Flexible dial indicator holder.

[Omnimill]

Standard Bearings are made from chrome steel* and are, according to "how it's made" hardened after rough shaping. They are then ground to size and then lapped. I doubt case hardening would be deep enough for this.

* used bearing races in the larger sizes are a handy raw material for all sorts of tools if you have a forge. Some folks make knives and woodworking tools from them as they can take a keen edge once re-hardened.

http://www.mountainhollow.net/graphics/belt-wharny.jpg

Chrome steel is certainly not a "soft material"!

 

[kd0afk]

Standard Bearings are made from chrome steel* and are, according to "how it's made" hardened after rough shaping. They are then ground to size and then lapped. I doubt case hardening would be deep enough for this.

* used bearing races in the larger sizes are a handy raw material for all sorts of tools if you have a forge. Some folks make knives and woodworking tools from them as they can take a keen edge once re-hardened.

http://www.mountainhollow.net/graphics/belt-wharny.jpg

Chrome steel is certainly not a "soft material"!

Is the knife forged from the races and balls, like Damascus? I like it.

 

[Omnimill]

To be honest, I can't remember how they make them but lots of folks do because they look so neat, don't they! I suspect the bearing is wrapped in stainless foil and heated before placing in a press to consolidate the race and balls but I'm only guessing here.

 

[kd0afk]

I'm playing around with the wire rope ends and I need to know how much to compress them for a good swage.
The terminator is aluminum with a 1/16" hole and an outside diameter of .245" I saw a sheet on copper ones that gave a diameter of .203". Will this be sufficient for aluminum?
Also I have aluminum, can I make these little cable ends or is it a special type of aluminum?

 

[kquiggle]

Just happened to run across this video which may be of interest here - drilling into a ball bearing using a solid carbide bit. Of course, ther may be reasons other than drilling for why you might want to "soften" a ball bearing (for example, drilling followed by tapping), but still interesting:

https://www.youtube.com/watch?v=-XA0BywJdR4

 

[kd0afk]

Just happened to run across this video which may be of interest here - drilling into a ball bearing using a solid carbide bit. Of course, ther may be reasons other than drilling for why you might want to "soften" a ball bearing (for example, drilling followed by tapping), but still interesting:

https://www.youtube.com/watch?v=-XA0BywJdR4

Already softened and drilled them. They came out perfect.

 

[kd0afk]

I finished the base except for the stud on the bottom. I believe the noga magnetic bases except an 8mm x1.25 thread but I'll have to confirm that. Or I might make it fit a Starrett mag base. I think that's a 1/4"x20 but again I will find out for sure.
I also still have to make the cable and the top section. So plenty more work ahead.

 

[kd0afk]

All the parts are made and it works ok. I need to work on the balls and spacers. I also need to find someone who can crimp stainless steel ends on to my cable. Aluminum just didn't have the holding power. When I tightened the cable up it gave way.
Anyway, if someone wants to do a good deed and you have a way to swage stainless steel, please let me know. Until then, I'm dead in the water.

 

[kd0afk]

It's all but finished.

 

[kd0afk]

I'm going to redo the cable ends to something stronger. Tom Lipton over there at Ox Tools gave me a hot tip on solder swaging.
I'm also having trouble with the fit of the balls and spacers so I'm going to try and lap the spacers and see if that helps. Once this thing is fine tuned and completed it should be plenty strong.

 

[kd0afk]

Here's the latest photo. I'll post again when it's on a magnetic base and holding an indicator.

 

[kd0afk]

Funny thing, it wants to be curved. If it's locked when it's straight, if you bend it it loosens up. If it is curved when locked, it doesn't want to straighten out. I think it's because the circumference of a circle is longer than the circumference of a polygon with the same diameter point to point.
Does anyone know if this problem is solvable?

 

[kquiggle]

It's looking pretty good. A question: On the straight segments, how did you turn the inner "chamfer" - is it a straight cut, or is it curved to match the radius of the ball?

About your locking problem - seems you need some way to keep tension on the cable - some sort of very strong spring attachment maybe? Alternatively, is it possible to use some sort of cable which has a bit of stretch or elasticity?

 

[kd0afk]

I ground a cutter with the same radius as the balls and used that to cut the inner chamfer. There really is no room for a spring. I think the problem is in the geometry of the thing. The flats that make up a polygonal shape are shorter than the circumference of a circumscribed circle of that polygon. I.e. if you wrap a string around a piece of 1" hex bar, it will be shorter than the circumference of a piece of 1" round bar. When the holder is coiled and locked the cable conforms to a polygonal shape. When it is straightened out the cable still wants to maintain that same length but when straightened out it wants to be the circumference of a circle but it can't. Conversely, when it's straight and then locked and then bent it loosens.
If this is the problem, what would be the solution and springs won't cut it.
Maybe making the hole through the spacers smaller and instead of a through hole in the balls, make the hole hourglass shaped so that the cable. Is bent into a curve instead of around sharp corners?

 

[tornitore45]

What is borace?

Borace is Borax when the Italian part of my brain overpowers the English.

 

[kd0afk]

Borace is Borax when the Italian part of my brain overpowers the English.

Not helpful.

 

[Omnimill]

Does anyone know if this problem is solvable?

It may be due in part to the size of the holes in the bearings, the bigger the holes the worse the effect. Try again, this time with much smaller holes?

 

[kd0afk]

I'm going to order more balls and instead of boring the holes to allow the cable ends through I'll countersink the holes so that the holes have an hourglass shape with a small diameter of 1/8". That should help.

 

[Omnimill]

Perhaps you could try sleeving the existing ones to prove the idea?

 

[kd0afk]

Perhaps you could try sleeving the existing ones to prove the idea?

That's a very good idea