3D Print posted by tomii
20th scale 3d model of a Burke pumpjack
History: When I was a kid, we were pretty poor. The whole "white trailer trash" thing. But we weren't trash, I guess. We *did* live in a trailer outside of town.
Anyway, the family owned a machine shop. My grandpa, my uncle, and my dad. My grandpa and uncle kinda took their cut off the top of revenues every pay period. My dad, though, made sure all his people were paid before he was. That meant he (we) sometimes went without getting paid for a few weeks.
Then, the oil embargo of the late 1970's happened. Oil exploration went through the roof (along with interest rates and the cost of living). My family started manufacturing and selling these pumpjacks. They were well made, and very reasonably priced (there is at least one still running today, over 30 years later, somewhere in S. Indiana). Selling these things got us to the lower middle class, I suppose. We actually bought a house and moved into town when I was 13 or so.
Back to the story - My dad tried to convince the rest of the family that we should get out of the pumpjack business, as he had friends in the oil business and knew things were afoot.
Unfortunately, he was the "baby" of the family (about the only one with any sense, IMHO), so there was *NO* way he could possibly know anything, right?
Churchill came out with a "disposable" unit for a *much* lower price. The machine shop went bankrupt practically overnight. A biog loss for us, but my dad managed to find work, and since he didn't have to take care of a bunch of employees first, we actually were a bit better off.
I spent a lot of time in that machine shop, and have plenty of memories from there. I still love the smell of machine oil and welding.
Anyway, these pumpjacks led us to a better life. It's only fitting that I've made a couple at 1/20th scale for gifts to myself and my mom.
I still have some of the original brochures and a photo album full of pics. I modeled it all up, and I have printed a couple on my ultimaker 2+.
gcode files (at GrabCad) are for an Ultimaker 2+ 3D printer (ABS).
Part files are SolidWorks 2016.
The bearings and shafts are from servocity.com (where I got 3d Models for them):
Flanged bearing: PN 535036
1in shaft: PN 634114
2in shaft: PN 634116
The motor model is one I put together from datasheet for another project (also on GrabCad). It has no internals, just the shell.
In the built-up model, I use O-rings for the internal pulleys. I don't have a part number, but they are about 1/16" x ~1"
The internal "gear ratio" is about 11:1 - that is, 11 turns on the input pulley results in one full cycle of the horse's back.
I'm working on a motor mount for it - I might add files for that and maybe a video if I ever get around to making it work.