SmoothBore

Perhaps I failed to adequately communicate, ... in a thorough, and concise fashion, ... or made erroneous assumptions about the frame of reference of the readers. A wire EDM is perfectly capable of burning multiple holes in the "core" of a broken tap, ... effectively destroying it's structural integrity, ... and allowing you to easily shatter, and pick out the bits and pieces of broken tap, ... without inflicting further damage to the surrounding part. Certainly a "sinker" EDM, ... or "tap burner", ... is a good choice as well, ... but it's not nearly as quick, or inexpensive, as a wire electrode. .

Based on the drawing, the "Autogen" device, and the magnetic starter for the motor, are both "hot" from the power supply. The only thing actually being switched, is the auxiliary 3 phase motor. If that is actually the case, then you want to pick up your "control" circuit, off one of the switched legs, feeding the auxiliary motor. .

If you've ever broken off a tap, in an expensive, or irreplaceable part, you NEED to have a relationship with your local EDM shop. .

Concur. MSC will sell you any quantity, at as good a price as you will find anywhere.

The most common example of a "Collimator", is the device used to "bore sight" a rifle scope. Basically, it projects, ... or focuses, ... a parallax free "point-in-space". They are also used to adjust the prisms in binoculars, so that both sides of the binocular are focused on the same point. .

A company called "DAREX" makes a line of excellent drill grinders, and sharpeners. Using CBN "diamond" wheels, they will make any drill, up to 1", sharp enough to cut yourself. They are however, ... pretty pricey. Around $1,500 bucks. .

Over the past 40 years, many, many "treasure hunts" for strayed parts, has made me exceedingly "anal" about keeping the little bits and pieces under control. I find that the clear, plastic Peanut butter jars are very useful. They don't break, ... they have a wide mouth, ... you can see what's inside, ... and they're free. Needless to say, there are probably 50 of them scattered around the shop. .

Concur. As soon as I saw them, I said to myself "Those are wrought !" Quite a find. .

A "Corn Shuck" torch is easily fashioned from #6 ( or heavier ) wire, ... or 1/4" round, ... or square bar. 3 or 4 loosely spaced coils, ( like a coil spring ) wrapped around a piece of 1 1/2" pipe, will form the "Shuck Holder" portion, ... and then you can use your imagination for the rest of the "handle" part. Recycled candles, scrounged from yard sales, and melted down in a tin can, are good for impregnating the Corn Shucks with wax. 2 or 3 wax impregnated Corn Shucks, "screwed" down into the spiral wire "Shuck Holder", will burn for several hours. Use enough impregnated Corn Shucks, so that they fit fairly snug in the Shuck Holder, and they will last a lot longer than if they fit too loose. .

Well, ... it might offend some sensibilities ..... But if I wanted to make a "forged" mortar, ... I'd start with an appropriate diameter slug, of Stainless Steel round bar. ... and rough the cavity out, on a lathe. Then I'd forge the final shape. But that's just me ..... .

Assuming that one of the drawings of the symbol is more or less correct .................. I would use a pipe of the required diameter, and about 2 or 3 inches long, to make the circle part, ... and a close fitting piece of round bar, about 6 inches long, to make the rest of the punch. Let's assume that you use a 3" length of 1 1/2" pipe, in order to get a circle of about 2" O.D. ... with roughly 3/16" wall thickness. That will leave you with an I.D. of roughly 1 5/8". Now, ... on the end of a piece of 1 1/2" diameter round bar, about 6" long, ... draw the triangle part of the design. It looks like 3 straight hacksaw cuts, about 1/4" deep, will define the "large" triangle. Grind away the 3 "shoulders", . at about a 45 degree angle, and you'll have a "male" triangle. Now, ... 3 more straight hacksaw cuts, across the raised triangle, will create the desired image. If the center triangle is to be a depression, ... punch the center of the "center" triangle, and drill it out, about 3/8" deep, ... to a diameter that removes most of the "center" triangle. With the bulk of the material removed, you can chisel, or grind out the remaining "corners" of the center triangle. A few spots of weld spaced around the round bar, about 1" back from the "face" of the punch, ... and again at about 2 1/2" from the face, should serve to take up the gap between the O.D. of the bar, ... and the I.D. of the pipe. You can grind the welds until the bar fits snugly into the pipe. Now, ... just sit the pile on end, on a flat surface, and put the bar inside the pipe, with the triangle shaped face down, on the flat surface, too. Weld the top edge of the pipe, to the round bar, ... and you're done. Good Luck.

