Easy Tailstock lock tang modification for Atlas - Craftsman, Southbend, Logan and others

[@cbrbt]

Great upgrade going to do this to my craftsman 12x36 this weekend as well

[@donsengine3158]

Jeez.. a 36", that's pretty lucky one to get ahold of. Hope it works well for you. This video was done a month back and every day I use the machine, I'm glad I did it. Don

[@kentuckytrapper780]

Good info don..

[@donsengine3158]

Thanks KT, it had been brewing in my noggin for a while. Don

[@theeddies]

Good one Don. I will probably do the same when I get the old girl back up and running.

[@donsengine3158]

In hindsight... I'm glad I did it.... Don

[@floridaflywheelersantiquee7578]

Thanks for the info thanks for sharing

[@donsengine3158]

Always welcome.. Don

[@tonypike5785]

I will do mine also. Thanks

[@donsengine3158]

I am appreciating the fact that I did it now, every day I get back on that machine. Don

[@melgross]

While I know we can’t always avoid it, the tang is never supposed to be used for the purpose of holding the tool from turning in the taper. It’s only for the purpose of removing the tool. We see torn off tangs all the time from that. If the tool does turn, it means that the taper is bad, or that there’s oil on the parts. When a tool is put into the taper and given a bit of smack when setting it. It shouldn’t turn at all, or no more than a couple of degrees before locking. If it does turn more than that, the taper is likely scored, either internally, or the one on the tool. That needs to be fixed. If that’s not it, then the internal taper needs to be cleaned with a paper towel with acetone or equivalent, as does the tool taper. If the tool isn’t “set” with a smack when it’s inserted, it may not lock. I know some people think I’m a spoilsport when I write things like this, but I’m just giving best practice. Just keep in mind that if there’s something that shouldn’t be happening, there’s always a reason. Find out what the reason is first before making modifications. This one for a small lathe is harmless as the torque isn’t high. But remember that’s it’s likely that the tailstock quill isn’t hardened, and so check to see the condition of the taper first. If it’s gouged, then your tool won’t be accurately pointing towards the headstock.

[@WinkysWorkshop]

A number 2 MT in itself doesn't have enough surface area to hold while drilling larger holes and once a taper slips quite often the damage is done. The tang is a huge advantage. If the tang is ONLY for ejecting the drill then why is it flat? Both my Logan and South Bend lathe eject just fine with or without a tang. Where I worked before I retired the machinist always used the Monarch lathe to drill which had a reduced section to hold the tang. To my knowledge they never broke a tang off. I'm not saying it can not happen but it takes a LOT to torque to do this. When rebuilt my Logan I reamed the tailstock ram and started out with new arbors on my chuck. They held great until I tried to drill a 1-inch hole and it scared both the male and female tapers. From that point forward I clamped vise grips on the drill shank to stop rotation. If the tailstock ram had been equipped with a reduced area to grab the tang the damage would not have happened. When rebuilt my South Bend 11 I installed set screws to grab the tang and it was the best thing I ever did. The Logan had a wimpy little pin to engage the ram so I never modified it. The SB has a substantial key that would be very hard to sheer. There is an patent regarding the tang by Cleveland Drill around the time Mores introduced this taper. The patent stated that it was to stop rotation when the taper failed. What you stated is widely accepted and supported by Morse but not the drill company. The purpose of the taper is also to help stop rotation and resulting damage. It just depends of who you want to listen to and how much taper damage you are willing to deal with.

[@donsengine3158]

Mel. Yes I know. Many things I don't say cause the guys watching are more than likely experiencing similar issues. Lower end machines have their own quirks and working around them can be half the fun. Don't know if you noticed that I did give the taper a nice whack to seat it. Sometimes we get lazy and don't send them home and a little catching or hang up when drilling and pulling back can cause a taper to come loose. We hope for a reseat when pushing back in, but a spin will cause galling. Adding the tang holder is meant to stop it short and give the taper a chance to seat under pressure. All points are taken and understood quiet well. Hope others that may not know these points see your comments. Don

[@melgross]

