Keyhole Surgery

Established readers will remember that last year, the lovely Jackie and I bought a brand new camper van featuring a bed that disappears into the ceiling using an electric motor.  Obviously the designers got a bit carried away at this point, because they also installed an electrically height-adjustable table.  I suppose they thought that the "touch of a button" concept shouldn't be compromised by having to actually do anything to get things out of the way underneath the majestically descending 4-strapper bed.  Anyway, for some reason they chose to fit a keyswitch to operate the table.  Here is is.

Keyswitch

After a while, this switch got so loose that you had to use two hands to operate it - one to hold the switch, and one to turn the key. 

At this point, any normal person would have just taken it back to the dealer to get it fixed, but obviously being me, I had to have a look first.  The switch is attached to the box it sits on by a screw installed from behind - there's no retaining ring on the front - and the box is, as you can see, it pretty much filled by the water tank. You can see the switch through that hatch, and even just about touch it, but you can't get your hand to it properly. The box has some brackets holding the sides together that you can't get at.  None of it comes apart in any obvious way.

And so, unusually, I did the sensible thing.  I booked it in, and drove it back to Marquis at Lee Mill, and showed the nice service man exactly what the problem was, and left it with them for and hour or two while I had breakfast at Tesco's (Eggs Royale: like Eggs Benedict, but with smoked salmon instead of ham.  Very good!)  Then I had a long discussion with the nice service man about the subtleties of the operation and resetting of the automatic frost valve, which stops the heater freezing up, but also (if you are unwary) dumps all the water underneath when you turn the pump back on.  Then everybody thanked each other for being so nice, and I drove home again.

It wasn't until some weeks later than I noticed that the keyswitch, now firmly attached to the van, no longer actually operated the table.

At this point, any normal person would have got very irate on the phone, demanded immediate special treatment and driven to Lee Mill for another excellent breakfast, but obviously being me, I had to have a look first.  It turned out there were two problems:

1. The nice service man had omitted to reconnect the plug connecting the switch assembly to the harness.
2. There was a loose wire hanging off the switch.

After a bit of yoga-assisted groping around the end of the water tank though the hole for the seat belt (not shown above) , I managed to reconnect the plug.  And by touching the loose wire against the empty terminal on the switch using braille, I was able to prove that reconnecting this wire would make it all work again.  But how to reattach it?  Here's the switch seen from the hatch (you can see the loose black wire too, on the right)

Here's the scene from the top, including my size 11 foot for scale, with the switch under my heel.

You can see that the switch is a long way down the rabbit hole.  You'd need a very long screwdriver.  But there's no chance of holding the wire in place and doing up the screw and seeing what's going on, all at the same time, without some kind of special tool...

I like it when you need a special tool.  Here's what I came up with, shown here grasping a rubber band:

And now in slightly closer-up:

grasping a rubber band

The other thing in the picture is my newly acquired extra-long #2 Pozidrive screwdriver.  One should have one for just such occasions, no?  Meanwhile, here's the business end of the special tool:

business end

And at the other end:

leisure end? pleasure end?

When you pull the wire back, the prongs retract and clamp whatever is between them at the time against the end of the Biro. This design isn't my invention, it's shamelessly stolen from the tiny little clips that Tektronics and others supply with their logic analysers, for connecting to the tiny little legs on tiny little electronic components.  Those ones have a spring inside, but mine has a ratchet clip to hold it shut; the wire loop at the back clips over the head of the carriage bolt.  The carriage bolt and the Biro are stuck together using the hobbyist's favourite tool, the hot glue gun.  In my view, there is only one sort of wire for this kind of work - stainless steel locking wire.  It's used on racing cars and aeroplanes to stop things coming undone, and it's designed to stay where you bent it, whilst being quite strong and a little bit springy.  When I had a microlight, I bought a reel, and it's been extremely useful for all kinds of things ever since.

Anyway, here is the tool in operation, seen from behind the head of the carriage bolt

approaching the command module

OK, so you can't really see anything at all in this picture, but you can take it from me the clamp is successfully holding the wire in place and the screwdriver is in there too, poised for rotation.  

And in this way, I fixed what the nice service man hadn't, and the van is 100% electric again.

There are a few lessons that can be drawn from this episode.  You can never have too many sizes of screwdriver, for example.  Or perhaps: locking wire is just as versatile as everyone's favourite, fencing wire, but on a smaller, more intimate scale.  Or maybe:  if a job's worth doing, it's worth making a special tool for.  But I suspect the real moral of the story is: don't assume those pesky service people at the main dealers will have tested their own repair before they give it back to you.

