Points changer finished

Matty F · 2009-10-01T02:17:59+00:00

I've been making devices to keep tram rail points to one side or theother by means of a spring.Here's the finished points changer: started with the usual block of steel and cut the end out of it.I made a roller in the lathe, which does a really good job of puttingthe hole in the middle and making the sides straight. And I got asteel bolt to use as a spindle. Even though I'm going to rivet it in,a rivet is too soft and may bend under the pressure I'm going to puton it. can use the lathe now since the man in charge of the lathe died of aheart attack. Now I'm using all of his machines to make all the thingsthat he said were impossible!Here is the roller assembly put together. As usual the angle grindermade a nice job polishing it all up. I put grease inside before Irivetted it together: I made a cam out of another block of steel. And that's the springthat will hold the cam against the roller: that the cam has a sharper slope near the middle. Try and makethat on your fancy milling machine! I just ground the curve on agrinder. The curve gives the cam a bit more force to flick the railover from the middle. If the angle is too steep the cam doesn't workat all. I already tried that! About 45 to 50 degrees is about all thatwill work.Here are most of the parts put together. I polished up the cam withthe angle grinder too! a tram runs the "wrong" way through the points the movable railsimply flips to the other side. It needs to be spring loaded so thatit stays on that side. When the tram is going the "right" way throughthe points we wouldn't want the points to move across when half thewheels have gone on one track while the second half go on anothertrack!The usual type of spring points changer is too wide for the box I needto put it in, and the design is inferior since the maximum force isapplied only at the end of its travel. A cam gives maximum force onthe movable rail for most of its travel.

Oct 01, 2009 50 Replies

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dennis 16 years ago

He will have bought a 3D printer by then and be making the stuff out of printed ceramics and nanotubes. The angle grinder will be screwed to the lounge wall as a reminder of the good old days.

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Tim W 16 years ago

dennis@home wibbled on Friday 02 October 2009 13:59

If I ever built a house from scratch (ha) I'd want one of those clay robot jigs (aka "A robot shat my house").

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Jules 16 years ago

when I was living over there.

I remember an expedition to the museum at Foxton (at the time I was scouring the land for bits of old electrical switchgear to populate a

1940's switchboard in a wartime generating room) and they've got some nice stuff there. IIRC they'd run lines out on the public roads, which is probably something that no other country would allow a museum to do :-)

Oh, the amount of 'heritage' engineering stuff still kicking around in NZ was staggering - in some cases sitting in piles at museums, in others in peoples' back gardens and sheds, and sometimes even still in-situ in abandoned factories and workshops. Never seemed to be any money to *do* anything with it, but it's all still there with potential at least (unlike just about any other country I've been to, where it's all gone to the scrapper years ago)

cheers

Jules

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Jules 16 years ago

Large-bore drain in the middle of the room and a waste pump - after all, who knows where that stuff's going to go? :-)

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Dave 16 years ago

It did me after my lunch time pint and a half :-(

Dave

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Bob Eager 16 years ago

Visions of adapting lorry windscreen wiper systems for the walls...

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Mit 16 years ago

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danger and fun very nicely. ;-)

Tim

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John Rumm 16 years ago

on. At first it looked like the far wall was sloping toward you at the bottom!

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John Rumm 16 years ago

A chrome bottle trap would look sooooo much better - the side exit of the pipe would let you lose that as well!

(still perhaps there is a pedestal to come we have not seen yet!)

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Matty F 16 years ago

The other shower doesn't seem very straight either:

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's supposed to be a ruined building.

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Grimly Curmudgeon 16 years ago

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Jules saying something like:

The Shitower lives!

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