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

[Ttrees]

@Alpha-Dave
Metal seems more forgiving than this stuff, but the issue is the same on any pillar drill I've ever seen, fault is likely to happen when changing bits.
This hopefully will sort that, although it will make the table more rigid also, so if it works will kill two birds with the one stone.

Can't see a way around this, unless you have an X-Y vise or table which is fixed,
which if not motorized looks a right pain to do, and doesn't lend itself to being as compact.
This seems an easier method than what I've seen, but awaiting embarrassment on that one with some easy solution.

Cheers
Tom

 

[Alpha-Dave]

Is the problem that when going up a drill-size you have to remove the work piece from under the drill so that you can change bits, and therefore the next size hole won’t be centered? If you are using 2-flute drills that should not be a major issue as the force on the 2-sides will try to equalise and so should just follow the previous hole, even if off by a small amount.

Going back to the original problem-statement, I have found that centreing a round hole in an already-round thing to be pretty much impossible; the trick being to make the hole first, then mount onto a mandrel with the same diameter as the hole, then cut the outside. I suspect the inverse of this is possible using some sort of collet to hold a round workpiece, but that would be huge.

 

[Ttrees]

Not having read my thread from start to finish, I have to presume that
my thread maybe a bit unclear to say the least, lol
And possibly likely other factors where some of the confusion is,
Not sure whether to apologize or not about my derailment, as hopefully the original
objective will be sorted.

Back on the matter again,
I might mention again that this stock is allready pre bored accurately
(not by me) so the issue of precision in that regards is met already.
All I wish to do is bore the work out to 30mm.

Seems plastics are more unforgiving than steel in regards to changing and lining everything up again, but I've had many's an issue before drilling anything beyond even 20mm thick.

I guess there is an easier solution than what I'm trying to make work, but have yet to see it, and surprised that some company doesn't do so.

Tom

 

[Ttrees]

Went mucking about with this today

Far from a tidy job as it is, but enough to get on with some testing

Had a go at resetting the bit, looks possibly promising.
Needing to press with too much force to eliminate slop as is,
so I figure welding a wee tab onto the bottom of the bracket, as to make contact with the jacks lifting plate at a lower position will reduce the effort needed to push to the right,
as it will hopefully be more rigid.

Had a wee mess around with the maximum distance for fun,
This isn't that important, at least not right now,
since the last photo above is the size needed to align centrally in the bore
i.e sunk in the work.

Thinking some sort of 3/2/1 hardwood block might be the best, or at least a simple solution for the meanwhile...
should support be of concern, say drilling stainless for example.

Around 80mil of a gap to bridge.
Thinking some sort of swinging stop might be simplified by the wee tab I mentioned.

Might see if I can borrow a bottle jack before doing this, just to see if it would be that much nicer of a contraption to utilize for this purpose.
Even with slop, likely would be easier to make more rigid, rather than attempting to make a bracket for this scissor jack of some sort.

Eager to see how I fair out with the wee tab, should it do the trick,
I'll be testing this out.

All the best
Tom

 

[Ttrees]

Hello again
Done some more head scratching and figured a plate long enough to get to the bottom of the scissor jack would be a good start.
Thankfully things are much smoother and gives a reassuring thud and seems to be
consistent

Some more pondering and I figured that I might as well try figuring out how to index to
the maximum distance,
as the jack needed to be shifted off center with the plate sitting so far away from the knee.
This was less than preferable, as it means more of the jack needed to be under the
table and more chance for the knee to foul against the jack laterally when swung away,
and also wanting to get a reference on two points of the jack gives better registration.

(shouldn't have ground a bevel on the bottom of the plate)
So why not make the thing as versatile as it should be, since I need to sort that wee gap.
Figured out a way, more work than planned, but what the heck, it'll be interesting!

Tom

 

[Ttrees]

Got most of this done, just some adjustments needed yet.
This seemed about the best way to align things, after briefly fumbling about with a plumbline unsuccessfully.

