Another drilling operation question

[bertterbo]

I appreciate this can be done on the drill press, ..but lets say you needed it done on the lathe, in my case, a wood lathe.

I wanted to drill a side hole at the end of this aluminium round bar. However, positioning in the chuck as shown below results in the piece moving/pivoting as pressure is applied (due to the gap of the spindle hole.

(cutting the hole before the piece is cut to length was not an option)

So I stuck a bar of metal behind the round bar to bridge the gap, secured with some double sided tape.

It was a little sketchy, so I'm wondering if there was a better way to do it? How would this have been done on a proper metal lathe?

 

[J-G]

You don't show the "bar of metal behind the round bar" so it's to some extent a guess as to exactly what you did. I have to presume that it was narrower than the dia. of the Alum bar and flat.

The whole concept is so wrong in so many ways but, skipping over that, you say "drill a side hole" but your second image shows a threading TAP in what could be a Jacob's or Key-less chuck - presumably held in the tail-stock.

Please don't tell us that this really is what you used to 'Drill' the hole!!

 

[niall Y]

I have carried out a similar operation on my woodworking lathe. In my case however I had a long enough bar to fit across the chuck. I'm sure some savvy machinist will come along shortly to enlighten you.
On a metal-working lathe I inherited I have a face-plate that has various slots to take hold-downs and an angled bar to which you could secure the rod to be worked on. So my guess would be that this would be the answer.

 

[bertterbo]

You don't show the "bar of metal behind the round bar" so it's to some extent a guess as to exactly what you did. I have to presume that it was narrower than the dia. of the Alum bar and flat.

The whole concept is so wrong in so many ways but, skipping over that, you say "drill a side hole" but your second image shows a threading TAP in what could be a Jacob's or Key-less chuck - presumably held in the tail-stock.

Please don't tell us that this really is what you used to 'Drill' the hole!!

Really? ...

 

[bertterbo]

I have carried out a similar operation on my woodworking lathe. In my case however I had a long enough bar to fit across the chuck. I'm sure some savvy machinist will come along shortly to enlighten you.
On a metal-working lathe I inherited I have a face-plate that has various slots to take hold-downs and an angled bar to which you could secure the rod to be worked on. So my guess would be that this would be the answer.

Ah ok. So I guess you'd have to center it up yourself then?

 

[J-G]

Really? ...

 

[niall Y]

Ah ok. So I guess you'd have to center it up yourself then?

Yes you would have to do this. In the past I've also drilled these sorts of holes using my pillar drill. The method is to first cut a section off the rod. This is then held in the chuck and drilled through its centre with the diameter required. The rod to be drilled is then held in the drill-press vice, with the machined section of rod positioned above where the hole needs to be. This centres the drill bit when drilling the hole. You don't necessarily need the pillar drill to do this , but you will need the vice.

 

[Torx]

Off the top of my head, take two opposing jaws out and hopefully the bar centres on the slot and the remaining two jaws clamp it sufficiently to do the operation at *very* low RPM. Internal jaws might be better (4 points of contact) if you have a set.

Or, find some scrap square stock, use the lathe to make a cube, drill a hole the size of the rod, interference fit or glue it in place and re-chuck it sideways.

Both incredibly sketchy, I’m sure there are other / better ways.

 

[Torx]

In a centre lathe you would probably try mounting something like this (or some variation) on a faceplate etc.

You might get away with an independent 4 jaw chuck (I’m assuming yours in self centering).

Or you might put the drill in the headstock chuck and mount the vee block on the cross slide.

But you’d probably just nip over to the pillar drill.

 

[Chief Sawdust Maker]

You don't show the "bar of metal behind the round bar" so it's to some extent a guess as to exactly what you did. I have to presume that it was narrower than the dia. of the Alum bar and flat.

The whole concept is so wrong in so many ways but, skipping over that, you say "drill a side hole" but your second image shows a threading TAP in what could be a Jacob's or Key-less chuck - presumably held in the tail-stock.

Please don't tell us that this really is what you used to 'Drill' the hole!!

