Tom, this was exactly what the doctor ordered for me! It's been years since I cut an external thread, and even longer since I cut female threads. I needed a refresher course, and this was it. I had forgotten about Machinerys Handbook, and using that for calculating minor diameter for female threads. The whole point is that I acquired an old Craftsman lathe with a threaded spindle nose. I need to make a faceplate for it, and I will have to cut female thread in a hub, to fit the spindle nose. The making of a male "plug gage" will have to be matched up to the same specs as is the existing threads, then I can use it, as you did to make the threads in my faceplate... Good job teaching an old dawg, old tricks. Yeah!
you know i watched all your videos for the past 4 years. and today i watched thie video on internal threading and picked up the threading formula wich i missed 4 years ago. 1 divided x the pitch divided x 1.5 i love it very simple thanks tom havent seen you around for some time hope your doing ok. get back into the shop we need some more knowlagable info from the master. thanks tom.
Thanks Jamie, I'm still around. I recently retired and am in the process of sorting out this new lifestyle. So far it's been busier than when I was working. :) Tom
This is just what I needed, your video was very helpful. I will have to re-watch both video series with a note pad to jot down your formulas. Also I like your boring bar holder, I think I will make one for my craftsman lathe. Thank you .
Hi Tom I have a 10" Atlas of earlier vintage than your dad's (by only 5 or 10 years, 1933ish). Yes, they're all pretty noisy in the back gear. I'm currently repairing mine since I broke a couple gears in the cross feed mechanism due to worn ways and tightening the gibs a smidgen too much, trying to get rid of the tool chatter. When I start to put things back together, I would like to email you regarding your experience rebuilding your dad's lathe. It's fun to see conversations still going on about work you did 2 years ago. This is a really nice series.
Thanks John. You can contact me through my website (tomstechniques.com) if you have any questions about your lathe, but since it's been forty years since the rebuild, I'm not sure how much help I'll be. Tom
Thank you for taking the time to do it on the Atlas, seeing it on the Hardinge was interesting, but not the same! I now need to find out the way to calculate the top slide depth of cut for metric threads, but that's just maths! The dial gauge is a nice thing, but it only works on "inch" threads, metric threads, there's no disengaging the half nuts, a little tricky but it's all down to getting the "routine" right! Thanks again, regards, Matthew.
Thanks. I'm in the process of setting up a website and one of my goals is to do a write-up on each of the videos that will include the reference data. That is a good solid boring bar holder. If I remember correctly, it's pretty much a copy of the Armstrong holder. Tom
I did notice that the lever wanted to move around, so I wired it down to make sure it didn't pop out in the middle of the thread. I'll check out that stop. Thanks, Tom
Yeah, my atlas is pretty loud too in back gears. Especially in the higher ranges lol. Grease is your friend😁. I like your boring tool, that's my biggest problem at the moment. Using the ol lantern style tool post and 1/4" hss blanks w/Armstrong tool holders. Thanks for the video😊.
My Atlas was built in 1944 and is really quiet. I do use a little oil on the gears though. Thanks for that video, I would have never known to put the compound slide in that position. Great job!
I do have another question for you. I replaced my lead screw awhile back and can't figure out how to cut the slot for the cross slide. ( no milling machine ) Any Ideas?
Hi love the videos i have a quick question,I'm cutting a 1" x 12 TPI internal thread but its a 55 deg whitworth thread..I know on the fishtail it says 0.053" depth of cut..But how do you work it out is there ea formula for British standard whitworth thread form please..?Any help would be appreciated..I'm at 0.051" and it just starting to screw on its an internal thread..Do i just keep taking a few thou now till it fits my spindle.. But also in my seco book on there inserts it says its 0.057" so kind of confusing but I'm not using the seco partial form inserts for this one just a standard AG55 insert..
