Tuesday, April 26, 2011

School days with a difference.

Back to school.

Photos by  Justine Leigh.

A couple of years back I had the great privilege of teaching part time at Massey University, Auckland New Zealand. At first I was just there for the occasional presentation on a given subject, then I got a 6 week paper to run, and then at the beginning of the next year Course Leader Bruce Woods paid me the huge compliment of giving me two days a week ongoing.
 The subject was “Transport design” and my students were  specializing in automotive and marine design, my brief was to teach and supervise the design and building of  model and full sized projects as well as some which involved “paper projects” . I had classes in years two and three plus mentored some year four students in their grad year projects,  they were a wonderful bunch of young people, almost all of whom worked hard and did well. 
Teaching these classes taught me a great deal, I had to stay a lot more than one page of the book  ahead of them as they were all of them pretty bright, and I spent a lot of time researching and swotting up ( cramming!) on each subject before standing up in front of them in the classroom, but even so I think that they taught me at least as much as I taught them, it was a really great experience and I’m hugely pleased that I got the chance.
I was surprised and pleased to come across a Trade Me ad for one of the year three projects that I supervised,  in this case a group of students were given the use of three 8 hp Yamaha outboard motors with remotes, and sent off to design, build and race three boats. 
Remember that these had to be designed, materials sourced, built from scratch, tested and run within one semester while the participants were also taking other papers!  There were some very late nights in the  Schools well equipped workshop!
We did a “car” one as well, each team getting a little 1 ¾ hp Honda stationary motor and sent off to design and build a vehicle to travel as far as possible on 100ml of petrol, that’s about 45 mins on the motors most economical speed and the winning vehicle which was a prone ridden motorcycle with hub center steering ( built by the students with the tools and machinery in the College workshop remember ) and a mountain bicycle gear train worked well hewever we didn’t manage to get a really good venue. But the testing we did do gave us an estimate of fuel consumption in the high 800  miles per imperial gallon at about 20 miles  per hour which was pretty good, and I am sure that with a longer track and some fine tuning we'd have done even better.
For the boats teams were selected, three in two and two in the third team.  All three opted for triple hull configurations, the winning one with a comparatively wide and short central hull,  the boat being got up stylewise to suggest a stealth bomber. The other two had long slender hulls, one semi displacement with foil stabilizers and the other a very graceful boat with conventional but very slender stabilizing hulls.
Alistair Thompson, Sophie  Amesbury and Tom Bryan built “Tri Ski”,  a very smooth looking boat built to a high standard and which performed well in the tests.  I’d say that the wetted area was just a little high for the 8 hp motor, but that’s ok, this was to be a learning exercise and the boat was still a lot quicker than you’d expect from the power plant, the handling near perfect and the concept very well executed.
Above are some photos copied from the Trade Me on line auction site where Tri Ski was recently up for sale.
Well done all that class, I hope you look back on that year as fondly as I do.
John Welsford
( Very proud) Senior Visiting Tutor
Transport Design,
College of Creative Arts
Massey University.   2006 / 2008

Friday, April 15, 2011

The Hobbit, Coming to a movie theatre near you

Not far away from where I live is a village called Hobbiton.  Some of you will know of it, I read the book when I was about 10 or so, every few years read it again and it never pales.
Its the outdoor set for the movie, the inn, the stone bridge, the Hobbitt holes, the lake and the river, all there and eerily alive, a window into a fantasy.

Kiwi film director Peter Jackson did an incredible job of translating the three books of "Lord of the Rings" into visual form, and I had several encouters with the production at various times, A neighbour was one of the founding members of the special effects company whos work was so effective, I did some technical work for a company who made many of the weapons, went on the Great New Zealand Trail Ride, a 6 day cross country ride that my wife and daughter went on and I taggged along as crew and baggage truck driver.  The catering company was fresh from the movie set, and several of those horses which starred as mounts for the Nazghul were there in a much less dark role.
It was a huge production, and in a country as small as ours there will be few New Zealanders who do not know someone who has had a direct involvement with the production. Its almost a part of our national psyche.
Over the years I have been in the many areas where most of the outdoor sets were so the when the movies showed off New Zealand scenery like no other movie before,I really felt "at home" as I watched the big screen, that added enormously to the veracity of the story for me.  Now there will be another.
Here is an introduction.


John Welsford

Saturday, April 2, 2011

The cordless drill that wont.

