# Help adjusting buck chuck



## VegasF6 (Jan 3, 2010)

Back in November I purchased a 3 jaw Buck chuck, seen here. It is a model 3634, a discontinued model. The seller called it a "true set" chuck, not sure what he meant by that but I assumed it was the same as "adjust-tru" or some other variant. What I am getting at, was I figured you loosen up a bolt on the outside of the chuck and tighten up one 180 degrees across and that allows you to adjust it. Like here:
http://www.buckchuckusa.com/userfiles/How to Mount and Operate(2).pdf

But, if I loosen say #2 half a turn, #4 won't tighten any more than it already is. 

Now my chuck has an L00 taper integral to it, it isn't a separate back plate from the chuck, so I guess that is the problem?? (at least, I don't THINK they come apart) And what would the 4 numbered screws around the outside do then? 

Should I dis-assemble this thing for cleaning, or leave it alone? I really dunno what is inside of it, I have only removed the jaws and cleaned and oiled what I could see from there.

Thanks


----------



## gadget_lover (Jan 3, 2010)

According to that pdf, there is a backing plate, and there should be 6 screws in the front of the chuck holding the chuck to the mounting plate.

The 4 screws will not do much unless you can loosen the 6 screws to allow it to move.

If there is no mounting plate I would guess it is not an "adjust-tru" chuck.

Daniel


----------



## wquiles (Jan 3, 2010)

VegasF6 said:


> Back in November I purchased a 3 jaw Buck chuck, seen here. It is a model 3634, a discontinued model. The seller called it a "true set" chuck, not sure what he meant by that but I assumed it was the same as "adjust-tru" or some other variant. What I am getting at, was I figured you loosen up a bolt on the outside of the chuck and tighten up one 180 degrees across and that allows you to adjust it. Like here:
> http://www.buckchuckusa.com/userfiles/How to Mount and Operate(2).pdf
> 
> But, if I loosen say #2 half a turn, #4 won't tighten any more than it already is.
> ...


I would definitely dis-assemble for cleaning before you do anything else. The back mounting plate does come out. Those 4 numbered screws are what gives the chuck the adjustability. Here are the pictures of my own Buck Chuck:
link ...

I have a set-tru Buck Chuck (6" model) and also a Bison set-tru (also 6" model). Both of them are setup/adjusted in the same way. Setting/adjusting one is easy, but a little bit time consuming the first time (while you get the hang of it).

Basically, the mounting holes for the chuck are cut oversize, which allows the chuck to move radially on the mounting plate/surface. Then the chuck has 4 bolts radially which move the chuck against the inner part of the mounting plate - like in this picture of the mounting plate of my Buck Chuck:







By using a straight shaft held in the chuck and a dial indicator, you mount the chuck, but not fully tight, and then use the radial screws to slightly move the chuck as you rotate it so that the shaft is centered. Then you carefully tighten the mounting bolts, as you continue to adjust the radial bolts (every time you tighten the mounting bolts the chuck will move slowly!), until you achieve the desired level of accuracy. For both of my chucks, I have been able to get them with a runout of less than 0.0005", typically around 0.0003" or so).

I have some pictures of adjusting my Bison set-tru chuck in here:
cleaning and mounting a 6" Bison set-tru chuck ...


Will


----------



## VegasF6 (Jan 3, 2010)

Thanks for the replies. There are 12 screws in the front, apparently they actually hold the chuck together (2 circles of 6.) Not really what I had expected, but then, like I said, I don't think there is a backing plate per say?

Will, thank you as well, I had already perused the post you linked with the Yuasa rotary table, very nice. The second, about your Bison chuck was new to me. I proceeded to try and take this thing apart today, and I did get it into some pieces, but I still can't figure out how to adjust it for run-out. I have to run out but let me post some quick pics:





















It looks pretty clean inside, I thought. (all those lumps are just grease, but it doesn't feel too gritty) so I dunno if I should clean that out or not. If I do, what do you all think of using moly-grease from my motorcycle differential to lube it up again??


----------



## wquiles (Jan 3, 2010)

What you are holding there is actually two parts: the bottom of the chuck, and the mounting plate. They are just fairly "welded" together from grime and rust - same thing happened to me.


VegasF6 said:


>





You have to remove the 4 radial screws that do the adjustment for the set-tru function, and keep working with degreaser (and time for it to work through all nuts and crannies) until you can get the two parts separated.


----------



## VegasF6 (Jan 3, 2010)

Ohhhhh..... ha, I don't know whether to be embarrased or not, but then, you never learn without asking I guess.





There she is, in two pieces (well, 2 more). And there are the chips that came with it. Please excuse the paint job. 





Here are the little things that push against the center thingy when you turn the outer threaded thingys. I hope I am not turning anyone off with the technical terms? I tried to count the turns when I took them out, but I kind of lost track. 





This is just another picture. Figured since I took it I would post it. Tomorrow I would like to clean it up and put it back together, but, like I mentioned above I don't have the special grease. Any suggestions for substitutions?


----------



## tkelley (Jan 3, 2010)

I have mounted several Buck Set True Chucks. Some "Chuck to mount" engagements have clearance to allow the "set true" bolts to be able to move the mount inside the chuck bore... but I have some that I have seen that had a tight fit. It depends on who..., and how they originally mounted the mount to the chuck...

Loosen the radial bolts, set two big blocks on the floor, turn the chuck "mount down" towards floor and drop it... in such a way that the chuck body lands on the boards and inertia will tug the mount out. With an "L" mount, you will probably have to have some tall boards...

The idea is the chuck body hits the blocks stopping the chuck before the mount hits the floor. 

