NortHACKton

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 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:

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.

Monday’s meet was relatively quiet, but this gave Alan and I an opportunity to turn the lights out, and try some photography tricks. The first was an art form of blurred photography called Bokeh. By placing a cap over the lens with something interesting cut in it, all the highlights that are out of focus become much prettier.

Secondly, we tried light-painting. As can be seen, we’re not terribly good at it, and are slightly transparent. We have learnt more for the future though. This could be run as a workshop in the winter, when it’s nice and dark outside.

Dates

I’ll host a talk on the 13th on Neural Networks. No previous knowledge required! It’ll start at 8pm on Monday 13th June. There will be a project night, for people to come and do whatever they like, on Monday 27th June. Alan will give a talk on Stirling Engines on the 11th July. The space will open at 7pm on these dates, and you can still come and work on talk nights.

For those who’ve missed it, we’ve also moved the date of the Ballistics Day to 6th August (still a Saturday), so that more people can come.

It was very popular last year, so we’re running another; a Ballistics Day will be held by Northackton on Saturday 23rd July 2011. We’ll be in Delapre Park, close to the NSME ground, and holding a competition for equipment that can launch tennis balls to in a set of trials. We’re looking for precision throwers as well as distance ones, so there should be something for everyone in there.

Last year we had water rockets, chemical rockets, trebuchets, a torsion catapult, a lot of bungee cord, a badminton racquet, a bow and arrow, and something that didn’t have a name.

We’ll aim to start around 11am, and run until we’ve tired of firing everything off. We’ll have the facilities of the clubhouse to hand, and there are shops much closer than at the Racecourse Park. Once the ballistics have finished we’ll have a BBQ if the weather holds.

Save the date: 23rd July 2011!

On Monday we spent most of the evening trying to get EMC to work on a donated PC, and then with Martin’s stepper driver board. Alan did some good work persuading the rather picky realtime Linux distro to work at all, and then we set to work.

The board consists of a breakout board connected to the parallel port of a PC, which opto-isolates its inputs before amplifying them up a small amount to be used with stepper motor drivers. These drives generate quadrature output from two input signals, a step signal (or clock) and a direction voltage. The job of the PC is to directly step each motor, and the accuracy with which it can do this affects the maximum frequency of steps that it can generate.

This is a hard real-time task and so a Linux kernel is used that allows tasks to be prioritised above nearly all of the kernel tasks and drivers. This kernel will not work with binary graphics drivers, and quite a few other drivers that are incompatible with its priorities, hence the difficulty in setting up. Once this obstacle was overcome we traced the stepper control lines to the right pins of the parallel port (in Martin’s absence) and eventually puzzled out the power supply to run the stepper motors themselves, admittedly pretty slowly to be on the safe side.

In lieu of having a mill to connect them to, we found some software for playing tunes via gcode and soon we were graced with at least the higher parts of the Super Mario Bros theme, played about 4 octaves too low.

May Day

The NSME May Day re-opening is now 3.5 weeks away, on Monday 2nd May. As part of this we’re having a stall ourselves (wiki page for organising here) in the afternoon and in the evening, a BBQ and hack session focussing on glowing in the dark! Whatever you’re making on 2/5, make it glow, by any means you like.

Next meet

Next meet is on the 18th April and will feature Mat talking about his quadcopter, how he built it, and how he controls it. This is also the only meet to test any contraptions for display or use at the NSME open day, so make the most of it!

We’re back #MFUKers!

Nobody’s sure if the hashtag for this year was deliberately chosen to sound slightly rude or not, but Twitter has certainly been busy over the weekend. Maker Faire 2011 was the busiest event at the Centre of Life ever, although this doesn’t totally guarantee the location will be the same for next year.

