2013 Meetings

Mendel 90 Makathon - Sunday 24th November.

Well, that was a very successful day..........!! Twelve hours!! to build and commission a computer controlled 3D printer!

Starting at 8:00am and finishing at 9:00pm with between 4 and 10 hands-on-kit during the day the workflow went very well.   It must be said that the Mendel90 kit from Nophead was absolutely first class.  The excellent instruction manual and its listing describing the various sub-assemblies made construction by a varying number of hands really easy to schedule.   Work seemed slow at first but gradully speeded up during the day.   We have video of the build, which members can view at the December meeting.

The picture below was taken in the late afternoon and is displayed here with apologies to builders who were not present at that moment.  The team must reassemble in a circle around the "90" and pat the back of the person in front for a more correct photograph.















Now that "the power of production is in the hands of the people", let's start pushing plastic. Its up to us to devise ingenious products making use of our unimaginable imaginations.


November Meeting 2013

The November T-Exchange meeting was one of these quieter "heads down, hands-on" evenings with everyone busy either assembling , dissassembling or just asking questions of the others.  Most discussion centred around either The Raspberry Pi or building the Mendel90 3D printer.

We agreed to have a serious focus on theRaspberry Pi at the next meeting, with everyone with a Pi and any examples of applications bringing them along to exchange ideas and info.

We also agreed to go ahead with a one-day "Makathon" to make rapid progress with the Mendel90 kit on Sunday 24th November.  The idea was to start really early and finish late with as many hands to the job as possible.   Watch this space.......

The third notable event was the addition of intelligence to Mark Dammer's "Ventian blind" satellite radio receiver.   Using a smart-phone with built in direction sensor and satellite location app, Mark is now able to just turn the Yagi array, as directed by the app and point it straight at the satellite.  His software defined radio then picks up the satellite's transmission and processes it on his lap top.

All great stuff.......  See you at the next meeting on 15th November.


October Meeting 2013

The October T-Exchange meeting saw 11 existing members attending and four new faces joining.

This was a bit of a breakthrough evening from three points of view.   Firstly, the first 3D printer to "push hot plastic" and produce real 3D parts arrived and merrily and productively danced the evening away.   The picture below shows members holding up some the parts it made earlier in the week.   The machine is a REPRAP Prusa machine with "local mods" including the addition of an toughened glass build platform.   Cleaning between each run ensured near perfect parts every run.   A bit of tinkering should see further improvements.   Never-the-less, the first parts from the printer resulted in much "Ooh"s, "Aaah"s and "That's amazing!"s  and "Can I have one too?".

Of course, being on the ball, the organising group had already ordered a kit of the latest Mendel90 machine, which had arrived just half an hour before the meeting and, after cutting the ceremonial Sellotape on the box, provided many more "Ooh"s and 2Aah"s  as the contents were examined.   The kit was bought by member shares and a grant from the British Science Association.   If any members out there would like a share, giving access to both the build and use of the printer, £20 at next meeting will secure a share.

















The third notable event was the addition of intelligence to Mark Dammer's "Ventian blind" satellite radio receiver.   Using a smart-phone with built in direction sensor and satellite location app, Mark is now able to just turn the Yagi array, as directed by the app and point it straight at the satellite.  His software defined radio then picks up the satellite's transmission and processes it on his lap top.

All great stuff.......


September 2013 - meeting and events

The September T-Exchange meeting was neatly sandwiched between the the Mega-events of The Orkney International Science Festival (OISF) and Forres, Kinloss and Findhorn Culture Day.   As the T-Exchange was involved in both of those events, the club September meeting was a little neglected owing to testing of "exhibits" for Culture Day, whilst reminiscing about the OISF.   Never-the-less, our focus tables were in full swing and with a high turnout again, there was much exchanging.   Bill Leslie is entitled to an apple from the box for stepping into the Arduino slot in the absence of Scott.   His new species of Arduino based insect was critically examined.  Thanks Bill.  Thanks to everyone, too, for explaining their projects to our Guest Jane Magill from the British Science Association.   I think she thought we were "doing good"............