It was about here when I realised that I have a bit more runout than was apparent before.
Spent a few days looking at various videos on the matter, and done some investigating,
might have to revisit this matter later.

Without having an indicator, I done my best with a rubber mallet and a long drill,
which was simply rolled on a flat bench to check for straightness.

Broke a tap not supporting the work properly, and my chuck fell out drilling the first hole for the slot, made a doofus move and picked up the wrong bit 12mm instead of 10mm

so is oversize but thankfully not important.
Need to fettle things a bit more yet, eager to see if this will work well, atall or the opposite

Hopefully see soon

Tom

 

[Ttrees]

Thinking the rest would be easy, I plodded onwards....

Just a wee bit of adjustment needed to make that parallel with the column, might as well make it work, if it's going to atall

Gaah went way too far, and it wouldn't bend back without turning to a pigs ear.
Here's a good way to break a clamp or two

At least I get to tell ya'll that the newer liddle clamps have very soft castings, compared to the old which snapped...
(thankfully not the good part with the thread, been thinking about making these longer, so will have these to work on.)

Got this about half right at this point,

But things needed more persuasion with some hammers...
I miss having an angle grinder, hopefully a good deal crops up soon locally

That will do for now, I expect I'd need to get the drill running with very little runout to achieve greater tolerances.

Only a few wee bits and bobs to do now it's half decent to test out.
Hopefully it works, whether it cancels out the runout, keeps the chuck from going out of center,
or just making entry less troublesome on this plastic, yet to find out.
Need to do a good clean up and that first.

Cheers for looking
Fingers crossed

Tom

 

[Ttrees]

Not done any drilling yet, as seeing how this was working.
Pleased to say it seems consistent, so will be having another go soon enough.
Got the other printer roller component from me folks, so have some more stock should things not work out.

Didn't make any proper bracket for the scissor jack, as I might have a play around with
a bottle jack instead sometime, it might inspire more jiggery should the need arise.
A world of possibility when there is a fixed point!

Still using a pair of clamps to keep things put for now, as I really need to make a proper top and bolt the drill to it.

Bit of an odd looking approach to mount the vise backwards, but cannot get both clamps on otherwise without remounting the vise on the base plate.

Two turns of the jack before untightening the knee

and making sure the sliding bracket is bottomed out on the jack.

Hopefully this might even counter any runout to a good extent, as I don't have a metalworking lathe to remachine MT's and go messing about down that massive rabbit hole.

I guess it might debatable as to exactly which is more troublesome in this operation!

Lining up the drill in the hole perfectly, but with an eccentric possibility,
meaning the ole isn't lined up atall!
Or...
A perfectly lined up hole, but with an eccentric chuck or other workings of the machine.
Could be a case of half a dozen of one, lol!
Eager to see how things fair out.

All the best

Tom

 

[Alpha-Dave]

Ah ha!

I think I now understand what you are trying to do; instead of using the drill press’s quill to drive the drill bit into the cylinder, you are leaving the drill bit in the ‘home’ position, and using the jack to raise the workpiece (and the whole table) into the drill bit, like a Milling Machine.

I have not heard of that being done before, but I can see how that potentially could be more accurate than having the quill run-out. Accuracy here would rely on the vertical travel of the table up the column being perfectly parallel to the drill bit, which would rely on the column-to-head interface being machined to a high tolerance as any discrepancy there will be amplified further down the column

 

[Inspector]

I know you have mentioned a hydraulic jack a number of times. I wouldn't recommend one simply because you won't have much feel and could easily bend or break things. I would look for/or make a screw jack (have one from my 1990 Nissan pickup that went to the scrap yard). They have a better feedback so you would be less likely to graunch things.

Pete

 

[Ttrees]

@Alpha-Dave the drill is still going to be used as normal,
just the table, or knee if you will
(I haven't looked for a diagram to have a better word for this part)
is supported with the jack, but also provides a stop.
Not having attempted to change from say a 5mm bit to say 30mm,
involving dropping the table, is likely where the confusion is coming from.

