annoying taps break when making endholes

[GreenFlagMan]

My friend (and I) trying to make 3/8 - 16 endholes, 1.5" deep in the shaft on a lathe. We're having a lot of taps break, which is a pain. So, we're thinking about using a treadmill instead, thinking that it might be less likely to break.
The problem is that the rods stick out from the lathe's jaws around 6-8 inches or more, and might cause the rods to chatter while we're trying to cut the threads. Tell me how to deal with this guys!

 

[_HumbleJeff]

My friend (and I) trying to make 3/8 - 16 endholes, 1.5" deep in the shaft on a lathe. We're having a lot of taps break, which is a pain. So, we're thinking about using a treadmill instead, thinking that it might be less likely to break.
The problem is that the rods stick out from the lathe's jaws around 6-8 inches or more, and might cause the rods to chatter while we're trying to cut the threads. Tell me how to deal with this guys!

According to thread cutting tool specifications, tap breakage is frequently caused by improper alignment or applying too much pressure. Rod chatter could worsen alignment, so stabilizing the shaft with a steady rest or center support can help reduce vibration. Have you tried using spiral-point taps or cutting fluid to make threading smoother and prevent breakage? Let me know how it goes.

 

[InfinityandBeyond]

Chatter might probably be the issue, try using a tailstock to support the end of the rod if you aren't already. Also, dial in your speed and feed rates, and use lubricant to reduce friction or even consider a tapping head, might help too if you're looking for more precision.

 

[autumnleaves]

My friend (and I) trying to make 3/8 - 16 endholes, 1.5" deep in the shaft on a lathe. We're having a lot of taps break, which is a pain. So, we're thinking about using a treadmill instead, thinking that it might be less likely to break.
The problem is that the rods stick out from the lathe's jaws around 6-8 inches or more, and might cause the rods to chatter while we're trying to cut the threads. Tell me how to deal with this guys!

Must have been fun doing it with a friend. Lately CNC hasn't been that much fulfilling to me. Probably uninspired or something. Anyway totally agree with @InfinityandBeyond of course use lube. Taps usually break if there are chips building up and there's bad alignment or too much torque. Don't blame the machine hahaha. Peck tap to clear chips for the deep holes and then also try a spiral flute top for the blind holes

 

[MaiTai1]

support the rod, 6 to 8 inches is way too much overhang. Also, you might wanna break chips after a few turns to clean the debris which is another reason why the taps could break. Let us know if this works

 

[weldmetenderly]

the rod is too long leave it hanging like that. Either shorten it or use holder to keep it steady and reduce chatter

 

[CutsBothWays]

Man, my dad (and me) have been there. Deep holes + overhang = bad day. You'll want to grab a spiral flute tap and some good lube.Then, just drill a bit deeper for better chip clearance.Don't forget to use a live centre or steady rest on that rod. Trust me, that chatter can ruin your taps consistenlty

 

[cuts&circuits]

Man, my dad (and me) have been there. Deep holes + overhang = bad day. You'll want to grab a spiral flute tap and some good lube.Then, just drill a bit deeper for better chip clearance.Don't forget to use a live centre or steady rest on that rod. Trust me, that chatter can ruin your taps consistenlty

Totally get that. I've been there too,those deep holes and overhangs can really challenge you.A spiral flute and some good lube are lifesavers.And having a steady rest or live center can really help

 

[viseclampcraft61]

Hope I'm not too late jumping in. Long overhang increases vibration risk during threading; using a steady rest or support and sharp spiral taps with proper lubrication will improve stability and reduce breakage.