Holding cylinder in vice for boring, what angle to make jaws.

[Limey Lurker]

I don't know how many of these holes you need to drill, but if it's a lot, and IIWY, I'd somehow make the drills to the same length (by cutting them down, or extending the shanks of the shorter ones), and leave the workpiece in the clamp until boring is completed. This would guarantee accuracy.

 

[Ttrees]

@Limey Lurker
How do you propose getting the work centered in the first place?
Theoretically, it should be easy enough as it's accurately bored already.

Seems either I'm doing something wrong, and/or folks are just not using their pillar drill to its potential.

Seems I'd be best making a cone, which is a lot of faff to rig that up ATM
The ones for the routers I've seen, they seem too wide.

ps yet to see what one of the pieces I made will turn out like, made extra wide to
clear up some funkiness of the start of the cuts
Partly used my old methods of flipping the work and it turned out a lot better than the other, should have kept at that and might have got acceptable results,
rather than getting that optimistic laziness.



Thanks
Tom

 

[Ttrees]

Seems it might be good practice to use a centering tool

Why isn't there something like this sold everywhere without the Morse taper shank?

 

[Phill05]

Hi Tom,

I can see a couple of points that need to be sorted before you will get a straight through cut, 1: is the type of vise you are using is all wrong you need a flat vice made to use on a drill like this one.

If you look at your image it looks like the handle end is tipping down try taking a height measurement from the fixed height jaw above your bolts and again a measurement to the top of the jaw on the handle end, when you have put some pressure on it.

2: when drilling with a large drill say 20mm or 3/4" you need a centre drill to go in and produce a small chamfer then using a say 6mm drill go all the way through then follow up with the larger drill, it will hold the drill bit more in the centre, if you are going to use your vise think if cutting metal you need to push the drill into the work so you are tilting the cut by pressure, if you are cutting plastic or brass it will drag the bit into the work and you will feel it bite so only small downward pressure needed.

Make sure the jaws are both at the same height by putting a block under the handle end then try again.

 

[Inspector]

The basic drill press is the wrong machine to use because as you have found out you loose registration every time you change settings. I would suggest you look at annular cutters to make the hole in one shot. They are similar to a hole saw except the hole is more precise and there is no centre drill so the plug that comes out will be solid. The only issue will be finding ones with a shank small enough to fit your chuck. They are meant for milling machines with a greater range of holding options.

Pete

 

[Ttrees]

Thanks for your thoughts guys, the vice isn't the issue here, it's pretty solid.
My money is on the table deflecting if anything.
My drill isn't likely plum which may well be the case from my photos, and the stock is already prebored, I'm just facing the work here to sit in the vise.

Seems one could design another bracket for the column which could go underneath
the the existing one, which would provide support and indexing.
Presuming someone could make this work, it would be the handiest solution.

I'm thinking some sorta frame which can be bolted to the the base,
that could provide support and a hard stop somewhere on the bracket.
Most likely a bottle jack would be good for the job, but I'm open to any ideas.

Thanks fellas
Tom

 

[TFrench]

Tom, if a bench vice was rigid or accurate you'd see them on milling machines. Listen to the advice you're getting, there's some very smart people on here and pooh-poohing their advice means you won't get any in the future. People don't like talking to brick walls. You're trying to do a milling machine's job with a cheap pillar drill. I've got a radial arm drill at work - not a monster by any means but it's a Swiss made precision piece of kit. If I have to swing the head to change bits, lining back up on a hole is a pig. Generally I run it slow in reverse to centre it if I have to. To be honest though generally I'll do jobs like that on a mill because it's so much easier to line up on a hole, or I can use a centering device or co-ax indicator.

 

[Ttrees]

@TFrench, Not poo poohing the advice, but this bench vice is not what the issue is,

I took the comment as a suggestion to check it, and can likely prove this easily with some biscuit tin feelers, and tramming again, and finding out whether the drill/table/bracket for the column is flexing more than I think it is.
Also maybe I should have mentioned that I've frequently used the above "drill vise" and also beautiful oversized ones on a bridgeport,
Still had plenty of issues with that drill vise on the folks one in the past.

It's the use of a pillar drill which is at issue as inspector says.
There is no index, so I'm questioning why a centering cone isn't sold for this purpose,
as at the very least one could stick their clock on the column, should those with a fancier drill have a more rigid table?

Tom

 

[Alpha-Dave]

Seems it might be good practice to use a centering tool

Why isn't there something like this sold everywhere without the Morse taper shank?

Does your pillar drill not have a morse taper onto which the jacobs chuck is fitted? If the quill is extended, is there a vertical slot exposed for a drift to go in?

This also gives the option to use morse-taper drill bits, which will be more accurate than the reduce-shank ones in a chuck.

 

[Ttrees]

@alpha Dave I believe it does, although not sure which taper it is.
Not attempting to remove it as things seems pretty good when you consider these are getting drilled out to 30mm.

Good point though, if one were to make the table non movable, then that might be the way to go.
Seems that still wouldn't be guaranteed otherwise, unless one measured or made a hard stop for the table, in which one would presume would be in some article or another?

