Sherline Thread Cutting Attachment Slipping

Yup, I'll send a project report in once I finish up the tool. And I'll be very careful measuring the center elevation and cutting the result into the tool. Thanks again for the help.
-Tom
 
I have had a 4410 (metric) for just over a year and the thread attachment is awesome. Reading some machinists' magazines shows that the biggest issue everyone has to deal with in threading is to make the automatic stop repeatable. Since I spin the work by hand under a loupe, stopping the thread at the right point is impossible to mess up.

Some of the gearing does tend to be a little 'touchy'. I find if I use a gear that hasn't been used yet, the setup can be a little tentative (seems about to skip). I've slipped once or twice (reefing down the bolts was enough to fix it), but never after I've started a thread.

Even though I've used the threading attachment only a few dozen times, I can get the motor off, the gears and handwheel on in less than 2 minutes, it really is pretty easy. And from everything I've read, threading under power seems a complete pain in the neck. Especially since I cut very small screws (0.25mm pitch), never more than 10 or 15 mm long, and I need only a few.

Where do you plan to sell your 4410?
 
I suppose I should assume that the guys who wrote this stuff a year ago have all made their threading attachments work. Did anyone talk to Sherline about this? I ask because my new Sherline 17" 4400 showed up yesterday and is now secured to an MDF board attached to one of Harbor Fright's $20 folding workbenches. So I got out the additional gizmos I bought with it and when I got to the threading attachment - set it up and found that it slipped just like the ones reported above.
.
It looks like the wisdom shared above is that the gears need lubrication and some experience - sort of run-in. This sounds pretty good. I must remember to spend some time on this before I get boxed in and have to produce some threads in a hurry.

I've been away from this stuff for a bit more than 50 years having gotten stuck in another profession, but now that I'm back to what I really like, I'm burdened to some extent by what I remember from the late '50s, or possibly mis-remembered.

I thought we cut threads on one face using the compound slide set at an angle which agreed with the geometry ot the threads we were cutting. The threads were cut in the direction of the chuck. We'd back off with the compund slide run the thing back bring it in some thoudsandths and do the next cut.

This obviously requires a compound slide. It looks as if this cannot be done with Sherline's compound slide unles you do the cutting on the back side ot the work where it would be hard to see what was going on.

Sherline offers a riser which would make it possible, but it doesn't look like the threading attachment could handle a head-stock sitting on a riser so this it out.

I realize that what I'm asking is probably nuts, but has anyone tried using the compound and cutting threads on the back?
 
Last edited:
You actually do not need or use a compound slide on the Sherline lathe to cut threads. You just mount the threading tool in the tool post, get it at center height and perpendicular to the work and then cut threads with the cross slide by feeding straight in. It works really well. The Sherline threading attachment works much better than you might think, and turning the leadscrew by hand actually gives you very fine control of the operation. I rather like it, myself.

You will be able to cut class 3 threads with this attachment. I don't happen to have any slippage issues with my set up.
 
I realize that the Sherline setup coes not require the compound, but at a cost of cutting both sides of a thread instead of one side. It's probabaly more of an artifact of the way I learned to do this that I was looking to do threads the same way I did 55 years ago. I haven't tried the Sherline method yet, but I am looking forward to it. I'm sure I'll get the geartrain reliable.

thanks for the thoughts.

john
 
I suppose I should assume that the guys who wrote this stuff a year ago have all made their threading attachments work. Did anyone talk to Sherline about this? I ask because my new Sherline 17" 4400 showed up yesterday and is now secured to an MDF board attached to one of Harbor Fright's $20 folding workbenches. So I got out the additional gizmos I bought with it and when I got to the threading attachment - set it up and found that it slipped just like the ones reported above.
.
It looks like the wisdom shared above is that the gears need lubrication and some experience - sort of run-in. This sounds pretty good. I must remember to spend some time on this before I get boxed in and have to produce some threads in a hurry.

I've been away from this stuff for a bit more than 50 years having gotten stuck in another profession, but now that I'm back to what I really like, I'm burdened to some extent by what I remember from the late '50s, or possibly mis-remembered.

I thought we cut threads on one face using the compound slide set at an angle which agreed with the geometry ot the threads we were cutting. The threads were cut in the direction of the chuck. We'd back off with the compund slide run the thing back bring it in some thoudsandths and do the next cut.

