# 5" Bison 6-Jaw Set-Tru Chuck Adapter for HF 8X14



## darkzero (May 24, 2009)

I originally planned to use my current adapter that I have for my 5" 3-jaw since the mounting holes lined up perfectly. It wouldn't make use of the Set-Tru feature though. Not knowing anything about making an adapter plate, I decided to try and make one. 

To make the job easier I drove down to LMS yesterday & picked up a 5" threaded adapter with no holes. Of course my spindle is not threaded but I thought of an idea to use this adapter "backwards".













I wanted to use the front side of the adapter where the chuck would normaly sit with the raised boss as the backside to bolt onto my spindle. I needed to machine the raised part off but I had couldn't chuck the adapter nicely in the chuck. First I had to machine the other side a bit.






Now I was able to get a good grip on it. I proceeded to remove the raised part.






Then I machined the entire face to make sure it was nice & flat then chamfered the edge.











Got sideracked & decided to roughly bore out the threads which I didn't plan on doing yet.






Next I bored the counterbore to fit my spindle. My current adapter for the 3-jaw fits very loose so I wanted to make this one as tight as I could. The register on my spindle measures 2.832". As inexperienced as I am with machining I managed to bore it out to 2.833". I almost have to press it on to fit. Perfect! 





















Next I had to make the holes to bolt onto the spindle. I originally planned on removing the spindle from the headstock so I could use a transfer punch. Well I couldn't get the spindle out of the headstock & didn't want to risk it screwing it up. 

I thought about making some pointed shanks like Will did but I was too lazy to put my chuck back on, adjust it, then make them. The screw holes on the spindle are bigger than the screws & there's a lot of play. Since I got the adapter to fit the spindle pretty tight I didn't think making the screws hole perfect was a big deal. 

I applied some double sided mounting tape then tapped the adapter against the spindle to make impressions of the holes. Then I eyeballed it & center punched them.











Drilled the holes but not all the way through, chamfered, then tapped the threads.
















Next I bolted the adapter onto the spindle. Again, machined the face to make sure it's nice & flat. Then I made the final through hole bore to match the chuck.
















Then I turned down the end which I would be using for the boss for the Set-Tru feature. I wanted this to be a perfect fit right now so the chuck is centered so I can transfer punch the mounting holes for the chuck onto the adapter. The bore on my 5" Bison measures 2.165". I turned the boss down to 2.164". Slid the chuck onto the adapter & transfer punched for the holes.











Drilled all the way through, chamfered, & threaded. Adapter is all done. Fits as perfect as I was hoping to get.


























Was a great experience, took most of the day & I'm beat. Not sure if I did it the "correct way" but it turned out good & mostly importantlt it works! I'm pretty proud of myself considering I had no idea what I was doing when I started. I don't like the pits in the cast iron, my adapter 3-jaw is like this too but I can live with it I guess.

Damn cast iron is messy & nasty! I hope I don't ever have to do this again. It took the second half of the day just to clean the mess & the lathe!

As for the boss for the Set-Tru. I'm assuming it should have more room for play rather than the tight fit I have now for adjusting? I came across a thread on CNCzone where some one says to make the boss with a 0.50" undersize. That seems like way too much if this is the part he is referring to? In Bison's PDF it says the bore is 2.1654" & the boss on their adapters is 2.164" which is what mine is at now. Should I leave it as is or do I need to turn it down some?

Thanks.


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## precisionworks (May 24, 2009)

Nicely done



> cast iron is messy & nasty... It took the second half of the day just to clean the mess & the lathe!


A shop vac, the type with the larger, 2 1/2" hose, is the ticket for turning CI. Either keep the end of the hose close to the tool, or make a collector end for the hose. Even after a few hours of CI turning & boring, there's just a light dusting on my lathe or mill.

I got the shop vac idea after watching some CI parts being run in a custom motorcycle engine shop. They specialize in big displacement V-twin motors for drag bikes, and machine the jugs from Durabar cast iron billet. Probably 95% of the Durabar ends up in the chip collector (after fining & boring). Each lathe has a 4" flex duct hanging right above the headstock, which is about what I do with the shop vac.

http://www.kingofcubes.com/prod-promotors.htm


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## Mirage_Man (May 24, 2009)

Looks great Will. 

I'm certainly no expert but I don't think the diameter of the register on the adapter plate is super critical. You're using the four bolts to adjust off it and the bolts on the face of the chuck to clamp it down.