I haven't messed about with that yet...as it is now, yet anyway
as it would involve making a block to fit between "the knee" and the "lifting pad" of the scissor jack, since the position of it is likely to change if moved,
which brings me onto @Inspector 's comments on the bottle jack idea.
Should it be able to travel whilst remaining parallel with the column ?
that would eliminate the need for a wee block.

Now onto the problematic part which you mention Pete.
I guess worth questioning folks what they think, i.e

With some practice, could one figure out how much of a shim one could put in-between,
should things be consistent with a certain amount of force,
and at that, if this remains the same throughout the travel of it,
as it sounds like it's not so easy to just sight it on the money without going backwards and forwards getting it set the right height.

Noted about the old style scissor jacks from the 80's & 90's, I've been lookin for a while for these!
This one doesn't seem too bad though, a lot more stout than it looks, and has remained good with testing for about 10 stops/bumps anyway, (about as good as I could hope those clamps to hold up for)

Might get the chance to have a good look at these soon enough, as I see large types of these going for 20 or 30 quid, should I ever need it a used one might crop up.
Can likely make do with some sorta block for now.

Cheers
Tom

 

[Ttrees]

That's not to say this is guaranteed to work yet, as I have yet to do any type of load test on this, hence my reason not to make a plate for the base of the jack.

I've yet to see if I can get the lifting pad to remain in the same location with the downward force of drilling, and also the lateral force of the bump.
I suppose it's still possible for the index to change after the first drilling operation.
I might try something like clamping something long onto the pad and seeing if it changes position yet, if I had a cone of sorts I could provide that force without graunching things up (new word for me)

This is possibly where the bottle jack shines, so that should explain things better.

Thanks
Tom

 

[Ttrees]

Uploaded a wee video so ye can see what I'm on about
Not got round to any more testing yet, I'll likely redo the video when I get round to it,
since you can't really see anything, and not used to its full potential either,
which seems possibly the source of the confusion

Still seems like a bottle jack might be a good call for this?

 

[Ttrees]

Hello again.

Duly noted by Inspector on a metalwork forum, that glazing on the grinder wheel was from my first attempt at making these spacers from a case hardened lump of steel,
which absolutely ate my rougher wheel for breakfast , but on the finer wheel it seems to be workable, (pity I didn't know that before, as I will need be extra careful now whilst grinding my plane irons and chisels).

After experimenting for a wee bit the results seemed good enough to make this a bit more user friendly.
Not got around to cleaning and painting, just cured my questionable OCD.

Started on making a mounting plate so I can have some more surety

Love this big old file, the brick a brack man wasn't going to charge me anything for it, but took a fiver for it,
left outside, I thought it was too far gone and took a gamble that it may come in useful, seems to be getting better after a bit of old motor oil!
was pretty smelly for a while though

Sorry no photo of draw filing with block along the length like sharpening a card/cabinet scraper.
I've been experimenting with filing along the length, both orientations of the block and file and in both directions makes 4 steps
of approaching the work,and not causing any twist.

Just noting that I've being becoming fond of using the block on edge rather than the face, much easier for some reason.

Nothing perfect here but the plate made nicely and (runner?) made for mounting onto the base and is quite solid.
Thought I'd just make sure that my measurements were OK after one runner done and the other tacked on one end.
Got stuck and things went slightly ar5eways.

Next job was both attempting to cure my OCD as I was having to skew the jack too much, and figured I could also scoot the
jack to the right and get a preferable location for drilling holes for fixing the jack onto the plate.

And a wee bit more scraping, not going overboard though as I will wait until I give the machine a refurbishment first, which I will get around to sometime, hopefully later rather than sooner ???

Don't have a piccy, but was unhappy with the table location, as the bit was too far to the left of the hole.
Thought I'd just tack some washers onto the pad component to sort, but me wee 50 quid parkie welder had other ideas RAAAH!
Decided to make the plate thicker after a tack started to give in, and a mess was made of the old one.

