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Post by peterl78940 on Mar 10, 2006 22:47:38 GMT -5
Russel, thanks, thats a good one.
here's another that I was thinking of: machine the nut first, with the last 1/16" turned down to fit in the hole for the O-ring, but without the center hole for the rod drilled; then machine the steam box femal threads and smooth bore for the O-ring, but not the center hole for the rod drilled; then screw the nut into the steam box while its still in the chuck and then finally drill the through hole for the rod.
I suspect the above will also be prone to errors, but I might try it just for the heck of it, and then when it fails, I'll either try your method or go back to Kozo's.
-Pete Lawrence.
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Post by peterl78940 on Mar 10, 2006 23:03:52 GMT -5
Here's a technique I use all over (all links and rods, and now my boiler end caps too), to make two identical, square, symmetrical parts...
in the case of the links, side rods, and piston rods: put the two parts together and slip a short stub of rod (or brass tubing is what I usually find handy) into the matching holes of the part to line them up, do this at each end. then start filing (I think it is called "draw" filing, where you take a fine single cut file and scrape it sideways) along the pieces you got stuck together. Turn it over and do the other sides. Then flip just one of the peices, and repeat. Do this over and over, and after a short time you can tell the pieces are symmetrical because when you flip one part over (and with the rod/dowel/tube holding them inline) they match up height-wise and the file makes file marks across the entire width of the peices (as opposed to filing off tilts and irregularities in the beginning).
And if it is a side-rod that is end-to-end symmetrical you can flip one peice end-to-end and file and repeat with flipping around the long axis as above, and after a short while the peices are very much a perfectly matched pair.
I just started also doing something similar to my boiiler ends, well for the A3 the firebox ends at least. for another boiler I'm making I also have to make matching ends for a "wagon top" rear section.
well, at least it works for me....
-Pete Lawrence.
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Post by peterl78940 on Apr 18, 2006 0:07:39 GMT -5
another design issue/question with Kozo's tube union joints. In his book these all have a cone (nipple) with 45-degree sides that mates with a cup (stud) that have 90-degree sharp point that would cut into the cone on tightening. I've made both my cups and cones with 45-degree mating surfaces, since that is how for example my barbeque connects to its propane bottle, and wonder if anyone else does it this way. After doing this I researched this issue and found that in the LBSC designes he also uses cups and cones that have equal 45-degree mating surfaces. -Pete Lawrence.
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Post by Russells on Apr 18, 2006 18:51:33 GMT -5
Pete,
Kozo's tube union joints are intensionally designed so that tightening them will cause a slight deformation of the sharp edge of the 90 degree piece. It is a form of "CRUSH SEAL". As the parts are tightened together, the 45 degree part crushes the sharp edge of the 90 degree part to form perfectly to its own shape. This type of seal is extremely reliable and has been used successfully in very high pressure steam applications (over 1000 psi).
The Master, (Kozo) has his reasons.
Russells
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Post by treinenbaas on Apr 19, 2006 17:30:57 GMT -5
Hi All, When you post a Kozo A3 note, it would be nice if you can mention the scale. 3/4" or 1.5" It makes it easier to understand and or evaluate the photos. Thanks Gerry (treinenbaas)
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Post by atlantic442 on May 14, 2006 21:53:27 GMT -5
A3 Switcher 3/4 scale
Has anyone made a Guide Yoke yet?
On page 100, Is the 2-7/8 vert dim from the top down to the center line of the cylinder? If so, then the 3-23/32 vert dim on the left side should be increased by 0.1449 to 3.8637
Anyone with AutoCad I'll be glad to send my findings.
Hans
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Post by locodan5416 on May 15, 2006 10:20:54 GMT -5
This will be my 3/4's of an answer, as in 3/4" scale ok, here is what i think about that drawing. The 3-23/32 is telling you how long the piece is...Gosh this piece is kinda complicated... Okay, 2-7/8 down from the top, that is the centerline. then going up 31/32, you find the midpoint for the radius rod opening. Going up 29/32 gives you the place for the reversing lever bracket. Also note that the 2 dimension going down is not the midpoing of the radius rod opening, that might be your error.
I recommend you use another layer aand redraw the piece, then inspect it. going through never works.
Dan
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Post by patyoung on May 16, 2006 13:29:40 GMT -5
Hello Hans,
I would like to talk to you further about the issue that you presented off line. Could you send me your email address so we can discuss this further?
Regards,
Pat Y. phty95014@yahoo.com
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Post by phutcheson on May 17, 2006 12:08:05 GMT -5
Pay H and Hans
I also would like to know the answer ... the drawing is somewhat confusing.
Could someone posting the results so we all could know the answer.
Thanks
Pat H
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Post by atlantic442 on May 18, 2006 0:20:53 GMT -5
For being "The first project for the beginner" this is one complicated poorly dimensioned part. If everyone would focus their attention to the Guide Yoke on page 100. I will explain how I reached my conclusions.
1: The 2-7/8" down from the top of part is the center line of cylinder. The center line of the cylinder is 7/8" down from the top of the Main Frame page 90 fig 16-1
2: From the cylinder center line down to the top of the Guide block is 0.520, (half of 1.040).
3: The Guide block mount is 1/8" thick
4: From the bottom of the Guide block mount to the tangent point of the 5/16" radius is 1/32"
5: And 5/16" radius at bottom.
Add all vertical dimensions (in decimals)
2.875 + 0.520 + 0.125 + 0.0313 + 0.3125 = 3.8638
Referring back to the drawing, the over all heigth is 3 23/32" or 3.7188"
The difference is 0.1450" The correct dimension is 3.8638
Hans
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Post by Russells on May 18, 2006 19:39:45 GMT -5
Hans,
I carefully reviewed your findings and the drawing in question and have concluded the following:
The source of your confusion is in assuming that the 5/16" radius is tangent to the straight surface where the 1/32" dimension is. It is not tangent. The 1/32" dimension is the distance that the straight surface continues below the bottom of the guide block mount. The center of the 5/16" radius is 5/16" from the bottom of the overall length of the part (3 13/32") and 0.236" over from the straight edge. It is tangent to the 2" radius only.
To prove this, enlarge the drawing on page 100 in a photo copier to twice full scale and trace the 5/16" radius with a compass. You will see that the radius is not tangent to the straight edge. I have enlarging many drawings to help make them easier to read.
The drawing of the guide yoke is complicated, but it is correct.
Russells
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Post by atlantic442 on May 18, 2006 23:32:30 GMT -5
Russells I concede defeat, it would have helped if the center of the 5/16 had been located with dimensions.
Hans
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Post by patyoung on Aug 5, 2006 12:43:03 GMT -5
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Post by Bill Holland on Aug 6, 2006 21:13:10 GMT -5
Im currently building the Kozo a3 in 3/4" scale in Solid Works. Im working on the bushings for the rods at the moment, the yoke is not too far off.
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Post by patyoung on Aug 7, 2006 1:45:07 GMT -5
Hi Bill,
I hope you will post pictures when you are done.
Pat Y.
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