# Compound dial question



## Investigator (Nov 30, 2017)

New issue.....  When trying to turn and set the scale on the compound dial to zero, it seems the dial will not move.  I have released the set screw, in fact I took it all the way out.   I can find only one set screw in the dial.  The dial still is 'stuck' to the handle.  In other words, it will not turn freely on the handle.

I have looked and thought and thought.  I am 'pretty sure' that it is just stuck from dried sludge and gunk.  However, I wanted to make sure I haven't missed anything before I start using more than just my hands to try to free it up.

Suggestions?


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## Investigator (Nov 30, 2017)

It appears from this parts diagram that the outer dial is attached by 2 screws to the 'hub', and the cross feed dial (which I can't get to move) is held firm by one set screw.  

My thought is to remove the 2 screws holding the handwheel on, and try to take the crossfeed dial off and clean everything.


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## Tony Wells (Nov 30, 2017)

It's not unusual for dials to get "stuck" from non-use. You're on the right track though, just take it apart and clean it. This happens a lot when people put DRO's on machines. Then the dials are virtually forgotten.


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## RandyM (Nov 30, 2017)

To aid in getting it apart, try applying liberal amounts of WD40 or another type of penetrant or parts cleaner.


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## magu (Nov 30, 2017)

For what it's worth, I don't even zero my dials anymore, I just work in relative measurements. Your plan looks good though.


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## Investigator (Nov 30, 2017)

magu said:


> For what it's worth, I don't even zero my dials anymore, I just work in relative measurements. Your plan looks good though.




I have considered that.   I realize though that I don't have enough experience to do it yet.  Training wheels first.......


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## magu (Nov 30, 2017)

That seems an awful lot like you're implying I _might_ have a vague idea of what I'm doing. I reject that notion! I actually didn't know you could zero the dials when I started, then I learned you could, but sometimes forgot to, so I said that's too complicated and just went back to ignoring the fact that they can be zeroed.


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## RandyM (Nov 30, 2017)

Be careful when you take the handle hub off, the ball bearings will fall out. Unless the old gunk holds onto them.


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## woodchucker (Nov 30, 2017)

RandyM said:


> To aid in getting it apart, try applying liberal amounts of WD40 or another type of penetrant or parts cleaner.


Blaster.. better than WD40


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## magu (Nov 30, 2017)

woodchucker said:


> Blaster.. better than WD40



Agreed, for me PB Blaster is like the franks red hot commercial: "I put that $h!t on everything!" 

WD40 has been relegated to quick and dirty rust prevention.


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## RandyM (Nov 30, 2017)

Let's not stray from topic gentlemen.

Thanks.


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## Investigator (Nov 30, 2017)

RandyM said:


> Be careful when you take the handle hub off, the ball bearings will fall out. Unless the old gunk holds onto them.


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## Investigator (Nov 30, 2017)

thanks, I did not see ball bearings on the exploded drawing. I will go back and look again


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## Nogoingback (Nov 30, 2017)

You should be able to remove the handle and then clean and lube the assembly.  On mine the dial will jam if the nuts that secure the handle
are too tight though adjusting them is finicky because they have an effect on backlash.  Though your parts diagram looks different than mine,
now that I look at it...


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## RandyM (Nov 30, 2017)

Investigator said:


> thanks, I did not see ball bearings on the exploded drawing. I will go back and look again



They are behind the hub and pushed on by the springs.


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## RandyM (Nov 30, 2017)

Nogoingback said:


> If yours is like mine, there is a bushing there: no balls to fall out.  You should be able to remove the handle and then clean and lube the assembly.



I was using the diagram he posted. LA1164 (spring) and 0945 (Ball) as shown. There are three balls and three springs. It looks just like my 6561H


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## Nogoingback (Nov 30, 2017)

RandyM said:


> They are behind the hub and pushed on by the springs.



Randy, didn't someone post something a while back on working that assembly?


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## RandyM (Nov 30, 2017)

Nogoingback said:


> Randy, didn't someone post something a while back on working that assembly?



Yeah, It was probably me asking how to assemble the spring loaded balls. I was struggling with it at the time.

I found the thread.

http://www.hobby-machinist.com/threads/logan-6561h-compound-dial.53694/


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## juiceclone (Nov 30, 2017)

yes, run some solvent down the setscrew hole, and I'd crack the handle nut loose.....u never know...


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## Nogoingback (Nov 30, 2017)

RandyM said:


> Yeah, It was probably me asking how to assemble the spring loaded balls. I was struggling with it at the time.
> 
> I found the thread.
> 
> http://www.hobby-machinist.com/threads/logan-6561h-compound-dial.53694/



Yup, that's the one I was thinking of.