Our presence at the massive OISF was not without note with Elidh Myrvang Brown busy spinning yarns around the schools and also on Family Day, while Maarten de Vries explored the stars with the inhabits of Hoy.  Not satisfied with that, and just to prove his extreme breadth of skills, Maarten took over the Town Hall in Kirkwall to explain the physics of the organ pipe and then went on to synthesise these sounds electronically in a synthetic organ powerfully and magificently played by organ virtuoso George McPhee.    Bill Graham, meanwhile, took on explaining the physics of aerodynamics and spaceflight to four school classes, finishing up with examining how to take a rocket to Mars.   Pupils then all had a shot of his Mars Rover.  The Rover also roamed in the Kirkwall King Street Halls on Family Day.  After 6 hours its batteries were reduced to two dimensions.   Howie, of course, whilst actually performing all the tasks of Festival Director, also gave the Eion F. Scott Memorial Lecture and a few other recitals and even helped a speaker by collecting the odd wayward toothbrush   Hmmm...  It seems likely that even more T-Exchangers will be heading for Orkney in 2014.

Culture Day was a bit of a shock, too, with far more visitors to the Village Centre than we expected.  Our room was buzzing all day, Elidh was carding this time with the aid of little Holly, while Bill was 3D printing (well, virtually) and Howie was "taking it out" on a giant HP printer requiring decomissioning.   Our T-Exchangers turned out in good numbers to provide physical and moral support.   So, thanks to Tom for explaining ways of cooking Raspberry Pi'es, to Claire for collecting the bits flying from Howie's screwdriver and producing some excellent sponges for energy, to Mark and Ian for learning how to drive the Mars rover at very short notice and introducing it to the many potential junior rover pilots.  Thanks, too, to other members who came along in support.

Talking of Mars,  you will see from the picture below that Bill's rover "T-X" has finally made it to the red planet. Positioned on a hillock overlooking the Martian plain, this picture was taken by the rover Curiosity.


















Just in case you believed all (or any) of that..... The backdrop for the OISF Family Day was kindly supplied by Fellow OISF participants, Tim Tomkinson and Paula Lindgren of Glasgow University.  Thanks a lot friends.  Much easier than going to Mars.

The Focus Table topics and coordinators are:

REPRAP printer  - Bill Graham
Arduino micro-controller applications  - Scott Boyle
Raspberry Pi micro-computer programming - Tom McCallum
De-construction of recyclables - Howie Firth.

Come along in October and get involved in one of these projects.


Meeting 20th August 2013

This Friday we had a pretty enthusiastic turn-out with twenty members working on a number of different topics.  The focus tables were beginning to attract attention and blogs on VOIP a SDR  spiced up the evening for those who preferred to investigate the latest hot-topic (see image below....).























Meeting 19th July 2013

On an amazingly, beeaauutiful, ultra-hot-hot, blue-sky, summer evening, with sensible people on holiday, nine members decided to play it cool and come to the T-Exchange meeting.   They were not disappointed as we were treated to a Blog-Spot from Mark Dammer with a very clear and interesting presentation on Software Defined Radio (SDR).  This technology effectively replaces the tuning, filtering and audio amplifier stages of a radio receiver with the software equivalent.   This allows reception of transmissions from 0 to 2GHz with a £10 (or so) USB dongle.   It makes it possible to tune into the ISS and other satellites with the simplest of equipment.   The image below shows how stations are picked out from the radio spectrum directly on a laptop screen.   As the UK Space Agency's first CubeSat satellite, UKube-1 made in Glasgow by Clyde Space, is due to be launched in October, SketchUp was immediately put to use in knocking up a concept for a satellite tracker.  This satellite, we understand, will be the first "Clyde-Built" to orbit the earth.

satellite tracker









Meeting 21st June 2013

This was a very typical busy evening.   Nothing special had been arranged and 16 members plust two "Newbies" were able to  concentrate on their projects  (between cups of tea and coffee).  Two old printers were re-purposed and a new robot hit the floor.










Public Event - 5th and 6th June 2013
GoNorth Festival of Film and Music - Inverness

The T-Exchange members designed and built four musical instruments using vegetables for interactive contact.   We had the Carotene simulating a grand piano but using carrots for keys; the Organica, simulating a church organ but with leeks for keys; the Rhubarbium, which behaved somewhat like a set of tubular bells and the Percolator using cabages and parsnips as drums.

Over the two days, some 300 visitors endeavoured to hone their musical techniques on these instruments.   The general reaction can be summarised in the image below.










Public Event - 11th May 2013 - Knockando Woolmill

The T-Exchange members helped out with bits of technology action on the Youth Activities Day at the Knockando Wool Mill.



