Machinist Tips and Tricks

[Badot]

I just ran across this on Youtube -- yet another one of those simple and effective 'why didn't I think of this?' tricks.

http://www.youtube.com/watch?v=XcU0LTavzDM&feature=related

So I decided to start a thread dedicated to these types of things. I'll throw in a few to start. Not saying they're new or fancy, but just things I've found useful... I expect some good stuff from some of you guys



For not-too-deep internal threads on a lathed part, turn the speed way down, throw the tap in a chuck on the tailstock, and let the turning motion slide the tailstock in as it taps the hole. Reverse it out.

For external threads on a lathe put a die in a die stock and rest the handle on the carriage, then start it in nice and straight using the tailstock. Same concept as the last one.

 

[oldbikerarlo]

Great Idea

I would not power the lathe, a broken tap can get ugly. Take it out of gear and turn the chuck by hand. If you have to you can use the chuck key, or an adjustable wrench on one of the jaws to turn it.

If your careful you can do a key way on a drill press the same way.

 

[mckutzy]

Ill second Badot, on the lathe you can tap pretty good if you do it right.
What typically breaks a tap or gals threads is not enough lubrication. Having a constant stream of coolant at the tool helps the best. Where I used to work, we made a die holder for the tailstock, fits right on the ram and has a setscrew for it not to move. Crank the ram almost the way out, unlock talistock from the bed and allow it to float, keep the coolant flowing, set the back gears to the lowest gear, ease the tailstock to the work and and once the die catches, let it ride while keeping the coolant at the cutting edges.
I have done this with 1/2" rods and we only need 6" of threads as the tailstock was only going to allow that amount anyways, but it worked pretty nice. Did a bunch of them, they were 3' long and threaded on both sides.

 

[ghostdog]

Just use the lathe to reverse the tap / die. Plunge in by turning the chuck with your hands.

 

[r_chez_08]

I have done the keyway one multiple times. I got it working amazingly on aluminium, but on steel I found my tool flexed too much, creating a tapered keyway.

 

[mckutzy]

If the tool is flexing, use a bigger bar, or shorten the amount of stick out from the tool holder.