This will seperate the mount, and in some cases can be the only way to do it. It might take several drops. Don't drop it from too much height.
All you need is a few good bumps.
Watch out that you dont get it on your toes.
Hope this helps.
Tom


----------



## gadget_lover (Jan 3, 2010)

The number of turns of the little thingys that adjust it don't matter much. When you re-assemble it you'll start will all of them loose, and slowly tighten / loosen them till the test rod is centered.

Congrats on the nice chuck!

Daniel


----------



## unterhausen (Jan 4, 2010)

I thought everything that could be screwed up on my lathe was screwed up, but my Buck adjusted just fine. Thanks for the pictures, interesting to see it taken apart.


----------



## 65535 (Jan 4, 2010)

Someone correct me if I'm wrong, but the 4 alignment bolts are used exactly how a normal four jaw independent chuck work.


----------



## wquiles (Jan 4, 2010)

65535 said:


> Someone correct me if I'm wrong, but the 4 alignment bolts are used exactly how a normal four jaw independent chuck work.



Yup, exactly in the same way. Once you get to the desired TIR, you tighten the mounting bolts (while still checking the TIR) and then the chuck will retain the TIR for a long time :devil:

Will


----------



## precisionworks (Jan 4, 2010)

> Watch out that you dont get it on your toes.




:welcome:


----------



## VegasF6 (Jan 5, 2010)

I didn't really get to this today, had more computer problems. But, I think I want to order the 6" x 1" thomson shafting mentione by Bryan in other posts from Enco. Trying to round up an order now. Still searching for something to use for grease, at this point I am looking at white lithium.


----------



## wquiles (Jan 5, 2010)

VegasF6 said:


> I didn't really get to this today, had more computer problems. But, I think I want to order the 6" x 1" thomson shafting mentione by Bryan in other posts from Enco. Trying to round up an order now. Still searching for something to use for grease, at this point I am looking at white lithium.



That is the same precision shaft I use - great surface finish!

For grease, the "ideal" is the one I used from Bison (supposed to be "designed" for this job), but probably any good grease will work OK for now. You can always open it up and clean it again with a different grease in the future


----------



## VegasF6 (Jan 5, 2010)

wquiles said:


> That is the same precision shaft I use - great surface finish!
> *Yep, saw it posted, sounds good. It actually might be part of my problem, but it won't hurt to go through this thing. Right now I am indicating an end mill shaft, and the surface isn't too good. And my indicator. And the magbase. Hmm, this sounds expensive *
> 
> For grease, the "ideal" is the one I used from Bison (supposed to be "designed" for this job), but probably any good grease will work OK for now. You can always open it up and clean it again with a different grease in the future


 
*Your Ebay auction link no longer shows, so I wasn't able to see the grease you bought, but is it the same as this?*
*http://brassandtool.com/Chucks-Collet.html*
*I did peruse a manual for a Buck ATSC chuck, but I didn't see anything about grease, only to properly lubricate. **(Source)*
*I really need to get it back together before I forget/lose interest as I am wont to do, but I agree I can always open it up again later. I already know it won't be today as I am worthless on Tuesdays.*


----------



## gadget_lover (Jan 5, 2010)

VegasF6 said:


> *... but I agree I can always open it up again later. I already know it won't be today as I am worthless on Tuesdays.*



Hmmm. Tuesdays. never thought plan my procrastination that far in advance. I bow to the master. 

See tag line. 

Daniel


----------



## wquiles (Jan 5, 2010)

VegasF6 said:


> *Your Ebay auction link no longer shows, so I wasn't able to see the grease you bought, but is it the same as this?*
> *http://brassandtool.com/Chucks-Collet.html*
> *I did peruse a manual for a Buck ATSC chuck, but I didn't see anything about grease, only to properly lubricate. **(Source)*
> *I really need to get it back together before I forget/lose interest as I am wont to do, but I agree I can always open it up again later. I already know it won't be today as I am worthless on Tuesdays.*



Yup, that's the one I used :twothumbs

But again, in all honestly, I think any good, quality grease for gears will work fine in this application.


----------



## Anglepoise (Jan 5, 2010)

It has been my experience that grease causes problems when used on a lathe chuck. The grease does not sling and stays where it's placed, but attracts swarf and that's the last thing you need. 

Use a quality way oil and you will be fine. This is one time when you do NOT want to take the manufacturers sugestions.


----------



## VegasF6 (Jan 6, 2010)

gadget_lover said:


> Hmmm. Tuesdays. never thought plan my procrastination that far in advance. I bow to the master.
> 
> See tag line.
> 
> Daniel


That is too funny. Tuesday is my first shift back to work and I am always doing it on very minimal sleep 



Anglepoise said:


> It has been my experience that grease causes problems when used on a lathe chuck. The grease does not sling and stays where it's placed, but attracts swarf and that's the last thing you need.
> 
> Use a quality way oil and you will be fine. This is one time when you do NOT want to take the manufacturers sugestions.


 
There does seem to be a lot of opinions on this. One that I found, and I liked it, was to grease the inside part of the scroll and such and oil the outer parts. Notice when looking at my pictures that the parts that already have grease on them seem to be pretty much chip free. The pictures showing the pinion. 

I emailed Buck and they told me to use a "standard chuck grease" like, for instance available from World Wide Chuck Services. So, I check that, and it appears the minimum order is 12 tubes. But, I didn't email them yet. If any reading this would like to, please post there results. We could try and set up a group buy. But, I am not going to sweat it that much at this point, and will use either the moly or the white lithium. 

The latest Enco flyer shows a sale on Mobil Vactra #2 way oil, I plan on ordering that as well.


----------

