The Home Machinist!

Lye is becoming progressively more difficult to find at the consumer level/in smaller quantities because every clandestine chemistry operation ever requires the stuff. Edit: Also, be VERY careful buying lye off sites like Ebay. It doesn't happen too often, but you can have the DEA knocking on your d...

I use three sizes: 1/2, 1/8, and 1/64. I also use some really big parallels, a 2" wide set, but that's probably not what you're looking for. The thick parallels (1/2 and up) are useful in other places besides a Kurt vice - the smaller ones, not so much. If I could only have one set of parallels...

Cold finished is put through a rolling line. Makes it more resistant to surface cracks, higher tensile strength, et cetera. It is also a bigger pain to machine; the stress rolled into the surface of the aluminum means the part's going to bow towards the cut as soon as you take any serious material o...

Just some pictures comparing ER-40 on a suitable machine taper versus an R8. http://photos-h.ak.fbcdn.net/hphotos-ak-snc1/hs112.snc1/4664_190865765082_692245082_7267111_454588_n.jpg The lineup. ER-40 collet and locknut, R8 collet, and CAT-50 collet chuck. http://photos-g.ak.fbcdn.net/hphotos-ak-snc1...

I know the issue is pretty much closed, but I use ER-40 at work. ER-40 is enormously rigid in what, in my opinion, it was sized for - a CAT-50 collet chuck and nothing smaller. In a CAT-50 chuck, there is very little overhang, and that's necessitated by the locknut that holds the ER collet in place....

My bet is an endmill for steel or cast iron. Stainless and aluminum enjoy higher rake/clearance angles (12-35 degrees), steel and cast iron less so (3-7 degrees). Multiple flutes don't help so much in aluminum, where you can maximize chip load and not break the tool. In steel, you may only be able t...

In my opinion, it's difficult to really get the full use out of a QCTP without having, at minimum, ~10 holders. Figure in a few boring/drill holders, cutoff tool, etc, in that number. We have around 6 per QCTP at school, and it's still annoying. Considering how mundane the turning is there, we could...

In Harold's example, he's measuring ground surfaces. .000050" repeatability is indeed a simple matter on a ground surface - the mic seats right down because the surfaces are flat and parallel. .0001 in most other things is because the surface ain't parallel. In my surface plate example, the par...

Personal responses because I've had this asked of me before. What if the person that calibrated the micrometers (at the standards lab) had a different "feel" than yours? "Feel" is really more about just that - feel - rather than pressure. When I am cranking a mic down on somethin...

I am perpetually confused why people want to discuss or even mention PM on the home shop forums. If you have been snubbed, and take offense, then don't go there? I'm not sure why this is controversial. PM is what it is by virtue of the discussions it doesn't participate in. Otherwise, it would be CN...

This is a very recently re-lapped surface plate. Note the matte finish as described above. Sorry they're not so great, these are cameraphone shots. http://photos-d.ak.fbcdn.net/photos-ak-sf2p/v646/171/100/692245082/n692245082_7078035_4479506.jpg http://photos-c.ak.fbcdn.net/photos-ak-sf2p/v646/171/1...

I know some people like pictures of machines, which is the only reason I'm posting. Sorry for the identical cross-post across forums, but some folks are on one forum but not the other who may like this. http://photos-e.ak.fbcdn.net/hphotos-ak-snc1/hs007.snc1/4173_181564875082_692245082_7057180_76375...