Mar. 2017

The February Meeting

Attendance at this meeting was much better than last time, maybe the spring-like weather helped to get people out. Unfortunately our treasurer was not able to attend (bad cold) so we had no update of our finances. On the fortunate side, Kasey Schuilenberg did get to the meeting. He is getting around again after his accident but keeps a cane handy.

There has been discussion in the past about how we might use some of the club funds to purchase something worthwhile for our library. Keith Orr had a proposal to take out a subscription for the Model Engineer and Model Engineering Workshop. These would then be available for members to peruse, the cost would be about $200 for a year. The vote that was taken indicated approval but a few people did not seem too happy with the proposal. Bruce has since contacted Keith and asked him to hold off until we have had an opportunity to re-visit the idea.

The equipment that Len Head had for sale was discussed: Information on this was passed on to us through Brian Lawson and Bruce Mannerow, I circulated a notice to the club and contacts in the Toronto area and I have since learned that the Ames Triple has been sold to a member of the TSME. Bruce has been in contact with Len, who runs the machine shop at Lambton College. He did not know about our organization and Bruce asked him along to the meeting. Unfortunately Len was unable to come this time.

available at Costco. These are relatively cheap and work in the standard fixture without removing the ballast or starter. They also work in a cold environment (like Bruce’s shop in winter), give a much better light and will probably last longer than most of us. Following this I bought a package of two tubes and tried them out in my workshop. I was so impressed that I have now bought enough to replace all the old tubes in the workshop and garage. (They are ~$18 for 2.)

One watch-out here is that they replace the type T8 tubes that work with the old technology (wound inductor) type ballast. Newer fluorescent light fittings use an electronic system to heat the filaments, limit current and give a high voltage spike for starting. These use different (T12?) tubes and I don’t think the LED replacements will work in these fittings

We had a couple of visitors; Tom Gogas and Dale Masters. Dale is from Michigan and is in the process of building a 3 ½" gauge Rio Grande K27 locomotive. (He is also getting into CNC which I find most heartening.)

Tony’s Traction Engine Tender

The Shaft with the Helical Groove

The Middle Point with the Reference Hole

Workshop Tips

Keith Orr has just bought a set of drawings and castings for a Perkins Gas Engine. Nothing has been started yet so he has quite a task ahead of him. It will run on gasoline (the original was probably gasoline/kerosene) and governing is hit and miss.

The outstanding item on Bruce’s 18 pounder is rifling the barrel. He needs a jig to do this and the critical component is a rod with a helical slot corresponding to the twist in the rifling. I offered to make this on my CNC mill using the 4th axis but it does not have enough travel for the 16" length required. The

calculations. Watch the video, it seems quite a good method.

https://www.youtube.com/watch?v=nLHXSXzQP3U

Something else he talks about is his preferred approach to threading: Assuming a normal RH thread, instead of going right to left with the normal tool arrangement and lathe rotation, he turns the tool upside down, runs the lathe backwards and goes left to right. He machines a groove in the workpiece at the left hand end of the threaded part and starts the tool from there. Doing things the conventional way the problem is always disengaging the feed or stopping the spindle at the right moment to end the thread where you want to. Going the other way you always start at what would have been the end point and run outwards. Where you stop is then no longer critical, you just need to run off the end.

In the video he talks quite a lot about finishing the thread using a file and scouring pad. Finishing a thread properly after screw cutting is never too easy unless you buy one of those expensive form tools that give the correct profile to the crest as well as the root. If you are cutting a non-standard thread and you do not have one of these then his techniques seem to be good. If you need a standard thread and are just screw cutting to make sure it is concentric, straight and of consistent pitch, then leaving the thread a few thou oversize and finishing off with a die is probably the best approach.

One aspect I was a little dubious about was what he said about the flat on the end of the tool. In truth the root of the thread should be a radius and a flat just gives on an approximation to this. (Grinding the appropriate radius on the tool tip is next to impossible unless you have special equipment.) His way of looking at things is that the flat should not be too large otherwise the thread depth will not be correct. The real issue is that if you do this the mating (female) thread will bottom on the root before it touches the sides.

I was thinking back to last time and Joe’s system for centering square stock in a 4 jaw chuck. Recently I have been working with rectangular bar that has to be centred in the chuck and this presents a similar problem. Some time ago I made a set-up that allows me to use a normal dial indicator (with 1" travel) and a magnetic base, for most of my centering needs. I saw the arrangement in one of the machine shops in town and it struck me as a good way to go. You start with a piece of solid rectangular steel bar (I used 3" x ½") and this just rests on the lathe bed providing something firm to attach the magnetic base to. It has to be heavy enough not to move in use and I epoxied a piece of Masonite board to the underside to avoid marking the lathe bed. I also attached a handle to make it easy to put in place and remove.

Bruce has been looking at more Joe Pieczynski stuff. This time it was about threading in the lathe: There is a link to a video below where he talks about this and how the compound slide should be angled at ~290 to the perpendicular (610 to the lathe axis) to essentially cut on one side of the thread only. The issue then is that the feed required on the compound slide to give the correct thread depth is greater than the depth as normally specified. You can use simple trigonometry to work it out (feed = thread depth/cos[290]) but he has a way of doing it that eliminates the need for any

The advantage of this arrangement is that one does not have to disturb the cutting tool to use the indicator, you just move the set-up in and out as required. Also, when centring a square or rectangular bar one can lift the stylus by pulling on the knob at the other end while rotating the stock 1800 to check the other side. The 1" travel allows one to do this. You don’t need Joe’s small pieces of flat stock and rubber band and it also works on rectangular bar if the thickness and width are not too dissimilar.

Club T Shirts

John Sibbick was at the meeting and came wearing the T shirt he had applied the club logo to which I had a picture of in the last newsletter.

He has some of the transfer sheets left over and I was volunteered to print off some logos using my ink jet printer. (I may have to hit the club up for some replacement ink cartridges.) Anyone interested can then take one, find an appropriate T shirt (not blue) and iron away.

Going back to our previous unfortunate theme we were very sorry to hear that John’s wife has passed away recently. John, please accept the condolences of the club members.

Our Website

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

The TSME Newsletters

https://sites.google.com/site/tsmeweb/the-modeller

Meeting Schedule for the remaining 2016-2017 Season

2017

March 20th (13th is March Break)

April 10th

May 8th

June 12th

John Lovegrove