I need to drill out a 10mm diameter hole to a depth of 3mm in a piece of
brass.
I want a `flat` hole not conical as a normal drill bit would give me .
I am looking for something like the fostner drill bits but something
that would drill brass.
Not sure if it is possible, any suggestions.

On Tuesday, 3 January 2017 22:41:13 UTC, ss wrote:
I need to drill out a 10mm diameter hole to a depth of 3mm in a piece of
brass.
I want a `flat` hole not conical as a normal drill bit would give me .
I am looking for something like the fostner drill bits but something
that would drill brass.
Not sure if it is possible, any suggestions.

A 10mm Forstner?

On 03/01/2017 23:05, wrote:
On Tuesday, 3 January 2017 22:41:13 UTC, ss wrote:
I need to drill out a 10mm diameter hole to a depth of 3mm in a piece of
brass.
I want a `flat` hole not conical as a normal drill bit would give me .
I am looking for something like the fostner drill bits but something
that would drill brass.
Not sure if it is possible, any suggestions.

A 10mm Forstner?

Would that drill brass? as most are advertised for wood.

On Tue, 3 Jan 2017 22:41:08 +0000, ss wrote:

I need to drill out a 10mm diameter hole to a depth of 3mm in a piece of
brass.
I want a `flat` hole not conical as a normal drill bit would give me .
I am looking for something like the fostner drill bits but something
that would drill brass.
Not sure if it is possible, any suggestions.

Isn't that just a centre cutting 'end mill' (or pre drill then finish
with a non centre cutting end mill)?

Cheers, T i m

On 03/01/2017 23:22, T i m wrote:
[...]
with a non centre cutting end mill)?

That would be a slot drill.
--
Andy

You can possibly do it with a 10mm slot drill milling cutter mounted in a pillar drill with the piece being cut secured well. Anything deeper or bigger in diam. and I think you will struggle.

Richard

On 03/01/2017 22:41, ss wrote:
I need to drill out a 10mm diameter hole to a depth of 3mm in a piece of
brass.
I want a `flat` hole not conical as a normal drill bit would give me .
I am looking for something like the fostner drill bits but something
that would drill brass.
Not sure if it is possible, any suggestions.

If you decide to try a slot drill in a regular chuck then make sure it's
very tight in the chuck to reduce the risk of it pulling out. I suggest
it would be far better (and cheaper) to make yourself a simple D-bit ...
Google is your friend.

On 03/01/2017 23:30, Andy Wade wrote:
On 03/01/2017 23:22, T i m wrote:
[...]
with a non centre cutting end mill)?

That would be a slot drill.

So could I use a slot drill in an electric drill.
I dont have a pillar drill.

"ss" wrote in message
...
On 03/01/2017 23:30, Andy Wade wrote:
On 03/01/2017 23:22, T i m wrote:
[...]
with a non centre cutting end mill)?

That would be a slot drill.

So could I use a slot drill in an electric drill.
I dont have a pillar drill.

No chance.

On Tue, 3 Jan 2017 23:53:51 -0000, "bm" wrote:


"ss" wrote in message
...
On 03/01/2017 23:30, Andy Wade wrote:
On 03/01/2017 23:22, T i m wrote:
[...]
with a non centre cutting end mill)?

That would be a slot drill.

So could I use a slot drill in an electric drill.
I dont have a pillar drill.

No chance.

+1 ;-(

Cheers, T i m

On 03/01/2017 23:45, wrote:
On 03/01/2017 22:41, ss wrote:
I need to drill out a 10mm diameter hole to a depth of 3mm in a piece of
brass.
I want a `flat` hole not conical as a normal drill bit would give me .
I am looking for something like the fostner drill bits but something
that would drill brass.
Not sure if it is possible, any suggestions.

If you decide to try a slot drill in a regular chuck then make sure it's
very tight in the chuck to reduce the risk of it pulling out. I suggest
it would be far better (and cheaper) to make yourself a simple D-bit ...
Google is your friend.

OK, points taken, are there any other options as a one off job to get a
3mm deep hole drilled in a piece of brass?

