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Thread: Using a Taper Attachment, How?
01-30-2010, 06:50 PM #1
Using a Taper Attachment, How?
Hello everyone, I originally posted the following two items in the Southbend forum but have recieved no responses so I thought I'd try here.
Hi all, I have a 1941 SB 16" tool room lathe which came with a taper attachment. I want to use it to make some MT-3 collets for my 3-in 1 mill/drill/lathe.
Would someone please explain the proper procedure to use the attachment. I REALLY don't want to damage my machine!
Does anyone know where to source a small amount (4") alligator size 7 flat belt lacing. Everywhere I've found wants to sell a whole box. I'll never live long enough to use a box full.
Thanks in advance,knn
01-30-2010, 07:45 PM #2
If you dont know how to use a taper attachment properly, this is an excellent E Book http://www.archive.org/details/textb...vanc00smituoft, lots of illustrations. There are 2 types of taper turning attachment, the simple and telescoping, with the simple, the cross slide is disconnected from the cross slide screw so it can freely move in and out, in the telescoping, there is no cross slide disconnection.
Il gives you an example of how to set up a taper attachment for a 3/4 taper per foot NPT. Roughly set up the taper attachment to the angle, then set up 2 dial indicators, one on the cross slide, another on the lathe bed. On a 3/4 inch taper per foot, your cross slide dial will move 0.03125 for every inch of travel along the lathe bed. Keep moving the carriage back and forth, altering the taper attachment angle with the fine adjustment screw, until you get a cross slide travel of 0.03125. 1 inch of travel horizontally on the dial on the lathe bed, should result in 0.03125 travel on the dial on your cross slide.
There is ALWAYS backlash in a taper attachment, and you should be wary to take up your backlash before you start a cut, or else your lathe will cut your shanks straight for an increment, and then it will begin to taper.
A good idea would be to seek out a mentor if you dont know how to use a metal lathe safely, many vocational schools offer night courses, and perhaps some crusty old codger in retirement would show you how to set up a taper attachment, eather one of these would be VERY beneficial towards your turning experience, not to mention the safety of yourself and your machine. Asking how to set up a machine on the web is not very helpful, especially to beginners.
You dont NEED alligator clips to lace a belt, In southbend book "How to run a lathe" they demonstrate alternatives, like using synthetic sinew, and skiving and cementing the belt together.
Books, mentor, night courses will all go along way to enhancing your ability to use your lathe to its full potential.
So wel recap:
If you have a simple taper turning attachment, your cross slide MUST be disconnected from the crosslide feed screw before you start using the taper attachment, your depth of cut is regulated by the compound slide, since the cross slide is disconnected.
Telescoping attachments, you do not need to disconnect the cross slide. and the cross slide is used to regulate your deph of cut.
01-30-2010, 08:15 PM #3
Thanks Hickstick,I just found this page before I checked back and found your reply.
I have about 3 years in a machine shop that only repaired machine tools. No production work at all. I was there because I am an old school master electrician but was often used as a machinist. Machine safety I am well schooled on as well as basic operation. We didn't have a lathe with a taper attachment. If we had to taper we threw the tailstock or used the compound.
My main concern was whether or not the lead screw had to be disconnected as I just could not imagine the taper attachment pulling the screw through the brass nut without stripping it.
Following is an excerpt from the site above :
HOW THE ATTACHMENT IS USED
When the attachment is set up for use, the cross-feed screw on the lathe carriage must be either disconnected or removed entirely, depending on the lathe. Use the compound to control the tool feed. After setting the carrier to turn the taper desired, move the cross slide so the tool is in position to start the first cut. Then tighten the nut that locks the cross-slide connector to the upper slide block on the taper attachment. The slide block should be adjusted so that there is no play in its movement along the track. Back off the cutting tool so that is clears the work for each return of the lathe carriage. Use a slow feed for the final cut. Before starting to turn a taper either inside or outside, make sure that the attachment is held rigidly in place on the lathe, that all nuts have been drawn tight and the slides properly adjusted. Apply light lubricant to all sliding parts.
Again, thanks for the reply. You were the only one.
01-30-2010, 08:48 PM #4
I recently went through the same learning process, because I wanted to make a tapered alignment punch that was way too long to use the compound.