Sorry, but the closest I've ever come to a Whitworth thread is in the '58 MGA I used to drive. If you have a male thread to match it to, I would just cut it to fit. How are you going to round the roots and crests? Tom
Toms Techniques Hum Well the 55 deg threading tool should do that ?At least the root..But i could swap the insert out maybe for the seco 12w CP500 which will do both it cuts the crest behind the thread..Do you think it might be best too swap out the AG55 insert for the partial form seco insert which will only cut the 12 whitworth thread and do the Crest as well and once it starts too do the crest i know I'm very close to size. My only worry is I'm 0.052" depth of cut already.I don't think its a massive deal to round the crest last time i purchased 2 back plates picked up the thread and made them deeper to fit my spindle,Then used some sand paper off the lathe too smooth the tops worked perfectly.. If what you are saying is important how comes many you tubers I've seen cut a 55 deg thread just use a HSS bar with a 55 deg tool and call it good ? Also the ER16 AG55 threading insert does not come with any way of rounding the crest,And is meant for a whitworth thread ?
I very rarely use inserts, I can't help you there. Whatever angle tool you use (60º, 29º or 55º), it should be fed on 1/2 the included angle for most of the thread and straight in for the last few thousandths. Otherwise it will put too much load on the tool. Tom
Toms Techniques Hi tom totally understand that and understand about the strength of the tool bit and insert,But a few spring passes takes care of that.I have got the answer to my question now pal.Which was at 27.5 deg angle on the compound slide.how much in feed depth in total only on the compound slide to reach the target depth of cut of 0.052"..It turns out to be 0.058" total then start testing the fit and then use the crosslide without touching the compound..At 0.001" increments testing the fit as you go for a 12 TPI thread.. Basically what i was saying about seco NR16 12w cp500 insert is it tops the crest behind while cutting the thread,but this time i was trying a different type of insert which does not and is..no different to a HSS tool bit really with regards to the crest not being touched unlike the NR16 12W seco insert i normally use.. But here is how it was worked out.. for a 27.5 deg angle..cosine of 27*30' and you get : .88741 multiply the needed depth (.052") by the reciprocal of the Cosine ( 1/.88741= 1.12687) and you get .0586..Now i dont fully understand the math behind the whole thing but am trying to learn about it.. 0.058" of in feed cut on the compound..I think this is an important subject that not many people cover in videos..As people are just looking at there fishtail and taking the 0.052" and dialling that in on there compounds..And there short of 0.006" and this is double depth of cut so would be short of 0.0012" on the radial depth.
What you say is true, but it's better to use the formula in the video (Pitch/1.5) to determine compound travel for a particular thread because it allows for the flat on the tool as well as the number of threads per inch. Rough the thread out using the compound, then switch to the cross slide to finish it up. That makes it much easier to measure and makes the tool cut on both flanks for a nice finish. There is a pretty good Wickipedia article on the Unified Thread Standard that is worth reading.
Hey Tom,any advice for a kiwi who bought an atlas metric 12700 lathe? I see alot of the american guys on UA-cam have them so i assumed they were quality and jumped at the chance now after further research I've come to know there's alot of hate there towards these lathes any tips or feedback would be greatly appreciated, Ben.
Ben, The Atlas lathes are very plentiful and inexpensive which is why so many people have them and they will serve you well as a basic, light duty hobby lathe. What they lack is rigidity and precision, so they can be challenging to use for larger parts, or for parts that require close tolerances. The good news is that if you out grow an Atlas lathe, the resale value is high so it won't be painful to step up to a more robust machine. Tom
It varies, but normally the nuts will engage about 1/8 turn before the mark, which will screw up the thread. Finishing the thread with the cross slide makes it easier to measure the pitch diameter, negates any misalignment of the compound and leaves a better finish. It's an easier and better way to thread and no, I'm not the only one to do it that way. Check out Doubleboosts channel for another example. You do have to grind the bit accurately, but alignment of the compound is less critical. Tom
Nice video Tom. I have a 1934 SB and it sounds almost the same. Question...what method did you use to know when to stop the travel? Kind of hard to see inside the bottom of the bore. I'd be afraid of crashing it. Also, that's a nice boring head, any thoughts on making that into one of your project videos? Nice work, we all really enjoy your channel. Best regards!
