Update to "Replacing the Arbor Bearings in a Delta Homecraft 8² Table Saw"

Nice job.

You could turn your pin remover into a handy toolmaker's clamp like the Starrett #160 until you need to press out another pin.

A small vise like that is useful to mill accurate angles by clamping it in the mill vise on an angle block, or to cut small pieces in a bandsaw. The I-beam shaped spacer on the Starrett snaps onto a ball on the end of the screw and pivots to fit work that isn't square.

-jsw

Thanks.

The roll pin removal tool is far smaller, being 2" by 3/4 by 3/8", and the fixed jaw is not flat. This is pretty much a one-purpose tool. Wasn't so hard to make.

I didn't realize that those little toolmaker's clamps had an articulated connection to the screw. I have always achieved the same thing using a spherical washer (male+female) pair between moving jaw and the workpiece.

Joe Gwinn

This #160 is ~3" long by 3/4" wide by 1" high. (wooden ruler)

The hole in the spacer has a wire spring ring in a groove. The end of the screw isn't really a ball, but a short cylinder rounded down on its ends and a conical end similar to a drill bit.

I think they added the spacer because a long unsupported clamp screw will slide and bend against a sloping surface.

-jsw

Yeah. Far too wide - would not fit.

And expensive, for that matter. I would hazard that most machinists made their own little clamps.

The catalog description talks of _slight_ (but unspecified) deviations from square.

Given that the deviation is "slight", the screw isn't going to be permanently deformed. If that were the danger, making the screw thicker is the most direct remedy. Stiffness varies as the cube of diameter, so the increase in diameter needn't be large.

Joe Gwinn

I didn't mean you should buy and hack up a genuine #160, but that your tool could serve the same purpose if you milled the fixed jaw flat and square to the base for a short distance above and below the vee groove.

I make a fair number of small parts for repairs, such as Variac brushes, and it's useful to be able to remove and inspect them and then put them back exactly. Sometimes a small insert vise holding the part locates against the milling vise stops more repeatably than the irregularly-shaped part itself.

If I'd had to account for my time playing a machinist they would have cost me more than $100 to make.

Yesterday I faced the roll pin problem on a neighbor's snow blower. The two 1/4" pins holding the impeller (centrifugal fan) to its shaft sheared. They are just barely visible through the discharge opening. I drove them out with 3/16" x 3' welding rod with a 1/8" centering pilot turned on the end, then drove in the new ones with stiffer 1/4" rod with a pilot.

-jsw

[snip]

I didn't think you were proposing machining a #160 (and the case hardening would hinder such a project).

I certainly can make a small flat-jaw toolmaker's vise, if the need arises.

For something like the replacement of the carbon in variac brushes, if I were in that business, I would certainly fabricate special tooling.

A friend of mine was making electric guitars, and my biggest contribution to that effort was to figure out how the tooling should work. The key is that there isn't time for careful measurement, so there must be jigs and fixtures so things come out right nonetheless, or it's impossible to make a profit.

The other thing I did was to teach his team how to solder, so they could make their own wiring harnesses, and avoid being gouged.

I'm glad that they sheared, versus the shaft et al being mangled. Roll pins are very strong. But, was there a shear bolt there originally? I'd be tempted to replace the roll pins with a Grade 5 bolt and a cone lock nut (all-metal lock nut - ). Cone lock nuts are available in larger hardware stores. I'd also keep a bunch of extras on hand.

Joe Gwinn

AFAIK the roll pins were original. He calls me to fix anything mechanical and I hadn't touched them before. He got the correct replacement 'spring' pins from Sears.