I made all the pins and bushings for my GT loader on a worn out 1898 Hendey lathe, converted from flat belt drive. Missing a bunch of gears, but it doesn't take much to make pins and bushings, they are all simple straight cuts, maybe a little drilling, boring, and facing off. Break the edges with a file. Don't even need to learn to use a cut-off tool if you don't want to, just saw it off with enough room to clean it up after. Surface finish can be horrible, it's just going to get welded into something else anyway. Learned to use it as I went. Bought it from a cranberry farmer...who used it to turn pins and bushings.
You aren't even doing fancy stuff like making sure surfaces are concentric and all that, you're just making tubes that will fit in hole sawed holes and accept a pin, and maybe drilling pins for zerks if there won't be a good place in the bushing to put one.
There were a couple places I forgot to put zerks when building, I found out the hard way and had the pins gall. Got them pressed out of the machine with a porta-power, reamed the tubes and polished the pins to clean them up again, drilled the side of the bushing, threaded 1/4 NF and added zerk, slapped it all back together, greased it right and proper and away we go.
Some of my pins are cold rolled, some hot rolled, some are 12L14, some are grade 5 bolts. For as little use as they get on a homeowner machine, they don't show much wear at all.
I follow a couple of excavator type guys on youtube, and every so often they will replace pins and bushings on their machines. What I have noticed is that a factory "tight" spec for them is what I would call a very loose running fit. Like 10 thou play or more, there is audible rattle on their machines even with "new" bushings. With grease, they still last a long time under heavy use.
So my take-away from that is that aim for a loose to merely snug fit. A too tight fit can cause problems. None of this is rocket surgery.