Now I've got it where I want it, favouring the other side of the hole, and should be future-proofed should the jack have a bit more give in it than appears, and if not can file a wee bit off again.

It'll be easier to keep an eye on it, now that I won't mind if it moves.

Must clean it up a bit by adding a bevel as it looks a bit disproportionate, hopefully that will do the trick nicely, and a lick of paint to hide my welds

Just have to tidy up and paint now, before I can test.

Tom

 

[Ttrees]

Most of this is done now, could do a bit more scraping but was happy enough to test out.

Done some inspecting of the Morse tapers, sledgehammer head "hardy hole" was great to use for getting out the chuck, as it was very stuck.
Blued everything with permanent marker expecting to possibly see something apparent, not so,
just trial and error using the long drill getting it the best I could,
and two wee file marks to align it again.
(shoulda wiped off the marker ink,I was to find out)

That done and everything properly affixed, I was getting some inconsistency, tracked down to the
(knee?) so drill and tapped for a pair of bolts for a hopefully permanent 90 degrees.

Will try editing this to explain, kinda messed up my experiment as I didn't have the table
low enough and clanged into the vice jaws.
Shoulda had it a few mm lower, doh!

And to add insult to injury
I proceeded to do what should win ultimate numpty move of the week,
and test out the jig after moving the scissor jack!

(Ideally one would want a tight fitting hole for indexing the bit from, and not a tapered bore from a printer roller, so some luck required/not a guarantee)

Seeing as the adjustment of the jack alters, I should have set the table height to suit the large bit first, which I forgot lol
This is where the plate can come into play, although need to do a bit more work on that yet, more eager to get on with the job.
i.e if I had the jack lower down I could have been using the plate to reach for the bottom of the jack.

If you're managing to understand my rambelings, you might question the indexing plates
use in this way, and the knee?/undertable support is omited!
I did use a wee shim of timber, but not sure if it was a good idea or not.
Certainly for my scissor jack, is too skewed to use for support, since pressing down would shift the index, so this is interesting to find out more about that.
Might keep an eye out for a bottle jack as I'm guessing this wouldn't be an issue?
I don't mind using a shim.

Some pictures
Loose old belts made this take a bit.

As said either a numpty move on my part, or the bit not a great fit, and edges well chowdered up from testing also.

Seems to have copied the above which one can't fault the jig for.

Needed a bit of filing to be a tight press fit needing knocking off with a mallet,
Very pleased I could get the error out, just about!

This is definitely a good enough fit to get the measurments I'm after.
Can face one side on the lathe now, bore is enough centered to turn faces on the mandrel.
(original face on one side bang on, so it is less guesswork)
and test the depth of the part more accurately than before, for documentation purposes.
remove again and bevel the part.
This might explain, too much variance in first attempt underneath.

Tom

 

[Ttrees]

Here's my entry, should anyone start a doofus of the week award type thread.
Don't know what came over me to ruin the edge of the ole?

So I am still in the dark if it works or not, and whether I only just got lucky this time! lol.

 

[Ttrees]

Hello again
Since had a few more attempts of making this jig work.
Two nice faces to mark from on either side to start with..

NO DICE, TRY AGAIN!

Well what could be the issue here...
Getting super consistent results indexing, but dynamic testing proving otherwise.
I'm guessing the most likely issue is when the table is deflecting, the jig being tight against the jack
is following the scissor jack contact/lifting plate.
I've mucked around with a shim, I've butted the indexing plate down to the arm of the jack
(potential support) both being unsuccessful,
and reckon the plate is better not bottoming out on the arm of the jack.
No point in ruining another bit whilst knowing this, and maybe something else I don't know yet,

Two pics of before slight altercation...

