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Old 02-21-21, 11:18 PM
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Andrew R Stewart 
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Mark's above comments are much what i thought watching the vid. I say that alignment table at one of the frame builder shows (forget which one) and wondered why they removed so much table material (well I guess it's for weight but I haven't had to pedal my cast steel surface plate up a hill ever)

In the vid Paul ponders about the whipping post allowing the shell to float about and seems to suggest this is bad. I wonder about that though. Mark ponders about using an insert in the shell (like the Campy facing guides) but says nothing about the thread clearances having some possible slop. I suppose if you really wanted to use the shell's bore to be your datum some way of really securing the guides in place and also not have the post touch the shell's faces at all, ever. On my own self designed post the top cap has a step to more easily locate the shell somewhat coaxially to the post. In the many frames I've had on the table I don't see any real life issues with the tiny amount of slop that a slip fit cap allows for.

I do agree with Paul on removing a frame and flipping it will bring up different measurements (not that Paul measured anything during his aligning work, he was using gages, not rulers and dial indicators). I also find the same drift of measurements happens when the frame is removed and replaced without flipping it. But a few thousandths of an inch of drift is a pretty much non issue, IMO.

I also agree with Mark on the tubes and shells not being perfect to begin with. I frequently see a tube's straightness change at the butt transitions and even straight gage tubes have some bow in their lengths.

Three quotes come to mind. "Show me a perfect person and I'll build a perfect frame for them" (A Eisentraut at the last VT building class in 1979), "What's a few thousandths between friends" (claimed to be the reply from the guy who did the sample run of a new component which would have changed front shifting as we knew it. The samples were so poor working that no manufacturer paid much attention), and "Just because you can measure a thousandth of an inch doesn't make it important" (me).

I use a pair of 5/16" thick steel plates when doing any heavy work in the vise. It looks to my eye that Paul's things are turned pucks with a step in their OD. The step fits loosely in the shell and makes moving the frame about in the vise jaws far easier then with my flat plates.

Here's a shot of my post. The bolt is a simple V thread 1/2x13tpi . Andy

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