Werowance attempts Upshur Vertical Single

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tjmatx

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It is actually completely against any known laws of physics how a small part can gain enough energy from a short fall to roll under the exact center of the nearest most inaccessible piece of heavy machinery.
I completely agree. I would even add that in my cramped shop, there is something going on where the fallen part is most likely to end up hiding behind a bench leg or cabinet wheel. I am constantly astonished by how often that happens, way beyond the laws of chance. I suspect it has something to do with quantum tunneling, which is a total mystery to me.
 

Art K

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I think you just have shop elves, they jump out and grab things out of midair and drop them in the most unlikely places.:)
Art
 

karlw144

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I call it “lateral gravity”, you drop it and almost before it hits the floor, it’s going sideways! Often easier to make another part, and 3 days later the dropped bit is laying in plain site.
 

RonW

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Well yeah but, I think the shop elves fits the observations better. The lateral gravity would have to be intermittent or something and that would need a whole new line of study.
And they're all named Murphy. As in Murphy's third law: why be awkward when with a little bit of effort you can be plain bl__dy obstinate!
There endeth the lesson. RonW
 

JohnBDownunder

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Them there Shop Elves and in my case Gremlins got a whole lot to answer for if ever somebody catches em. 👿 👺 👹 💩 Not sure which one most resembles the little monster that seems to inhabit my playpen.
 

werowance

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well after the third attempt i finally have the start of a 2 piece rod after this weekend. i broke 2 drills. the slitting saw left a really nice finish that required almost 0 touch up. you could hardly see the parting line when bolted back together. now i need to figure out how i am going to scribe and cut the 1.75 deg angle on the rod. i just cant think of an easy way to lay that out. ill do some reading of other posts for ideas before i start and i will probably waste a lot of dykem marking and remarking multiple times until i figure out how im going to do it. but here are some pictures of the start of the rod

1588600814774.png


1588600854171.png
 

Brian Rupnow

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Regarding the 1.75 degrees on the rod. If you have a cad program to work by, or even if you can lay it out on a piece of paper, the center of the radius at each end is the center of a "hole" twice the diameter of a radius. So--best way is to start with an over-width piece of stock, determine where the four holes should be, and drill them thru. Then take a short piece of round stock the size of the hole and press in two short pieces about 1" long. Now set the con-rod up in your vice with the two pins resting on top of a parallel setting on top of the vice jaw. Tighten the vice and then remove the round rods and the parallel and the tool path will be truly horizontal. And it will be 1.75 degrees from the centerline of the rod. The problem with using a narrow piece of material to start with is that you can't drill a hole which is only partly on the stock.
 

awake

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now i need to figure out how i am going to scribe and cut the 1.75 deg angle on the rod. i just cant think of an easy way to lay that out.

Weworance, will you be using a rotary table for any of this, e.g., for rounding the small end? If so, if you set up your fixture to hold the rod such that you know where it is straight, then you can dial in the 1.75° on the table. (That doesn't help with marking it, just with cutting.)
 

werowance

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Regarding the 1.75 degrees on the rod. If you have a cad program to work by, or even if you can lay it out on a piece of paper, the center of the radius at each end is the center of a "hole" twice the diameter of a radius.
well my problem is that the piston end of the rod does not give a radius there. but yes I have seen you and others do it the way you describe and leave drill bits in the holes and let the rod be supported by the vice jaws with the drill bits thus you have your slope from one end to the other. but I'm just not seeing it on these drawings. and on top of that the plans call for it to be turned length wise in the late to make it some what of a cylindrical shape lengthwise. maybe that's how I'm supposed to achieve the 1.75 taper. use my compound set at 1.76 when turning the cylindrical shape of the rod? I think the whole engine was designed to be able to be done on a lathe only but if I can figure it out id rather do the area between crank and piston holes on the mill.

in the shot below on the crank side he does give a radius on both edges but on the piston side he doesnt

1588625124965.png
 

CFLBob

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Brian - how does someone know where to measure the rod to get the 0.349"? That number is only valid at one point along the length because of the taper. The .359 measurement appears to be where the .09 radius curve into the base starts while the 0.349 appears to be some distance left of that radius.
 

Brian Rupnow

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That number is a "resultant". It is actually a "result" of using hard, solid numbers and a "true" 1.75 degrees. If you look at the original drawing it says "about 1.75 degrees". "Hard" numbers are given numbers that I arbitrarily use to develop the geometry.
 

Cogsy

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and on top of that the plans call for it to be turned length wise in the late to make it some what of a cylindrical shape lengthwise.

Bear in mind that the radius on the outside of the rod might be needed for clearance to the cylinder skirt at half stroke. I don't know about this engine but on some the rod will foul if left 'square'.
 

werowance

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now that is very much appreciated. with this I can drill the radius holes on both ends and mill it out. then if I need I can still turn it for piston skirt clearance if need be.

question, how did you arrive at the r.211 at the piston end of the rod? best guess or was there something in the original drawing that allowed you to calculate that as I was trying to figure that part out as well last night.

thank you very much for this
 

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