It's easy to know when to stop when cutting a thread in a through hole, because all you have to do is listen for when the tool stops cutting. The boring bar holder is on the list of future projects, so you'll see a video on it eventually. Thanks for watching. Tom
Thanks for sharing, great video. I know it was camera angle but when you were trying to see in the bore and the Atlas was running it "looked" like it was about to wrap you up in the lathe.
@@TomsTechniques Sir, I went to your website and tried to email you and the security feature will not let me email you, I cannot find the machinist handbook you spoke of I found the new American machinist handbook 1955 is that what you were talking about or no.
Sorry. That part of the website has some issues that I haven't been able to fix. The best machinists reference book is any of the Machinery's Handbooks (not American Machinist Handbook). They have been published for many years, so there are lots of used ones available. Tom
I think this Atlas lathe video is the one that caused you to give up tutorials LOL (just kidding) I have an Atlas and love it....its the only lathe I have so I have to! Thanks for the lesson...I need to cut a 7/8-20 internal thread and dont have a that tap size so off work :)
How close to the number do you need to be when setting the half nut, in other words how far off could you be and still start the thread correctly? I have watched a lot of threading videos and you are the only one to use the switch from the compound feed to the cross feed, Gould you give the thinking on that. It sounds reasonable to me but the bit must be formed perfectly, Right?
I'm working on it. I know how the website will be laid out, I just need to have my son help me set it up. It's definitely painful to find your way through the UA-cam channel. Tom
I have used many different lathes, so there were no real surprises here (other than the fact that there was no quick change gear box ;) ) The biggest difference (as expected) was the lack of rigidity. That thread would have taken less than half the number of passes on the Hardinge that I took on the Atlas with no problem. I may have to take a look at it for my dad and find out where all that noise is coming from since the general consensus is that it is noisier than most. Tom
That noise is probably coming from the backgear engagement mechanism. The counter shaft must be locked in position with minimal play of the gears. On a logan 200 there is an a adjustable stop on the end of the push rod for this purpose. If not adjusted properly it makes a loud ringing noise and the lever pops in and out as load changes.
Make sure the lathe you choose has a large enough bore to handle barrels for crowning and chambering. Not too large though since most of your work is going to be on the small side like screws and such. Guns also use some odd pitched threads, so make sure the lathe can handle them. Tom
Not all that loud, but it requires a lot of lube and adjustment to quiet it down. You end up trading mess for noise. y sanity being a bit on the short side to begin with, I I deal with the mess to avoid the noise. 140wt on the backgear shaft, heavy gear lube (basically light tar) on the gear teeth, proper greasing in the countershaft cups (make sure the ports are clear and the grease is getting in), and proper set of the tooth clearance. Then, it is about as loud as a comparable south bend.
Tom, You gota just love those old Atlas lathes, made in Kazoo, I'm in G.R. and have a question on a Atlas 101.28990 with a quick change gear box. I'll call if you don't mind. Stony
The best way to get in touch with me is to contact me on my website at tomstechniques.com. I'm not much of an authority on Atlas lathes, but maybe I can help out.
Found something out the hard way that might be useful to someone else. When backing out with the cross slide to return to the start of the thread if you don't add a little more each time you back out you will cut the thread up on the way out. You have to add a little more because your advancing the depth of the cut with the compound each pass.
Just be sure the tool is well clear of the bore before starting and you shouldn't have that problem. You aren't the first to find that out the hard way ;) Thanks for the heads up. Tom
Like this I have tried to send u a message but it will not go, I need to make a left hand thread nut never cut a thread 3/4 bore 11 tpi do feed out on the nut?
Richard, Not sure what's up with the messages, but the best way to contact me is like you did, through tomstechniques.com. Left hand nuts are fun to cut because you feed from the inside out (to the right), so you don't have to worry about stopping. Everything else is the same as for a RH thread. Tom
When using the same cutting tool that you made for external threads to cut internal threads, aren't your cutting edges reversed?. . . i.e. the original cutting edge (geometry) is now on the opposite side of the tip.
