Lathe - Drill and Tap

You are required to square the end of a 1" diameter mild steel shaft on the lathe, and drill and tap a 1/2 - 13 UNC thread 3/4" deep, with 1/4" thread clearance. Install the stock in the lathe, and choose the next step: [[Center Drill]] [[Drill]] [[Face the Part]] [[Tap]] [[Countersink]]

Not quite ready for this yet... please go [[Back|Start]]

Whoops, not ready for this step yet. Please go [[Back|Start]]

Excellent! At what RPM will you set the lathe? (CS = 80 ft/min) [[200]] [[320]] [[640]]

Definitely not ready for this yet, please go [[Back|Start]] and look again.

Sorry, can't countersink if there isn't a hole...Please go [[Back|Start]]

It's going to take too long at this speed, please go [[Back|Face the Part]] and select another. Try the calculation.

That is the correct speed, you have now faced the part. What's next? [[Center Drill|YY]] [[Drill|NN]] [[Tap|NN]] [[Countersink|NN]]

Whoa, that's too fast! You risk damaging the work and the tool. Please go [[Back|Face the Part]] and recalculate the RPM.

Excellent, the speed choices on the lathe are: [[200|no C drill]] [[320|no C drill]] [[640|no C drill]] [[900|YYY]] Which will you choose for the center drill?

Nope, please go [[Back|320]]

That's not the best speed choice for the center drill... c'mon. [[Back|YY]]

900 RPM, good choice. What's next? [[Drill|YYYY]] [[Tap|NNN]] [[Countersink|NNN]]

Sorry, [[Back|YYY]]

Yes, it's time to drill. Select the best RPM. [[200|no drill]] [[320|no drill]] [[640|YYYYY]] [[900|no drill]]

That's not a good speed for this drill. [[Back|YYYY]]

Good choice for speed! Now what? [[Tap|NNNN]] [[Countersink|YYYYYY]]

Well, you could tap at this stage, but if you countersink first, there is less liklihood of a burr on the thread. [[Back|YYYYY]]

Excellent choice! At what RPM would you run the countersink? [[200|YYYYYYY]] [[320|no CSK]] [[640|no CSK]] [[900|no CSK]]

That's the best choice. Even 200 RPM is faster than preferred for a countersink, but it's as slow as the machine will go. Tap the hole, and you're done! ''Great work''

Nope, that's too fast... way too fast! [[Back|YYYYYY]]