Mike BR

On the preview screen, that looked like "Thanks Chad. I am recovering well. Yeah, I could fabricate a new arm so that is something to consider in the future. . ." Sure glad I read the "prayers" thread first. And far gladder that things are looking up.

This is a complete shot in the dark, but a couple times now I've had something start acting up intermittently, and eventually traced it to failed solder joints on a PC board. (In both cases, the behavior changed when I flexed the board, so that might be a give away.)

The Summer 2025 Hammer's Blow includes a review of Homemade Padlock II and the Ancient Art of Forge Brazing by Thomas Boucher. The review has a short description of the process covered in the book, which includes a clay shroud and sounds like the same process you have in mind.

That top part of the case is only a cover. It easily could have broken and been replaced, or even accidentally switched with another blower in the same forge.

The parts need to be specially prepared so the that surfaces are flat to a molecular level -- and that's likely only possible if they're quite small. But it's ultimately the same principle as forge welding; if the molecules get close enough together, they join to form one piece. It can be done at low temperatures in space because there are no air molecules to get in the way, and no oxidation.

Both processes have their place. It’s a lot more efficient to forge a swivel hook and turn the shank true than to mill the whole thing out of a big block of steel. I love my little lathe — a little too much. I end up spending hours standing in front of it, when forging would be more fun.

Cold could cause condensation, corroding contacts.

Just in case the signal got lost in the noise, I was serious about Little Machine Shop. The little 7X10 lathes are pretty much identical between manufacturers, and the corresponding mills use the same electrical parts. (There are also some slightly larger machines that look like they might use a scaled-up version of the motor controls.) There are also very different drive systems, but if your mill has variable speed and a brushed motor, the troubleshooting guide on their website may well be helpful.

Can you push it back across the Rubicon? If you go to littlemachineshop and click on “Learning Center” at the top, there’s a link to “How to Guides” part way down on the right. On that page, there’s a link to an article called “Troubleshooting the Variable Speed Drive” that might be helpful. At least I promise it won’t be less helpful than my advice.

That’s a neat idea with the C-channel. The vice sure ain’t going to rotate, and King Kong could stand on the channel and tug on something in the vise without anything moving.

I actually have a horn with a (completely) circular cross section and wish I didn’t. I’m looking for a section on top that matches the inside radius of the ring I’m making. But since the horn is circular, the ring won’t fit on far enough to reach that part until it’s already perfectly round. It’s not terribly hard to work around that (sorry), but an oval cross section would let an imperfect ring clear the body of the horn while still reaching the needed radius on top.

For various reasons, I’ve made more stitch welded circles than forge welded ones. Either way, I pick a spot on the horn with the correct radius, heat the whole ring, and tap wherever there’s air in between. This is probably obvious, but once it’s welded, the radius can’t be too slack anywhere unless it’s too tight somewhere else. It may take a couple of passes, but once you’ve eliminated the tight spots, you have a perfect circle.

I agree. Just didn’t want to say “throw it in the forge” and find out you had the one vise out there with a spring thin enough to require hardening. (It would be possible to make one that way, and if it can be done, someone somewhere has probably done it.)

First of all, I'd open the vise wide and push on the front jaw. If you can push it closed with moderate (or even fairy heavy) force, it's probably the screw and not the spring that's causing the resistance. If it is the spring, I think I'd take it out of the vise and try to take some of the curve out cold on the anvil. (I'd also make sure the vise moves freely with the spring out; in theory the pivot could be binding. Of course, that shouldn't make the screw hard to unwind -- unless maybe someone reset the spring to make up for it.) If cold forging didn't work, heating the spring and straightening it some would be an option. It would probably work normalized, but conceivably you'd need to re-heat treat or work harden after forging.

How many things can a hammer do? I suppose you could make your own blades for hot cutting in a commercial shear. That would be a lot easier than making a shear, and you could set the factory blades aside for cold work.

I have to say, this looks tricky, given the configuration. But first, I’d try a test with a small mold and a couple pieces of copper to see what happens. The texture on the copper should mechanically lock it into the tin, so I wouldn’t use any flux. That would likely end up where you don’t want and cause what you’re trying to avoid. Jewelers use yellow ochre dissolved in water or alcohol as an “anti-flux.” That might be effective in preventing the tin from wetting the exposed copper, if you need it (there are also a number of commercial solder masks). Finally, you might look into silicone molds. Not sure how easy it would be to form one cleanly around the copper, but the silicone would probably keep the tin where you want it.

I've only fooled with Champion blowers, but they don't have oil seals on the shafts. If you overfilled one, most of it would end up in the fan housing fairly quickly. Speaking of which, given the mechanical advantage, excess drag on the fan shaft or fan itself would slow the blower a lot faster than anything else. So the first thing I'd check is that the fan spins freely. (Because the fan turns so much faster, it also holds most of the momentum when the blower is turning. I can't see a counterweight on the slow-turning handle -- or the lack of one -- making much difference.)

A few inches cut off one end would probably be the right size for the pan on a rivet-type coal forge. I've seen some made that way from water heaters.

If you've ever had an anvil throw the hammer back at you when you missed your work, you've experimentally verified that hard steel has better rebound. Whether it makes a difference how hard the anvil is under a piece of hot steel (assuming you hit the hot steel), I'm somewhat doubtful. H-13 is generally air hardening. I'm guessing it may be usable as-cast (or as-cast and tempered) for an anvil, saving the not-insignificant challenge of heat treating a couple of hundred pounds of water-hardening steel.

https://www.ecfr.gov/current/title-31/subtitle-B/chapter-I/part-82

Some clockmakers use flat burnishers on "pivots" (bearing journals). Much smaller than the one here, of course.

It is hard? If not, maybe someone slipped a couple of blanks into a gross so they could knock off early Friday afternoon. If not, the obvious answer seems like a burnisher -- but for what?

One other thought: before you straighten or replace the U-bolt, try to work out why it bent in the first place. If the legs are misaligned with the forces they see, a new or repaired bolt may bend back the same way pretty quickly. It's also possible that it won't fit in place with the legs straightened. (I can't be the only smith who's jammed something together any-which-way so I could finish a project, and never got around to redoing something that worked.)

If it came apart, you can probably get it back together like it is. But my first attempt at straightening something like that would probably be clamping it in a vise with aluminum inserts in the jaws. (In this case, you might need to heat the cross bar and twist the two legs of the U out of alignment to get it in the vise the right way.)

This (quasi) parallel has always grabbed me. Quench steel, and the carbon is trapped within the grains, distorting them and locking them together. Reheat to a few hundred degrees (temper) and some of the carbon precipitates out, ending up between the grains and doing, basically, nothing. Quench aluminum, and the copper (or other alloying metal) is trapped within the grains, doing, basically, nothing. Reheat to a few hundred degrees (age) and it precipitates out, ending up between the grains and locking them together.