South Bend 9A Tailstock Critique

Still, using a level to get a long surface flat and parallel is fraught with opportunities to accumulate errors, and so requires other ways to help with validating the results.
You are right, of course, and surely the main "other" way is to have available a wide enough 36", or better still, 42" straight edge!

I do have a Chesterman No. 88R "Rustless", which is 36" long, 2" wide, ground steel straight edge with a "hang it up" hole in one end. It is only 0.0416" thick, so probably started out as 1/16" or maybe 3/64". Another, more sturdy type, is 24" long, and 1/8" thick, with one edge bevelled down to 1.32". I think these are the sort of thing mechanics use across an engine block.

They can be put up against a long surface, and probed with feeler gauges, though the longer one is too "floppy" for that game to be practical without a whole lot of trouble. Not the sort of thing you can use to "take a print" like the "lookcreations" dude does it on YouTube. Did I mention that I have nothing that "scrapes"?

I have to think this through, get up a better plan, and consider raiding my "machine stuff slush fund", a sort of home version of "skunkworks".
 
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Is it a crazy idea to sacrifice an old aluminium beam-type builder's level, put some release agent onto a granite surface plate, lay on some carbon fibre strips between a couple of wood or MDF side stops, and place the old level on top to bond to it?

After the cure, trim off the excess, and you have an exact replica of the plate surface!

Yeah - I know, the carbon/resin combo has a different thermal expansion coefficient to aluminium. :(
 
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The usual tool that is used is a camel back straightedge, made of cast iron and scraped in using a certified accurate reference surface to high tolerances. They are available, not exactly cheap, and do the job well. The skills to use the straightedge properly and then scrape in the lathe bed need to be learned, and are best learned from a good teacher, like Richard King, who happens to have a vendor account on H-M. It takes time to learn the skills well enough to do good work.
 
The usual tool that is used is a camel back straightedge, made of cast iron and scraped in using a certified accurate reference surface to high tolerances.
Indeed. I see them on eBay. You are right about not exactly cheap!
--> eBay LINK to 36" Camelback
Translating exchange rate, that is $359.89 plus $26.17 postage - so $386.
There is no maker's mark, no certificate, and "some scraping marks visible".
It would have to visit a granite surface for a check before one could trust it.

I have a pal who may be able to arrange one I may borrow. While I put together everything I need for the more tricky stuff, there are still lots of things to be fixed up that do not need anything special.
 
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