R8 Arbor With Jacobs Taper

[kingmt01]

I can't match those numbers to anything standard.

The more you do precision turning the better you get at it. It seems that in it's current state the arbor is useless anyway so if you screw it up, all you are out is your time.

Just seem your edit. I didn't know if it was the arbor out chuck. The chuck is cheap so I don't care to lap it. If you think it is the arbor I'll just lap them to fit together. I'm really hurting for a chuck ATM.

 

[JimDawson]

The angle on the arbor seems to be too shallow for any Jacobs taper. A Jacobs #33 is 3.6371°

 

[kingmt01]

But I wonder if me being off a thou or two could have that angle that far off. I really think a standard to check them with is probably the best option here. I'll pull one of my others apart. Maybe two of them since I don't know if any of them is correct. I'll check a working one with another working one & that should be reasonable proof to validat it. Then I'll have a standard to see which one is bad.

 

[chips&more]

I believe if it saves “JT” that means a Jarno taper and not a Jacobs taper.

 

[middle.road]

I believe if it saves “JT” that means a Jarno taper and not a Jacobs taper.

You don't suppose??? I haven't seen Jarno in years. At least Jarno is a consistent angle whereas Jacobs taper is all over the place.

 

[kingmt01]

I no longer believe it is a Jacob's. I pulled the chuck from my larger lathe & it was a different taper. Something that started with a B. Sorry I already forgot what it was but it comes pretty close to fitting. I believe it is the correct taper but still needs lapped.

 

[buddy3223]

I have the same machine that you have. I had the same problem with mine. I found that the r-8 shaft that came with the machine is a JT-3 not a JT-33. I bought a new JT-33 to fit my chuck. Hope that this will help.

 

[kingmt01]

Thanks buddy3223. The chuck marked B16 that I have seems to fit pretty close. I think if be better off buying an chuck instead of an arbor.

 

[kingmt01]

I believe the B16 is the correct taper.







It fits my mill arbor much better then it does the Morris taper from my lathe which it came with.