Meeting - 19th April 2013

Following our busy Open Evening last month this was a quiet evening with a good turnout but heads down.    Tom McCallum did a serious workshop introducing most of the group to C, C+, C++ and C#.   Just about enough for one evening.........   Bill Leslie had a table (quietly) exploring the mysteries of ultrasonic transducers as rangefinders.   The remainder of the T-Exchangers got into some serious deconstruction, extracting all the good, usefulbits from three printers and an "all-in-one".   As we've been salvaging one or two per week for some weeks now, it's amazing how our stock of parts is building up.  The axis guide bars in the older printers are precision ground and mostly just the job for the axis motion of X,Y,Z machines of REPRAP ilk.   Sensors like microswitches and optical gates are really useful, as are the vast range of DC and stepper motors, together with their gears and gearboxes.  Even the formed steel baseplates are very desirable.   At least two of these, cut-down and reconfigured, are already providing bases for breadboards and Raspberry Pi mountings.  By the the time the team of hyenas had finished only the plastic mouldings and some circuit boards were left for Council recycling.












Two of the hyenas deconstructing a couple of printers

Meeting - 15th March 2013

This was our first Open Evening.   The objective was to make our regional community more aware of what the T-Exchange did and what our aims were.   Pre-event publicity included an article in the Forres Gazette, various A4 posters around our community and direct invitations to councillors and other parties who might like to be updated on a new activity in the area.   Consequentially, we had a good turn-out, occupying two rooms at the Centre rather than just our usual one.  We had some excellent exchanges with our visitors and four new members signed up.











Some of our Open Evening visitors getting into exchanges with the "experts".

All of the table topics attracted attention and lots of tricky questions for T-Exchange members.   However, everyone declared great interest and surprise at the range of activities.  In fact some had so many questions they stayed all evening and helped to tidy up and switch the lights out.

Thank you one and all for a very interesting evening.











Three ladies, (Elidh, Olivia and Cllr. Lorna Creswell) spinning yarns

Materials are very important to anyone who claims to be a "maker" and whilst metals, plastics and computers have their applications so do materials and processes that have been in use for hundreds or even thousands of years.   Here the ladies are using spinning tops to spin wool fibres.   Just after this picture was taken Scott intervened and soon they were spinning wool with metallic fibres spun in.  AhAh............ electrically conducting wool.  What might be done with that?  Built in lighting conductors for the golf-jackets ..........  ??? What about illuminated clothing for when the streetlights go out or maybe walking bill boards with digitally inspired messages.........  I'm sure you have some (even) better ideas.










Introducing SketchUp

Even although she has just moved into a new house, Olivia has now spun some new conducting fibres (curtains that light up at night??) so a new house will need to be designed to exploit these.   What better tool than SketchUp?

Meeting - 15th February 2013

There was a lot going on at this meeting.  I'ts a good job there is no janitor to chuck us out when it gets very late.....

We started off with a slide illustrated talk from member Duncan Easter, who manages the wind turbines at the Findhorn Windpark.  Duncan explained the rationale behind the development but a deep exchange quickly followed on "availability", "efficiency", "power factor" and moved on by stages until we were all up to our necks in "synchronisation" and very hot "hydraulic oil".   Member Mark Dammer, also from the Findhorn Windpark, joined in and demonstrated how to access the turbines through the mobile phone network and see how they are performing at any moment.  This was particularly useful when things get rough (usually about 5:00 am on a wet winter's night).   The exchange revealed a lot about running a wind turbine installation, slaking much ignorance.

Thanks guys.  I'm sure that lots of ideas for "better", "more effective" wind machines will soon be revealed by T-Exchangers............ possibly.


As soon the turbines were sorted out the members were into Jamboree mode and the sounds of snipping, ripping and unscrewing were interrupted only by cries of "Look at that!" or more often "I'll have that!", as another Canon printer was returned to its constituent components.










                The biscuits didn't fare much better!


Having got the house building out of the way, Bill Graham revealed some progress, at last, with his REPRAP Mendel Prusa Longboat 3D printer.   As the REPRAP is a generic device you are expected to show its ancestry in the name but perhaps Sueno or Fred might be better.   Being a canny Scot, Bill is building and testing each sub-assembly before moving on to the next stage and was able to demonstrate the Z-axis (up and down) and the extrusion head pushing plastic.  The heated build-platform has also been checked out.   One problem with "Open Source" designs like the REPRAP printers is that there are many varieties and no "best" or "correct" way to build them with lots of wrong ways and bear traps lying around.   Bill has resolved a number of problems in getting to this point and will be posting some tips for constructors on the Hot Topics>3D Printers page before long.











