2021 April Virtual Meeting

This meeting coincides with the funeral of HRH Prince Philip, Duke of Edinburgh. We recognise that many of our members will be watching the funeral and those of us that are attending will observe the one minute silence to pay our respects.

Who would have thought last year that we would still be having virtual meetings this April? Well, here we are, still building and showing our models.  Hopefully, later in the year, we will be able to meet in person.

John Day has built a 'ball bouncer', which is similar to a ping-pong bouncer but uses marbles instead. The advantage of this is that it is not subject to the whims of a breeze. He says it is 100% accurate unless one marble collides with another in the catcher.

Philip Bond: Here is my latest Meccano project - a Meccano workshop lathe, pillar drill & power hacksaw. I hope to power them with my Mamod SE3 Steam engine fixing up a line shaft to run them all.

Andrew Jefferis: 

I have spent some time with an old favourite from the Supermodel Special Instruction Leaflet - the "Meccano Hammerhead Crane". I have followed the plan mostly but have used a mains motor (a microwave motor) instead of the Meccano motor, adjusting the gearings obviously, for a quieter model. I have also added a Cabin Cover and used a different method of rotating with helical gears moving a flanged ring with large tooth quadrants.

Eric Pentecost has continued with his build of the Titan Block Setting Crane:

In the end I decided to rebuild the whole thing again except possibly the jib. The traveller is near enough complete now . I had some trouble with the drive because of the weight so decided to drive the bogies with 4 separate motors as seen in the pictures. This seems to be working at the moment and should be interesting with full weight on board.

I think I have resolved the turntable rack and pinion by using a long plastic caterpillar turned inside out and clamped to a ring. I haven’t tried it out yet and if it doesn’t work I may have to put a hidden motor inside the turntable - we shall see. I am also looking at easily assembled sections because of the overall weight at the end of the day.

And I am hoping that it will be complete by the time we go live in July, if not I shall still bring it along.

Steve Briancourt:

Since completion of the Penny Falls machine, I have had to restock certain parts, so have been spending some time on restoration paint work.  Much of this was for all strip sizes of 11 holes down to 3 holes, but I didn’t take pictures.  However, I also did a batch of the longer strips, and this is where a problem became apparent.

I finished a spray can and started a fresh one to do the reverse side of the parts, but the results came out much darker.

A comparison of all these recent batches to some I sprayed a few years ago showed the batches to be generally darker, with this latest can being the darkest of all.  The paint manufacturer – Plastikote – advised me that there is a production batch date, but not an expiry date.

The can on the left is the oldest without a batch date, but it was the new cans which varied in colour.  Plastikote say the cans will be ok for 10 years after production. Also, not to bake the paint dry which can discolour and crack the paint, so I have stopped using my workshop oven!

In the end, after consulting other members, I shook the next can vigorously for much longer than two minutes until my arms gave out, and this gave much more consistent results.  So in the end it is probably down to good mixing in the can if it has been stored for a long time.  Time to make a mechanical shaker!

Here is a batch of short angle girders freshly painted on one side, and the same batch turned over ready for the reverse coat.  For one side, they rest on notched plastic extruded angle (see picture), and for the other side they rest on bamboo skewers to keep them off the paper.

I then remove them from the pallets and lay them out on paper to air dry for several days.  I hope over time the paint will harden to the extent that baking them did.

I have spent quite some time thinking about how to achieve the motion in my next model, so I have only just started to assemble the base.  The base uses eight 24½ inch girders, which had to be dead straight to mitigate distortion.  The ones I bought ‘new’ are all curved in the usual manner (see picture), so had to be straightened out first.

For straightening angle girders I have a number of techniques.  For small curvatures like this I use a wooden former, planed to a right angle.  This sits inside the Meccano angle girder to prevent buckling under strain.  The wood sectional shape is important to allow it to bend readily without much effort or risk of snapping.

The girder is then gently pulled against the back of the vice in the appropriate direction, gradually moving along its length for the next pull.

If the bend is only in one plane, the girder can be held ‘square on’ to the direction of curve and pulled, as shown in the picture.

The result is perfectly straight girders as seen here.

These girders have been used in the partially made base of the model.  There will be more structure to give it stiffness soon.  The ring of sector plates is to gauge the size of the intended model, but won’t actually be arranged like that if completed.  I say ‘if’ because I’m still thinking of a build solution, which may not be possible in the end.  Perhaps by July’s meeting I’ll have a solution and can say what the model will be.