Good catch Lee. That tool would have been better to use on the back side of the bore. Apparently there was still enough clearance even with the helix angle reversed because the thread turned out fine. Good thing I wasn't cutting a square thread. :) Tom
Hearing that my videos instill confidence makes my day. Thanks!
Tom
Tom, this was exactly what the doctor ordered for me! It's been years since I cut an external thread, and even longer since I cut female threads. I needed a refresher course, and this was it. I had forgotten about Machinerys Handbook, and using that for calculating minor diameter for female threads. The whole point is that I acquired an old Craftsman lathe with a threaded spindle nose. I need to make a faceplate for it, and I will have to cut female thread in a hub, to fit the spindle nose. The making of a male "plug gage" will have to be matched up to the same specs as is the existing threads, then I can use it, as you did to make the threads in my faceplate... Good job teaching an old dawg, old tricks. Yeah!
Thanks Jim, you old dawg. Glad you enjoyed it.
Tom
Tom, looking forward to your master index that will certainly make it easier when looking for related videos. Thanks for you're good work.
Tom,
Great Series on cutting threads on an Atlas lathe. I too have a 10F Pick-O-Matic lathe. Still learning how to use it. Thanks again.
+Gus Lint
Thanks for watching, Gus.
you know i watched all your videos for the past 4 years. and today i watched thie video on internal threading and picked up the threading formula wich i missed 4 years ago. 1 divided x the pitch divided x 1.5 i love it very simple thanks tom havent seen you around for some time hope your doing ok. get back into the shop we need some more knowlagable info from the master. thanks tom.
Thanks Jamie, I'm still around. I recently retired and am in the process of sorting out this new lifestyle. So far it's been busier than when I was working. :)
Tom
lol thats what they say when you retire take care enjoy your retirement.
This is just what I needed, your video was very helpful. I will have to re-watch both video series with a note pad to jot down your formulas. Also I like your boring bar holder, I think I will make one for my craftsman lathe. Thank you .
Hi Tom
I have a 10" Atlas of earlier vintage than your dad's (by only 5 or 10 years, 1933ish). Yes, they're all pretty noisy in the back gear.
I'm currently repairing mine since I broke a couple gears in the cross feed mechanism due to worn ways and tightening the gibs a smidgen too much, trying to get rid of the tool chatter. When I start to put things back together, I would like to email you regarding your experience rebuilding your dad's lathe.
It's fun to see conversations still going on about work you did 2 years ago. This is a really nice series.
Thanks John.
You can contact me through my website (tomstechniques.com) if you have any questions about your lathe, but since it's been forty years since the rebuild, I'm not sure how much help I'll be.
Tom
Thank you for taking the time to do it on the Atlas, seeing it on the Hardinge was interesting, but not the same! I now need to find out the way to calculate the top slide depth of cut for metric threads, but that's just maths! The dial gauge is a nice thing, but it only works on "inch" threads, metric threads, there's no disengaging the half nuts, a little tricky but it's all down to getting the "routine" right!
Thanks again, regards, Matthew.
Thanks.
I've been considering building a gantry type CNC mill. I'll have to check out your site.
Tom
Thanks.
I'm in the process of setting up a website and one of my goals is to do a write-up on each of the videos that will include the reference data.
That is a good solid boring bar holder. If I remember correctly, it's pretty much a copy of the Armstrong holder.
Tom
Great video Tom it helped me immensely!
I added a link to the video description above.
Thanks,
Tom
Thanks Tom, very helpful.
You are welcome, and thanks for watching.
I did notice that the lever wanted to move around, so I wired it down to make sure it didn't pop out in the middle of the thread. I'll check out that stop.
Thanks,
Tom
Excellent video series!! Great work.
Thanks Kevin.
