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Post by electrosteam on Feb 13, 2016 3:30:48 GMT
Chris, I just happened today across some old ME with a series on designing radial gears, including Joy. 4052 10Oct97, 4054 7Nov97, 4056 5Dec97, and later that I don't have. "Radial Valve Gears Revisited", Duncan Webster.
A neighbour also commented that the Joy valve gear in his Clayton Undertype Waggon worked very well. Apparently it is a copy of the Don Young arrangement for the Derby 4F.
Good luck, John.
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nonort
Part of the e-furniture
If all the worlds a Stage someone's nicked the Horses
Posts: 277
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Post by nonort on Feb 13, 2016 10:47:42 GMT
As you quite rightly state the gear is to fit your particular loco so the Docstader sim is a great tool to draw out the gear and tweak the dimensions that you have come up with. I believe that the curved slides correct the eccentricities of the gear when applied to a loco with moving axles. The Clayton gear works well because of its fixed crankshaft. I built mine with the curved slide as an exercise in making the entire component from solid, don't ask I was young and foolish at the time. But the result was that the wagon would move in excess of 30 stone in mid gear. As the 'Joy' gear is a radial gear it should have constant lead this criteria is all but impossible with a straight slide. Hope this helps clear some of the smoke from the thread.
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Post by bambuko on Feb 17, 2016 14:06:07 GMT
Chris, I just happened today across some old ME with a series on designing radial gears, including Joy. 4052 10Oct97, 4054 7Nov97, 4056 5Dec97... Thanks John, the article is available for download, here on modeleng.proboards.com Just found it hereIn the meantime, I have checked "Engineering in Miniature" index, and found the following:
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Post by bambuko on Feb 20, 2016 10:18:38 GMT
My back issues of E in M arrived today and it all looks most interesting. I will have enjoyable weekend trying to take it all in Thank you Don again, for pointing me in the direction of Simon Bowditch!
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steam4ian
Elder Statesman
One good turn deserves another
Posts: 2,069
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Post by steam4ian on Feb 20, 2016 12:22:36 GMT
See! Don's not a "Kill Joy" after all.
:-)
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Post by bambuko on Feb 20, 2016 12:41:04 GMT
I never said so! Don't you put words in my mouth I was hoping to read Duncan Webster article in detail as well (originally in 1997 ME) I found his simulator is very easy to use, but the link I have mentioned earlier in this thread, is full of missing pictures making it difficult to follow the article, so I might have to dig deep and buy back issues of ME from epay (unless someone has them?). and finally... (I know it is a scarilege for some) for Gauge 1 inside cylinders and inside valves on top, I feel strangely attracted to Greenly's valve gear. Compared to slip eccentrics I am sure it is perfectly adequate for what I want? Small gauges are full of compromises to make it possible at all, so one more is fine afaic.
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Post by donashton on Feb 20, 2016 14:34:52 GMT
Well I for one admire your tenacity. Inside cylinders valves on top is a pain for room in 5"G and I have that task right now. What do you seek? Full forward, full back, more? Best wishes, Don.
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Post by bambuko on Feb 20, 2016 14:51:04 GMT
Thanks Don, What I seek is ability to control (remotely RC)typically British inside cylinder loco in Gauge 1. They normally run around in circles like demented dervishes chasing a ghost with the owner in hot pursuit to tweak some control with a "hand of god"... My dream is Gauge 1 loco doing leisurly shunting in the yard, going back and forth with prototypical speed (with me at the transmitter). Like I said "adequate control" would be a lot more than what seems to be usual at the moment.
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Post by donashton on Feb 20, 2016 15:50:30 GMT
That is a brilliant description of many 5"G drivers, whether intended or not!
Seriously, what an grand challenge - I wish you well.
Don.
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Post by bambuko on Feb 20, 2016 16:15:03 GMT
...what an grand challenge - I wish you well. Don. Thank you Don! I do realise, that until I have something to show, I am yet another "talker" rather than "doer", so I appreciate your encouragement I am not familiar with 5" drivers, so it was purely coincidental BTW, this is what I have in mind (click for a full size): I am sure it is far from perfect as far as valve gear goes, but far more "doable" than some other options...
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Post by donashton on Feb 20, 2016 18:00:46 GMT
Studying the illustration (I have the book in my library) its singular asset is that the gear and connecting rod all occupy the same area in plan view. Most gears on a typical 0-6-0 have cranks and connecting rods forcing the valve gears into the small strips alongside, so your interest in the Joy gear or Greenly is indeed shrewd.
I read somewhere (and this ties in with Duncan Webster's gallant efforts) that the great user of the gear (the L & Y) relied heavily on correctly setting the slideshaft. Consequently it was craned in, temporally clamped to the frames, and valve events checked. When they thought the results were best the clamps were changed for permanent rivets/bolts as necessary. Good for interchangeability?
However, this could well form the basis of a good Gauge 1 solution. The oddity is that what in most gears would be a radius rod is nothing of the kind in Joy gear. I look forward to seeing progress.
Cheers,
Don.
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Post by bambuko on Feb 20, 2016 20:32:14 GMT
Yes, when I have drafted LBSC's Minx in CAD to have a good look at it, his instruction were to "... adjust to approximate position... and when correctly adjusted, mark frame holes on weighshaft bearings...", so I played with few different positions on CAD - it was remarkable how, very small changes in the position, resulted in messed up valve events (even I could see this ). I now got to the fourth part of Simon's articles about Joy gear in E in M and he is also most encouraging about Greenly's "corrected" valve gear and straight slides, particularly as applied to small gauges! Amother source, was couple of articles by K.N.Harris about radial valve gears in ME (Jan 1972)- interesting. I am overloaded with information and need time to digest it and play with and try to understand it (a bit at least), before I make use of it.
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