particularly mobile.  He showed us some of the many things he’s made for his blog, and his lightbox for photographing them.

    Onto newer things, we printed a NortHACKton stamp for visiting passport-holders.  After learning how to etch rubber, I then provided an object lesson in the power of cyanoacrylate glue by adhering to the stamp rather effectively.
    Secondly I had made an SVG of a bokeh rig for my camera for Martin to convert and cut, which produced a passable first attempt at a kit that can fit to my D3100.  Not all of the pictures were good, but it was certainly a learning experience.  See Martin’s blog for the design, and the results are here, in the February pictures of this set.
    March’s meetings – we meet in the space as normal for Monday 5th, and on the 19th there will be another pinball evening in Bedford.  See the mailing list for more details.

    Hackerspace Passports Accepted Here

    So, the first meet of the New Year was on the 9th January, and we all brought our presents along.  I brought a model steam carriage kit, that was an exciting puzzle to solve as the instructions were particularly vague, and Alan brought polymorph to play with.
    The polymorph was slightly more successful than the engine which due to some presumed error in construction, does not self-propel.  This is due to the piston being unable to turn the flywheel, itself due to the axle somehow jamming in place.  It still looks moderately elegant.
    Next meeting 23rd January 2012.

    This post is unfortunately almost two weeks late, but last Monday, Pat gave a chainmail workshop, similar to Martin’s at Nottinghack.  This covered the easier European and Japanese styles and also how to make rings from fencing wire or similar.  Many scraps of chainmail were produced, but nothing to rival Pat’s half-finished chainmail shirt!
    Nick continued to resuscitate aging hardware in Linux and we discussed methods of supplying Internet to the NSME clubhouse.  Via a landline this would be expensive, wireless access of the nearby BT Openzone hotspot, or 3G personal hotspot appear to be the more affordable ways forward…
    Next date for the space: Monday 17th October.

    Very busy on Monday, we had:

    • Light painting with a strobe
    • Knitting
    • Conkers fights
    • CNC planning
    • Raspberry Pi tinkering
    • Kinect tinkering
    • Workshop planning.

    I may have even forgot some things!  Most importantly, thanks to Nicholas for bringing the Raspberry Pi board for us to have a look at.  We couldn’t do too much with it as unfortunately the monitor used was having resolution issues on the HDMI interface, but it booted, and we were able to login and have a brief look around.  Connected to a network (it supports networking over USB  too) would allow more interesting things to happen.  This rather overshadowed the Kinect Nicholas also brought, and I think we’ll need an evening just for that.

    The NSME has a rather large horse chestnut tree overshadowing the clubhouse, so knitting wool was graciously donated to the cause, and an in a textbook case of over-engineering, a pillar drill was used for turning conkers into implements of war, and soon geeks were hitting themselves very hard while missing target conkers.
    Light painting with the strobe did not work so well, as it is not as bright as a camera flash, and outside it is not able to light up targets at any range.  Strobes are very good for inducing headaches and nausea though.  If nobody wants it, it will be thrown away at the end of the month, as it’s reasonably bulky and has no (useful) purpose at this time.
    Due to renewed interest in chainmail, Pat will be running a chainmail workshop on the 3rd of October, from 8pm.  If you have rings or pliers, please bring them along, and let us know on the list, so we can ensure everyone has enough.

    The summer feels over, but despite some shock showers on Monday the space was open.  Adrian took the clock we were given by Nottinghack (couriered by Martin) and with Mat started writing up what they found inside.  A number of repairs were performed by a few different people, fixing a bicycle inner tube, a DVM, and the identification of a car part for order.

    We also discussed what events we could run at meetings.  Some suggestions:
    • Nanode workshop
    • Photography (light painting)
    • Kinect hacking
    • Revisiting OpenCV hacking

    The idea is for very limited scope projects that allow a sense of accomplishment within a few hours.  Suggestions are welcome on the mailing list.

    Date of next meeting: 19th September from 7pm

    Despite some initially poor weather, it dried out, brightened up, and the wind died down to allow us to launch some stuff!  Check the flickr feed here.  For those interested in the telemetry data from the payload we sent up, it looks like this.