The Jamboree was followed by our first AGM.

If you really want to know about this then you should visit our Members' News page.


Meeting - 18th January 2013

This meeting was the anniversary of our first meeting in January2012 and was well attended with eighteen participants all eager to tear apart the birthday cake and some old printers for scrap (sorry, recyclable) parts.

We had invited Jim Boyd , formerly head of product design at Johnstons of Elgin, to pass on a smidgen of his expertese in textiles and fabrics.   Within a smidgen of time, as you can see below, he was able to spin his knowledge of alpacas, jumpers and cardigans and pullover all of the women for most of the evening.   Thanks for coming Jim you were the big attractor.  However, it is clear from the picture below that the other men happily got stuck into the cake, biscuits and the various “T”s.

First into the birthday cake were the four who had managed to stick it out for a full year and who like to style themselves as “The Organising Group”.    In case you haven't met them, in the picture below, they are from the left, Bill Graham, Scott Boyd, Howie Firth and Tom McCallum.  Why don't you come along to the NEXT MEETING and see what we get up to.


Meeting - 14th December 2012

The "grab-a-table-and-start-exchanging" format is working well and as these see everyone talking at once in several different languages, these have now been labeled "Jamboree" sessions.  This December meeting was again much enjoyed with hot spots covering, weaving (Eilidh, using composite fibres in looms), robot races (inconclusive........teknikel issues.......), Organic piano (covering 1.2 and a bit octaves), Sketchup (Duncan, modelling components for a foldable cycle trailer),  RISCOS with GPIO on the Raspberry Pi and giant Lego (much enjoyed by Tom and Eilidh's little Ceilidh - age 3).

We also had member Alex Leggatt Skype in from Edinburgh.  Our roving vidcam and microphone succeeded in sending only cacophony to Edinburgh and Alex has pointed out that there is room for improvement (Isn't there always....?).   We have ideas - watch this space.

















Howie is on the oranges, Alex is cornered in Edinburgh in the upper right.


Below is one of the parts for Duncan's bicycle trailer.  This has been 3D modelled in SketchUp.  When the other parts are defined, Duncan plans to build a kit of parts for the trailer using 3D printing.   Who is going to bethe first in the T-Exchange to get their REPRAP working?

duncan's trailer component


Meeting - 15th November

The meeting adopted the new "grab-a-table-and-start-exchanging" format.   Once again there was lots of noise with eleven members "interacting".

The  great success of the evening was the first positive steps of our first autonomous robot.  Built by Scott and John TEX, the Arduino brained insect, struggled into life at the October meeting but has now speeded across the floor at several meters/hour.   Clearly, the gait demonstrated by Howie at the last meeting has now been learned by the Arduino.











                                Everyone likes to be associated with success.........

A second team were busy at another table building a "second generation" robot.   As this one appears to have six legs, we are all looking forward to a more advanced gait demonstration by Howie.

New member Mark appeared with a dual axis digital magnetic compass, which he intends to build into an autonomous boat.  No gait instructions required.  Another success was the construction of an interactive table-top screen built by Tom.   He was able to demonstrate this using a video but hopes to bring the real thing along to the next meeting.   Bill demonstrated the new alternative RISC OS Pi operating system for the Raspberry Pi.   As this was written specifically for 32 bit ARM processors by Acorn, it boots and runs much faster than the LINUX Raspbian OS and has thousands of APPlicationS available.  The included BBC BASIC language is ideal for beginners who would like quick results.   Bill also demonstrated an 8 port GPIO buffer for the Raspberry Pi and the Python code to run it.  The buffer is built on stripboard and details will be uploaded to our site library.


Meeting - 19th October

This was the first of our new format meetings with a number of parallel activities and much more of a free format.   As a result we could smell solder vapours from the DIY table; hear screams of laughter from the table evolving an Arduino controlled, four-legged, walking robot; sighs of despair from the "deep SketchUp" table trying to find work-arounds for advanced geometry screwups and deep, concentrated silence from the table investigating Raspberry Pi programming; all to the sounds of a banana piano.

Perhaps the highlight of the evening was a hands-and-feet-on demonstration of the limb motion sequence for the desired gait of the Arduino robot.   This was performed by our resident Dr. Firth who was much, much fitter than expected and who performed the gait to much aclaim.

