CAD vs Drawing Board (CAO vs la Planche) 2

Murphy's law is far reaching and can make you eat your words.  I recently posted a gripe about the downgrading of the engineer in certain companies in the CAD era.

Well, I made up a CAD model of the brake lever in that post and I uploaded it onto the excellent Grab Cad site.  I was very quickly answered by a bloke called Cameron Reid who has already done the engine, gearbox, carb etc. for a Thruxton.  Self- taught, he's done a ton of bloody good work and is happy to share it provided you have the good manners to credit him wherever you use it. 

I still love the original drawings for their style but it has to be said that this stuff looks great on CAD.  That's as near as I'm getting to actually eating my words.

Little things that count

Thinking Juice

I got my oil pump banjo bolt back.  I gave a bottle of very good rosé to a chap I know who has so many machine tools at home that he's got a lathe in his kitchen because there's no where else to put it!  I also gave him a grade 8.8 7/16" BSF bolt to base it on and he has done a lovely job.  

In addition, this week I have received my valve collets (cotters to some).  These came with a nice touch.  In the past I have bought sets of collets for Triumphs and BSAs and I usually got two, four or eight pairs in a little plastic bag.  I suppose they would have been factory original spares.  The new ones for the Venom were not separated, but still unevenly joined at one end with little curls of swarf still attached.  I called Grove Classic Motorcycles Ltd to ask if these were as they should be, after all if they were a couple of pairs of duds I wouldn't be able to measure and check the shoulders so I wouldn't want to fit them.  The guy was out but called me back and explained to me (somewhat impatiently as though I was asking foolish questions) that they were all like that so that they always matched.  

It would seem that making a batch of these and then allowing the same size ones to be mixed up is undesirably risky.  In this age of hi-tech precision engineering this could be smiled at, after all, if you bought Honda ones, they'll be separated.  I would not be so dismissive.  Wherever I come across these practices I usually find there's a good but not obvious reason behind them, indeed I find them comforting because this has been thought about.  My collets can't be mixed up, so then they're a bit like parts for a flintlock pistol.  That's rather a romantic notion to me.  

To the left the banjo bolt story from correct part to re-made upsized bolt to replace the bodged one that snapped.  Looking closely at the "propper" one, it has stretched, so I suppose I'll replace them all.  To the right, the valve collets, old and shiny new "flintlock" ones.

Cad vs Drawing board 1

Having just put down the engine in my nice newly sorted out workshop, I strayed near the computer, so here I am again posting a post.

I looked up "Drawing Office" on google images, an impulse after deliberations earlier today, and quite by chance I turned up this image:

This bloke offers a brilliant service here:
http://owensvelos.co.uk/
where you can buy copies of many of the original Veloce factory drawings.  I shall be ordering shortly.

A veritable blast from the past.  I once worked in drawing offices where we were all on drawing boards.  CAD was an exciting prospect, but not suffeciently developed for normal day to day working.  The drill then was to agree on the design, get the (paper) drawings done, have them checked and when the bits were made / samples in, go and do a 100% inspection on them.  You then had be on hand for when the assemblies were made and sort out problems that arose and if there were problems, then the usual first lament was "drawings must be wrong" even if they weren't.  With all that accountability to all levels of the heirachy from boss to stores ckerk's assistant's mate, you ended up wearing the job as you would a coat and you usually had a lot of these coats to wear.   

What I'm getting at here is that the business of design engineering seems to have been a lot more hands on before the CAD era.  I think it's reflected in the products too.  Take an injection moulded plastic part for example.

These days, we can get a rapid done (say an SLA), that is a model of the final part to-be, and the evaluation is mostly done off of that before the T1 samples (the first parts made from the mould) comes in.  By now the non-engineers from other interested parties have been involved for a fair while and no-one really wants to back off if the money on the tooling has been comitted.  This was once a "backroom boffin" affair that could be "massaged" before it produced a product prototype for other managers to evaluate later on.

In my opinion we made more attractive products under the old system.  We made things that were a more human scale.  Things we could repair rather than replace, more characterful things like these:

As opposed to :

Yes, they're more advanced and arguably better built, but that's the technology.  Imagine what the guys who made the first three could have done with modern technology.  Making CAD models of real things is a skill in its self and I feel it adds a layer of virtual glass between the bloke that should be accountable and his design whilst everyone else has a finger in the pie.  This mindset percolates upwards in the organisation to affect the product it's self.  This is contrary to modern "design industry" dogma and I think it's a shame.

SolidWorks "ultimate CAD Chair project" sponsored by the biggest CAD company and run as an interactive project with young design engineers across the world.  It has a motorised seat, three screens, a sound system....

...and looking remarkably similar is your average cheap Arcade game.

My CAD workstation is now on another table and my own desk is clear.

Why do we do it?

Blokes in sheds, rusty old machines, the smell of grease and hot oil -where's the motivation?  Hard to explain, but this chap puts it well:

Staying on the Plot

Still working away, but not much blogging done.  These are the times that you can become so ensconsed in the workshop that you can lose sight of why you're doing the project.  So here's a tantalising reminder as to the why.

Progress!!!

It's been a while, three months I believe, but that's the nature of rebuilds when your life dosen't depend on it.  It took what seemed like forever to get on with the head and I didn't really want to get started on something else in the meanwhile as that's the route to project creep with me.

Come on Daddy, clear this up and get on with it!