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## wquiles (May 24, 2009)

Mirage_Man said:


> Looks great Will.
> 
> I'm certainly no expert but I don't think the diameter of the register on the adapter plate is super critical. You're using the three bolts to adjust off it and the bolts on the face of the chuck to clamp it down.



+1. That is the beauty of the set-true feature 


By the way Will, GREAT job - looks very professional :twothumbs

You are going to love the set-tru chuck 

Will


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## darkzero (May 24, 2009)

Thanks fellas. I thought I would need more play than 0.001" for the register. But then again it's designed to make adjustments under 0.001" with the four adjustment bolts so I guess I should just leave it as is?


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## Mirage_Man (May 24, 2009)

darkzero said:


> Thanks fellas. I thought I would need more play than 0.001" for the register. But then again it's designed to make adjustments under 0.001" with the *four* adjustment bolts so I guess I should just leave it as is?



Depends how close it is now I guess. 

I know you can use a drill shank but I ordered a 6" piece of 1" diameter Thomson shafting to indicate in my Set-Tru. I can't remember if I got it from Enco or MSC but it was only like $5 or $6. I also use it in the collet indexer on the mill to set center.


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## gadget_lover (May 24, 2009)

Since the adjustment bolts are the bearing surface, the fit does not have to be quite as tight. I'd take the time now to make the shoulder .005 undersize so that you have that much adjustment available if you ever need it. Not that you'd ever wear spring a jaw, wear a bad spot on the scroll, etc.



Daniel


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## wquiles (May 24, 2009)

darkzero said:


> Thanks fellas. I thought I would need more play than 0.001" for the register. But then again it's designed to make adjustments under 0.001" with the four adjustment bolts so I guess I should just leave it as is?



It is great that the mounting plate has a tight fit to the spindle, but that Bison chuck with the set-tru "has" to be allowed to move radially from the center of the spindle, so that the set-tru bolts can center the chuck. If the chuck can't move on the mounting plate radially, then you are wasting money by using a set-tru chuck, as it would negate the adjustability of the radial bolts.

This is also the case with my Buck Chuck 6" that I have mounted in my RT. It and the Bison can move a few mills on the mounting plate - that is how they should work 




gadget_lover said:


> Since the adjustment bolts are the bearing surface, the fit does not have to be quite as tight. I'd take the time now to make the shoulder .005 undersize so that you have that much adjustment available if you ever need it. Not that you'd ever wear spring a jaw, wear a bad spot on the scroll, etc.


+1


Will


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## wquiles (May 24, 2009)

Mirage_Man said:


> Depends how close it is now I guess.
> 
> I know you can use a drill shank but I ordered a 6" piece of 1" diameter Thomson shafting to indicate in my Set-Tru. I can't remember if I got it from Enco or MSC but it was only like $5 or $6. I also use it in the collet indexer on the mill to set center.



I tried to find it some time ago when you first mentioned, and I have not been able to find it yet. Can you please let me/us know more specific details, a part # perhaps?

I tried using plain drill rod from Enco, but it is not nearly as smooth, surface-wise, and it is completely worthless to set the chuck as the needle on the indicator jumps not from the alignement, but from the poor surface finish. I have a smaller dia higher grade drill rod that I use now, but I want to get a 6" piece of 1" as well.

Will


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## Mirage_Man (May 24, 2009)

wquiles said:


> I tried to find it some time ago when you first mentioned, and I have not been able to find it yet. Can you please let me/us know more specific details, a part # perhaps?
> 
> I tried using plain drill rod from Enco, but it is not nearly as smooth, surface-wise, and it is completely worthless to set the chuck as the needle on the indicator jumps not from the alignement, but from the poor surface finish. I have a smaller dia higher grade drill rod that I use now, but I want to get a 6" piece of 1" as well.
> 
> Will



HERE ya go.


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## wquiles (May 24, 2009)

Mirage_Man said:


> HERE ya go.



Ordered. Thank you my friend 

Will


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## darkzero (May 24, 2009)

gadget_lover said:


> Since the adjustment bolts are the bearing surface, the fit does not have to be quite as tight. I'd take the time now to make the shoulder .005 undersize so that you have that much adjustment available if you ever need it. Not that you'd ever wear spring a jaw, wear a bad spot on the scroll, etc.
> 
> 
> 
> Daniel


 
Cool, thanks Daniel for the recommendation. I planned on taking more off after fitting the chuck, just didn't know how much. I'll see what TIR I get now & will take off another 4 thou while I'm at it.




wquiles said:


