Jacobs Taper?

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   I have searched extensively online but cannot find the information that I am looking for.
I have a old lathe that has a jacobs taper tailstock. I would assume the lathe is American but there is no identification on it anywhere. The autofeed gearset is missing and I can only assume that the manufacturers name would have been on the cover for the autofeed.
A British electric motor has been retrofitted a long time ago but that is because our mains voltage in Australia is 240 / 415v.
Anyway, is/was jacobs taper a industry standard in the USA in the 1930's-1940's?
I cannot seem to find a live center for the machine. I have had to make special holders for jobs that can be chucked into the drill chuck, this is not ideal and am thinking of modifying the tailstock to accept morse taper which is readily availible.
There is plenty of data about this but nothing about the industry standards in each country over the years. I know there are a few very talented machinists on here that may be able to shed some light on the situation. Thanks. 
Lucas.

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Lucas660 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Apr/16/2012 Location: Vic, Australia Status: Offline Points: 1344	Post Options Post Reply Quote Lucas660 Report Post Thanks(0) Quote Reply Topic: Jacobs Taper? Posted: Nov/26/2014 at 4:41pm
	I have searched extensively online but cannot find the information that I am looking for. I have a old lathe that has a jacobs taper tailstock. I would assume the lathe is American but there is no identification on it anywhere. The autofeed gearset is missing and I can only assume that the manufacturers name would have been on the cover for the autofeed. A British electric motor has been retrofitted a long time ago but that is because our mains voltage in Australia is 240 / 415v. Anyway, is/was jacobs taper a industry standard in the USA in the 1930's-1940's? I cannot seem to find a live center for the machine. I have had to make special holders for jobs that can be chucked into the drill chuck, this is not ideal and am thinking of modifying the tailstock to accept morse taper which is readily availible. There is plenty of data about this but nothing about the industry standards in each country over the years. I know there are a few very talented machinists on here that may be able to shed some light on the situation. Thanks. Lucas.

70RebelGeezer Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Nov/28/2010 Location: Canada Status: Offline Points: 508	Post Options Post Reply Quote 70RebelGeezer Report Post Thanks(0) Quote Reply Posted: Nov/26/2014 at 5:43pm
	Morse Tapers are standard on North American built Lathes......never heard of, nor encountered any lathe that had anything but a Morse Taper in the tailstock. I've used lathes, since starting my trade in 1975, that were manufactured as old as 1910 right on up to modern day machines and all had Morse Tapers. No exceptions. Those machines were both North American or European built. Jacobs tapers are used on drill chuck arbours, where the chuck mounts onto the arbour. I hope this is helpful. Ron
	'68 Rebel SST Selling Bellcranks '67-69,'70-up big body cars 3rd gen. American with V-8 Bellcrank assemblies Gremlin and Hornet Z-bar now available Z-bar Bronze Bushing Rebel Gas Tank Straps

401MATCOUPE Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: May/20/2010 Location: Salisbury, MD Status: Offline Points: 5368	Post Options Post Reply Quote 401MATCOUPE Report Post Thanks(0) Quote Reply Posted: Nov/26/2014 at 5:54pm
	I agree with 70RebelGezzer, on tail stock taper on most Lathe's, US or foreign made have Morse Taper. The Jacobs Taper is a very short, self locking taper for drill chucks adapters or drill spindles. Check out how short the taper is on the chart below. My experience is a J33 is most common on 1/2" drill presses and hand drills. JACOBS TAPERS JACOBS LARGE SMALL TAPER# DIAMETER DIAMETER LENGTH --------------------------------------- 0 .25000" .22844 .43750 1 .38400 .33341 .65625 2 .55900 .48764 .87500 2 short .54880 .48764 .75000 3 .81100 .74610 1.21875 4 1.12400 1.03720 1.65625 5 1.41300 1.31611 1.87500 6 .67600 .62409 1.00000 33 .62401 .56051 1.00000 --------------------------------------- Here is the data on Morse Taper...loook how long it is. The Morse Taper Number on a lathe tail stock is usually based on the "swing" of the lathe. My 10" swing South Bend has a #2 MT, My 14" has a #3MT and My 22" Drill Press has a #5MT. MORSE TAPERS LARGE SMALL MORSE DIAMETER DIAMETER TAPER# (A) (B) LENGTH --------------------------------------- 0 .35610" .25200 1-15/16 1 .47500 .36900 2-1/16 2 .70000 .57200 2-1/2 3 .93800 .77800 3-1/16 4 1.23100 1.02000 3-7/8 4-1/2 1.50000 1.26600 4-5/16 5 1.74800 1.47500 4-15/16 6 2.49400 2.11600 7 7 3.27000 2.75000 9-1/2 --------------------------------------- Some old Milling Machines and Lathes had a Brown and Sharp Taper...very unusual, but here is the Taper data for them. BROWN + SHARPE TAPERS LARGE SMALL B+S DIAMETER DIAMETER TAPER# (A) (B) LENGTH --------------------------------------- 1 .23922" .20000 15/16 2 .29968 .25000 1-3/16 3 .37525 .31250 1-1/2 4 .40233 .35000 1-1/4 5 .52315 .45000 1-3/4 6 .59961 .50000 2-3/8 7 .72537 .60000 3 8 .89873 .75000 3-9/16 9 1.06705 .90010 4 10 1.28927 1.04465 5-11/16 11 1.53176 1.24995 6-3/4 12 1.79681 1.50010 7-1/8 13 2.07310 1.75005 7-3/4 14 2.34375 2.00000 8-1/4 15 2.61458 2.25000 8-3/4 --------------------------------------- Hope this helps!!
	Ross K. Peterson 68X,GoPac,343,AT,52A(1stCar) 68X,GoPac,390,4sp,52A 69X,GoPac,390,4sp,64A 70X,GoPac,390,4sp,87A,8 70X,GoPac,390,4sp,BBO,8 70 Jav SST,390,AT,BSO 74MatX,401,AT,Prototype 74MatX,401,AT

Lucas660 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Apr/16/2012 Location: Vic, Australia Status: Offline Points: 1344	Post Options Post Reply Quote Lucas660 Report Post Thanks(0) Quote Reply Posted: Nov/27/2014 at 1:35am
	This does help and it seems the machine has a Brown and Sharpe taper. Might be time to do some modifications to the machine. Thanks for your help.

401MATCOUPE Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: May/20/2010 Location: Salisbury, MD Status: Offline Points: 5368	Post Options Post Reply Quote 401MATCOUPE Report Post Thanks(0) Quote Reply Posted: Nov/27/2014 at 5:51am
	Just a thought, if you do have a Brown and Sharp Taper, depending on the size, you may be able to rework with a Morse Taper reamer. I have built a couple of tail stock rams for old lathe and used such reamer to establish the proper taper....using another lathe. Hope all the helps.
	Ross K. Peterson 68X,GoPac,343,AT,52A(1stCar) 68X,GoPac,390,4sp,52A 69X,GoPac,390,4sp,64A 70X,GoPac,390,4sp,87A,8 70X,GoPac,390,4sp,BBO,8 70 Jav SST,390,AT,BSO 74MatX,401,AT,Prototype 74MatX,401,AT