zombieresponder

Lot easier to resharpen that lathe bit than a dovetail cutter too.

You might be onto something there. They just might fit some of the small cultivator points I've seen.

Not complicated....you'd very likely set the vise at an angle(or the part at an angle in the vise) if you were to cut a tapered dovetail on a mill...why wouldn't you do the same on a shaper? <===machinist

Picked these up at a scrapyard, haven't managed to find a picture of anything like them.

Thanks for the input fellas. It's the time of year that has me concerned about finding lump charcoal. It's usually available during spring and summer when everyone is grilling, but I don't recall seeing it any other time. I'm going to look, just for grins, but even if I don't find any it won't be a problem. I found a place an hour or so away that has coal. Gotta check their hours to see if I can make it down there on a Saturday morning.

The last bridgeport I worked on(repair, not machining) had a "made in singapore" sticker hidden behind the head. Never would have known it was there if I hadn't had to pull the head off to repair it. I thought the wells index I ran was a better machine than a bridgeport....it seemed heavier built and more rigid. I didn't mean for it to read as though I advised against buying a bridgeport, just that the name shouldn't be the main criteria in selecting a mill. Bench top mill = drill press with "repeatable" x/y, and very rarely, z axes. I would find an industrial radial arm drill and a good x/y table to use long before I'd ever consider a bench top mill.

The first part is sort of correct. There are no SAE thread pitches that coincide with metric. A couple are very close, but not close enough to match. The second part is correct. Usually one or more gears can be changed to allow the machine to cut metric threads. You should be able to find that information in the manual for the machine, although it's also sometimes on the inside of the cover on the side of the headstock. It's possible that you could find generic gears(or gear blanks) with all of the correct specs except maybe a little boring/keyway cutting or facing the gear to the correct thickness.

I have run quite a few bridgeports, along with a few other brands. It's easy to just say "buy a bridgeport", but many are well used and may not be worth the investment. A toolmaker I used to work with had a profitable machining business on the side, and he used JET machines. He did say they didn't have the longevity of bridgeports, but otherwise they were a good enough machine. Most of the bridgeport knockoffs I've run were used hard before I touched them, so I can't comment on how well they held up....about all I can say is that they were still capable of making good parts if a person knew how to work around the limitations/quirks. I don't think replacement parts were easily available, if at all, for some of them. The bridgeports aren't a problem to find parts for, unless perhaps you stumble upon a very old machine or an oddball. I recommend you find an old machinist or toolmaker to look over whatever machine you're considering before you hand over any money. Anyone that's spent 8+ hours a day making parts on one for a living is going to know pretty quick if the machine is used up, or just used. As an example, the owner may tighten up the gibs to try to hide wear. That sort of thing is readily uncovered by cranking the axes to their extreme limits. Typically most of the wear will be in the center of the travels, so it will be easy to crank there and then become more difficult as you near the ends of the travel. If it's really loose in the middle and tight on the ends, you might even it out by just replacing the gibs....but it could also(and probably does) have a fair bit of wear on the ways, and that is only correctable by rescraping the ways. Since I'm already commenting on this, I'm going to add that you should be protecting your machine tools from dust and grit, especially grinding dust. The ways will last much longer if kept clean and properly oiled(engine oil is not way lube).

Howdy all. My nephew has been watching the forged in fire series and wants to try his hand at forging a knife with his grandfather. They were going to try it on a charcoal grill, but I have an extra(no sentimental attachment) riveter's forge pan and a couple of other things I'm going to loan them instead. I'm thinking that they will either need lump charcoal or wood for fuel, and not the briquettes I believe they were planning on using. Am I correct, or would briquettes work as well? I've got no experience, thus my question. I can also supply them with wood if needed, but lump charcoal may be difficult to find. I don't know of any place around to get coal...the last fellows I talked to said they ordered theirs. Thanks in advance, and I'm going to direct them here to the forum as well.

Most 4140 will be in the normalized state...that is to say that it's not hardened. Some of it comes pre heat treated though, which we use pretty often at work. Usually only 28-32 HRC, so it's still relatively easy to machine.

Too much heat for too long while exposed to oxygen. Seen a few parts come out of the heat treat ovens like that when the stainless foil had a hole in it.

Tempering 4140 at 350F doesn't accomplish anything other than some slight stress relief....if it's held at temp long enough(2 hours per my Crucible books and every other source I've checked). Tempering at 450 will only knock maybe a point or two of rockwell C hardness off. Water is fine to use as a quench liquid for thicker sections of 4140. I would definitely add some dish soap to the water though, to keep it from boiling away from the steel surface as quickly. I can only recall doing heat treat/tempering on 4140 once....all other heat treating I've done has been on tool steels(A2/D2/H13/etc.). If you are unsure about the taper, then verify that two sides are parallel. Clamp those sides in the vise, then use an indicator(dial test type) on the dovetailed surface to determine the amount of taper(if any) from end to end. Then repeat on the other side. Your machinist brother should understand what I'm getting at. The other way to measure external dovetails is with two pieces of round stock. I've seen people use drills(same size), but precision ground shaft or drill blanks are much better. Put the round stock in the "v" on each side and measure over it. A little bit of right angle trig will give you the actual measurements with this method. The same method works in reverse for measuring internal dovetails, though it's easier to use an adjustable parallel and then measure the parallel after removing it. Cock the mill head over for one angle and shim it in the vise to achieve the second angle(if required). I'd use a sine bar + indicator to set the mill head and an accurate protractor to set the angle in the vise.