 It would seem that there is no-one in Herault who is prepared to take on blast cleaning of old motorbike engine parts.  That's an area big enough to not want to be bothered driving beyond for the sake of a clean up.  

Herault is number 34 at the bottom on the coast of the Med.  Loads of open country and almost no services for the erstwhile motorbike restorer.

In the end the way you know is the best / quickest / easiest, so I went and dragged the head all the way back to Blighty.

Criterion Engineers Ltd are advertised in the Velo club magazine and website and as far as I can tell that's the extent of their marketing.  Nonetheless, it turned out to be a remarkably trouble free way to go.  As I work for a firm based not far from them in Swindon and I have to go there from time to time, I called up Criterion Engineers Ltd, arranged to drop the head and rocker box off and collected it again a few weeks later.  Whilst I was there I saw evidence of some very sound, well developed engineering techniques going on, mostly concerning Velocettes.  When it came time to pick it up they were going to be out, so the head assembly was left in a coal bunker outside with the invoice.  I simply picked it up and popped a cheque for a pretty reasonable £153 through the letter box.  Very civilised stuff, particularly when followed by an excellent lunch with a pint at the nearby Royal Oak . 

So that's a blast over, new hardened valve seats, new valve guides, a new exhaust spigot and the dodgy threads sorted out and helicoiled.  It looks so nice that I couldn't resist placing the parts together to see what they'd look like.

Oooooh, aaaaaah......

There's a happy final note too.  When it came to grinding the new valves in I blued them up to start off so that I could see how much work I had to do.  The light smear of blue on the valve face left a perfect unbroken ring on the seat.  I know it's logical given that the new seats and guides were put in at the same time, but all the same, nice work Criterion Engineers Ltd.

Rude awakenings part 2

Sometimes you can know too much.  Since joining the Velocette Owners Club, I have used some of their excellent facilities available online.  For example, thanks to their hard work and dedication, I have a better understanding of how the part numbering system worked and most disturbingly (even more disturbing than finding a part numbering system interesting), I have found out when my engine was made - 1958.  Cast your eye to the right and you will see that the basis of this project is to rebuild the bike that was registered on the day I was born in 1961.

I was at first disapointed, to say the least.  How could it be?  Was the market so slow that they didn't sell the bike for three years?  I suppose it's possible.  As I mentioned before, when it came to me my bike was in fact a bitza and not an original thoroughbread.  Could it be that the whole thing is a mish mash of bits from other sources that someone threw together and only one of the wheel spindles is of the original 1961 machine?  This is more likely and the fact that the magneto turns out to be a rare competition type (for which parts are difficult to find) seems to support this.

So what?  My Venom was never going to be museum material (thank goodness), so why should it matter?  I have hung on to this bike all these years because it was important to me and in doing so I have made it into a personal icon.  None of that can be erased and so I suppose it is no less special, in fact quite the opposite now.  I think Terry Pratchet hit the nail on the head when he wrote in his novel The Fifth Elephant:

"This will become in time, the axe of someone's grandfather," said the King "and no doubt over the years it will need a new handle or a new blade and over the centuries the shape will change in line with fashion, but it will always be in every detail and respect the axe I give you today.  And because it'll change with the times it'll always be sharp.  There's a grain of truth in that see."

Shiny, Shiny, Pretty, Pretty

The Solvol Autosol arrived the other day.  That is good stuff.  Slap it on, work it in, then buff away and your aluminium or chrome comes up with a lovely deep shine.  Applied with an old tooth brush into nooks and crannies it works just as well.  Shiny, shiny, my precious…

Good gear.

So where are you with all the rest Andy?  What’s this about polishing stuff? That should be at the beginning or end and since this project started some six months ago or more, is this evidence of slow progress?  Procrastination?  Bang on with all counts.  It is going slow.  I do procrastinate. 

I wanted to finish off the head but I have run into a cleaning problem.  I don’t want to knock out the guides before having the casting cleaned but there are very few firms around here who can do that sort of thing.  Luckily I found Peter Clark in a village nearby.  He featured in an issue of Café Racer magazine:

http://www.cafe-racer.fr/?p=935

…and was mentioned as a very helpful chap who runs a Ducati race preparation workshop in Paulhan.  He gave me the following advice:

1. Don’t be tempted to sandblast because it renders the casings porus and makes life difficult.
2. Vapour bead blast instead  http://www.motalia.com/Html/Blasting/what_is_it.html

Armed with this I’m getting enquiries out. 

It seems like it’s taking an age, but I want this bit done properly.

On other areas, I have checked the gudgeon pin fit in the small end (I couldn’t remember if this had been looked at back in 1993) and it is a lovely smooth play-free fit.  Looking at my planning sheet I inspected the studs and crank casings with a view to a rinse and blow through just to be sure.  That’s when I found the bodged banjo bolt. 

This one’s not mine, but a previous owner.  Evidently someone has stripped the thread out of the oil pump outlet side and reworked it with a 7/16” BSF thread.  The connection is made with a raised flange set screw that has been drilled to serve as an oil union bolt.  The problem with this is that it leaves precious little material after the holes are drilled and this one has sheared.  What I really need is a bolt with just enough shank to provide the extra material needed.  Thinking cap time.

Shear bodgery

Meanwhile I occasionally stray into the workshop as I wait for the kettle to boil in the kitchen and if I do, I usually polish something.  Such lovely shiny things…

Precious...