Dec. 2018
Bluewater Bulletin
Bluewater Model Engineering Society Sarnia, Ontario
Vol. 34 No.3 December 2018 Editor John Lovegrove
Our next meeting will be on
January 14th, 2019 @ 7:30 pm
Northern Collegiate Room 125, Indian Road, Sarnia.
The December Meeting
As usual we started with the Treasurer’s report all isstill well with our finances.
Bruce Mannerow started by talking about the show guide he puts together each year. This used to be included in the May or June newsletter but it is now just posted on our website. The real question is how many people make use of it and is it still really worth
the effort to assemble all the information? A few
members did say they have used it and this led to a discussion on the lines we have had before; that
these shows seem to be on the decline. Some
thought that comparable shows across the border in Michigan seem to be holding up somewhat better.
Last time I mentioned the problems I had getting the e-mail version of the newsletter to go through. I did have similar problems this last time, even using the work-around that seemed to solve the problem before did not work straight away this time. I must have
spent about 2 hours on the phone to Teksavvy and it seems they really have no idea of what is going
wrong. The conclusion seems to be that technology can be a curse as well as a benefit to us. Also that the people who handle service calls really do not understand the complexities of the systems they are dealing with.
Back to model engineering stuff: Bruce talked about Mr. Crispin who is a fairly young guy in Britain who is working on a 5” scale model locomotive (and a few other things.) He then went on to talk about “This Old Tony” and here are a few YouTube videos.
https://www.youtube.com/watch?v=K0XfRPi_h2M
https://www.youtube.com/watch?v=eLdlV3-JaH8
https://www.youtube.com/watch?v=PO-Ab7YfBzY
The first two are about putting together your own 2 axis CNC system then using it to run EtchASketch
and make a drawing. He is using Mach 4 which is an updated version of the Mach 3 that I use, but the setup configuration all looks very much the same. The last one is helping people understanding simple
trigonometry – in particular what is involved in setting up a sine bar. (I am not sure why he bothers to use trig tables when almost everyone has a scientific calculator that does it all for you!)
the books and the profits from sales then go as grants to worthwhile literacy organizations.
Show and Tell
Bruce had made further progress with his howitzer and I contributed a little by machining
some helical grooves in a piece of tube that has ended in the cylinder of the recoil damper (more later.) He has also made a few other items using conventional machining - as shown in the photograph.
Tony Koolen has carried out a lot more machining on the boiler feed pump for his Case traction engine.
The design of the internal looks fairly complex and the machining likewise. Stainless steel balls are used in the inlet and discharge valves and the one for the inlet is smaller so that it can be passed down through the seat of the discharge valve to get it on to its own seating.Dave Dazer brought along the horn assembly he
had last time
but with some hand-work carried out to improve the finish of the cast component.
Bruce’s other favourite producer of workshop videos is Joe “Pi” (Pieczynski) and here are a few more he has produced on different machining operations:
https://www.youtube.com/watch?v=FnEl6Kj-F-E
https://www.youtube.com/watch?v=JFuLjT3QmwA
https://www.youtube.com/watch?v=eSeYUxV1A4Y
Another theme he went back to was “CAD programs
be dumb.” He gave an example he found of threads
drawn on a shaft that would not work out in practice. The message seems to be that a little human intelligence is needed however clever these programs are.
Following the discussion last month regarding Dave
Dazer’s item where he wanted to improve the surface finish on a cast component; Bruce brought along some small wheels that were basically an abrasive grit encapsulated in Neoprene rubber. Apparently, these are very effective in smoothing down rough surfaces and come in various grit sizes. It seems that care is required in using them because you can easily end up removing more metal than you really intend to.
We sometimes get on to the topic of the Model
Engineer website:
https://www.model-engineer.co.uk
There is a forum that one can join that has many
items of interest. One thing I found when I checked
the site is that subscribers to Model Engineer’s
Workshop can get a 6 month free trial of the Alibre
Atom3D CAD program. Alibre used to offer a fairly
cost effective (~$200) 3D CAD program that was fairly popular with hobbyists. However, they were taken over by someone who did not seem to be interested in selling to the amateur world and no longer offered the low-cost option. They seem to have gone back to offering this for about the same price as before - and it now contains a CAM package as well.
We sometimes get to talking about books that are of interest to our hobby and Don Hayes mentioned a website that deals in used books:
https://www.betterworldbooks.com
They have a wide range available including technical books and textbooks. They seem to be a (semi?) charitable organization that relies on people donating
As mentioned earlier, Bruce brought some abrasive wheels for Dave and Brian Lawson also brought aIong a powered device for Dave to try.
Peter Esser brought along one of those gasoline fueled camping stoves that were popular back when.
The burner part has to be pre-heated to get the thing working. Kerosene blow-lamps and stoves were very common where I grew up and my father told some horrific storied about the gasoline fueled variants so I suggest that Peter treats this with a lot of respect.
I did manage to complete the rear manifold piece for my Sealion and the pictures show it on the engine and on its own. One key aspect of the design is that no gasket is required, all the sealing is carried out using “O” rings in machined grooves.
above, there are some examples of what can be done very easily using this technology that would otherwise be a lot more difficult. I have developed a series of programs for different operations that can be adapted as required. One of these is to machine plates with complicated shapes and various holes. This can be modified as required by inputting key coordinate points from the CAD drawing program. Another is machining the periphery of the 2-hole flanges shown: You mainly just have to input hole centre distance and radii for the middle and end parts, then the program does the rest. Another is machining the recesses for the “O” ring seals. There are three diameters of recess on the component above and all of them were machined using a 3/16” end mill with programmed circular cuts. Doing this using conventional machining would probably mean 6 different set-ups on the lathe with a 4-jaw chuck or faceplate.
Some more Comments on CNC
I do get on to this subject from time to time. I know there are some cynics around but for me it really gives another dimension to the hobby. In the picture
January meeting but here is the set-up used for the machining:
Turning now to the item I machined for Bruce to use in the recoil damping cylinder of his howitzer: This involved machining 4 helical grooves on the outside of a piece of tube. The helix is fairly “slow”; 1 turn in 30”, but this really does not matter. You need a 4th axis which is basically a rotary table driven by a stepper motor, then it is mainly down to the software. I have machined several components of this kind before and you can do things relatively easily that would be essentially impossible on the conventional machines we have in our shops. Any helix angle can be programmed and this can be changed over the length of the component, essentially in any way you wish. Anyway, this is the machining job I did for Bruce. As I mentioned, it was a tube but a solid piece (being held) was soldered in the outer end so that it could be supported during the machining operation.
And the component before parting off.
To explain the rest of the story, the above component was soldered inside an outer tube (tube sections in fact.) The inside was then bored out, leaving the four little grooves on the inside of the tube that remained.
The next task was to make a piston with 4 helical flights to go inside. Hopefully Bruce will have it at the
As I say, I feel it does bring another dimension to the hobby.
Remaining Meetings this Season
2019
January 14th
February 11th
March 18th (11th is March break)
April 8th
May 13th
June 10th
Our Website
https://sites.google.com/site/bluewatermes/
John Lovegrove