Tool test. Ryobi
I generally tell people to buy good quality tools on the basis that a cheap tool that does not do the job is an expensive purchase. But sometimes I get hooked by a really good price on something that I’d not normally look twice at.  In this case the old Black and Decker 14.4 volt 2 speed cordless drill that I’d got through a customer rewards program about 10 years back was getting tired.
I’d gone through three sets of batteries, and the current set were ok but I could see the end of them off in the distance, and the mechanicals were getting very rattley. Time to think of a new one, my choice would have been a Makita 14.4 volt LI battery equipped unit, if you watch the guys building houses that’s a very popular unit. Light, powerful, tough and good parts backup.  But, its quite a lot of money, and that’s not in good supply around here so I was putting the decision off until later.
However, walking through the big box hardware down the road (You can imaging me at a Hardware Stores Anonymous meeting, “ My name is John and I’m a Hardware storeaholic”.  I should go in with a minder, walk around and come out having not bought anything, just to prove it can be done).  Anyways. There I was, coming along the aisle with some plastic plumbing fittings for the house in my hand and a sign jumped out and ambushed me. 
It said,  “ Ryobi 18v Cordless Drill kit.  High torque, 2 Speed, two batteries, quick charger, drill and driver selection  $69.90 ( that’s about fifty bucks US) ”
All in a nice plastic case encased in a cardboard sleeve with pretty pictures on it that promise that you’ll be an instant success at whatever you do if only you buy this tool.

Direct hit!
Some of the Ryobi tools that I’ve had have been very good, mostly the ones I’ve had for a long time.  In fact my first cordless drill was a 7.2 volt Ryobi with battery inside the handle, I miss it.  It was small, light, had enough grunt to drive medium sized screws, and had a good true running keyed chuck.  Absolutley no frills, but then it didn’t need any. 
It died after a long innings, and about the same time I had a bunch of Fly Buys points about to drop off if I didn’t use them so the B&D came into my life, and its done well. I’ve had three other B&D cordless drills since that, all have been so bad that I wouldn’t even give them away.
So, home came the Ryobi, first impressions were ok, it fit the hand well, was reasonably balanced, the variable speed trigger works smoothly and is in the right place, the battery though is a pig to get on and off,  I’ve slight arthritis in my thumb joints and it takes considerable pressure to get the battery clips disengaged from the drills body in order to remove it to put it in the charger. Yes I can do it, no its not really a big deal, just annoying.
The charger, I plugged it in, dropped a battery in it, and a green light came on.  Ok, came back in half an hour, it turned the drill over half a dozen revolutions and carked it.
Tried again, read through the very confusing section on charging in the book of words, and tried again.  Green light, no result.  But there are two lights on the charger, and a tiny recessed button between them.  Whats that for?
Its printed on the label on the charger, true, but that’s not that clear either, it doesn’t work unless the battery is in there first.
Hmmm, try it with the battery in, push the button.  RED light came on.  Left it for a while, bingo, the green light comes on when charged. Ok, got that.
So, off to work, reasonable torque, not as much though as the tired old B&D even now, the slip ring behind the chuck that changes it from one torque setting to another is too easy to move which means that it goes from drill (no torque limitation ) to one of the settings where it stops and growls at you if its required to work too hard and you have to stop and reset it.
But its still a drill, and still does its job, or would if the chuck was a bit better.
This is the real grumble.  While it is fine with hexagonal shaft screwdriver bits, its not able to hold a drill bit with any competency, any size at all, any torque of any consequence and no matter how tight you wring the thing up  the chuck goes around without the drill.  You know how a drill bit hangs up a little when it gets to the other side of a piece of metal?  This one allows the drill to stop while the chuck merrily goes on discharging the battery.  Even with aluminium or copper. Or wood for that matter which makes it really annoying.
So,  I’ve a drill that can only be used as a screwdriver, and STILL need to buy another cordless drill.
I should take my own advice.
John Welsford

Friday, April 1, 2011

Lighting up the trailer.

