Talking with blokes in pubs – 3d Printing

OK, so one of my hobbies is “going to the pub”. As I happen to be on holiday, and living less than 100 yards from a pub (well, really a hotel bar) then it is natural that I have been in there a few times. It’s also natural that I should make the place my “last port of call” before going home to bed. Go out, visit a pub (or two) in the town, drop in at on the way home. As a result, I’ve become friendly with the owner, and a couple of the regulars.
I knew that one of these “regulars” knew something about software and engineering and was from the North-East of England, where I worked a long time ago. I thought that he was in Fife on business. It turns out that he lives there. He works nearby for a company that makes surgical devices among other things. He also makes a lot of use of 3d scanners, printers and CAD (Autocad, Solidworks and others).

He told me a number of things that I did not know about 3d printing. Here we go:

  • 3d printed ABS (I think that is what he said) are approximately 80% of the strength of injection moulded parts.
  • 3d objects can now be scanned accurately with hand-held scanners, rather than a turntable scanner. Presumably some clever software compensates for the operator not holding the scanner steady. 
  • The accuracy of scanning and printing is now about 0.1mm, which is adequate for surfaces which are not touching other things or are going to be machined. 
  • Shapes which would be unstable during construction (for example, large overhangs) can be made by constructing in two materials. One material (which he said was like “sugar glass”) is used as scaffolding to support the real material and then dissolved away. This is rather like “Lost wax” or “Investment casting”, except that the temporary material is around the shape being made, rather than part of it.
  • This technique can also be used for making parts which are going to interconnect, could be moving parts. You design them, then interconnect the 3d models, and then use the filler material to fill the gap between the interconnecting parts. Finally, when the parts are finished, you dissolve away the filler and, “hey presto” the two parts are connected or interconnected. No further assembly is required!
  • Finally he told me a little about commercial 3d printers.

I’m going to try and “bump into him” next week. I’d like to add him to my list of contacts.

Laundry, sightseeing in the mist, and a change in the weather

Today we went to a launderette to do a week’s laundry. We went to Rosyth as there is not washing machine in the cottage. I found out later that one of the dry cleaning shops in Burntisland takes in service washes. The sat-nav made finding the place again a piece of cake.

The laundry took a little time, and while it was finishing we had lunch in a little cafe. Noreen was a bit dubious about it, but I thought it was pretty reasonable for the kind of place that it was.

I asked Noreen where she wanted to go. She didn’t know, so I suggested going to look at the Forth (railway) Bridge. Initially I said “South Queensferry” but then changed my mind to “North”. We found it without any difficulty. The bridge is impressive, but was concealed by the “Harr” (sea mist). At this time of year the harr feels strange. Not cold as you would expect, but warm and damp at the same time. To me it felt a little like being in a luke-warm turkish bath. Quite suddenly the mist started to clear, and we could see the top of the bridge structure.

Since returning home I have been to town and back, prepared tea (poached egg on toast, followed by a doughnut) and tea has been eaten. In the meanwhile the weather has turned quite nice. Both the sky and sea are blue. It’s nice and warm.


(Monday 2nd July 2012 – Evening)
Why do people like things? Why do I like the things I like?

I’m sitting looking out of the window across a beach. The sand is covered by very shallow water, which reflects the grey of the sky. Because it is more sand than water, the water on the beach is completely still. Further out I can see the boundary where the beach ends and the sea begins. There the light grey of the beach becomes a darker blue-grey. The whole scene seems to be composed of shades of grey: pewter, dove-grey, battleship-grey, blue…

I like being near water. I like lakes and rivers and I especially like being near the sea. I find the being near water relaxing. I like the colours people associate with water. Right now, I’m on vacation and I’m concentrating on doing very little. I’m simply relaxing, going with the flow, drifting (two water related metaphors there). It’s very pleasant.

(a little later)
The scene has changed. I’m sitting in the same chair. The beach has dried a little and the scene now contains more brown shades. The sea is now a deep, blue-grey and the sky above dull grey. Close to the boundary between the sand and the sea I can see two tiny figures. With the aid of binoculars I can just make out that they have fishing rods.

I just thought: I wonder what the phase of the moon is? I wonder because, the sea is an awful long way out. Obviously it’s low tide, but is it a Spring low? I think it must be, that would make the phase of the moon either New, or Full. If I think, and the sky is clear enough, I’ll look up in the sky tonight.

Someone is almost bound to suggest looking it up on the internet. Unfortunately, the internet connection isn’t working properly at the moment, so this is being written on Monday evening, but may not be posted until some time in the future.

(later still)
At the boundary between the sea and the beach I can see a flock of white sea-birds on the ground. They are moving around and from time to time some of them fly into the air and then land again. It gives that area a sparkling effect.