Hello and a part-built blowfly

[Jim]

That set up has certainly done a great job silvering the end on to the rod. I use LPG but also added a swap and go D sized Oxygen cylinder to make an oxy-propane gas set for boiler work. It's so much cheaper than oxy-acetylene with the bottle rentals etc.

Keep up the good work.

Jim

[Lisa]

Coupling rods now cleaned up and the second crankpin hole bored:


This does show up a couple of marks on the front end of the rod though, they'll need to be filed off.



Both are now lightly oiled to keep them shiny; still not entirely finished in shaping though, as I want to round off the outer corners of the bosses a bit. But that can wait till my arms have recovered from todays lot of draw filing. Boring the holes was a bit iffy, and I suspect the left rod may need an off-centre bush. Still, the old bench drill did all right, considering that 16mm is a bit much for it (hurrah for reduced shank drills!).

I'll probably poke about with the lathe a bit tomorrow, at least get it setup for machining the bushes. Oil holes are obviously not done yet either.
Once all is done, I may paint the centre section of the rods red, leaving bright bosses, maybe, we'll see.

[uuu]

I did see a film of full size coupling rod fitting. They heated the rod and whacked it until it went on.

Wilf

[Lisa]

That wouldn't surprise me Wilf; the bigger the loco, the more you can get away with.

[Lisa]

A quick shot of the rods (sans bushes, clearly) in place on the loco.

[Lisa]

Spent a couple of hours poking around in the workshop this afternoon, with dad looking over my shoulder and trying to ask questions. He likes the shiny rods, so I guess there'll be no painting.

I rounded off the end corners with a file, and drilled the oil holes; which now brings the coupling rods to completion (besides bushes).
Here's a rather unforgiving close up:


So next will be the bushes, then I should probably do the connecting rods. I'm considering doing some timber cylinder mock ups, which will at least allow me to do the rear cover, and thus the crosshead, slidebar, and motion bracket could then all be done and fitted.

[Lisa]

Today I turned up the front crankpin bushes for the coupling rods, this was made slightly more fun in that they have 12mm bore, and the tailstock chuck for the lathe can't hold bigger than 10mm (well 10.5mm, but it claims to be a 10mm chuck). So it was a case of drill to 10mm, bore out to about 11.7mm, then ream to 12mm; which was probably the best way of doing it in any case. The outside diameter is a locktite-fit in the rod bosses, but I haven't fixed them in yet as as previously mentioned I may end up putting an off-centre bush in at least one if the rods aren't quite right; so that can wait till the rear/driving bushes are made.

[Jim]

The rod ends are looking great Lisa, you've done a cracking job there. I think you're wise to wait until the rods can be tested before fixing the bushes as a pair of off center bushes may be needed for final adjustment, though given your work to date I'd doubt it.

Jim

[Lisa]

Thanks Jim, I certainly try to get it right, but drilling that 16mm hole was always going to be a bit iffy; case of 'fingers crossed' for the holes being where they should be.

As an aside, and because I don't recall seeing others do this; this little lathe needs as much support as it can get when parting, so here's my way of giving the job a little extra support. A long centre to run down the bore of the material to give a little support on the chuck side of the job (thus not jamming the cut). Also has the added bonus of catching the finished bush, rather than it just dropping on the lathe bed, or flinging off down the back of the bench.

[Roger]

Hi Lisa,
This is a very good idea, and one I've had to use on occasion where I didn't want to cut the bar down and it wouldn't fit through the headstock.
I use a centre to support quite a lot of jobs, you can crack on with much bigger cuts on any size of lathe if it's supported like that.
Thanks for sharing, this is useful.

[Lisa]

One of those days, made the rear bushes, and was quite happy with them. Then I discovered a slight error; the outside diameter of one is precisely 1mm over size. Guess I'll stick it on a mandrel later/tomorrow/monday/etc and turn it down to the correct size.

Forgot the old addage: "Measure twice, cut once." Oh well, these things happen from time to time.

[Roger]

Oh well, it's just annoying rather than scrap. I'm sure we've all made something perfectly to the wrong size. My favourite annoying habit is to take something out of the vice or chuck and then realise I've not finished something to size. I've done it yet again today! Grrrr...

[Jim]

Aug 13, 2016 9:35:22 GMT Lisa said:

One of those days, made the rear bushes, and was quite happy with them. Then I discovered a slight error; the outside diameter of one is precisely 1mm over size. Guess I'll stick it on a mandrel later/tomorrow/monday/etc and turn it down to the correct size.

Forgot the old addage: "Measure twice, cut once." Oh well, these things happen from time to time.

Welcome to the club Lisa. At least your muck up is recoverable unlike most of mine which are total muck ups. Still the cast offs are worth keeping as you never know when they might get a new lease of life.

Jim

[Lisa]

Thanks Jim, I think.

Roger, yeah fortunately it was oversize, so it could be corrected easily enough, so more annoying than anything.

Speaking of which:


Done! Well, I need to drill though the oil holes once the loctite's set, but otherwise they're done. My worries about needing an off-centre bush were unfounded; there was a slight tight spot, but a couple of wipes with a round file in a bush got rid of it.
So I spent a little while just pushing the chassis back and forth, before taking the rods off again to loctite in the bushes.
Next I'm thinking of taking the "valve gear" (slip eccentric, so 2 rods) off, and just giving them a bit of a clean up and polish. They were done with a bit of a "can't see it, so doesn't have to be pretty" attitude many years ago, and now their untouched black steel look is annoying me. Then I'll do the connecting rods, which are an almost-repeat of the coupling rods.

Today's soundtrack was provided by the whistle of, I believe, DD17 1051, out on the mainline after a recent overhaul. She ran past the end of my street, but I didn't get into a viewable spot in time to see more than the guards van disappearing.

[Roger]

That's good progress, it's not easy to get nice close fits to all of the parts of that mechanism and have it run without tight spots. I think it's the thing I had the biggest worry about.

[Deleted]

nice work Lisa...we all make mistakes..hey just look at my wheels issue...none of this really matters..being able to work around such things is what's important.....well done on a rolling chassis with rods...must be a great feeling...keep up the good work...

cheers..

Pete

[Lisa]

With the loctite set on the bushes I gave the rods a clean and a light oiling to keep them pretty, then went to fit them on the loco... suddenly remembered I had yet to drill the oil holes through the bushes. So now they're actually complete and fitted. Dad and I took turns pushing the chassis from one end of the stand to the other (about 1.5 revolutions of the wheels).

[Lisa]

One eccentric rod and strap cleaned up, still need to do the left one once my arms are less jelly-like. The photo' shows why I was less than happy with the rods and straps as they were.

[Lisa]

Both eccentric rods and straps are now nicely cleaned up and looking good. I figure that while they're off I should do the bushes for the valve spindle end, so that'll likely be the next job.


Dad wanted to help a bit today, mostly just holding the far end of the rod while I worked the other end clamped in the vice, but it's nice to see him still interested on his good days.

[Jim]

You're to be admired Lisa for providing your dad with a chance to contribute to this great project. He must be very proud of you and the work you're doing.

Jim.