Help with 'Speedy' valve gear and other issues...

[jma1009]

Hi Gary,

I would also agree with Malcolm to take a great deal of what Tuplin wrote with a hefty pinch of salt. I have read all his books and articles.

Have a look at Tuplin under the 'index' on Steam Index

www.steamindex.com/library/tuplin.htm

Cheers,

Julian

[Roger]

A slight change of plan on all of the steps and brackets... the fixing bolts and rivets have been increased in size to M1.6 and 1.6mm because they just didn't look right when compared to the pictures of 1501.

That's meant drilling out around 80 holes to accommodate the new fixings and tapping the frames to the new size. That's all done now and the bolts and rivets are now on order.

[JonL]

You are certainly dedicated! I can't wait to see it as it comes together.

Following these build threads is almost like building it yourself; I feel your enjoyment and frustration!

[Gary L]

Dec 30, 2018 20:05:14 GMT jma1009 said:

Hi Gary,

I would also agree with Malcolm to take a great deal of what Tuplin wrote with a hefty pinch of salt. I have read all his books and articles.

Have a look at Tuplin under the 'index' on Steam Index

www.steamindex.com/library/tuplin.htm

Cheers,

Julian

Hi Julian

No historian would treat any source as completely reliable without corroboration, or at the very least some consideration of motivations, and Tuplin is no exception. As Malcolm suggests, he 'goes off on his own' in plenty of places in the book cited. I haven't read him as much as you have done. But when he launches into his own plans and projections he is vain enough to make it clear that they are just that - his own. His motivation isn't hard to find, and his style certainly betrays a certain want of modesty in his own abilities and opinions.

However in the case of the pages I reproduced, he does not do this. He makes it plain that the plans discussed are not his. It would be nice to have his own sources cited, but 1967 is still a bit soon after the event to expect him to reveal them. Given all that, on the very narrow area we are discussing, if he is to be doubted, then the question to be answered is: Why would he lie?

In this case there is corroboration, albeit a bit circumstantial, but I consider it valid until proved otherwise. What he describes about the design processes of 1944 is exactly what we would have expected to happen in a well-regulated locomotive works, which Swindon undoubtedly was, and Hawksworth was thoroughly, perhaps even excessively, steeped in its traditions. What would be most surprising would be if Hawksworth did not have a wider scheme in mind when the otherwise inexplicable 15xx was produced. Thus, I believe on this point Tuplin should be trusted, until we have hard evidence to the contrary.

Best regards

Gary

[Roger]

Dec 30, 2018 23:43:55 GMT JonL said:

You are certainly dedicated! I can't wait to see it as it comes together.

Following these build threads is almost like building it yourself; I feel your enjoyment and frustration!

Dedication is what stands between an unfinished and a finished project, and I'm determined to not only complete it, but to develop, improve, and enjoy driving it. The only way to do this is to put in the workshop hours and keep going even when I don't feel like it. It's so easy for a project of this size to stall, excuses are easy to find.

Going 'off piste' and trying to make something closer to the real thing is certainly frustrating at times, but ploughing on when you know it looks wrong is only going to bring regrets later on. The hole sizes in this case are a pain, because not only have they all had to be opened out, but all of the 3D models and drawings have had to be updated too. You could argue that it's a waste of time doing that, but I want the documentation to be a true and faithful representation of what was actually built. That will help me and anyone else in future who needs to maintain it.

I too can't wait to see it come together, but that's not going to be in the near future. There's still a lot to design between the frames. Things like the bypass and three way valves need designing, mounting and the method of operating them decided. Then there's the whistle and how to get the pipe from the 'tender' neatly bracketed past the firebox while still allowing access to the grate. I need to be disciplined enough to answer all of these questions before reaching for the spray gun, frustrating though that is!

[delaplume]

The Night is usually darkest just before the Dawn !!--------

[Roger]

The brake actuating shaft pivots on two supports that hang below the frame. I'd made these before to the LBSC plans, but those won't put the brake shaft in the right place to attach the steps to the ends.

Here I've rounded the profile and made it thicker as well as adding a larger hole so it can be bushed. Yeah, I know that's over the top, but it's easy to do, so why not!


20181231_095633 by Roger Froud, on Flickr

After parting off, I ground them flat and brought them to the right thickness...

20181231_210108 by Roger Froud, on Flickr

... then held them on a mandrel to reduce the thickness of the flange, leaving a nice radius at the root of the boss.

20181231_212232 by Roger Froud, on Flickr

It's all unnecessary really, you can't see it unless you get on your hands and knees.

20181231_223434 by Roger Froud, on Flickr

[dscott]

Come on Roger. When your locomotive is complete and on show there is only one way we will all approach her?
Reading club has two new Kneeling mats ready for your visit!!

David and Lily. Only 10 hours to Club running!

[David]

Very nice!

It clearly works but how do you find the carbide with the interrupted cut? I can't believe it doesn't chip the tool given they're sintered.

[Roger]

Jan 1, 2019 10:06:42 GMT David said:

Very nice!

It clearly works but how do you find the carbide with the interrupted cut? I can't believe it doesn't chip the tool given they're sintered.