First order of business would be to determine if you have the detaching or the telescoping crossfeed screw. My SB13 has the telescoping variety. I found the marks on the taper attachment to be quite accurate as to taper and it only required a little very fine adjustment with a dial indicator on the bed and a test indicator on the (untapered) workpiece.
The SB How To Run A Lathe book has a pretty good description of the taper turning process and a found a couple more helpful references with Google.
I'd say look at all the resources and then dive in; it will all become clear pretty quickly.
01-30-2010, 09:45 PM #5
knn, I have some alligator wire lasing. I don't know what # until I look in the morning. I will send you a piece if it is a size you can use. Kenny
01-31-2010, 12:17 AM #6
01-31-2010, 07:13 AM #7
Thanks Kenny, I could use about 4" of #7. For now I have used some tie wire (about 16 ga.) Drilled holes on each side of the splice and "sewed" it together. Works so far. Don't know how it will do when I go for a healthy cut though.
I have a job to put on the lathe hopefully this week after which I will buy a box.
Thanks again, knn
01-31-2010, 01:17 PM #8
Couple of extra points which aren't in the books:-
1) Taper turning attachments in general rarely get used so they do tend to attract gunge and crud leading to stiff movement. Before using its important that everything runs smoothly and freely without shake. This is especially the case with the SouthBend unit which has two dovetail slides to get sticky. I'm not sure about the 16" but most SouthBends don't have any anti rise guides under the front edge of the saddle. Any stiffness in the taper turning unit will try to skew the saddle causing it to climb up and down the front Vee way messing up your taper. The TT unit is hung well out the back so it has plenty of leverage. Hit that problem with my Heavy 10 whose TT unit was, I thought, nicely adjusted and well lubricated. About 3 years sitting around made it sticky enough to cause problems. The 16" saddle is a lot heavier but the potential problem remains.
2) It its a telescoping feed screw type verify that the telescoping key and key-way assembly moves freely throughout its full travel. Lubricate and de-crud as required. I'd had my Heavy 10 for nigh on 20 years before I figured out that the telescoping unit travel covered the maximum end to end offset of the TT slide rather than about 3/4 of it. Turned out the key-way on mine hadn't quite been machined out fully and needed a bit of careful swiss filing to get things to go the whole way when assembled. I suspect that the telescoping unit and screw weren't completely co-axial and co-linear so needed a touch of clearance.
3) When running the carriage back and forth along your master taper you shouldn't see any measurable variation when you change direction. The indicator needle will flick when you stop and go the other way but it should read pretty much the same. If you see a change investigate. Usually sticktion and crud causing saddle twist but it can be gauge trouble. Lever type gauge is best here. Goes without saying that good bed and slide lube job before starting is very desirable.
4) When you set-up your master taper to align the TT unit put it in the same way as you intend to machine the new one. Its a bit frustrating if you set-it all up the wrong way round. If you do you won't be the first by a long chalk!
01-31-2010, 07:49 PM #9
Jeff and Clive, I spent about an hour investigating the taper setup today.
I am aware of three options with regard to cross feed screw disposition during taper operations;
A) Dis-connect crosslide from crossfeed screw nut.
a) Removed the bolt that holds the crosslide to the nut. Crosslide still moves with crossfeed screw leading me to believe that the nut has a register mating into the crosslide or maybe a location pin.
B) Remove crossfeed screw entirely.
b) Attempted to remove handle. Negative results. Left handle nut off.
c) Removed nut and jam nut from TT end of crossfeed screw.
d) Started backing out retainer collar at handle end (which threads into crosslide). Long story short it started to get tight about 1/2" out. I'm watching ten things at once during the process. I rightly (finally) presume it's getting tight because it's trying to press the handle off. The crossfeed has a center on the handle end so I tapped it with a 60 deg. center punch and the crossfeed screw backed up and the handle came off. Graduated collar off, retainer collar off. That got me about 1" free movement of the crosslide.
I got baffled at this point. Couldn't make any more headway, had other obligations to attend. Hate leaving parts lying about. Began to re-assemble the handle end. Retainer collar on. Graduated collar, not enough shaft! Pulled crosslide back manually and got enough shaft to complete re-assembly of handle end. Start re-assembly of tt end. Not enough shaft! It's getting late and the temperature is dropping,it must have shrunk!!
Removed from the TT end were two nuts, one spacer, one thrust bearing washer and one thrust washer. Now only room for one nut. Just for grins,put nut on and turn handle so as to tighten. THE DARN SCREW STRETCHED!!!