Yeah, my atlas is pretty loud too in back gears. Especially in the higher ranges lol. Grease is your friend😁.
I like your boring tool, that's my biggest problem at the moment. Using the ol lantern style tool post and 1/4" hss blanks w/Armstrong tool holders. Thanks for the video😊.
Thanks Tom. Very clear and informative.
That's good to hear David.
Great video Tom. I just got my first lathe, which is small. It's a Craftsman 101.21400. I can't wait to try out your technique.
My Atlas was built in 1944 and is really quiet. I do use a little oil on the gears though. Thanks for that video, I would have never known to put the compound slide in that position. Great job!
This one is quiet in direct drive, it's only the back gear that makes a racket. My dad can't really hear it anyway. ;)
Thanks for watching.
Tom
I do have another question for you. I replaced my lead screw awhile back and can't figure out how to cut the slot for the cross slide. ( no milling machine ) Any Ideas?
shortribs11
Why don't you contact me on my website and we'll discuss it.
tomstechniques.com/
Tom
This lathe - in back gears, sounds exactly the same as my Myford 7....
It is missing a tooth in the greatest of the two back gears - LOL! Nice video!
Thanks Scott.
A small lathe will do everything a large lathe will do, just on a smaller scale.
Tom
Hi love the videos i have a quick question,I'm cutting a 1" x 12 TPI internal thread
but its a 55 deg whitworth thread..I know on the fishtail it says 0.053" depth of
cut..But how do you work it out is there ea formula for British standard whitworth
thread form please..?Any help would be appreciated..I'm at 0.051" and it just starting
to screw on its an internal thread..Do i just keep taking a few thou now till it
fits my spindle..
But also in my seco book on there inserts it says its 0.057" so kind of confusing but I'm
not using the seco partial form inserts for this one just a standard AG55 insert..
Sorry, but the closest I've ever come to a Whitworth thread is in the '58 MGA I used to drive. If you have a male thread to match it to, I would just cut it to fit. How are you going to round the roots and crests?
Tom
Toms Techniques Hum Well the 55 deg threading tool should do that ?At least the root..But i could swap the insert out maybe for the seco 12w CP500 which will do both it cuts the crest behind the thread..Do you think it might be best too swap out the AG55 insert for the partial form seco insert which will only cut the 12 whitworth thread and do the Crest as well and once it starts too do the crest i know I'm very close to size.
My only worry is I'm 0.052" depth of cut already.I don't think its a massive deal to round the crest last time i purchased 2 back plates picked up the thread and made them deeper to fit my spindle,Then used some sand paper off the lathe too smooth the tops worked perfectly..
If what you are saying is important how comes many you tubers I've seen cut a 55 deg thread just use a HSS bar with a 55 deg tool and call it good ?
Also the ER16 AG55 threading insert does not come with any way of rounding the crest,And is meant for a whitworth thread ?
I very rarely use inserts, I can't help you there.
Whatever angle tool you use (60º, 29º or 55º), it should be fed on 1/2 the included angle for most of the thread and straight in for the last few thousandths. Otherwise it will put too much load on the tool.
Tom
Toms Techniques Hi tom totally understand that and understand about the strength of the tool bit and insert,But a few spring passes takes care of that.I have got the answer to my question now pal.Which was at 27.5 deg angle on the compound slide.how much in feed depth in total only on the compound slide to reach the target depth of cut of 0.052"..It turns out to be 0.058" total then start testing the fit and then use the crosslide without touching the compound..At 0.001" increments testing the fit as you go for a 12 TPI thread..
Basically what i was saying about seco NR16 12w cp500 insert is it tops the crest behind while cutting the thread,but this time i was trying a different type of insert which does not and is..no different to a HSS tool bit really with regards to the crest not being touched unlike the NR16 12W seco insert i normally use..
But here is how it was worked out.. for a 27.5 deg angle..cosine of 27*30' and you get : .88741 multiply the needed depth (.052") by the reciprocal of the Cosine ( 1/.88741= 1.12687) and you get .0586..Now i dont fully understand the math behind the whole thing but am trying to learn about it..