Hi David,
Carbide tools these days are amazing, you're no more likely to chip them than HSS tools. HSS is pretty much obsolete, I doubt if anyone uses it in industry any more for general machining. Don't get me wrong, HSS has it's uses, I do occasionally use it, but frankly it isn't anywhere near as convenient and long lasting as carbide tooling.

[Rob]

The problem I have with carbide inserts is the finish on steel - I still can't get anywhere near as good a finish as I can with HSS, except on that rare occasion when the planets align and I get that lovely 'rainbow' finish. Be damned if I can repeat that on a second cut though. Mostly use carbide for roughing and HSS for finishing and a tighter root radius.

Having said that, seem to have no trouble with bronze and cast iron!

[Roger]

Jan 1, 2019 10:39:35 GMT Rob said:

The problem I have with carbide inserts is the finish on steel - I still can't get anywhere near as good a finish as I can with HSS, except on that rare occasion when the planets align and I get that lovely 'rainbow' finish. Be damned if I can repeat that on a second cut though. Mostly use carbide for roughing and HSS for finishing and a tighter root radius.

Having said that, seem to have no trouble with bronze and cast iron!

Some bar is hard to get a good finish on, whatever you use. It might be worth experimenting with different inserts. I use polished ones for finishing pretty much any material and that works really well.

I tend to buy whatever's cheap on eBay, they're mostly general purpose ones and I use those for all roughing out. Most of these don't have that razor sharp edge you get when you sharpen HSS tools yourself so they are more robust. I have a roughing and facing set permanently set in holders so I don't have to keep swapping the inserts.

The polished ones are every bit as sharp as HSS though, so maybe you could try those, they're a different animal.

[Rob]

Which holders/insert shape do you favour? I've been meaning to try a named brand insert so I don't have to guess the grade or the required speeds and feeds.

I'm using 16mm CCMT at present (I assumed this was the largest I could get away with) but I've noticed you using what look like much chunkier holders and a variety of insert styles. I believe we have similarly sized lathes.

[andyhigham]

I use the WNMG332MN inserts. 6 cutting edges on each insert

[simplyloco]

Jan 1, 2019 10:39:35 GMT Rob said:

The problem I have with carbide inserts is the finish on steel - I still can't get anywhere near as good a finish as I can with HSS, except on that rare occasion when the planets align and I get that lovely 'rainbow' finish. Be damned if I can repeat that on a second cut though. Mostly use carbide for roughing and HSS for finishing and a tighter root radius.

Having said that, seem to have no trouble with bronze and cast iron!

If your lathe is up to it I would double the speed and feed and take decent depth of cut. Carbide tools tear the metal away and burnish the surface to leave a fine finish, they do not 'cut' as we know it. In addition, if the metal comes off in coils then the feed rate isn't high enough to let the chip breaker do what was it was designed to do. That is why Hss suits ME so well as most small machines are not suitable for this type of work.
John

[Roger]

Jan 1, 2019 11:19:30 GMT Rob said:

Which holders/insert shape do you favour? I've been meaning to try a named brand insert so I don't have to guess the grade or the required speeds and feeds.

I'm using 16mm CCMT at present (I assumed this was the largest I could get away with) but I've noticed you using what look like much chunkier holders and a variety of insert styles. I believe we have similarly sized lathes.

The ones I like are these style which can be purchased in a variety of tip radii. The 04 means 0.4mm which is good for general purpose machining because it spreads the load along the edge and it leaves a nice stress relieving corner. I sometimes use the 02 version if the corner needs to be a bit tighter, or finish it afterwards with a HSS tool if it needs to be sharp. I try to avoid sharp corners wherever possible.

TNMG160404 or TNMG160404ALUAK10 for aluminium

The holders I use are 16mm square which makes them nice and rigid, even if there's an overhang.

[Roger]

Time to rivet the steps onto the various brackets...


20190101_192919 by Roger Froud, on Flickr

... cutting the rivets to length using the fixture. This works really well, partly by design and partly through happy accident.
Fitting this to the lathe using the quick change toolpost means I can take it off to change the rivet. It also means that I can hold it in one hand and use a file to take the sharp edge off the machined end. That's not easy to do if it's left in the lathe.
There's also the chance of dropping and losing the rivet, and that's not such a problem if it's done over the bench.

20190101_214709 by Roger Froud, on Flickr

Going through my pictures again, I can see that the narrow step on the rear buffer steps on 1501 is held on with rivets on one side of the locomotive and with bolts on the other! I've elected to rivet them on both sides because I think it looks nicer.

20190101_222420 by Roger Froud, on Flickr

I've also noticed on my pictures of 1501 that the bottom row of rivets on the larger step on one side also has bolts instead. This is clearly a common fix if it has to come apart for repair.

[don9f]

Great start for you in 2019!

No workshop time for me though as we had a run at the track today.

Cheers Don

[Roger]

Jan 1, 2019 23:18:40 GMT don9f said:

Great start for you in 2019!

No workshop time for me though as we had a run at the track today.

Cheers Don

No excuses Don, we had a run too!

I believe this is an Ajax. It's a new acquisition of a club member who's going to finish sorting it out so it runs properly and get it painted. Even so, like most steam locomotives, it runs even though it's clearly not right.


Vinces New Years Day 2018 by Roger Froud, on Flickr

[JonL]

Nice little engine that, I fancy something similar, but it would detract from the time I spend building!