Compound dial question

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.
 
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:
20171130_191333.jpg
20171130_191242.jpg

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:

20171130_150500.jpg

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.
 
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
 
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
Click to expand...

We have a winner. :encourage: You are correct Ted.
 
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.
 
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.
Click to expand...

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

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.
 
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.
 
You must log in or register to reply here.
Back
Top