Sawdust

The other day I found myself pondering how to cut some bits of wood down to size for narrow shelves.  In the past, I would have grabbed the first bit, measured it up, marked it out, and clamped another piece of wood with a straight(ish) edge on as a guide, while clamping the whole thing to the bench, or some extension to the bench, or something, in such a way that running a hand held circular saw down the guide wouldn't saw the bench in half.  And then done it all again for the next piece.  And so on.  This classic DIY technique will work, but... (step)son Leo has a table saw.  With a table saw you can just set the guide using the built-in rule, and push the workpiece through the saw - that's it.  To do the next piece, you just push it through - no tedious marking each piece out separately.  So, I thought, I could take the (few) pieces of wood to Leo's... or I could just get on with it the old-fashioned way...  or I could buy myself a table saw...

So I started investigating on the world wide web-o-net.  It turns out you can buy an entry-level table saw from Screwfix which has a desirable 40-tooth blade, a monstrous 2hp motor, gets pretty good reviews, and comes with free delivery, all for the princely sum of £99.99. Really.  https://www.screwfix.com/p/titan-ttb674tas-254mm-table-saw-230-240v/9486j

You have to assemble it yourself, and reviewers mention that there are lots of nuts and bolts involved (as if that's some kind of drawback!).  So, I got one.  And it's all true!  Lots of nuts and bolts, and it works pretty well. The guide is only held at one end, which is a bit junior, but it's not too bad really. It may not be the most accurate device ever, but it certainly works.

£99.99!

It also make a horrendous amount of sawdust!  As you can see, it's fitted with pipes for a dust extraction system, so I started wondering about making one - possibly using the nice universal motor from the old washing machine.  Poor thing, it had started to behave rather erratically, stopping in odd places, but only in certain wash cycles.  I was all for mending it (or course), whereas the lovely Jackie wanted to throw it out and buy a new one immediately.  I did have a slight concern that it might be a bit hard to find the fault, because individually, all the bits seemed to work OK.  There were a few moments of stalemate, but then she pointed out that the poor thing was more than 18 years old, so it had served us well enough (including a couple of repairs along the way to keep me amused), and I relented.  We bought a new one, and I stripped down the old one for interesting parts.

Anyway, I was going to need a whirly chamber thingy from a bagless vacuum cleaner to catch the sawdust, so the next time I was at the "recycling centre" I took a look in the "small electrical" skip.  Nothing.  Who'd have thought it? Usually there are a few dead Dysons in there at least, but not this time.  So I tried Gumtree - and got a VAX vacuum for a tenner, from near where we used to live.  Of course, this one actually works, somewhat spoiling the project.  In fact it's practically new; it was left behind in a rental flat by the departing tenants.

dearly departing tenants...

All that's needed is to connect the (small) VAX hose onto the (big) dust extraction outlet.

I thought of a few possible ways to do it before I remembered the washing machine.  It was a washer-dryer, so it had lots of ducting and rubbery bits around the drum.  And lo!  It came to pass that the perfect part was already on site.  Here it is, installed.  

Note the absence of any need for clips (Jubilee or otherwise), tape, or any other bodgery.  It's all self-supporting. The big end fits snugly round the saw fitting, and the little end fits snugly into the VAX hose.  The redundant corrugated hose sticking out to the left is blocked by a snugly-fitting plastic bottle top.  Sadly, although the picture below make it look like evidence of my successful achievement of cold nuclear fusion, it's really just a green plastic bottle top illuminated by my phone camera's flash.

Cold nuclear fusion

Anyway, the whole arrangement works remarkably well.  There's a footswitch on the vacuum cleaner to turn on the extraction while you're busy at the saw controls, and with the handle removed, the whole thing fits underneath the saw table.  Marvellous!

The saw tilts, so I was able to make two 6ft long 45 degree wedges to stabilise the piano room's new IKEA Billy corner bookcase installation.  Unusually, the IKEA solution was not really good enough,  and left gaps between the upright edges.  No gaps for me!

Writing about the project being spoilt by getting one that still works reminds me of an episode from my youth.  When I was about 15, I started to get interested in electronics.  My father, who was an accountant, had a client who ran a TV shop with a repair shop in the back, so I asked if I could get a scrap TV to take to bits - you know, for "projects".  When it turned up, it was a fully working TV, which was obviously too good to take to bits.  Also, I now had a TV in my bedroom.  Thus were my early ambitions of earnest industry turned into idleness and lethargy by the generosity of a kind man.  Still, the idleness and lethargy are turning out to be quite useful in the long run.  They have much more application in today's world than a modest understanding of thermionic valve circuitry.