Author Topic: where / what is a ball with internal thread?  (Read 5059 times)

Offline PekkaNF

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where / what is a ball with internal thread?
« on: August 29, 2015, 03:27:34 PM »
I was trying to find a small sphere, like ball bearing ball with ready made internal thread.

Any ball, up to 10 mm and any metric thread (or imperila screws fro the same address...).

It would simplify measurement fixture, sort of spherometer.

I'm finding a bunch of setcrews with round end or decorative balls....

Probably could buy a ballbearing (don't have any crapy ones around), break it, anneal, fight for mount, drill/tap, but if i can find a bag of perfectly round ones readymade, I would be happy.

Thanks,
Pekka

Offline awemawson

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Offline PekkaNF

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Re: where / what is a ball with internal thread?
« Reply #2 on: August 29, 2015, 03:59:15 PM »
too pretty...and too long.

normal steel would do, but a good sphere (or semisphere) would be nice. Just a sphere with internal thread. In a pinch grease nipple looking, but semisphere business end and male thread.

Pekka

Offline Manxmodder

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Re: where / what is a ball with internal thread?
« Reply #3 on: August 29, 2015, 04:54:27 PM »
Helixes aren't always downward spirals,sometimes they're screwed up

Offline shipto

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Re: where / what is a ball with internal thread?
« Reply #4 on: August 29, 2015, 07:30:31 PM »
Have a look at belly bars some of them have a threaded ball to hold the bar into the belly piercing.
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Offline Brass_Machine

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Re: where / what is a ball with internal thread?
« Reply #5 on: August 29, 2015, 11:06:44 PM »
Have a look at belly bars some of them have a threaded ball to hold the bar into the belly piercing.

I was going to suggest finding a body piercing shop. Plenty of jewelry has a ball with internal threads.
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Offline PekkaNF

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Re: where / what is a ball with internal thread?
« Reply #6 on: August 30, 2015, 02:55:26 AM »
This type may fit your needs. They can be drilled and tapped and are available in various sizes.
http://simplybearings.co.uk/shop/Loose+Balls+&+Rollers-All+Hardened+Steel+Ball+Bearings/c23_5005/p221148/12mm+Diameter+Grade+100+AISI+316+Stainless+Steel+Ball+Bearings/product_info.html
......OZ.

Sweet. I could order some brand name bearings from there to justyfy shipping. Thanks a lot. I could't have found that.

It looks like tehy could be drilled with ordinary tools. Have you used them? Anything special (appart from they being stainless and therefore needs a little attention)?

Thank you a lot.

Pekka

Offline awemawson

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Offline efrench

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Re: where / what is a ball with internal thread?
« Reply #8 on: August 30, 2015, 03:47:54 PM »
Carbon steel ball bearings are pretty easy to drill and tap. You just need to remove the case hardening with a carbide endmill or grinder.  I did a dozen for my delta printer with no problem. 

Offline texta

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Re: where / what is a ball with internal thread?
« Reply #9 on: August 30, 2015, 06:26:01 PM »
have a look on this site . if its made they can get it .

https://www.smallparts.com.au/

johno

Offline Manxmodder

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Re: where / what is a ball with internal thread?
« Reply #10 on: September 03, 2015, 07:05:24 PM »
This type may fit your needs. They can be drilled and tapped and are available in various sizes.
http://simplybearings.co.uk/shop/Loose+Balls+&+Rollers-All+Hardened+Steel+Ball+Bearings/c23_5005/p221148/12mm+Diameter+Grade+100+AISI+316+Stainless+Steel+Ball+Bearings/product_info.html
......OZ.

Sweet. I could order some brand name bearings from there to justyfy shipping. Thanks a lot. I could't have found that.

It looks like tehy could be drilled with ordinary tools. Have you used them? Anything special (appart from they being stainless and therefore needs a little attention)?

Thank you a lot.