We arrived on Friday and started building. And building. And building! At 7pm we finally finished the cardboard spider, which should be visible in the site’s new sidebar to the right. It is huge. A significant number of people visited our stand before spotting the spider, as they didn’t look high enough. From the second floor it looked pretty good. The Centre for Life technicians were very helpful and put a spotlight on it directly and added a green gel, which I think really improved it.

Nestling by the front left leg was the racetrack. This project was unfortunately more of a qualified success. We did get a TV and the the car could be driven around the track via wiimote. After a bit of feedback, the control was changed to use MarioKart-style tilt steering and buttons for forward/back, which participants found slightly easier. However despite having two batteries, the car spent most of Saturday waiting for a battery to charge, and many children (and some adults) had to be told to come back later. On Sunday this worsened when one of the battery packs gave up overnight (undervoltage is permanent on Team Losi batteries). The backup pack simultaneously also deteriorated to the point where the car could not be driven long enough to complete a lap, and reluctantly we closed the exhibit.

It still generated some interest from the public, in terms of the use of cardboard (as did the spider), and just leaving the camera on kept a lot of children entertained. However it required no maintenance whatsoever, which turns out to be useful as talking to the public is surprisingly tiring as everyone present concurred. Martin’s Etch-A-Sketch had no problems in this regard and children could use it unattended for the whole weekend.

Tree’s chainmail was incredibly popular, although unfortunately there aren’t any pictures of it to show, but it was good to meet our honourary member in Newcastle. Having someone so tall was also useful when lifting the spider body off the ground. It looks very impressive, and it’s gratifying to still be using the present tense, as the Centre for Life have kept it, hopefully to use in an exhibition this week, titled Spiders On Drugs part of a rather more titillating event. Fingers crossed!

Finally, and most importantly, we had a chance to meet makers from around the country and beyond. The London and Nottingham guys are a little closer to home, and were very friendly, even when drunk. We’re going to definitely do more events with them this year.

Notes from the NSME committee meeting of relevance to Northackon:

1. If we choose dates for events sufficiently in the future, they can enter the Blower magazine (bimonthly, due out soon) and the events calendar of the club, so other NSME members can easily find out what we’re up to. This is also good planning anyway.
2. Money for guest members and money for refreshments both go in the same pot by the kettle, there’s no paperwork involved.
3. The NSME AGM is on Tuesday 15th February for Northackton members that are also NSME members.
4. There is discussion in the NSME of organising workshop courses as the workshops are currently underused. Previously a Model Engineering course ran from the Wellingborough campus of Tresham College, but this is not in the 2010-11 prospectus.
5. We reported back that we’ve been accepted into the Maker Faire UK 2011, can take NSME leaflets up to distribute for the May opening (details below), and gave details of our recent talks.
6. For the May opening, we’d be welcome to have a stall in their marquee and/or to put on some activities in the parkland adjacent, from midday onwards. R/C planes would not be permitted, but the kites are of interest.

Specifically regarding May, the NSME are having a Grand Reopening on Monday May 2nd. The Mayor of Northampton will be unveiling the new station names and opening each line. All rides to the public will be free for the day. The actual opening will be occuring around 1pm, but the site will be open to the public from midday. Suggestions for activities are welcome, but don’t forget the Park will also be used for public parking for the day as well.

On Monday we had a talk by Stephen Billings on things to do in the sky. He makes kites and hangs teddybears off them! When released they gracefully fall to the ground, under parachutes. Another way of getting into the sky is with a solar balloon, which is one that heats its hot air through solar power. A number of thin black bags taped together will heat their own air and provide lift enough for a small payload. He finished by demonstrating how to build a kite from scratch. I’ll upload some pics later.

The next dates for meetings are:

• Monday 7th February – Project evening
• Sunday 13th February – Building the cardboard racetrack (times TBC)
• Monday 21st February – Talk evening, topic TBC
• Monday 7th March – Project evening
• Monday 21st March – Talk evening, "Steam Power"

Except where stated differently, the space will be open from 7pm, and any talks will start at 8pm.