That block with the leaf spring at the bottom right of the second picture looks a lot like an underbucking tool for a cross cut saw. Not certain of it since I've only seen poor pictures of them though.

I've got a pile of inserted carbide drills, some of them brand new, that I picked up at a scrap yard a few weeks ago. There were a couple tons of morse taper shank drills, spade drills, and HSS spade inserts there as well. Found some inserted threadmills at a garage sale a couple weeks ago too. Sold the threadmills to my boss. Need to clean the other stuff up + some cat 50 holders and put it on craigslist. Anyone need any cat 45 pull studs? LOL.

Get rid of the loose rust and then use clearcoat, as was suggested earlier.

I have never seen a Dormer set of drills, or any other industrial/machinist brand. All of the sets I've seen, including in machinist tool catalogs, have been off brands, and overpriced. Drilling pilot holes isn't a bad idea, though it's typically best to use a drill that's the same size as the web of the drill. That said, if your larger drills are split point and properly sharpened they will go right through with much less effort than you might expect. I've seen right hand twist drills from reputable brands that were factory sharpened with left hand cutting points. I've also seen the flutes straighten out due to improper heat treatment.

About $40. The blower isn't turning at all right now. I'm guessing it was left outside for quite a while from the moss on it. I'll have to make some legs for it after I get it freed up. Shouldn't be a problem since I have another one with the original legs on it to use as a pattern.

I have a nice Hay Budden that belonged to my great grandfather. Since this was in the yard, I figured there might be more. It still might be there and I just didn't see it because of all the other junk piled up. Hate to think someone is using a good anvil as yard art.

Picked this up at the scrapyard this morning. I don't know what the cross peens weigh, maybe a 3 and a 6, but the sledge heads are 12 pounders. Unfortunately, didn't find any more hammers or an anvil.

I am a machinist by trade, just so you have some background. Drill bit "sets" are a waste of money. All of them I have ever looked at are overpriced for what you get. The comments from others about buying them from an industrial or machinist supply house are right on, and you'll probably spend less or about the same as going to the hardware store and buying a single drill. If you're drilling hardened steel(above say 45 HRC), then your only real options are carbide or EDM. If you're drilling something like PHT4140, which is around 30HRC, then I would suggest a cobalt alloy drill with a 135 degree(most drills are 118 degree) split point. For anything else, standard 118 degree HSS drills will work just fine. Just don't buy them at big box stores or the ones made in china. I don't ever recall using any Presto brand drills, but Dormer makes good stuff as do many others. The chinese drills generally have poor heat treating and are either way too hard and chip/break or are too soft to hold an edge.

If you want to make such a fixture(quick and dirty way from a machinist): Weld(arc) a small strip of square stock to a plate. Find a couple of bolts that will fit through your punched holes. Then weld a thicker piece of square stock to the same plate, spaced to allow the bolt heads to slide between it and the first piece. Weld a couple more pieces of square stock to the second piece to form a t slot that captures the bolt heads and still allows them to slide. Then locate and weld on your round stock to bend around.

Why would I "stock up" when I have the keys and the alarm code? If I need to make something, I go do it.

Just an FYI from a machinist with a minor bit of experience in tool and die: H13 is a hot work tool steel alloy typically used in something like injection mold cavities. S7 is a shock/impact resistant tool steel alloy typically used in something like blanking or forming dies. The letter designation preceding the number in some AISI-SAE designations for tool steel is a guide as to what the alloy is for. H = hot work, S = shock resistant. H13 is easily machined...S7 is more like trying to cut rubber with a landscaping timber. With other alloys, the AISI-SAE letter designation indicates the method of quench. A2 for example requires an air quench, while O6 needs an oil quench. I happened to find this by chance: http://www.alro.com/datacatalog/014-toolsteel.pdf

Just about any steel can be at least surface hardened/case hardened. Here's a product to do just that. http://www.mscdirect.com/product/details/77470417 I also found some links to topics about making your own version of it. There are also pre heat treated steels available. We work with PHT 4140 regularly at work, though at 28-32 HRC, it's probably not hard enough for an anvil.

I'm a machinist by trade. I'd much rather use a clean up die like this one http://www.amazon.com/Right-Hand-Thread-Die-TPI/dp/B008ASBBRU than mess with a thread file. Unfortunately, that one is plain carbon steel and will be more prone to chipped or broken teeth than a high speed steel version.