Taping small holes

[VicParticipant @vic]

Some good answers folks, thanks.

I saw this video.

https://youtu.be/PqU5wS0J4MU

But I’ve not been able to get a suitable small straight shank arbor. So I’ve decided to go the route of using a small ER chuck with this setup instead. I managed to get a chuck for £7.29 and a set of collets Range: 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 1/8 ,1/4 for £12.84 from Amazon.

Here’s the video. For drilling I can just slide the chuck in and out of the MT2 arbor I’ve ordered.

https://youtu.be/L0ZTw5J8oTE

 

[John PurdyParticipant @johnpurdy78347]

Vic

You previously asked for a link to a sensitive drill chuck, there was an article on making a sensitive drilling adapter for the lathe in MEW #335 and 336.

John

[VicParticipant @vic]

Thanks John but I no longer subscribe to the magazine.

[John PurdyParticipant @johnpurdy78347]

Vic, you have a PM.

John

[old martParticipant @oldmart]

You mentioned brass or stainless steel, brass would be my choice or 303 if stainless had to be tapped. You can get taps from industrial suppliers like APT specifically for certain metals. I missmatched one of those taps when threading 2mm in Densimet tungsten alloy for holding carbide inserts in lathe tools. I thought a tap for hard steel would work, but the brand new Osborn would not cut very well. I probably should have chosen a tap intended for aluminium. Fortunately, in the masses of taps that the museum has I found an old one that worked a treat in the Densimet.

[Martin Kyte]

On Martin Kyte Said:

My main objection to countersinks is it’s difficult to control the diameter. If I am fitting countersunk screws I will always grind a drill to the correct angle and use that. It just looks neater.

My advice about countersinking was given on the assumption that Vic was drilling and tapping the end of a rod on a lathe. This is what he said he was doing at any rate. In most cases like this the countersink won’t be intended to accommodate the head of a CSK screw, surely, and therefore the actual size of the countersunk recess won’t matter much as long as it serves to guide the tap in without causing it to snag on a burr.

I rarely use a machine countersink as a prelude to tapping into the end of a rod on the lathe; instead, I use a manual Noga rotodrive countersink held in a Shaviv handle.

[Bill Phinn]

On Bill Phinn Said:

On Martin Kyte Said:

My main objection to countersinks is it’s difficult to control the diameter. If I am fitting countersunk screws I will always grind a drill to the correct angle and use that. It just looks neater.

My advice about countersinking was given on the assumption that Vic was drilling and tapping the end of a rod on a lathe. This is what he said he was doing at any rate. In most cases like this the countersink won’t be intended to accommodate the head of a CSK screw, surely, and therefore the actual size of the countersunk recess won’t matter much as long as it serves to guide the tap in without causing it to snag on a burr.

I rarely use a machine countersink as a prelude to tapping into the end of a rod on the lathe; instead, I use a manual Noga rotodrive countersink held in a Shaviv handle.

Sounds good. I normally use a hand held countersink for such jobs, it’s quicker.

[VicParticipant @vic]

Ok, the arbor has arrived. The only one I could get big enough for a good price is this 40 x 40 from RDG. Thinking about the video I posted earlier. Would you remove some of the bulk or leave it as it is? Also, if you watch the video, it only has one bearing. I know some revolving centres use two, so is it worth adding another? I’ve got the bearings. Your thoughts please chaps.

[bernard towersParticipant @bernardtowers37738]

considering the load I would have thought 3 or 4 mm walls to be sufficient and the more bearings the better.

[VicParticipant @vic]

I suppose I could use it as is, and perhaps reduce the diameter at a later date if it becomes intrusive. I think I’ll fit two bearings whilst I’m boring it out.

Thanks for the input.

[Russell EberhardtParticipant @russelleberhardt48058]

I bodged up a tapping stand from an old Dremel stand for tapping 10 BA in clock wheel collets:

Not a single broken tap.

Russell

[Nicholas FarrParticipant @nicholasfarr14254]

That’s a smart idea Russel.

Regards Nick.

[Author]

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