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## Investigator (Nov 30, 2017)

I got it all apart.  It there is more to it than the parts diagram shows.  Some of it I don't understand why they did it.  I will post pics tonight or in the morning.  Parts are soaking to clean the 'stuff' off of them.


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## Investigator (Nov 30, 2017)

RandyM said:


> Yeah, It was probably me asking how to assemble the spring loaded balls. I was struggling with it at the time.
> 
> I found the thread.
> 
> http://www.hobby-machinist.com/threads/logan-6561h-compound-dial.53694/



What do the three spring loaded balls do?


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## Investigator (Nov 30, 2017)

OK, got her cleaned and pretty much figured out.   After getting some of the gunk and crud off, it was much easier to see what was going on.

Some pics:





Seems the set screw on the dial pushes against a brass pin against the brass hub.  I assume so that a steel set screw wont mar the hub.  In my case, the pin was stuck in the tight position.  I think I've got it all cleared up now.  

However, I have another issue:




When I unscrew the hand wheel portion of the dial, behind it are three holes.  According to the thread linked above, each should have a ball bearing and a spring.  i'm not sure what they do.  In my case, I have three holes, ony two of them have springs in them,  and of those two only one has a bearing. 

I guess a trip to the hardware store is in my near future.


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## Technical Ted (Dec 1, 2017)

I'm not familiar with your lathe at all, so this is just a guess from looking at the pictures and drawing. But, maybe those spring loaded balls act as a drag mechanism to hold the dial in place while turning the hand wheel so you don't have to lock it in place all the time using the set screw???

Ted


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## RandyM (Dec 1, 2017)

Technical Ted said:


> I'm not familiar with your lathe at all, so this is just a guess from looking at the pictures and drawing. But, maybe those spring loaded balls act as a drag mechanism to hold the dial in place while turning the hand wheel so you don't have to lock it in place all the time using the set screw???
> 
> Ted



We have a winner.  You are correct Ted.


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## Bob Korves (Dec 1, 2017)

Use brass balls, not steel ones.  The steel ones will make indentations when you tighten them down, and the dial will become rough turning.  Brass balls will provide friction only.


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## RandyM (Dec 1, 2017)

Bob Korves said:


> Use brass balls, not steel ones.  The steel ones will make indentations when you tighten them down, and the dial will become rough turning.  Brass balls will provide friction only.



The originals are steel. the spring force is not a lot. I just lightly oiled mine.


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## Technical Ted (Dec 1, 2017)

I'm curious... Is the piece that the balls ride against hardened? Bob brings up an excellent point, but I guess I might also be concerned that brass balls would quickly develop flat spots and just start rubbing instead of revolving. Maybe this wouldn't effect their function much though. Of course, they are easily replaceable if they do.

Just curious,
Ted


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## RandyM (Dec 1, 2017)

Technical Ted said:


> I'm curious... *Is the piece that the balls ride against hardened*? Bob brings up an excellent point, but I guess I might also be concerned that brass balls would quickly develop flat spots and just start rubbing instead of revolving. Maybe this wouldn't effect their function much though. Of course, they are easily replaceable if they do.
> 
> Just curious,
> Ted



Ted,

I don't think it is hardened, but I could be wrong. I think you could use the brass as Bob mentioned if one was inclined. For what it all does I don't think that it is that big a deal. My machine is well used and I don't recall a large groove etched in to the hub. In fact, check out the link to my thread and I have a picture there that shows the mating surface. I think that the balls just provide a point contact instead of the spring pushing on the hub. Hard to say if the balls actually turn, my guess would be, no.


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## Bob Korves (Dec 1, 2017)

The balls will not rotate when compressed against a spring, they slide on the single contact point.  My Millrite mill has a single brass ball against a spring and thumb screw for adding friction to the dial scales.  Nothing is hardened.  It works good and is totally smooth, the balls on each of the three dials are not perfectly round, maybe never were, but it does not really matter.  We are only trying to add a controlled amount of friction and smooth movement to the dial.
Edit:  Steel balls would work just as well as long as the spring does not get completely collapsed and the ball gets pushed hard enough to dent the sliding surface.  The brass balls, being softer than the steel surface they rub against, make the installation more idiot proof.


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## Investigator (Dec 1, 2017)

the only bar that was present when I took mine apart with steel. I bought new steel ball bearings of the same size and replaced all three with new ones. I had considered actually undercutting the dial and using a sheet of Teflon type material to provide the friction without spring pressure whatsoever. However as a newbie, I thought that might possibly be outside my scope of ability right now. in the future, if it looks like it may be an issue, I believe I would undercut and use a slightly thicker piece of Teflon sheet as a friction material after removing the springs and balls completely.


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