Drawings – which way up?

[AndyfParticipant @andyf]

I've never found printing from the digital edition terribly satisfactory, Bob. This may be because I have only ever printed from early editions, where it may be that the scanned originals aren't too good.

But it is more probably something to do with the "Toner low; prepare new developer cartridge" notice which comes up each time I use my laser printer. It's been saying that ever since I took it over from my wife more than eight years ago (!). Letters for snail mail still look OK, though.

Andy

[Sub MandrelParticipant @submandrel]

I fold my magazine in half so it becomes irrelvant whether the spine is at the top or the bottom.

I'm drawing some quite complicated drwawings (loco frames) and discovered I needed three drawings to cover all the dimensions without confusion. The alternative is blowing up to full size, but then it takes just as much paper and you can't see the full picture at once!

It is quite stressful working out the best ways to dimension objects; I have decided to leave off things like the radii of square holes with rounded corners, as in 99% of cases the radius used will be that of the cutter or file used to finish the job. Technically, of course, some would like to see these as toleranced dimensions.

I dimensioned the holes from a datum point (bottom left), except for the ones for the horn rivets, as its more important these align with the cut outs for the horns. In other words I tried to reference each dimension from the point where I would measure it in practice: I think this should make sense and minimise actual errors.

I'm always amazed at how few dimensions seem to be used on older drawings in ME yet there always seems to be sufficient detail to make the things!

Neil

[Mark CParticipant @markc]

Having had a chuckle at some of the early posts I thought it might be turning into an interesting thread. I would have to agree with Neil above, the main object of a drawing is to convey information in a clear and usefull way. As someone who draws and designs for a living I always try to work the dimension scheme as the operator would work the machine (it's surprising how many shops still work with manual machines).

A lot of the drawings in the mag could be much better presented simply by using a logical datum and working all dimensions from there (particularly helpfull is the use of ordinate dimensions and hole tables).

The down side to this is the need to really have a DRO fitted to the machine so you don't loose track of how far you have gone in any direction!

Mark

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