0.058" of in feed cut on the compound..I think this is an important subject that not many people cover in videos..As people are just looking at there fishtail and taking the 0.052"
and dialling that in on there compounds..And there short of 0.006" and this is double
depth of cut so would be short of 0.0012" on the radial depth.
Muhaa Haloa o
What you say is true, but it's better to use the formula in the video (Pitch/1.5) to determine compound travel for a particular thread because it allows for the flat on the tool as well as the number of threads per inch. Rough the thread out using the compound, then switch to the cross slide to finish it up. That makes it much easier to measure and makes the tool cut on both flanks for a nice finish. There is a pretty good Wickipedia article on the Unified Thread Standard that is worth reading.
Very good tips and demonstration.
Hey Tom,any advice for a kiwi who bought an atlas metric 12700 lathe?
I see alot of the american guys on UA-cam have them so i assumed they were quality and jumped at the chance now after further research I've come to know there's alot of hate there towards these lathes any tips or feedback would be greatly appreciated, Ben.
Ben,
The Atlas lathes are very plentiful and inexpensive which is why so many people have them and they will serve you well as a basic, light duty hobby lathe. What they lack is rigidity and precision, so they can be challenging to use for larger parts, or for parts that require close tolerances. The good news is that if you out grow an Atlas lathe, the resale value is high so it won't be painful to step up to a more robust machine.
Tom
It varies, but normally the nuts will engage about 1/8 turn before the mark, which will screw up the thread. Finishing the thread with the cross slide makes it easier to measure the pitch diameter, negates any misalignment of the compound and leaves a better finish. It's an easier and better way to thread and no, I'm not the only one to do it that way. Check out Doubleboosts channel for another example. You do have to grind the bit accurately, but alignment of the compound is less critical.
Tom
Nice video Tom. I have a 1934 SB and it sounds almost the same. Question...what method did you use to know when to stop the travel? Kind of hard to see inside the bottom of the bore. I'd be afraid of crashing it.
Also, that's a nice boring head, any thoughts on making that into one of your project videos?
Nice work, we all really enjoy your channel.
Best regards!
It's easy to know when to stop when cutting a thread in a through hole, because all you have to do is listen for when the tool stops cutting.
The boring bar holder is on the list of future projects, so you'll see a video on it eventually.
Thanks for watching.
Tom
Thanks for sharing, great video. I know it was camera angle but when you were trying to see in the bore and the Atlas was running it "looked" like it was about to wrap you up in the lathe.
Yeah, I get that all the time. Camera angles lie.
Thanks for watching.
@@TomsTechniques Sir, I went to your website and tried to email you and the security feature will not let me email you, I cannot find the machinist handbook you spoke of I found the new American machinist handbook 1955 is that what you were talking about or no.
Sorry. That part of the website has some issues that I haven't been able to fix.
The best machinists reference book is any of the Machinery's Handbooks (not American Machinist Handbook). They have been published for many years, so there are lots of used ones available.
Tom
@@TomsTechniques Thank you sir
I think this Atlas lathe video is the one that caused you to give up tutorials LOL (just kidding) I have an Atlas and love it....its the only lathe I have so I have to! Thanks for the lesson...I need to cut a 7/8-20 internal thread and dont have a that tap size so off work :)
Where do I find the drawings on the carriage stop and the cross slide dial? by the way nice job on the video
How close to the number do you need to be when setting the half nut, in other words how far off could you be and still start the thread correctly? I have watched a lot of threading videos and you are the only one to use the switch from the compound feed to the cross feed, Gould you give the thinking on that. It sounds reasonable to me but the bit must be formed perfectly, Right?
I'm working on it. I know how the website will be laid out, I just need to have my son help me set it up. It's definitely painful to find your way through the UA-cam channel.
Tom
i like your boring bar tool holder. And i also have this type of an Atlas 10" lathe, hard working tool...