Pekka

Hi Pekka, I have never used these stainless balls for anything yet but I have used ordinary hardened carbon steel balls and softened them by heating to a bright cherry red and cooling slowly before drilling.

I don't think these stainless ones should present much of a problem to machine provided a little cutting fluid is used and the drill speed isn't too high.....OZ.
Helixes aren't always downward spirals,sometimes they're screwed up

Offline PekkaNF

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Re: where / what is a ball with internal thread?
« Reply #11 on: December 01, 2018, 02:59:33 AM »
And new project needs new balls :lol:

1: ordered 10 pcs of the soft ones:
https://simplybearings.co.uk/shop/p221140/10mm-Diameter-Grade-100-AISI-316-Stainless-Steel-Ball-Bearings/product_info.html
...
10mm Diameter Grade 100 AISI 316 Stainless Steel Ball Bearings
AISI 316 Stainless Steel with a hardness of 25 - 39 Rockwell Scale equivalent to 140 - 160 HB (Brinnel Scale).
..
Unhardened austenitic stainless steel with good corrosion resistance to sea water, dilute nitric, sulphuric and acetic acids, photo chemicals, inks, bleaches, dyes etc.

Can be machined / drilled

2: 50 pcs of hardened balls:
Industry Standard Grade 100 Hardened Steel Ball Bearings: High Quality Graded Hardened Chrome Steel Ball bearings made from Chromium AISI 52100 steel. Hardened to 60-67 Rockwell Scale equivalent to 700-900 HV (Vickers Scale) and are hardened all the way through the ball.

This actually might be a problem....cheap ebay chinese carbide slotdrills probably will not cut it. Their (usually overly optimistic) description says up to 45 or "HRC50"

These I bought to be pressed into 10 mm hole and left like that or ground flat if more than 3-points.

Pekka

Offline efrench

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Re: where / what is a ball with internal thread?
« Reply #12 on: December 02, 2018, 02:18:21 AM »
I bought these two years ago. The surface quality is fair, but not as good as a ball bearing.  The main reason was to use in a magnetic ball joint.  There are quite a few stainless and brass threaded balls available.  Their main use is for jewelry, so it's hard to say how spherical they are. 

I used 12mm ball bearings on my delta 3d printer.  They were just surface hardened, so it wasn't too hard to drill and tap them.

Offline PekkaNF

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Re: where / what is a ball with internal thread?
« Reply #13 on: December 04, 2018, 08:25:47 AM »
Those might do...

I mikked the soft and hard ballbearing balls I got from Bearingboys both seem to be more or less hobby grade than exact. Nothing too bad, but regularry 0,003 mm off, some facets over 0,004 mm off. No problem on my application.

4 mm HSS-Co centering drill made very close to 4 mm hole to soft ball with ease. I used 10 mm ID aluminium pipe, taped the ball bearing in amd thightened into three jaw chuck. Drilling was easy.

I haven't tried the hard balls yet. Having trouble finding any garage time.

Pekka

Offline efrench

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Re: where / what is a ball with internal thread?
« Reply #14 on: December 04, 2018, 09:42:43 PM »
Case hardened carbon steel balls may be a better choice.  The case hardening can be milled with carbide.

Offline RodW

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Re: where / what is a ball with internal thread?
« Reply #15 on: December 05, 2018, 04:29:01 AM »
Well, you could have an endless supply of balls if you make something like this:



This is only half a ball but if you had some 10mm rod, you could thread it and make a full ball as shown on the handle in the earlier pic.

RodW
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Offline drmico60

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Re: where / what is a ball with internal thread?
« Reply #16 on: December 05, 2018, 12:49:07 PM »
Well, you could have an endless supply of balls if you make something like this:



This is only half a ball but if you had some 10mm rod, you could thread it and make a full ball as shown on the handle in the earlier pic.



Most boring heads are too large to use as ball turners on a 7 x 12 minilathe. I made a more compact unit, see:
http://mikesworkshop.weebly.com/ball-turner-mk-2.html

Mike