Tail lights for the trailer.
A new boat will always have a few things that need to be altered or added to make it ones own, and there can be much quiet pleasure in doing that. With a boat that comes home on its trailer that puttering around with tools brings the pleasure home into the backyard thus extending the involvement with boating and the water into time that should really be spent mowing the lawn or whatever.  It’s a much more pleasant way to spend an afternoon.  Agreed?
However, boats on trailers also have trailers to customize, and while I’m not as enthusiastic about that prospect it has to be done.  When I got this wee boat of mine  she had a piece of white plastic square section tube, all wired up and looking nice, but it had no way of properly mounting it on the after end of the boat, it bounced around chewing up the varnished coamings and toe rails and, to be honest was not that secure when under way on the road.
In the end it dropped off and destroyed one of the lights which meant that doing something about it came abruptly to the top of the “to do” list which was feeling good about having reduced to  about 2 pages long.
So,  with bottom lip out, I dragged a piece of 20 x 90 ( ¾ in x 3 ½ in about ) pine out of the rack and cut it to the same “beam” as the trailer across the mudguards.  Went down to Super Cheap Autos (the Wal Mart of the Australian and New Zealand motor parts world, you can have cheap or good quality, one guess what they have!) and bought a pair of tail lights with tail, indicator and stop lights plus a clear window for the tail light to illuminate the number plate.
The cable and plug from the old system was ok, I checked all the wires for continuity using a 12 volt battery charger and a spare bulb from one of the discarded lights as a test rig to ensure that although it had the dreaded black corrosion on what should have been bright copper wire at one end, it would work.  I had plenty to spare so cut it back to the bright stuff at both ends and after tinning the ends with solder coated the ends of the insulation with silicon to try and avoid that in the future. While it wont ( hopefully) be coming into contact with salt water it will be out in the weather so some care was warranted.
Now, the real problem here was how to mount said lights on the back of the boat, and while the boat itself does not present much in the way of opportunity the outboard motor bracket is just right.  Right height, aft of the transom, nothing to obstruct it and clear of the boat at the sides so the forward facing clearance lights would be easily visible.
I’d recently changed the woodwork on the bracket, it had been such that the power head of the outboard motor had not sufficient clearance from the transom to allow it to be easily operated so I’d made a new wooden pad that moved the motor out 20mm and up 50mm which made life very much easier when using the little 3 hp longshaft Tohatsu.  ( I’ll tell you about that motor another time, I’m quietly reasonably impressed with it.)  That meant that the top edge of the motor pad formed a 180mm wide, 36mm thick tongue sticking up 120mm from the metal part of the rise and fall bracket.
I made a couple of pads, just a couple of mm thicker than the “tongue”, each pad the depth of the  light board and about 80mm long, then screwed a section of the same 20 x 90 across to form a socket into which the “tongue” fit reasonably neatly.  I didn’t want to fight with it to get it on or off, but I didn’t want it too sloppy either and it took a couple of dry assembly runs to get it right.
Glue and screw, screws overlapping where they went through the spacer pads and the two main pieces so it cant split off, added a piece of plywood as a number plate mount and painted it with white housepaint.
Mounted the lights and wired it up.  Electricity was invented just to annoy me, did you realize that?  Other people have no trouble at all, but me?  Grrrrrrrrrrrrrr! 
But I got it done, all ends tinned, all insulation silicone at the end of the shielding, all wiring properly secured and with some slight faffing around SURPRISE ! It all worked!  !  Drawing a circuit diagram before I started and being very careful with the many colours in the wires must have paid off.

The outboard bracket, yes I should have reorientated the pic before I put it in here, but you can see how it works.

The 20 x 90 light bar with the bracket ready to trial fit . Thats scrap plywood left over from a house project, you use what you've got.

Same again with the orientation of the pic, sorry. But thats the lightboard all mounted up, shock cord stabilising cord visible at the far end, I tried to secure the wiring with hot melt glue but it doesnt want to stick and I ended up with stainless steel cable clips.

The finished result, looks good, nice and tidy, easy to mount and dis, highly visible and about 3 hours work in total.

I added some reflectors so it will be more easily seen by following cars, stabilized the rig with a couple of shock cords through the fairleads on the stern quarters to the mooring cleats, run the cable to the car along the side decks inside the sheet and stay points and out through the bow fairleads, through the trailer winch post and thence to the car, all nice and secure but will only take a couple of minutes to rig.
 Should I wish to use the trailer without the boat, the lightbar will simply be strapped across the back of the trailer frame with the shockcords, and when left in the car park while I sail off into the sunset will fit comfortably into the car, cable and all.
Tick. One less job on that %(*^%#  list.
Good, now to go sailing.
John Welsford