Thanks
Tom

 

[Fergie 307]

Perhaps I have missed something here but why don't you bore them in the lathe?

 

[Fergie 307]

If you are trying to drill a 30mm hole with a two flute drill in Acetal you will definitely need to dull the cutting edges of the drill or it will snatch like mad. For centering you could try using a length of silver steel rod the same size as your pilot hole, and the same length as your next drill. Put it in the chuck then position the vice so that it will slide cleanly in. But overall I agree with the view that what you are attempting is beyond the rigidity of your set up. You would be better off to get a chuck on the lathe and bore them.

 

[Limey Lurker]

@Limey Lurker
How do you propose getting the work centered in the first place?
Theoretically, it should be easy enough as it's accurately bored already.

Seems either I'm doing something wrong, and/or folks are just not using their pillar drill to its potential.

Seems I'd be best making a cone, which is a lot of faff to rig that up ATM
The ones for the routers I've seen, they seem too wide.

ps yet to see what one of the pieces I made will turn out like, made extra wide to
clear up some funkiness of the start of the cuts
Partly used my old methods of flipping the work and it turned out a lot better than the other, should have kept at that and might have got acceptable results,
rather than getting that optimistic laziness.



Thanks
Tom

I've just re-read the entire post again, and found your comment on initial centreing. I've always considered that a bent wire in the chuck, rotated by hand, will establish the centre of a bore pretty accurately. For more accuracy, I'd use a dial gauge.

 

[Ttrees]

Thanks folks
Messing around with an index, just to see how it might work.
Unfortunately the bore of the table is too bad to make something proper with,
but I've stuck some tubing up through anyway for dry runs to see if I can work without it fouling.

Not sure, but I reckon a bottle jack could be affixed and an easy bracket under the table can stop against it, might need to be made rigid though, as I've never handled one.
Liddles didn't have any in stock, so guess I might try make it work with a scissor jack instead.
Very surprising indexing isn't a real popular thing with a machine like mine, since folks do use car jacks for under drill tables, but I did manage to find someone who
uses a centering cone, but favours an edge finder.
Seems like that person along with others, uses a X-Y vise on the table for indexing.

Need to make the part again, done a numpty on the lathe and went past the line.
Stock cut from the other end of the tube this time, the hole is smaller on this end of the remaining cylinder, (tapered bore) so can't face it easily as is too small for mounting on a mandrel, so last chance to do it easily.

Would love to be able to flip the work this time, but having no good face will mean I have to file it flat on the cut side.
Being trying to advance from that, but guess I'll have to stick with the ways which have always worked for me in the past.


The table bracket flexes when trammed and weight applied, so that needs taking care of also, the vise is very much a skookum wee thing, so that's a non issue.

Not sure if I mentioned it, but I'm running with loose belts, which makes any suitable RPM and feeding issues not applicable in my case.

Will report back later, hopefully I have a little scissors jack somewhere.

All the best
Tom

 

[Ttrees]

Found the jack, had a good ponder and seems it might do the trick
Made a start on making it mountable, dang nib for the other end was missing
got there in the end though.

Looks like I'm gonna have to start getting used to mounting the vise the other way from now on.
Gotta to get the thing solid from the bottom up first.

All the best

Tom

 

[Ttrees]

Found this shape a bit puzzling to bash somewhat flat, lots of trial and error but got results in the end

Had another rethink of the hard stop/index idea after pondering about the maximum extremities in which the table would need dropping.
After having a good look at the knee, its seems made for the job!

Fixed me wee 5 quid hacksaw with a cut masonry nail, wasn't sure if it was going to be a make or break moment gulp!

Yet to bash flat and clean up but things are looking promising.

Tom

 

[Jacko264]

How many. Bits do you need to drill ?
how much material do you need drilling out ?
have you thought about a reamer
Graham

 

[Ttrees]

How many. Bits do you need to drill ?
how much material do you need drilling out ?
have you thought about a reamer
Graham

I haven't delved into anything but consumer tooling so far in my workshop, and don't know much about reaming, but seems a bit more specialized than my basic equipment.
It is only two bearing spacers for bandsaw wheels, and the first one I made is sufficient, while the other seems to be holding up so far.

I frequently need the drill for all sorts of stuff, so a case of making the machine possible to do this sorta work for again.
I'll possibly be making two more spacers just for fun.

ps If you've read through my whole post I must apologize that it's taken a differing turn.
I should possibly make a new thread, as I cannot edit the header,
hopefully the overlords can change that sometime.

Cheers
Tom

 

[Ttrees]

Got the bracket welded up

Somehow ground the chamfer on the opposite side like a big eegit,
(was rushing to get the noisy work done with the grinding)

Few tacks on the ends and a bit of back and fourth

Getting closer to mocking things up to see what the drop is like, so I can muck around with figuring the flip down hard stop/index plate.
The scissor jack is a lot more stout than I was expecting it to be,
but at the same time I still expect some slop, even when persuaded to the extreme right, so am eager to see how things fair out in that regards also.

Tom

 

[Alpha-Dave]

I don’t understand why you are doing what you are doing (massively increasing the rigidity of a quite rigid thing to then drill plastic), but I wish you luck!