Drilling forged mild steel balls for vice handles

[Alpha-Dave]

Hi all,

I’m restoring a Record 112 vice, and while it is in great condition there is a kink in the handle which is slightly annoying. The cost for some replacement EN16T 3/8 rod being £6 delivered makes it an easy choice for just replacing the handles rather than heating and straightening the old one given that I don’t have a method for heating the bar.

So now I just need a way to stop it falling through the boss. I have purchased some forged mild steel balls that are 35 mm in diameter, and so all I need to do is: drill the rod for an m8 threaded hole; drill the balls for a 5/8 recess and the further drill for an m8 threaded hole; tap the holes; connect with some threaded bar & loctite and all done.

The only step in this process that concerns me is getting the hole in the balls perpendicular to the surface. I don’t have a metal lathe, but do have a 2hp Jet 3520, and the Axminster 114 chuck with engineering jaws, and have drilled out 1” holes in copper and aluminium before so I’m not worried about the power, just the accuracy.

I think I need a small ‘flat’ on the surface of the ball, but how to achieve that without a toolpost tool?

My gut instinct would be to try to flatten the surface of the ball while rotating slowly in the jaws, but both an angle grinder or file seem less than ideal. I have some carbide wood turning tools, but a not keen on trying those as I doubt the angles would be right. I might try scraping the surface with some HSS tools to see if I can remove enough to make a flat spot.

Any pointers or advice welcome.

Thanks in advance.

 

[Alpha-Dave]

Vice for reference.

 

[sunnybob]

belt sander will give you a starting flat. Why are bothering with threading it? drill an interference hole and then whack the end of the bar over with a club hammer.

 

[Nigel Burden]

If you have no intention of using the existing bar, why not cut the ends off that and use them. They already have a flat.

Nigel.

 

[Alpha-Dave]

belt sander will give you a starting flat. Why are bothering with threading it? drill an interference hole and then whack the end of the bar over with a club hammer.

Good point on the sander, I don’t have a belt sander, but I could try a sanding pad in a drill that I use for sanding bowls.

Threading: mostly because I have seen others do it this way (blame YouTube), and it seems simple. I would love to be able to make an interference-fit hole and shaft pair, but I don’t want to get into serious metalworking at this point.

 

[Alpha-Dave]

If you have no intention of using the existing bar, why not cut the ends off that and use them. They already have a flat.

Nigel.

They were originally made in the factory by ‘upsetting’ the 5/8 rod, so are completely part of the shaft. Therefore when I cut them off, the ‘flat’ will be whatever shape the end is from my cutting with an angle grinder or hacksaw, so back to the same problem of levelling what remains.

 

[sploo]

A small centre drill (e.g. Centre Drill Bit 1/8" x 3/64") in a chuck in the toolpost should get you a hole that's sufficient to then drill the ball without the drill bit wandering.

 

[porker]

One technique that you may be able to use when trying to drill perpendicular to a curved surface that is used in machining, is to use something like a small engineers rule or something similar and put this between the drill and the surface of the ball you want to drill. When the rule which is pinched between the two is perpendicular to the drill centreline you know the drill is perpendicular to the surface. Using a drill like sploo references will mean it should drill without having to make a flat as they are much stiffer than ordinary twist drills.

 

[sploo]

One technique that you may be able to use when trying to drill perpendicular to a curved surface that is used in machining, is to use something like a small engineers rule or something similar and put this between the drill and the surface of the ball you want to drill. When the rule which is pinched between the two is perpendicular to the drill centreline you know the drill is perpendicular to the surface. Using a drill like sploo references will mean it should drill without having to make a flat as they are much stiffer than ordinary twist drills.

In theory, if the OP has a lathe, and a chuck that can adequately grip the ball, and the headstock and tailstock are properly aligned, then it should drill perfectly in to the centre of the ball, and perpendicular to the surface.

In theory

 

[Alpha-Dave]

One technique that you may be able to use when trying to drill perpendicular to a curved surface that is used in machining, is to use something like a small engineers rule or something similar and put this between the drill and the surface of the ball you want to drill. When the rule which is pinched between the two is perpendicular to the drill centreline you know the drill is perpendicular to the surface. Using a drill like sploo references will mean it should drill without having to make a flat as they are much stiffer than ordinary twist drills.

