Using a pillar drill

[paul_f]

I have never really been taught how to use a pillar drill, so am wondering if I am doing some things wrong.

I need to make some adaptors in square bar, that are drilled through in one direction and then drilled in tapped at 90degrees to the other holes - and it needs to be accurate so I want to make sure I do things in the best way

I have a nice old startrite pillar drill (that was approx 25 years old but brand new - it was sitting in a machine shop that only used 3 phase machines and it was single phase), with a non tilting table and a couple of vices - one is big, heavy and drilled all over the other is a cheap machinemart one which isn't actually flat (it wobbles on the table)

When I am drilling something like a piece of flat bar, should I clamp it directly to the table, or clamp it in a vice.
If I use a vice, should the vice be clamped onto the table or just loose (I seem to remember at welding evening classes there was no way of clamping the vice in the pillar drill)
And what is the best way of exactly lining up the drill with the centre punched dot? For a small diameter drill its easy to bend the drill.

I have looked online and haven't found many resources for using pillar drills - if anyone has found one I'd be pleased to see it

Cheers
Paul

 

[Welderpaul]

If your drilling machine and clamp are accurate, you are half way there to drilling accurate holes.
The vice will normally have slots running back to front, that should, with a bit of lining up, align with slots in the drilling table. The vice should be bolted down in the correct location. Failing that, a couple of decent clamps can be used to hold it down.
If its mega accurate, i would smear the surface with marking dye, then scribe the lines and centre punch where the lines co-incide. Its important that the centre punch mark is accurate, although it is possible to re-punch if necessary by leaning the punch over and remarking.
I would start the hole using a centre drill (Same as used in a lathe), as these wont wander, and give a steeply tapered hole for the first drill to follow. Drill with increasing-diameter drills until you get to the size you want. We use a mill/drill so it allows you to clamp the workpiece somewhere near then move the drilling head in X and Y planes to get it exactly where it is needed. - We used to hold a needle in the chuck and use an eye loop (Small magnifying glass) to align the head. (No CNC)
Have a practice on some scrap until you get the hang of it.

 

[mart]

Paul,
i remember using that blue engineer`s marking dye at school in metal work class in the 70s, and felt that it was quite useful. What sort of shop/place would stock it these days?

 

[Welderpaul]

Paul,
i remember using that blue engineer`s marking dye at school in metal work class in the 70s, and felt that it was quite useful. What sort of shop/place would stock it these days?

Its sold in spray cans - it comes in white and blue. I've seen it in quite a few engineers merchants, and i know Rocol do it. - Stick it in google/ebay and i'm sure an on-line supplier will show up.

 

[Paul.]

For small items you can use a marker pen, it works quite well on bright bar and stainless, a wiggler is a handy tool for accurate work on a drill too.

 

[Welderpaul]

I've had a wiggler stuck in my hand once. *shudders*

 

[eil]

Quite a bit on here.
http://techtv.mit.edu/genres/24-how-to/videos/142-machine-shop-1

 

[scott0031]

Generally the rule of thumb is if your drilling over 1/2" (12.7mm) you should clamp the work piece or vice to the table. Experienced people can get away with a lot more, it does come down to experience so don't take risks. A decent piece of bar or plate will make a mess of you if it goes wrong.

If you are drilling a longer piece of work rest it against the pillar on the left hand side of the pillar the job cant spin that way if the drill picks up. That way all you need to worry about is applying downward pressure.


If the vice is a real heavy old beast then its more forgiving with bigger drills. I would advise clamping. With the pillar drill you have as it will only be 5 speed and the speed ranges are often ideally to fast for a 1/2 " drill with hand work.

You can normally cobble up G cramps to hold vices in place on a pillar drill. that's the method i use most of the time for the sake of 2 min setting it up can save a very nasty injury.


It really comes down to applying a bit of good old fashioned common sense. If in doubt play safe.


Kind regards,


Scott (ward eng)

 

[brightspark]

just doing a mod on my drill at the mo the table has no slots in for clamping . so just milled a couple in and rebuilding drill after a few near acidents .gear flinging round and parts climbing up the drill bit which ruined the chuck and stripped bark of me fingers better to learn the 1st time

 

[BChild]

I've got a small pillar drill - 3 speed (hop the belt on the pulleys) and seeing as peoplen here have some knowledge I'm going to threadjack again

What can I do to improve the torque - as if I am drilling something it's very easily stalled

 

[fluxcored]

If its mega accurate, i would smear the surface with marking dye, then scribe the lines and centre punch where the lines co-incide. Its important that the centre punch mark is accurate, although it is possible to re-punch if necessary by leaning the punch over and remarking.
I would start the hole using a centre drill (Same as used in a lathe), as these wont wander, and give a steeply tapered hole for the first drill to follow.

If I can add to WelderPaul's comment on marking out - I use a sharp scribe. Sometimes I use one with a diamond tip. I then take the centre punch and follow the line that I scribed until I feel resistance which is exactly where the other line coincides with it - the center of the hole you want to drill.

I always use a centre drill to start out. I set the drill to it's lowest speed and do'nt even clamp the stock and once the drill is spot on the punch mark, I just enlarge the punch mark.

