Midland
Elder Statesman
Posts: 1,870
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Post by Midland on Jan 26, 2021 11:10:17 GMT
Which M is 5 BA please? D
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Post by simplyloco on Jan 26, 2021 11:25:21 GMT
M3 is 0.0078897637795276" smaller diameter than 5BA, approx.!
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Post by simplyloco on Jan 26, 2021 17:29:14 GMT
Valve Chest Cover Beautification
This cover is held on by six huge 4BA studs, and to me it is as ugly as sin! I determined to rectify this, and I spent this afternoon making a 1.6mm thick pierced steel plate, tapped for 20 x M2.5 stainless steel studs. This will be attached to the valve chest cover using four of the M2.5 studs, the cover underneath being held on with six countersunk 4BA screws instead of studs and nuts. It is just an experiment, but it has to be an improvement! It's all Roger's fault... John A better idea of scale. I'm thinking of chemically blacking it and the nuts, leaving the stainless studs bright. I have to say I like it very much!
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Post by coniston on Jan 26, 2021 22:32:16 GMT
That looks much more delicate John, should work out well.
Chris D
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Post by simplyloco on Jan 26, 2021 22:36:08 GMT
That looks much more delicate John, should work out well. Chris D Yes Chris, I'm looking at blacking just my nuts and leaving the rest polished. Bling rules OK! John
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Post by coniston on Jan 26, 2021 22:45:06 GMT
I used a blacking kit from Polly on my passenger trolley braking parts, overall I was not impressed for the money. Just as easy to heat them and drop them in some oil, probably get the same effect.
Chris
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Post by simplyloco on Jan 26, 2021 22:48:57 GMT
I used a blacking kit from Polly on my passenger trolley braking parts, overall I was not impressed for the money. Just as easy to heat them and drop them in some oil, probably get the same effect. Chris I'm not surethatI want to heat my nuts and then drop them in oil...!
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Post by coniston on Jan 26, 2021 23:11:26 GMT
Go on, it doesn't hurt, honest.
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Post by simplyloco on Jan 27, 2021 19:19:17 GMT
Valve Chest Cover is Now a Little Prettier! I know that some people will hate this approach, but I love it. The Victorians were very good at what we now call 'Bling'.😱 I blacked the nuts, it's proper cosmetics for blokes! I haven't bolted it on yet, but I will tomorrow The cover plate is held on to the original cover in four places. You can see the studs that will be used. All the nuts and studs fitted, including the steam inlet flange. Victorian Bling methinks! I'll put it together tomorrow and see what it looks like
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Post by simplyloco on Jan 28, 2021 19:27:10 GMT
I couldn't resist a tryout!
Choice of Piston Rings.I see much wailing and gnashing of teeth over the choice of piston ring material: Cast iron, PTFE, Fluorosint etc.. I intend to build this to be run by an electric motor, but with the option of running it on compressed air. Steam is OK on locomotive tracks, but is is hot, smelly and makes an awful mess on the mantlepiece... I'm no expert on bearings, but Visconite is a self lubricating plastic bearing material which is used for low speed/temperature applications such as marine prop shafts. It also doesn't expand much in the presence of water, and most handy of all, it doesn't go rusty, so this is what I'm using in my engine, mainly because I just happen to have a lump of it in the drawer! It's lovely stuff to machine, leaving a silky smooth finish. Scarfed joint made with a thin saw blade. It fits just fine in the cylinder! The four fixing studs on the valve chest faceplate are curing under Araldite right now, so tomorrow should see the cylinder group completed! Beam or flywheel next? John
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Post by simplyloco on Jan 30, 2021 17:34:36 GMT
It's been a busy couple of days!Buying a part built is always a gamble, and this one was no exception. Careful examination is a must! Today I cleaned up a pile of bits, made some 2BA studs and locknuts for the crankshaft bearing blocks, machined the crankshaft and was thus able to do a trial assembly. The green painted bits have not been touched yet, apart from some rust removal, and the difference in overall finish is profound! There are still some glaring errors, and the parallel links will be time consuming, but I should be finished by the Summer Holidays!
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Post by simplyloco on Feb 5, 2021 19:43:44 GMT
Eccentric and Valve Rod. Not a lot going on lately as we have had two recent Covid tragedies in our close family. However, I got into the workshop today and worked on the eccentric and the drive rod. I did something about the eccentric: I cut off the offending bit and silver soldered another piece on to it! The eccentric body was 1/8" too fat so had to be machined down, and the bronze casting finish was 'orrible...
Once again, I refused to make this out the solid! Three pieces silver soldered together. I also dumped the slotted design and used a threaded bearing end cap, as with the other actuator bits.
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Post by simplyloco on Feb 8, 2021 20:11:27 GMT
More Legacy Issues: the Beam Mounting is Inebriated!I made some nice 2BA studs for the beam bearings and did a trial assembly. You can see from the picture that the beam end is about 1/4" out of position! I removed the studs from the LHS and it came back into alignment, so the bearing holes need to be slotted oh so slightly, and a little shaved off the end of the bearing foot. Precision engineered it 'aint, but easily fixed! Onwards and Upwards!
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terryhowlett
Active Member
Actually retired (almost as planned) in late 2019.
Posts: 47
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Post by terryhowlett on Feb 9, 2021 11:07:12 GMT
To my very untrained eye John, those bearings and housing look way out of line! Could it ever have run properly before?
Terry
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Post by simplyloco on Feb 9, 2021 11:14:58 GMT
To my very untrained eye John, those bearings and housing look way out of line! Could it ever have run properly before? Terry It was incomplete and has therefore never run. It will soon! John
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Post by simplyloco on Feb 10, 2021 21:08:59 GMT
Throttle Valve BodyAnother straightforward little job, incorporating a butterfly valve. Brass is specified, but I had some bronze the right size which when polished will look much nicer! Once again, I fabricated it, making the gland separately and loctiting it into the valve body. The interface on the underside will be improved by filing a small flat and pressing the thing in a bit!. I now have to do the 3/8" piping. As with the Stirling smokebox, I'll look for some proprietary preformed bends!
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Post by simplyloco on Feb 15, 2021 21:19:45 GMT
Valve Chest Main FeedI bought some elbows, and here is the result. Quite happy! GA. Large sweeping bends , not for me! I'm pretty sure that the real ones had heavily insulated pipes and sharper bends, so here goes... I used proprietary 10mm elbows, and machined and drilled some brass rod to make flush connections. A little more elegant methinks! Soldered while in position using solder paint. That way the flanges are guaranteed to line up with the studs! The Biz. The pipes are lagged with 1/16" wide waxed cotton tape. I've had this in my toolbox since 1975 when I was the production foreman at a London electronics assembly sweatshop!
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mbrown
Elder Statesman
Posts: 1,713
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Post by mbrown on Feb 15, 2021 21:59:05 GMT
Looks lovely.
Do you happen to know where one can get narrow waxed cotton tape like that these days? I gave lots of lagged pipework to do on 99 3462 and it would be just the job....
Malcolm
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Post by David on Feb 15, 2021 22:08:26 GMT
Large sweeping bends , not for me! I'm pretty sure that the real ones had heavily insulated pipes and sharper bends, so here goes... DAG Brown agrees. A recent Model Engineers Workshop has an article from the archives where he says the chemical industry found the best compromise was bends 3x the dia or radius (sorry, can't remember) and then straight runs between.
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Post by simplyloco on Feb 15, 2021 23:19:40 GMT
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