    Rocket

    Quite a short run as the rocket didn’t take long going up or down.  Acceleration data isn’t terribly readable – the peak acceleration is obviously off the +- 4g scale of the accelerometer.

    One bad data point on the pressure causes the smoothed graph to have a small dip in it, but otherwise the data appears consistent (if unverified).

    Temperature data isn’t useful, the sensor is cooling from a previous high of 35C from being wedged into the rocket nose cone.

     

     

    Plane

    Mat’s plane made a couple of trips up and down and around.  The temperature data again doesn’t appear to useful, as the sensor is much less responsive than the barometric one (they’re in the same package).  Currently it’s not used for altitude calculations.

    We’ve fleshed out (a little) the plans for the ballistics day for this year.  It will be held in Delapre Park, hopefully very close to the NSME facilities (inside the park, next to London Rd).  If fate intervenes and we need to be further away, we will mark up on the NSME gates where we are, for ease of navigation in the park.

    We’ll start gathering at 11am, but will not be aiming to launch anything before midday.  So if you’re coming to watch, you don’t have to be present from the very beginning.  We’ll run until we get bored, which will be 4pm at the earliest.  In case of (mild) rain we’ll have a marquee and the NSME clubhouse will be available in dire emergencies.  It has toilets, and a water supply for the filling of water rockets, so you don’t need to bring litres of water with you.
    The firing range will be marked off with traffic cones and rope.  This is not an insurmountable barrier, particularly not children or toddlers, so if you bring children it is very important that you do not let them cross the ropes when someone is launching.  Also, unless you’re launching something, you should not cross the ropes either.
    Please bring your own rockets and tennis-ball launching devices, and launch with us!  If you want to make a water rocket, use a plastic bottle from a fizzy drink and add fins, nosecone, and anything else you like with card or cardboard.  Why not turn the afternoon into a picnic and bring food and a blanket?  You might even be able to launch your drinks bottle!

    We had a (very small) meeting this week, which mainly consisted of planning the Ballistics Day (details in a second post).  I also attended the NSME committee meeting and that was also productive:

    1. If we start supplying bracket specifications to the NSME someone will produce the resulting brackets, possibly producing cardboard ones first to check fit.  We’ve agreed doing one axis at a time would make sense.  If the mill is useful to the club they would then consider purchasing the parts that are still Martin’s.  If the endeavour fails or is unused by the club then Martin’s parts can be given back, and the rest sold.
    2. A marquee will be left in the clubhouse for use if required on the Ballistics Day.  There is also a water supply and hose for steam trains and water rockets which we can use.
    3. The NSME are impressed with our railway clock, but do not desire one of their own, as it would not be in keeping with the station’s aesthetic.

    Alan gave a very interesting talk on Stirling Engines, and buoyed by his information that they’re very simple and have few moving parts, we tried to make one.

    Surprisingly, this didn’t work, possibly due to:
    1. Poor tolerances
    2. Wrong materials (it’s supposed to be a steel can for a better temperature differential)
    3. Patrick
    4. High mechanical friction

    In other news, the Ballistics Day approaches, 6th August.  A poster is being prepared, and will be posted on here shortly.

    Monday was a busy evening in the end! Mat demonstrated a robot that he’s building (no details, it’s a secret!) for a competition at the end of the month, and took advantage of the concreted courtyard in the NSME. Adrian brough some Nanodes to show to the group, and I (Stephen) talked about neural networks, ably assisted by Nicholas. The slides are on the wiki. This was attended by some visitors from the Northants Linux User Group (mailing list here) who hopefully haven’t been permanently put off.

    I investigated how to polish 3D printed stainless steel, and Alan tried another form of light-painting, where a long night exposure is taken, and the subjects are lit with a flash gun and many flashes. Pictures hopefully to follow.

    Mill

    We’ve not done anything with the mill regarding controlling it yet, and so we discussed that as well. The feeling was that we should continue the computer control of it, but only with the assistance of someone who could manufacture the brackets required. We will ask the NSME for assistance, rather than attempt it ourselves.

    Next meet

    The next meeting is on the 27th June.