Automotive engine valves are FORGED from Stainless alloys, ... but often have hard surface weld applied to the seat area, and a chrome-moly wafer welded to the tip, as a wear surface. Sodium filled valve stems are sometimes used in Marine engines, ... and high performance engines, that are subjected to sustained, high temperature, high rpm operation. They are waaaay too expensive for use in stock, production engines. .

AutoCAD is my most useful "power" tool. ( I like to know exactly where I'm going, before I start. ) And the ability to "play" with scale and proportion, ... without having constantly regenerate a drawing, ... is a huge time saver. .

I assume you mean "Gear Oil" rather than "Automatic" Transmission Fluid. That being the case, ... Yes, a "heavy" ( #140 ) Gear Oil would be a good choice, ... and coat everything with a graphite paste, like "Never-Seize" when you re-assemble.

During the Viet Nam era, the local AMF plant ran a "bomb line", where they built bomb casings. AMF employees carried lots of "scrap" casings home, ... and used them for all sorts of things. The front half of the bomb casings were about 8" diameter, 2' long, and taper to a point. Like I said, ... it's not a perfect "floor cone", ... but it works well enough, for the few times a year that I use it. I still occasionally see them around the area, where someone has used them for some decorative purpose.

I've been using the front half of a bomb casing. It's not perfect, ... but it serves the purpose.

Sounds like a job for a Die Filer.

I think, in this case, "cast" iron is too general a term. If the replacement part is cast from "grey" iron, it's crystalline structure will prevent it from bending. But, ... if it's cast from "malleable" iron, ... well then, ... it's malleable, ... and therefore CAN be heated and bent. ( Malleable Iron is basically Grey Iron that's undergone an annealing process, to remove some of the carbon. ) It's difficult to tell the difference between cast and malleable iron, without destroying the piece in the process. But, if the part has an area that could sustain some minor damage, without ruining it, ... you might try hammering it, to see if it breaks, ... or bends. You might also try to "spark test" the material, and compare it to a piece of malleable iron, in that fashion. ( A forged pipe fitting is a readily available source, for a sample of malleable iron. )

I would think a power pipe threader might put out sufficient torque, at a very manageable speed. A simple, easy to make, "square to round" adapter, can be made by splitting a piece of round bar lengthwise, and then milling a "V" groove in each half. This will allow you to chuck the square stock in the 3 jaw pipe threader, ... and one adapter could easily accommodate several sizes of square stock. Welding a lug on the O. D. of one half of the adapter, will give you a positive drive "dog", ... so that you don't have to worry about the adapter slipping in the chuck. ( Obviously, this would work with a 4 jaw, as well. ) Slipping a loose fitting length of pipe over the square stock, before twisting, should help to keep it straight. A vise might work better than a "tailstock", to hold the static end of the bar.

Yeah, ... a Gate or Damper type valve would be a simple, effective solution, ... but on this unit, the blower bolts directly to the tuyere. Still, it wouldn't be a big problem to introduce a sliding Gate between the blower and the tuyere. I'll surely give that idea some more thought.

Thanks for the info. At this point, the resurrection of this old Forge, will most likely be a "Winter" project. It's currently disassembled, and resting upside down, on a pallet, ... but as soon as I get it back together, pictures will be forthcoming. In a very general sense, is it safe to say that a "variable speed", or "multi-speed" blower motor, is the most desirable way to deal with the Blower Volume issue ?

Many years ago, ... in one of the "Foxfire" publications, ... I read a very complete description of the "Cow Bell" process, using material from steel drums. ( barrels ) There was info on tempering and tuning, as well as the "nuts & bolts" of shaping the bell. I'm sure a "Google" search of "Foxfire Cow Bell" would locate the article.

I've just acquired a coal forge, with a blower that was originally made to operate off a line shaft. The problem is, ... that I have no clue what speed the line shaft operated at, ... or what RPM range, the blower requires. I have NO EXPERIENCE with coal forges, and wouldn't know a properly aspirated coal fire, if it was burning my backside. ANY information about blower requirements, ... or performance, ... would be helpful in flattening out the learning curve, and save me a lot of trial and error.