This obviously requires a compound slide. It looks as if this cannot be done with Sherline's compound slide unles you do the cutting on the back side ot the work where it would be hard to see what was going on.

Sherline offers a riser which would make it possible, but it doesn't look like the threading attachment could handle a head-stock sitting on a riser so this it out.

I realize that what I'm asking is probably nuts, but has anyone tried using the compound and cutting threads on the back?

I don't think what you are asking for is nuts. I would prefer to do it the same as you. I, like you, learned to cut single point threads on an engine lathe in the late 60's. Always used the compound slide set at the correct angle. Cut many threads that way. Never did I cut a single point thread by plunging straight in with the cross slide...............until this year when I needed to cut some threads and the only choice is my Sherline lathe. So I did it the way other posters recommend. I did not feel comfortable doing it that way, but I took it slow and it worked. But I am retired and now am a "hobby machinist" instead of a real machinist because of my tooling.

I too have the Sherline compound slide and was disappointed that it doesn't work like a normal one. I would much prefer to have the compound slide work from the front instead of the back (and holding the tool upside down). I've looked at trying to modify compound slide to work on the front but haven't come up with a satisfactory way to do that. You can mount the compound slide like you would on a regular lathe as long as it is set off at some angle to miss the cross slide handles but, because the slide itself holds the 1/4" tool bit directly (instead of a tool post/holder), the tool bit is 1/4" above center if mounted right side up.

Gotta be a way. You keep thinking about it.
 
I don't think what you are asking for is nuts. I would prefer to do it the same as you. I, like you, learned to cut single point threads on an engine lathe in the late 60's. Always used the compound slide set at the correct angle. Cut many threads that way. Never did I cut a single point thread by plunging straight in with the cross slide...............until this year when I needed to cut some threads and the only choice is my Sherline lathe. So I did it the way other posters recommend. I did not feel comfortable doing it that way, but I took it slow and it worked. But I am retired and now am a "hobby machinist" instead of a real machinist because of my tooling.

I too have the Sherline compound slide and was disappointed that it doesn't work like a normal one. I would much prefer to have the compound slide work from the front instead of the back (and holding the tool upside down). I've looked at trying to modify compound slide to work on the front but haven't come up with a satisfactory way to do that. You can mount the compound slide like you would on a regular lathe as long as it is set off at some angle to miss the cross slide handles but, because the slide itself holds the 1/4" tool bit directly (instead of a tool post/holder), the tool bit is 1/4" above center if mounted right side up.

Gotta be a way. You keep thinking about it.

Hi Forty Niner,
I bought the Joe Martin book which is really interesting. I wish he was still around - so many similar experiences over the years. He writes about why he got into cutting on the back side of the work. Apparently he found that screw machines which were a bit over the hill could cut on the back such that the tool was lifting the slide instead of forcing it down - and this with tooling which wouldn't work on the front due to chatter.

I've got a backlog of things I need for projects before I get to threading, but I think I am going to try cutting threads on the back. No that the way Sherline and Mikey suggest but because I'm a bit perverse.
 
I understand what you guys are saying but I can assure you that the direct feed method works very well. You simply need to take lighter cuts and you will be able to cut beautiful threads on a Sherline lathe. The pic below is one of the few pics I have of theading but this is a class 3, M8 X 1.25 thread at the end of a 1144 stressproof steel leadscrew. Other than blowing off the debris, this is just as it comes off the Sherline lathe.

IMG_4830.jpg

I wanted to use the compound, too, but it turned out that cutting straight in poses no issues for me. Not trying to convince you not to do it; just saying that it wasn't worth the hassle for me. I've cut many, many threads on this lathe and actually enjoy the process. It is actually easier for me to hold tighter tolerances with this machine, and this extends to my threading.
 
I have not cut a lot of threads on my Sherline lathes but when I did they were good. Just do not try to take a large bite any any one time. do not have any pics of ones I have done, bit they look good.
 
Exercising new gears seems the answer to them jumping out of engagement. Mine works just fine now. I think I'll try the Sherline methiod first. Clearly it's less trouble than setting up the compound and cutting on the backside.
 
Back
Top