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Engineering tribulations

Friday, May 15, 2009 11:37:45 PM Categories: Bob Knight's fairing engineering problems
Today le chausseure est sur l'autre foot, as a Frenchman would very probably say if he knew what it meant and also couldn't remember how to say pied, because I am very reluctantly forced to seek Mr Knight's engineering opinion. Mr Knight's father was an engineer as was mine, but Mr Knight Snr has the advantage over Mr Middleton Snr in that he's alive. (Axshually I generally contact my brother who's yet another engineer and who gave me 'zackly the same information only quicker, but this blog is currently dedicated to the Daring Exploits of Mr Knight.)(Persons wishing to see what my brother gets up to in his spare moments have to Google 'Arthur Middleton FF' where they will be dismayed to find that he uses large engines in his recumbents.)

Accordingly:

Immediately tell me how to fix my micrometer which I am disconcerted to see is whicked (1). It's a Starrett, and as far as I know was always fine. It measures 0 at the 0 setting, but 9.99 on a 10mm Guering drill shank, and 3.97 on a 4mm drill shank. This mis-measurement seems consistent on all the drills I put through it including brand new ones. - R

That's because drills are not accurate. My father chided me for doing exactly that, measuring drill shanks - even really expensive ones aren't. I suspect that your micrometer is fine, but to properly test it you need to get hold of some test pieces to compare. Some micrometers have them included; most don't however. Alternatively measure some silver steel which is ground to fairly precise tolerances. Lots of progress on the fairing this weekend, pictures later after I had me tea. - Bob

We assume 'e 'ad 'is tea because later in t'evening came the following:

I tested the hot glue on the corriboard and if I leave the glue gun for a full 5 minutes, I'm then unable to break the glued joint. It is very strong. - Bob


There followed some gluing, resulting in an encouraging development and if I could be bothered to go and consult my book on aeroplane fuselage construction I would use the Correct Term. As it is the photo will have to do:




Next young Mr Knight learns something about seats, which I being just Wonderful had already told him but he being Stupid had dismissed as irrelevant:

I extended the top temporary fairing to cover my knees and discovered that I needed an extra 5 mm for comfort. So that was handy. I also discoverd that I will need to put in a lumbar and a neck support to maintain the correct position, since slipping just a little makes a difference to the clearances. - Bob

In fact it was a Foreigner who told me about the neck support and I wish I could remember his name but it was at least ten years ago and my Brane is week and feeble with age. Anyway what this is is this. If you support your head then your brains get jiggled and eventually fall to pieces inside your skull. If you can somehow support the base of your neck to keep it upright, then the head balances nicely on top of the neck and less brain jiggling takes place.

However more tribulations were on the way:

Whatever possessed my wife to light a fire in Maud without putting a four-inch piece of industrial hacksaw blade in it? So now just before bed I have had to sacrifice a large handful of twigs in order to get it red hot and allow it to cool overnight. Sometimes I really wonder if she has a brain at all. - R

OK, I'll bite. So why do you need an annealed 4" peice of high carbon steel? What zackly are you making?- Had a fuck up last night, I cracked one of Gavin's welds on the Ratracer steering. I'll put a frankenbolt through for now and get him to reweld before the race. Other than that, just panicking that I don't have enough time left to finish the thing. - Bob

I never did tell him why I wanted a piece of annealed high carbon steel, and I don't propose to tell you either, mostly because it adds an air of mystery to the proceedings. I'm not going to tell you what Maud might be either for the same reason. (Axshually Maud is the name of one of our sheds. We have sheds, in New Zealand, and a good deal of scenery, and an awful lot of weather, and quite a few earthquakes - there was a little one last night - but not many people.)

1. Whicked. A New Zealand spelling. The Wh is pronounced F, as in Whakarewa Street (pr. Fucker-reewer Street. - No, that's true, and it's where the children's High School is). The i is pronounced u, as (famously) in Fush and Chups.

Another useful New Zealand word is 'munted.' I very much doubt if I will be able to complete this account without using it.


 

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