I agree with J-G
As an apprenticed machinist I cant see any reason to try to attempt what's shown. It breaks so many machining principles and that's before we start on H&S. You would have more success with a bench vice and battery drill!!!!!!
Depending on the required accuracy either the use of a pillar drill and a vee block and clamp or a vice, or if a more accurate hole is required the a set up on a vertical milling machine with the use of an edge finder followed by dialling in the required dimensions, if the hole is to be tapped then the tap shown is suitable for hand tapping but a spiral tap should be used for machine tapping

 

[bertterbo]

I agree with J-G
As an apprenticed machinist I cant see any reason to try to attempt what's shown. It breaks so many machining principles and that's before we start on H&S. You would have more success with a bench vice and battery drill!!!!!!
Depending on the required accuracy either the use of a pillar drill and a vee block and clamp or a vice, or if a more accurate hole is required the a set up on a vertical milling machine with the use of an edge finder followed by dialling in the required dimensions, if the hole is to be tapped then the tap shown is suitable for hand tapping but a spiral tap should be used for machine tapping

How would you have more success with a cordless drill? How would you even center it without making another jig?

Can you explain the machining principles it breaks?

 

[Chief Sawdust Maker]

The success with a cordless drill would depend on what accuracy is required, a centre punch mark and being able to drill square and level no jig required

With regards to machining principles the ones that I would list would depend on the knowledge and experience of the OP.
The one that leaps out is that a 4 jaw chuck is designed to clamp items axially not gripping with the side of the jaws.
The first picture shows forces being placed on the chuck that it was never designed for, centrifugal force could easily throw the part from the chuck.

D

 

[Fergie 307]

How would you have more success with a cordless drill? How would you even center it without making another jig?

Can you explain the machining principles it breaks?

I find it hard to believe that anyone who has a lathe doesnt have a pillar drill, which is the obvious way of doing it. If it has to be done on a lathe then I would have though that a v block and faceplate as suggested by torx is a far better arragement.

 

[clogs]

`Pease dont use ur lathe in that manor, very dangerouse.....if u lived near me I'd happily do it for u.....

no wonder peoples projects take so long........lol....set up time.....
lost count of the times out on a job where no machine are available.....
a vice/G clamp, batt drill n a sharp drill will do it all.......
but most of all good eyesight and a little experience.....
remember there's a lot out there that can't bang a nail in straight....let alone drill a hole......

seems like a good excuse to go buy a pillar drill to me.......
speaking of accuaracy ur mostley better off doing it by hand than buying a cheapo drill press.......
plenty of good old drill makes out there, Meddings for example, mine is from the 40's, all fully rebuildable and a fully adjustable quill etc if ever needed....

 

[Bingy man]

This thread reminds me of a motorist that asked me for directions to the nearest Petrol station as he was about to run out of fuel, I gave him clear directions to the nearest and to my surprise he then began telling me I was wrong and he’d just come from that direction and there was no petrol station and certainly no Sainsbury’s. I repeated my directions and he starts arguing again so I politely reminded him that he was the one who asked for help, and that he was running out of fuel. A little later I was going to town ( the opposite direction to the petrol station I saw the same guy in the bus lane , parked up with hazards on and his missus giving him a hard time . The moral obviously is don’t argue with good advice from those with more experience and knowledge than you . There are hundreds of years of experience across the members here and their advice is second to none. A wise person would heed that advice!!!!

 

[bertterbo]

This thread reminds me of a motorist that asked me for directions to the nearest Petrol station as he was about to run out of fuel, I gave him clear directions to the nearest and to my surprise he then began telling me I was wrong and he’d just come from that direction and there was no petrol station and certainly no Sainsbury’s. I repeated my directions and he starts arguing again so I politely reminded him that he was the one who asked for help, and that he was running out of fuel. A little later I was going to town ( the opposite direction to the petrol station I saw the same guy in the bus lane , parked up with hazards on and his missus giving him a hard time . The moral obviously is don’t argue with good advice from those with more experience and knowledge than you . There are hundreds of years of experience across the members here and their advice is second to none. A wise person would heed that advice!!!!

When did I say someone was wrong?

 

[John Hall]

 

[Bingy man]

When did I say someone was wrong?

I didn’t necessarily say that -my post was because you seem to be disagreeing with the advice given . If your method is deemed as dangerous it’s probably because it is or someone else has done something similar and paid the ultimate price. I may of read you wrong , my apologies if I have but the members here collectively know the best method to achieve your goal safely.

 

[Phill05]

There was what was called a cross drilling part that fit onto a Morse taper that fit in the tailstock and had a V cut across the end, you put the centre drill/drill in the headstock chuck and moved the work in the tailstock up to it to drill , I had one but cannot find it at the moment.

Phill

 

[Limey Lurker]

I'd have put the drillbit in the lathe chuck, and mounted the bar on the toolholder and advanced the bar onto the drillbit. It's always worked for me!