@@WinkysWorkshop I’m not going to say that the tang isn’t helpful in an emergency. But there are adapters that fit a larger taper into a smaller taper. We’ve all seen them. They’re really long. But because something is there, doesn’t mean it’s correct. People use tooling incorrectly all the time. A big mistake is using a drill too big for the taper, and over torquing it. I believe a 7/8th is the max for a #2, but I could be wrong. The point of what I was saying is that you are not supposed to use the tang as part of your work holding. That’s wrong. Period. A tang will help prevent scoring on a taper, if it slips. That’s why it’s flat. So yes, you’re partly correct there. But again, that’s telling you something is wrong. It’s not an excuse to do things incorrectly. Also, a tang will not prevent the tool from pulling out of the taper under certain conditions. You also might notice that many tools don’t even have tangs anymore, with self ejecting tailstocks being prevalent, something that wasn’t even available when the tang was invented.

[@melgross]

@@donsengine3158 yes, I did see it. It was hard to miss. Let me get something straight. I’m talking to people who are new to this, and see an experienced person, such as yourself do something g that you understand quite well, and miss a lot of the points. I saw a lot of people with these problems saying they they were gonna do this too. I’ll bet that very few of them understand the implications of it. I’m not being insulting, but there’s little out there to really help home shop people who buy equipment and don’t know how to use it.

[@WinkysWorkshop]

I'd say you are right, 7/8" is about the maximum for a #2 taper but this also means that under the right conditions a 1/2 drill may also spin the taper which makes the tang a great safeguard. >"You also might notice that many tools don’t even have tangs anymore". Centers have no tang but every drill chuck taper I have seen has one and no way would I have a drill chuck without a tang. >The point of what I was saying is that you are not supposed to use the tang as part of your work holding. That’s wrong. Period. Call me a rebel or even defiant but I have a problem with this statement. If a tang stops my chuck from spinning and does not create a danger to me or the lathe then I see no problem whatsoever. Wrong is your judgment. I say whatever works is correct. Quite honestly I commend anyone that works around the limitations of their machines (safely of course) and gets the job done. My Logan with a perfect tailstock ram and new taper was a pain in the butt... My South Bend with the set screws that grab the tang is a dream. If I was working to a #3 or #4 taper I might see things differently. I guess I see rules and procedures as guidelines only. Following them without question is stagnation. This is probably also why I was responsible for over 100 machine modifications in the printing industry. There is ALWAYS a better way!

[@dalemcinnes1834]

Hi Don , i was wondering how hard did the quilt seem to be. Even though I watched the video I could not tell but it did not seen to be to hard. One thing I did wfh mine (atlas 12 x 36) was pick up a reamer and used it lightly and it seemed to take out some crud out of the spindle so I got a mt3 reamer for the chuck spindle and found the same thing and got crud out as well. They seemed to help hold better after that. I bought the lathe second hand but it was in beautiful shape and did not have much wear at all. I try to watch the tapers close and keep them clean. I sure like your idea and will consider doing this as well. Thanks for the video. Dale in Canada 🇨🇦

[@donsengine3158]

Dale the quill drilled a lot easier than expected. I started with two sharp drills and they stayed sharp... I also use a tapered reamer for clean up. I did a short show of that i my tailstock torque bar video. Thanks for watching. Don

[@dalemcinnes1834]

@@donsengine3158 Thanks for the reply. That is a video I have not seen yet but will be soon. Dale in Canada 🇨🇦

[@tonypike5785]

@@donsengine3158 i was wondering why didn’t you run the drill all the way to the other side, you must have flipped the tailstock over to get the other side?

[@donsengine3158]

@@tonypike5785 Hay Tony, I drilled right through. I cut a lot of footage to speed up the video and I guess I wasn't getting the full through cut image. But, yes, It was one shot, no flipping. Don

[@davidprince4538]

Hey, Don, what a great modification. I will do this on my old Taiwanese lathe. My tailstock tube is 1.3” in diameter, is that about the same as your Atlas? What diameter grub screws did you use, please?

[@donsengine3158]

I think it is about the same diameter outside. I used 3/8 X 3/8 NC grub screws. I shaved the heads by about .080" to keep them from protruding. Good luck. Don

[@davidprince4538]

@@donsengine3158 Many thanks, Don

[@joeh1940]

Hey Don did u make the die holder that goes into your tailstock for threading?

[@donsengine3158]

Hey Joe, No, I picked that up when I was living in Germany. Can't even remember the manufacturer. It works pretty well and has changeable die heads. Don