Recent content by cds4byu

A post from 2018 lists this email for Bob: [email protected] There is also a user on this thread: 1/6 P&W R-985 Wasp Jr by Bob Roach / Vernal Engineering that has a set of drawings. If Bob has passed and the drawings are no longer commercially available, you might be able to get a copy...

My boring head has 3 gib screws. I have them adjusted relatively tight, and I use the center gib screw for locking. So I loosen the center gib screw, adjust the screw, and then tighten the center gib screw to lock it. Doesn't take much time, doesn't mess with the gib adjustment, and holds...

Here's a set at manually-machinable chessmen from Popular Science December 1968. Carl

That's a lucky 12 year old. Nice starter setup. Carl

I know a guy who has a company that makes custom babbit bearings. I don't know how much he charges or if they would work for your tractor. I can give you contact information if you'd like. Carl

I have no personal experience with their machines, but FoxAlien seems to have some good cnc capabilities at reasonable prices. Here is one of their more expensive systems: https://www.foxalien.com/collections/cnc-router/products/cnc-router-machine-vasto-with-20w-laser-bundle-kit It comes with...

Have you got a copy of this manual? https://manuals.harborfreight.com/manuals/44000-44999/44859.pdf

There are two different shrinkages discussed in this thread. Solidification shrinkage is the volume change on solidification. It leads to shrinkage porosity in the case metal. The purpose of risers is to make the last solidification happen in the riser so that the shrinkage porosity is in the...

You can also use nitric acid to remove taps from aluminum.

K2, do you have a reference for this data? I've never heard of a metal having compressive strength that is 20% of the tensile strength. Metals (especially ductile metals like copper) have nearly equal tensile and compressive strengths, in my experience. I'd like to learn more about thjis...

Actually, the 9/16 diameter hole probably doesn't have a 9/16 diameter (as measured with a true cylindrical go/no-go gage). So instead of putting a diameter, I usually just say to drill with 9/16 drill (or whichever size I prefer -- 9/16 is too small for a clearance hole on a 9/16 bolt). Carl

And if you don't specify the temperature, you don't have a prayer of having a 240" part to even within .010, let alone .0001. Carl

I had a student this year put a clearance hole for a 7/16 inch bolt at 0.40 inches. Oops! Carl

Another 2D Cad product that is free is QCAD. It's a German prouct Carl

Hardwood or micarta. Possibly corian.. Carl