Brilliant, thank you. The forged balls are not-quite round, so I can use this to keep rotating the ball in the jaws until I find a part of the surface that is perpendicular to the incoming drill bit.

 

[Alpha-Dave]

A small centre drill (e.g. Centre Drill Bit 1/8" x 3/64") in a chuck in the toolpost should get you a hole that's sufficient to then drill the ball without the drill bit wandering.

Thank you, I intended to start small and drill out anyway, so I might as well try one. I have ordered one from ebay.

 

[Alpha-Dave]

My order of forged balls arrived today. Credit to www.dciron.co.uk/ for fast and low cost. They are close to the cost in pence-per-mm, e.g. the 30mm balls are 30p, while 50mm are 80p and 25mm are 20p each.

I ordered a range because I wasn’t sure what would look/function best.

50/40/35/30/25/20 mm

 

[Alpha-Dave]

The 50 is definitely too big, 40 is a bit big, but could be an aesthetic choice.



35 and 30 look good.




25 is ok (and the same as the original ‘upset’ ends)


20 is too small.


Any opinions?

 

[Droogs]

to my dodgy eyes the 35 looks good

 

[sploo]

30 or 25 for me. Just enough to stop it dropping out is fine. Can't immediately think of a good reason to go bigger (more likely to get in the way, or just more mass when the handle slides vertically through the boss hole).

 

[Alpha-Dave]

30 or 25 for me. Just enough to stop it dropping out is fine. Can't immediately think of a good reason to go bigger (more likely to get in the way, or just more mass when the handle slides vertically through the boss hole).

I was wondering how much weight they would add. Doing some quick calcs:
The bar is 475g
The original 1” cylindrical ends added 74g (15%)

20mm balls add 18g (4%)
25mm balls add 41g (9%)
30mm balls add 181g (17%)
35mm balls add 142g (30%)
40mm balls add 234g (50%)
50mm balls add 500g (105%)

So the 50 and 40 are out. 30 mm are the same as the original, and 35 are just about acceptable (I will be adding a gasket/o-ring anyway).

 

[AES]

Blimey! IMO, you're going a bit too "far". No disrespect intended, but this is "only" a bench vice and doesn't really need to look "pretty", just be "tidy" and work well.

Like sunnybob I can't see the point of drilling and tapping the balls, but why are you worried about using a file to put a SMALL flat on the ball? Just about any file will do that job easy-peasy if the ball is held firmly in a vice.

And to drill the hole, after filing a SMALL flat, start off with a "Slocombe" (aka centre drill - VERY short and fat) using lathe, drill press, or even hand drill - whatever. Drill the hole SLIGHTLY undersize (if you've got a mix of Imperial and Metric drills, this is an ideal "bodge" method), then just hammer the ball onto the lever- If the fit is a nice interference fit it'll work like a charm, AND you don't even need to drill all the way through the ball and peen the end of the bar over like sunnybob suggested. You can even use a drop of Loctite (bearing adhesive) or ONE drop of superglue if you want to be doubly sure. But if so make sure the hole and the bar are CLEAN first (e.g. acetone).

For an even "bodgier bodge", why not just thread the end of the bar, then use a nut (the flats of which you can round over a bit to make it look a little less "bodgy" if needs be).

 

[Alpha-Dave]

Of course you have all been on tenter hooks waiting for an update to this. I took a few photos to show progress, so here we go:
The EN16T was cut by a bandsaw, and reasonably square, so no cleaning up of the end needed:


I chucked it close to the end, and used a centre drill as a pilot as per sploo’s recommendation:


Then drilled 20 mm deep with a 4mm and 7.2 mm drills, and the tapped with taper, middle and plug:

 

[Alpha-Dave]

Then for the balls themselves. I went with 35 mm because they ‘looked right’ (tastes may vary).
Centre drilling again, but using Porker’s suggestion to put a metal ruler between the bit and the ball enabled me to find a perpendicular spot on the not-quite-round ball.
Set up:


Not aligned:


Well aligned:

 

[Alpha-Dave]

Drilling 20 mm deep again with 4mm and 7.2 mm:


Then 5 mm deep with a 5/8 bit to create a recess:


Tapping again:


With a cut-off bolt inserted. :