APR. 2016

The April Meeting

Show and Tell

Our Treasurer was present and gave his report; as usual we have money left in the bank. Bruce reminded us of the need for someone to volunteer for the Treasurer position because Larry has told us that he will not continue with the job. Bruce also asked us to think about books we would like to buy for the club library, to make use of some of our surplus funds.

The subject of the club logo was discussed again. Martin Beales brought along something to add to the ones already suggested. To resolve the issue, at the next meeting we will look at all those that have been submitted and take a vote. Bruce will prepare some voting slips.

We quickly got on to websites and this one looks particularly interesting:

http://www.modelengineeringwebsite.com/

It is a kind of on-line model engineering magazine and plans etc. for models come out every week. Instead of advertisements it has links to the various suppliers who presumably sponsor the website. However, since it is UK based the supplier information is of limited use here. Having said that, I still order a few things from the UK if they are just not available here. Suppliers there are geared up to serve the international market and stuff normally arrives within a week.

NAMES was discussed and carpooling arrangements were made. As I write this, the event has come and gone but I will include a short write-up later.

There was some discussion about aluminum welding. The method of choice is TIG using the AC setting. Bruce has had some experience in doing this and the main caution is that it needs way more amps than the equivalent thickness of steel. Aluminum is a much better conductor and heat disappears rapidly from the weld zone. There was also some discussion about aluminum brazing (there is usually someone at NAMES demonstrating this.) Opinion seemed to be that if you try to use the technique on anything thicker than a pop can, you will have problems.

Continuing with Kasey’s work, I was not present when he brought his spot welder along before so he brought it again this time. He also brought some samples of thin sheet metal to weld together and demonstrate the effectiveness of his device.

Nick Jonkman brought along the main component for a resistance soldering system he is working on. It is based on an article in an old Science and Mechanics magazine. The main item is a transformer that Kasey Schuilenberg put together for him making use of an old transformer, retaining the original 120V primary windings but cutting away the secondary windings and starting over.

The volts per turn Kasey measured was 0.9V so this enabled him to calculate the number of turns of heavy gauge wire needed to give the recommended ~5V output.

(I tried to get a photograph with sparks flying but was not successful.)

Bruce has made some more progress on his 18 pounder. Here is the optical sighting system:

I have not been able to spend very much time in the shop during the last month but I did manage to get the gear train drive to the overhead camshaft on my Sealion mainly finished. I measured the optimal gear mesh distances before finalizing the design and it turned out these deviated significantly from the theoretical ones shown on the drawing. In the worst case the C/L distance had to be increased by 0.012" to avoid the gears binding (interfering.) The bolt holes in the timing cover also had to be re-positioned to get them acceptably centred in the bosses provided on the casting.

And here is the safety guard that protects the gun layer from the recoil of the barrel, together with the forming tools used to make it:

Keith Orr has been pressing on with his Tiny Power engine. He has had some problems with the cylinder/vaIve chest alignment relative to the support pedestal on one of the cylinders. This means that the valve rod does not align properly with the eccentric etc. on that side. He is pondering how to correct this. In discussing construction details, apparently the crank pins are secured in place using Loctite. This

NAMES

Bruce and I went down on the Friday to get set-up. Tony Koolen, Kasey Schuilenberg, Stu Brownlow and Keith Orr came on the Saturday to join us. Mike Green was at the show and stopped by our stand. We arrived early afternoon on Friday but by this time most of the available display space has been taken and we struggled to find anywhere for our models. This is a distinct contrast to the last few years when there have been empty tables even on the Saturday. The likely explanation is that with Cabin Fever now moved back to January, potential exhibitors are not put off by having to attend 2 shows very close to each other.

Anyway, the standard of the models on display seems to be holding up and there also seem to be more aircraft and boats being shown. Here are a couple of pictures of our display (yes there is someone under the hat.)

spend so much time thinking about how to carry out each individual operation.

Metal Selection

There was some discussion about this, particularly around grades of steel, at our March meeting. We did not pick up on this at the April meeting but it would be interesting to pursue the subject further. Please come along to the May meeting ready to discuss what you use for which application in the hobby.

Our Website

https://sites.google.com/site/bluewatermes/

I continue to be amazed at how much work must go into some of the models and how my own productivity is put to shame. In particular I was looking at the 14 cylinder, double bank, sleeve valve radial engine on display - and it is clearly not the first radial engine he has built. You probably have to spend a solid 40 hours/week in the shop (and maybe significant OT) to make any real progress where this level of complexity is involved. Another factor is that if (unlike me) you have spent you working life as a machinist, you don’t