> It is great that the mounting plate has a tight fit to the spindle, but that Bison chuck with the set-tru "has" to be allowed to move radially from the center of the spindle, so that the set-tru bolts can center the chuck. If the chuck can't move on the mounting plate radially, then you are wasting money by using a set-tru chuck, as it would negate the adjustability of the radial bolts.
> 
> Will


 
That's exactly what I was thinking. I only made the fit tight to start to help me get the mounting bolt locations done. Guess it wasn't really a big deal since there's enough play with the mounting bolts. The link from CNCzone said 0.050" which I thought was way too much. I'll go with Daniel's recommendation. I'm glad I decided to take on making this adapter as my original plan was to use my current adapter which would not have made use of the Set-Tru feature. Thank you for always posting your very informative threads. It has helped me a lot with my lathe! Thanks for all the help you've kindly gave me! :thumbsup:

Brian mentioned 3 bolts. Does the 6" set tru have 3 or 4 bolts? Is it tedious to get it adjusted under 0.001" TIR?




Mirage_Man said:


> HERE ya go.


 
Thanks Brian. I'm going to order that too. I'm using .75" drill rod now & I too notice inconsistencies through out the rod. Not a big deal as I can't get my current chuck under 0.002" TIR anyway.


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## Mirage_Man (May 24, 2009)

darkzero said:


> Brian mentioned 3 bolts. Does the 6" set tru have 3 or 4 bolts? Is it tedious to get it adjusted under 0.001" TIR?



It's the 3 bolts on the face of the chuck that you cinch up tight to lock it in place when you get the chuck dialed in with the 4 bolts around the outside of the chuck.


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## precisionworks (May 24, 2009)

> I ordered a piece of 1" diameter Thomson shafting


 60 Case shafting comes in quite a few tolerance classes, with the L class being the most common. 

L - For use with XA, Open and Adjustable Ball Bushing bearings and Pillow Blocks as well as Super Ball Bushing bearings and Super Smart Ball Bushing bearings 

S - For use with A type ball bushings 

D - For use with Thomson Die Set Ball Bushing bearings 

G - Ball Grooved for use with Thomson Super Ball bushing 

N - For use with needle roller bearings 

For Class L, S, D & G, roundness is within 0.000080”. Class N is tighter, with roundness of .000050”. Not a great deal of difference between the two.


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## darkzero (May 24, 2009)

Mirage_Man said:


> It's the 3 bolts on the face of the chuck that you cinch up tight to lock it in place when you get the chuck dialed in with the 4 bolts around the outside of the chuck.


 
Thanks for clarifying. I was confused by this:



Mirage_Man said:


> I'm certainly no expert but I don't think the diameter of the register on the adapter plate is super critical. You're using the* three* bolts to adjust off it and the bolts on the face of the chuck to clamp it down.


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## Mirage_Man (May 24, 2009)

darkzero said:


> Thanks for clarifying. I was confused by this:



Ahh I can see why you would be confused. A typo on my part. Will fix momentarily.


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## wquiles (May 24, 2009)

darkzero said:


> Brian mentioned 3 bolts. Does the 6" set tru have 3 or 4 bolts? Is it tedious to get it adjusted under 0.001" TIR?



The 6" chuck that Brian and I have uses 3 bolts on the face, to bolt down to the mounting plate; and 4 radially-adjusted bolts, to adjust the run-out.

Yes, it is tedious to get under 0.001 TIR, but only because you never done before. Once you do it 2-3 times, it starts making more and more sense.

The thing that makes it harder, is that as you start to achieve the under 0.001 TIR and start tightening the 3 mounting bolts, the chuck will move and increase the TIR!!!. So, the key is to get the TIR adjusted, tighten the bolts, adjust the TIR again, tighten some more, etc.. Every time I have done it, have been able to get under 0.001" TIR, both on the Bison and on the Buck Chuck 

Will


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## darkzero (Jun 14, 2009)

I must say, I'm pretty damn happy right now!


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## Mirage_Man (Jun 14, 2009)

Sweet! :twothumbs

BTW if you're not already doing it a little squirt of WD-40 or kerosene on the aluminum while you're turning it will improve the finish and reduce BUE on the insert.


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## wquiles (Jun 14, 2009)

Didn't Brian and I tell you that the Bison set-tru was the bomb? :devil:

That looks awesome dude :twothumbs


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## darkzero (Jun 15, 2009)

Thanks fellas. Yup you guys were right & I'm glad I did listen you guys (my wallet is not though)! What a huge difference. Turned down some plastic reflectors which my 3 jaw was not able to hold very well. :twothumbs


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