C) Telescoping lead screw.
c) Don't know how to identify one.
However given that the screw "stretched" and Clive mentioned a keyway and assembly, I did see under the compound rest a piece around the feed screw about four" long with gear teeth on the handle end and the feed screw has a keyway part way back towards the TT end. I may just have a telescoping setup.
The lathe in question is as follows: Ser. # 111685, ?/?/1941, 16" x 6', Cat # 8117-C QCG Tool room lathe.
Clive, this lathe lived outdoors for a very long time. I've been several months freeing things up, cleaning and oiling. To confirm what I already suspected I locked the crosslide down to the TT and applied a bit of longitudinal force back and forth. Locked tight as a drum.
Next project, complete dis-assembly of the TT unit.
Thanks truly to everyone for all the help. I'll report back when I've made some progress.knn
01-31-2010, 08:43 PM #10
knn, I can't find the number you speak of on the wire lasing. The wire diameter is 0.054 and the length of the short side is 0.540 and the long side is 0.660. It is not unibar. It is individual wires held with cardboard. If you want a couple 4" pieces, send me your snail mail by PM. Kenny
01-31-2010, 08:51 PM #11
Hi Kenny, that would be Clipper rather than alligator. Clipper takes a machine to install which I don't have. I've got it rigged pretty good at the moment. I think it'll get through the job and then I'll buy a box of alligator.
Thanks loads for the offer though !
I really mean it.
02-01-2010, 12:10 PM #12
According to my parts book your 16" lathe should have a telescopic cross feed screw. Essentially the handle, graduated collar and power feed gear are on a separate sub shaft running in the cross feed bushing / support assembly. Lathe end of this unit is bored so the end of the feed screw can slide in and out under the influence of the taper turning unit. The bore has and a couple or three inches of the end of the feed screw have a matching pair of key ways. A rectangular key floats in these ways to transmit the drive from handle or power feed to the screw.
PM me and I'll send you some exploded diagrams.
02-01-2010, 01:19 PM #13
I used to own a 16" Southbend toolroom lathe, same vintage as yours.
Yes, you should have a telescoping lead screw.
You DO NOT have to loosen, remove, or in any other way mess with the nut on the cross feed screw. Just position your taper and cutting tool and attach the bed clamp. Tightening the handle on top of the taper will engage it. The cross slide handle will now be locked. Use the compound for fine adjustment. If you watch the end of the cross slide screw you will see the "telescope" moving in or out as the bed travels.
People tend to either love or hate Southbends. I am in the later group but I have to admit that their taper attachment is pretty much fool proof and easy to use compared to my other machines where the cross feed nut does have to be disconnected.
02-01-2010, 08:24 PM #14
Scottie and Clive, thanks for the confirmation. After that foray yesterday my assumption was that I have a telescoping screw. I didn't expect to be so fortunate hence starting in the direction I did.
Clive I will PM you for drawings, thanks.
Scottie, in the shop I worked in we had four lathes, all old, all manual. I remember a Clausing, Lodge & Shipley a Cincinatti and I can't remember the other one. I really, really, REALLY liked the Cincinatti. It was about a 6' bed gear head. Feeds and speed changes were a snap. Apron controls great!
But this Southbend is MINE. I still can't believe I OWN a lathe. I will admit though that I'll be doing a project in the shop and think " I can make up a tool in the lathe pretty quick" then look over at the SB and........... darn, it's in back gear.......... Runnin' 2 rpm!! ...... It'll take me longer to change the speed and feeds than to do something different.
OK, I'll stop whining now. It's just a time management issue that's all. I didn't realize how spoiled I'd become on the Cincinatti.
I'll completely dis-assemble the taper unit when time permits and report back. It'll complete my understanding of the workings anyway.
Thanks all for the help, knn
02-01-2010, 09:05 PM #15
I don't mean to run your lathe down. I proudly owned my SB for a couple of years, made lots of parts, and learned a whole lot with it. I just never fell in love like my other machines. It's kind of a Ford/Chevy sort of thing.
BTW - the other answer is Chevy. :-)
02-01-2010, 09:33 PM #16
No offense taken, my heavy work truck is an old Chevy, my light runner is a Ford. If it's in my price range (cash) and it gets the job done it's golden. I upgrade when I can.
Turnin' out the work and feedin' the family is the game.