I have used many different lathes, so there were no real surprises here (other than the fact that there was no quick change gear box ;) ) The biggest difference (as expected) was the lack of rigidity. That thread would have taken less than half the number of passes on the Hardinge that I took on the Atlas with no problem. I may have to take a look at it for my dad and find out where all that noise is coming from since the general consensus is that it is noisier than most.
Tom
How did you like the challenge of using a "lesser" lathe than you are used to for threading?.
That noise is probably coming from the backgear engagement mechanism. The counter shaft must be locked in position with minimal play of the gears. On a logan 200 there is an a adjustable stop on the end of the push rod for this purpose. If not adjusted properly it makes a loud ringing noise and the lever pops in and out as load changes.
Any advice for a gunsmith getting into machining for the first time? My gunsmithing education is more on the refinishing side of the aisle.
Make sure the lathe you choose has a large enough bore to handle barrels for crowning and chambering. Not too large though since most of your work is going to be on the small side like screws and such. Guns also use some odd pitched threads, so make sure the lathe can handle them.
Tom
Toms Techniques Thanks!
I found using bar oil or Skil Super Duty Lubricant or any oil with tackifiers in it makes those Atlas spur cut gears purr like a kitten.
Great series! Just like my little lathe only looks much cleaner and in better condition. Yes, they are all that loud back gears or not!
+Mark Helms
Thanks Mark.
Not all that loud, but it requires a lot of lube and adjustment to quiet it down. You end up trading mess for noise. y sanity being a bit on the short side to begin with, I I deal with the mess to avoid the noise. 140wt on the backgear shaft, heavy gear lube (basically light tar) on the gear teeth, proper greasing in the countershaft cups (make sure the ports are clear and the grease is getting in), and proper set of the tooth clearance. Then, it is about as loud as a comparable south bend.
Oh yeah.... and lots of heavy oil in the oil port for the drive pulley bushings, which only come into play in back gear.
I think most of the problem is that I'm used to my belt drive Hardinge. :)
Tom, You gota just love those old Atlas lathes, made in Kazoo, I'm in G.R. and have a question on a Atlas 101.28990 with a quick change gear box. I'll call if you don't mind. Stony
The best way to get in touch with me is to contact me on my website at tomstechniques.com. I'm not much of an authority on Atlas lathes, but maybe I can help out.
Many thanks for a great explanatory video!!.
I'd apply a little lube between each cutting pass, though...
Found something out the hard way that might be useful to someone else. When backing out with the cross slide to return to the start of the thread if you don't add a little more each time you back out you will cut the thread up on the way out. You have to add a little more because your advancing the depth of the cut with the compound each pass.
Just be sure the tool is well clear of the bore before starting and you shouldn't have that problem. You aren't the first to find that out the hard way ;)
Thanks for the heads up.
Tom
Like this I have tried to send u a message but it will not go, I need to make a left hand thread nut never cut a thread 3/4 bore 11 tpi do feed out on the nut?
Richard,
Not sure what's up with the messages, but the best way to contact me is like you did, through tomstechniques.com.
Left hand nuts are fun to cut because you feed from the inside out (to the right), so you don't have to worry about stopping. Everything else is the same as for a RH thread.
Tom
Thanks this explains a lot!
Thanks.
nice vid tom thanks for sharing i have a atlas lathe and ya they are noisy.
Denis
When using the same cutting tool that you made for external threads to cut internal threads, aren't your cutting edges reversed?. . . i.e. the original cutting edge (geometry) is now on the opposite side of the tip.
Good catch Lee.
That tool would have been better to use on the back side of the bore. Apparently there was still enough clearance even with the helix angle reversed because the thread turned out fine. Good thing I wasn't cutting a square thread. :)
Tom
Very nice vid Tom like the other one. Thanks :-)
I also have a channel about machining and CNC maybe you will like it !
yes my Atlas is just as loud.
wow that machine makes a racket...must be something loose, yes?
OK !
Yes my atlas is basically as loud as your fathers. Mine might be a bit quieter.