Just mucking around yet, seems the way this might work, is...
That the jack stays at the exact same height,
and if it must be altered, then the shim (door handle spindle bar seemed adequate)
needs to be adjusted.
Fair enough, I can get the mating surfaces perfect to deal with most of what might be held in the vice, or work of that height sitting on the table.

With that said,the big question is,
Does the contact plate from the car jack, need to be parallel with the column, or was it just causing an error as it was skewed to favour the table walking away from the column, due to the weight of drilling.
That's the only thing I can come up with, since indexing was working well,
i.e the cutting lips were not catching anywhere on the hole.

See underneath to see contact plate now slightly skewed the other way, if atall.
A small change in adjustment of the jack, and it makes a big difference.

Bit of faffing now to prep these, hole too small on one side to get a mandrel through.
Most of the cylinder is bored larger though, so don't have to come up with a solution for that ,
if need be.

At least I'm getting better results turning the stuff
Well pleased with that

Hoping I get to use this piece, fingers crossed.
Keen to see if the little change makes a difference.

Tom

 

[Ttrees]

Seems @Phill05 might have been onto something,
Having mucked about with some more tests, it seems my clamps are proving to
be a pain in the bum.
Not sure if it's because of my shenanigans or not, but seems I could improve matters
by making some more holes in the vice plate, and maybe some inserts for the table.

Whilst pondering about this a bit, another thing struck me about more possible
methods I could attempt without the clamps being in the way!


Seems properly mounting the plate might sort all out, and if something else is the solution to this bodgery, then a possible solution to making a hole oversize... possibly even accurately,
if you're thinking what I'm thinking, eh?

 

[Ttrees]

Gonna make some solution to mount this now, should that be the solution,
but wouldn't it be ironic if my original title was actually suggesting the answer!

 

[Ttrees]

Made a start on making hold downs for the drill table

Did I mention that i REALLY like this file?

First time properly gang filing to some sort of tolerance(ish)
Not going mad as these are only clamps, so no scraping nor switcharoos of the plates.
Approached from four sides of the work, and really trying to hollow the centre,
but anyone who's done this kinda thing before will know that's not really possible to have a hollow doing this in both axis, as abrasion always favours the edges.

So takes a bit of time to gradually take down a high spot, and back to focusing in the centre,
and canceling out the error in the other axis, say after each dozen or so.

I found it helpful not to lift the file on the backstroke when I got to about this stage

And finishing on the longest surface, any high corners should be long gone by the time this is done,
and one would be going back and fourth in the centre a few times.

Basically If you've just filed a facet on the far edge, then you need to approach the work from the other axis/90 degrees and scoop out the centre.
If you immediately try and remove a high corner you will tip the file because you cannot file out the centre in both directions
You have to make sure there is a noticeable scoop from the centre of the worst area before touching it before feathering onto that high corner, but you can only do a bit, as you need correct that.
Eventually getting to a stage where you can file from both centres only.

More lessons to be learned doing a square compared to a rectangle, but trickier, glad I made a start at this first.

Last face to file was the mill scaled rough edge of the old plate which was notably harder than the hacksaw cut edges.
This took ages to file and arguably was a lot worse for the file than not lifting it off the work on the back stroke.
I will definitely take the bench grinder to that if/when doing this again.

Finished the filing work for now, be interesting to get the tolerances better if it were something else.
I suppose I'd scrape the centre out with a narrow file, maybe a bit of second cut filing, scrape centre again and lap, with possibly some switcharoo of the plates going on would most likely get them perfect.
Not needed for this kinda thing though.

That's all for now
Will have to wait until it rains until I can get back at this.

Hopefully I can get away without needing something to tip them,
thinking I can just grind a bit of a taper into the small plates,
since I figure a bit more surface area would be more suitable for the large slots in the drill table.

Thinking tapping these wouldn't make sense, but am open to suggestions, might mock up one
with a smaller bolt before drilling to correct size and see.

Thanks to Tom for the inspiration, even though they won't be as nice, they should hopefully do the trick.

Cheers
Tom