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Post by pkastagehand on Jan 3, 2011 11:10:53 GMT -5
Happy New Year all! (Cross posted also on Live Steam BBS so sorry if you've already seen this.) I haven't posted too much lately and haven't been working much on the loco lately either. (Penn. A3 from the Kozo book in 3/4" scale) I did over Christmas have time to finally go back to it a bit. It still needs condensate valves on the cylinders, packing glands and piston rings. It has also been put together dry (no gaskets or gasket-maker compounds). In spite of all the air leaks however IT RUNS! A chassis on air finally. Link to Flickr site with video clip of the A3 running: www.flickr.com/photos/pa56/Paul
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Post by kvom on Jan 4, 2011 12:56:28 GMT -5
Watched the video, looks great!
Question: How do the bushings on the side rods get lubricated? I am assuming there is a through hole in the bushings not shown on the plans.
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Post by pkastagehand on Jan 4, 2011 14:37:14 GMT -5
Watched the video, looks great! Question: How do the bushings on the side rods get lubricated? I am assuming there is a through hole in the bushings not shown on the plans. The book does show holes in the rod ends (or at least some of them) if I remember correctly. I don't have the book here since I'm at work. I assume one is supposed to drill through the bushings after inserting them in the rod ends. Once they are in the rods (pressed in or put in with locktite) they can be drilled through accurately. Paul
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Post by kvom on Jan 4, 2011 14:48:39 GMT -5
That's what I assumed. A friend at my club suggests cutting a groove in the bushings so that if they come unstuck and turn inside the rod, the oil can still get to the crankpin.
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Post by pkastagehand on Jan 28, 2011 14:15:35 GMT -5
Start of the Rachet wheel for the lubricator. Bad photograpy but you get the idea. I machined the housing for the lubricator from a single block of steel. Guess I should get a picture of that one day. The rachet wheel was the first use of a dividing head I've had for several years. My grandfather borrowed my mill for a few years back in the early 90s before he died when I had no shop space for it. He was doing some dividing stuff so he bought the dividing head and I inherited it when I took the mill back after his death in '96. Since Kozo called for 40 divisions and the head is a 1:40 ratio, it was a piece of cake. One rev per cut coming back to the same hole I started with. Once set up it took less than 5 minutes to mill all the divisions. Rachet Wheel by stagetech56, on Flickr
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Post by daveb1 on Jan 28, 2011 15:34:44 GMT -5
Hi Paul, I am building the new shay and it appears that the lubricators are the same for both engines or at least the rachet. I used Kozos method using the lathe. The teeth on the rachet I did do not seem as sharp as the teeth you made using the mill. When I install the rachet it does get hung up on a couple of teeth that did not form well. My question is what type of end mill or cutter did you use. I have a rotatory table and would like to try cutting as you did, but I'm not sure that I can use a straight end mill.
Thanks Dave
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Post by kvom on Jan 28, 2011 16:26:12 GMT -5
I'd be interested in the cutter as well.
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Post by pkastagehand on Jan 29, 2011 15:31:11 GMT -5
I used a 2 flute 3/8" dia. end mill. I redrew the rachet in CAD to get shape right etc. then used numbers from that to offset from center and cut to depth. The shaft I cut the ratchet onto was parallel with the table in centers with the dividing head and a tail stock center for the div. head. Should have taken a picture of the setup.
Paul
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Post by kvom on Jan 29, 2011 18:15:54 GMT -5
That's a good method. I did a drawing also, which makes it easy to do the numbers. Thanks for the tip.
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Post by daveb1 on Jan 30, 2011 10:45:17 GMT -5
Hi all, When I used Kozos method the cutter I made had about a 15 degree angle making the angle between teeth about 75 degrees. I assume the offset and depth you figured would compensate for the 90 degree end mill cut. Do you have the offset and depth? Thanks,
Dave
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Post by pkastagehand on Feb 1, 2011 12:01:45 GMT -5
Hi all, When I used Kozos method the cutter I made had about a 15 degree angle making the angle between teeth about 75 degrees. I assume the offset and depth you figured would compensate for the 90 degree end mill cut. Do you have the offset and depth? Thanks, Dave I put a jpeg of the cad file on flicker. Rachet wheel by stagetech56, on Flickr If it is too hard to read send me an email address where I can send attachment and I'll send a DXF or something. Paul
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Post by phutcheson on Feb 1, 2011 14:12:53 GMT -5
Paul,
In another thread you mentioned about using an
".... automatic condensate valves for the cylinders rather than make all that linkage for drain cocks. A couple designs are floating around online."
Can you tell us more about that idea? It really sounds interesting.
Thanks,
Pat H.
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Post by daveb1 on Feb 1, 2011 15:17:06 GMT -5
Hi Paul, I could make out the flickr diagram fine. I will try it. It should come out better than my hand cut . Again thanks
Dave
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Post by pkastagehand on Feb 1, 2011 15:49:09 GMT -5
Paul,
In another thread you mentioned about using an "automatic condensate valves"
Can you tell us more about that idea? It really sounds interesting.
Thanks,
Pat H. On the BBS for Live Steam magazine there are a couple of links relating to drain cocks from the last year or two. I have a sketch for one design scaled for 1" and 1.5". I started trying to scale down for 3/4" but it may take some fiddling. I'm not sure my first attempt will work. The author of that article described blowing a mouthful of water through it and when empty air would close it. In my case even the water closed it. I need to adjust some thing somewhere; maybe the amount of free space on the closed side of the ball. I'll put the document I have on Flickr. Paul drain cocks by stagetech56, on Flickr Here's my first numbers for trial unit in 3/4" scale: A .059" No. 53 drill 2 places B .161 No. 20 drill C #10-32 D 5/64" stainless steel ball E 1/4" round or hex F 5/16" G #8-32 (not on drawing but the size I have in the bottom of my cylinders.)
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Post by pkastagehand on Feb 10, 2011 14:54:33 GMT -5
Another not very good picture of some more progress on the lubricator. Ratchet wheel after final machining and hardening/tempering. (Not sure if my heat treatment really worked.) Microscope slide glass is the right thickness for the side window. Have a piece cut but not epoxied in yet. Paul Lubricator parts for A3 by stagetech56, on Flickr
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