Cylindrical square from a lathe tailstock.

[tonyfoale]

Microscope stand from an orange press, (2 buck flea market find) a PC plastic offcut and a HD disk.

Mine is from an old enlarger.

Homemade hand thread tapping machine.

[Frank S]

I linked to that video only because it showed the use of large gudgeon pins as cylindrical squares in response to Johan's posts. I could see that it was a tedious video and so I only skimmed through it at double speed with no sound on. Frank, you obviously studied it much closer than I.

Tony I've never claimed to be one of those ultraprecision machinist but in doing a lot of hydraulic piston pump and valve repairs there were a few tricks I had to try and teach myself. Be they the correct accepted norm or just a hack if I could take a multi thousand dollar assembly and bring it back to 100% serviceability while saving at a minimum of half the cost of replacement was what grew my customer base and brought repeat business

[Toolmaker51]

Tony I've never claimed to be one of those ultraprecision machinist but in doing a lot of hydraulic piston pump and valve repairs there were a few tricks I had to try and teach myself. Be they the correct accepted norm or just a hack if I could take a multi thousand dollar assembly and bring it back to 100% serviceability while saving at a minimum of half the cost of replacement was what grew my customer base and brought repeat business

Toolmaking is not restricted to "high precision" endeavors, nor jigs and fixtures. Often we replicate a single piece, originally a production item. It's more utilizing means at hand, producing objects satisfying required accuracy, durability and/ or quantity.

Visualize adding however many zeroes to right of decimal point, add cost to left side. And such costs do not guarantee profit.
Excess work = excess cost = less customers.

[tonyfoale]

I know very little. I am totally self trained in machining work and so I only know what I need to do what I want. My education was theoretical not practical.

[DIYSwede]

Totally coincidental, I stumbled across a 29 min video with a shop tour of Daryl Smith (Michigan CNC service guy, semi-retired).
He's also a confessed "Cylindrical Square Fetishist" and apparently a compulsory scraper,
as he hoards old tools, restores them to service to a high degree of precision and finish, and puts them on Craigslist (link in vid)...
The guy has paradoxically also a very pragmatic approach on acceptable tolerances which could be found offensive by some people.

Warning to sensitive persons: -As this video is just a shop tour, not a single frame of how-to machining is included,
which might be perceived as tedious by most, but perhaps a bit thought- and action-inspiring for the happy few of us easily entertained?
Not all of us are within physical or financial means of scoring at Craigslist, so we just have to grind our own to achievable tolerances.

Thus, you've been warned.

ATB
Johan

Ah, yes - a new, EMD 567 wrist pin is app 72 mm dia, 163 mm tall and micropolished to 2 µin RA.

[Frank S]

Totally coincidental, I stumbled across a 29 min video with a shop tour of Daryl Smith (Michigan CNC service guy, semi-retired).
He's also a confessed "Cylindrical Square Fetishist" and apparently a compulsory scraper,
as he hoards old tools, restores them to service to a high degree of precision and finish, and puts them on Craigslist (link in vid)...
The guy has paradoxically also a very pragmatic approach on acceptable tolerances which could be found offensive by some people.

Warning to sensitive persons: -As this video is just a shop tour, not a single frame of how-to machining is included,
which might be perceived as tedious by most, but perhaps a bit thought- and action-inspiring for the happy few of us easily entertained?
Not all of us are within physical or financial means of scoring at Craigslist, so we just have to grind our own to achievable tolerances.

Thus, you've been warned.

ATB
Johan

Ah, yes - a new, EMD 567 wrist pin is app 72 mm dia, 163 mm tall and micropolished to 2 µin RA.

Quite an interesting guy I would have loved to have known about that 16" rotary table he had for sale I used to have an ultra low profile 14" that cost me many, many times more than the price he was selling that one for

[Toolmaker51]

DIYSwede's insert on EMD 567 wrist pin illustrates good proportions [~72 mm Ø x ~163 OAL or 2.8" x 6.4] for a medium cylinder square, multiplied by near perfect microfinish. An unheralded benefit; it's hollow...via clamping utilized like a magnetic cylinder square.
Guiding search to similar pins, dimensions of EMD 567 are 8 1⁄2" (216mm), a stroke of 10" (254mm) for displacement of 567 cu in (9.29 L) per cylinder.

[DIYSwede]

Thanks, TM51.
For a bigger cylindrical square, you'ld have to go to the repair shipyards, perhaps finding a wrist pin from a Wärtsilä 64 or similar:


That beast cranks out just over 2 MW (@ 333 rpm) per cylinder, which has 640 mm bore and 900 mm stroke.


Guess that pin would land in the ~210 mm Ø x ~500 mm OAL range,
which is a tad too big a bite for my mini lathe, and would cover about 30% of my surface plate.

Illustrations above from:



915 informational pages on REALLY BIG DIESELS!
https://manualzz.com/doc/36457927/2-...--ross-revenge

Nice read to y'a all!

Johan

[Toolmaker51]

Dang it. Midwest not so bad for real estate, not so hot for shipyards . . .

[Frank S]

For a cylindrical square that is already very nearly +- .0000 in every dimension get your hands on box of new old stock racing solid lifters for a big block chevy Ford Chrysler they wont be the largest but at about .875 to 1" by 2.25" if you are checking something not very large you can't beat one of them an added plus is they are polished to mirror and the hardness will be off the books