I then insert my twist drill and without powering the drill on, feed the bit down untill it's in the centre drilled hole. I then lock it in position and twist the chuck by hand so that the bit can accurately settle in the hole. Then I clamp the part or vise really tight.

I unlock the quill and do one last check to verify that the drill is spot on by moving the quill up and down feeding the drill bit in + out of the centre drilled hole and adjust the piece if necessary. If I see the twist drill bending coming in or out of the hole then I adjust the vice.

I then step drill up to the desired size using cutting oil and adapting the speed for the appropriate bit size.

I used a lot of oil and found that it's very wasteful to just squirt it out of an oil can and settled on using a brush to oil the bit and the hole.

With regards to speed - I found that I was drilling too slow with twist drills and hole saws and started to up my speeds resulting in much better looking holes and faster drilling times.

Initially I used a wiggler and discovered to my dismay that it did'nt help much - no fault of the wiggler, my technique was simply sloppy.

I always use marking blue - my eyes are'nt what they used to be.

I always use sharp drill bits but I do'nt throw the dull ones away. I still need to learn how to resharpen drills.

Hope this helps.

 

[scott0031]

Hi BChild,

First thing make sure its not the belt slipping. Doubt it is as you said its 3 speed, which indicates its a specialist piece of Chinese play dough. Quality play dough i will add

Options are:

1) Throw the drill away and get a decent second hand British one.

2) Lower the pulley ratios. Not advisable, awkward and prolly not cost effective. It will lower the spindle speed and the extra torque will most likely snap the drilling machine clean in two.

3)Put a more powerful motor on it. (as above also applies)

4)Third option is Throw the drill away and get a decent second hand British one one. <------ yes i said it twice!

5) learn lesson and never buy chinese poo ever again!



Kind regards,


Scott

 

[scott0031]

Points to remember with using a centre punch and centre drill with a pillar drill.

Centre dot mark will only be as good as the marking out and your ability to mark out and centre dot in the correct place. Those two nullify the use of a centre drill alone. Your better off simply using a pilot drill then open out to suit. The fact that its also hand marking out also nullifies the use of a centre drill. It will still follow the original centre dot mark. If its wrong then it will be wrong by that method. No centre drill will change that unless used in a milling machine where you have control of the x and y axis.

The point of a centre drill is to create a centre point for the drill to start. Centre dot then centre drill = 2 centres created. You always run a risk of breakages with centre drills, due to the fact they are so ridged and they are not forgiving with any run out of the spindle. So probably better to skip that step and pilot.

Last time i used a centre drill in a pillar drill was ermmmmmmmmm never!


Kind regards,


Scott

 

[paul_f]

Thanks for the advice, I saw there was a list of drill speeds so I will print that out and laminate it and have it next to the drill.

When should pilots be used, and what sizes should I increase by?

If I am drilling a 6mm hole, do I still need a pilot? Should the pilot go all the way through or just part way?

I am going to need to get myself a nice square to help with marking out, I have some nice steel rules but only woodworking squares.

Thanks
Paul

 

[brightspark]

generaly drills bigger than quarter of an inch require a pilot drill 1st. if u look at the end of a larger drill theres a flat chisel in the center .the bigger the drill the larger the chisel so when drilling the center scrapes the hole out .this results in having to put more pressure on drill to force it through which is less eficiient .the pilot drill overcomes this problem .general rule of thumb small drill high speed large drill slow speed

 

[Ratty]

If you are drilling a longer piece of work rest it against the pillar on the left hand side of the pillar the job cant spin that way if the drill picks up.

That's so obvious and yet it's never occurred to me! Brilliant tip Scott, thanks

 

[paul_f]

Should I put the pilot all the way through the piece of work though?

 

[brightspark]

yes

 

[BChild]

Hi BChild,

First thing make sure its not the belt slipping. Doubt it is as you said its 3 speed, which indicates its a specialist piece of Chinese play dough. Quality play dough i will add

I don't think it's chinese - I'd estimate that it's at least 20 years old - probably closer to 30

Options are:

1) Throw the drill away and get a decent second hand British one.

2) Lower the pulley ratios. Not advisable, awkward and prolly not cost effective. It will lower the spindle speed and the extra torque will most likely snap the drilling machine clean in two.

3)Put a more powerful motor on it. (as above also applies)

4)Third option is Throw the drill away and get a decent second hand British one one. <------ yes i said it twice!

5) learn lesson and never buy chinese poo ever again!

Kind regards,

Scott

OK ignoring the chinese stuff - motor option looks favorite - it's not belts slipping and to give you an indication of how little torque it has sometimes you have to start the chuck spinning by hand to get it moving!!!!

It has however seen very little use in the 20 years and certainly if it runs for a while it then starts up straight away

Would pics help?

 

[peterd51]

Hi,

I made some clams for a drill vice a few months back, detailed on here somehwere. I have a bit of sideways movement on the vice (maybe 6mm) as well as the normal front to back movement, for lining up. I usually start with a 3mm drill and the vice loose, line it up by eye and then with the drill switched off I move the chuck down and watch the end of the bit as it touches the punch-indent.

I can see if it deflects and adjust the workpiece position. Next I turn the chuck by hand through 90 degrees and do the same again. Once it's centered I hold the workpiece with my left hand while tightening the clamps with my right.

What's the Wiggler do? It sounds interesting!

Regards
Peter