This unique walking action will no doubt be referred to henceforth as "Firthgate"


Here is TEX, Scott's Arduino robot trying to emulate Dr. Firth's demonstration.   As he is still attached to the motherboard by his umbilical cord, he is struggling a bit (well, a lot really....) but TEX and the rest of us are looking forward to a second lesson on gait control at the next T-Exchange meeting on 15th November.


Meeting - 21st September

As this was a jam session, there was a very heavy emphasis on raspberry pi(e)s of various varieties and flavours.   Fortunately, only the edible variety were eaten (with gusto).    However, all varieties were digested.  Much proding and questioning went on and much was taken on board.   An introduction to Linux from Tom settled everyone and we are all looking forward to the next workshop.


Meeting - 17th August

This was a very busy evening again with eleven members attending including four new friends introducing themelves.

After the first lot of tea and biscuits, Bill got underway introducing the very low cost Genie range of micro-controllers.  These are 8 bit processors but are available with various non-volatile memory capacity and a number of printed circuit boards.   With 4 analogue/digital plus 4 digital only inputs and 8 digital outputs, these are very capable, but simple controllers.  Programming diffficulty is lowered to a whole new level with a drop and drag graphical programming method.  One of the Genie boards demonstrated illustrated a set of pedestrian controlled traffic lights total cost around £4-£5.   The program for this is copied here.

Another of Bill's projects on a soldered strip board showed how a Genie controller could be used to control 8 PWM servos.  This could form the basis of a walking insect.  Goto www.genieonline.com for full details of these very useful, very cheap devices.

After some more refreshments, Maarten waxed lyrical over the Raspberry Pi and launched into an in-depth explanation of how to get the Pi up and running.   He followed this by hints & tips on using the latest Linux OS.  The piece de resistance was his demonstration of how to program the Pi to drive a small robot arm available from Maplin (Ref A37JN).  This arm can also be used on a PC and is supplied with the necessary drivers.   However, Maarten (a true hacker) is hell-bent on upgrading the robot arm servos to full feedback control on the Raspbery Pi for improved precision and location stiffness.    In a very engrossing discussion he explored the possibilities with the members.   See the picture here and for more on the Raspberry Pi, see our HOT TOPICS page.











20th July Meeting

This was a very busy (late) evening with eight members attending and everyone with lots to say (and contribute).   Firstly, Bob Sims arrived from Inverness with his Prusa 3D printer.  Although not yet spinning plastic Bob's machine is fully functioning with the X,Y, and Z axes all happily dashing about under the control of his own geometry definitions.  We're all looking forward to seeing the first parts made by the first machine running in our group.

Secondly, Maarten de Vries stunned us all by producing several cathedral organ recitals (well it sounded like that) using the freeware Synthedit.   This synthesiser is not so much a music generator as a versatile sound generator.  Realising that there were aeromodellers present, Maarten went on to “run up” a Merlin engine and then two together (slightly out of sync to be authentic) and finished off with the throaty roar of four Merlins simulating a fully loaded Lancaster taking off.

This versatile software is freely available and Maarten has placed details of how to download it and a use it on the T-Exchange Library.  He has also promised to run a proper workshop later in the year and we are all looking forward to that.

Bill Graham then introduced a bit of simple electronics using the ubiquitous 555 timer chip to produce a pulse width modulated signal (PWM) suitable for driving a standard hobby servo.  T-Exchange kits of parts to build these signal generators are available from Bill.   Bill also rolled out his radio controlled model Mars Rover, which  uses PWM control signals.  The model has a CCTV camera on board and can send motion pictures back to “base”.   It is used in schools by pupils to explore the geology of “alien” places such as the school kitchen and staff room from the safety of their own classroom.

Bill then demonstrated his Raspberry Pi micro-computer that had arrived the previous day.  It had been easy to download the operating system and get the images up to a high resolution screen via an HDMI cable.

The Raspberry Pi machines use Python as the default programing language and, as Scott Boyle had written a number of games programs in Python, examples were rolled out and demonstrated.  Maarten has posted a “T-Exchange Absolute Beginner's Guide to Python” on the T-Exchange Web Site Library.

In between all this there was lots of animated discussion with contributions from Alex Leggatt, Howie Firth and Ian Hampson.   Lots of tea, coffee and biscuits were consumed.

We concluded it was a great way to spend an evening (and for only £3)

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