On 04/01/2017 00:36, ss wrote:


are there any other options as a one off job to get a
3mm deep hole drilled in a piece of brass?

Brass is supposedly one of the more easily machined metals BUT there
are a lot of posts etc about modifying drills to do it (zero rake angle
etc) .

Maybe try one of the model engineer/model machinist type forums they
are bound to know,as making a stopped hole in brass should be bread and
butter to them

On Tuesday, 3 January 2017 23:09:15 UTC, ss wrote:
On 03/01/2017 23:05, tabbypurr wrote:
On Tuesday, 3 January 2017 22:41:13 UTC, ss wrote:

I need to drill out a 10mm diameter hole to a depth of 3mm in a piece of
brass.
I want a `flat` hole not conical as a normal drill bit would give me .
I am looking for something like the fostner drill bits but something
that would drill brass.
Not sure if it is possible, any suggestions.

A 10mm Forstner?

Would that drill brass? as most are advertised for wood.

Tool steel is way harder than brass. The cutting geometry won't be designed for it, so need to take it very easy in the drill press.


NT

One possibility is to layer the brass. Use two pieces, one 3mm thick which you drill through 10mm diam. and the other whatever makes up the total thickness. The two pieces then need securing together probably soft soldering it all depends on the overall size of the finished component.

Richard

ss wrote:
On 03/01/2017 23:30, Andy Wade wrote:
On 03/01/2017 23:22, T i m wrote:
[...]
with a non centre cutting end mill)?

That would be a slot drill.

So could I use a slot drill in an electric drill.
I dont have a pillar drill.

If you drill with a normal drill first part way,you could probably
finish with a slot drill if extreme depth accuracy were not a problem
but even that could be achieved if you made a depth stop ferule.

On 03/01/2017 23:47, ss wrote:
On 03/01/2017 23:30, Andy Wade wrote:
On 03/01/2017 23:22, T i m wrote:
[...]
with a non centre cutting end mill)?

That would be a slot drill.

So could I use a slot drill in an electric drill.

.... No.
If you haven't got a pillar drill, drill stand or (at a push) variable
speed router then get someone else to do the job.

On Wed, 4 Jan 2017 00:36:55 +0000, ss wrote:

On 03/01/2017 23:45, wrote:
On 03/01/2017 22:41, ss wrote:
I need to drill out a 10mm diameter hole to a depth of 3mm in a piece of
brass.
I want a `flat` hole not conical as a normal drill bit would give me .
I am looking for something like the fostner drill bits but something
that would drill brass.
Not sure if it is possible, any suggestions.

If you decide to try a slot drill in a regular chuck then make sure it's
very tight in the chuck to reduce the risk of it pulling out. I suggest
it would be far better (and cheaper) to make yourself a simple D-bit ...
Google is your friend.

OK, points taken, are there any other options as a one off job to get a
3mm deep hole drilled in a piece of brass?

Not knowing what the actual project is, would it be possible to fit a
3mm thick x 10mm ID 'washer' to the surface of the brass, if it was
just to carry a shaft or somesuch?

Cheers, T i m

On 04/01/2017 09:44, T i m wrote:
Not knowing what the actual project is, would it be possible to fit a
3mm thick x 10mm ID 'washer' to the surface of the brass, if it was
just to carry a shaft or somesuch?

The item in question is a piston for a small steam model.
There is the piston rod that goes through the centre of the `brass`
piston and is attached by a small nut on the underside of the piston.
We are talking approx a 2 inch stroke and 1 inch dia piston.
The piston stroke is fractionally too long so the piston hits the bottom
of the cylinder so I need to sink the nut in to the brass by 3 mm.

On Wed, 4 Jan 2017 10:21:46 +0000, ss wrote:

On 04/01/2017 09:44, T i m wrote:
Not knowing what the actual project is, would it be possible to fit a
3mm thick x 10mm ID 'washer' to the surface of the brass, if it was
just to carry a shaft or somesuch?

The item in question is a piston for a small steam model.
There is the piston rod that goes through the centre of the `brass`
piston

When you say though, is the piston very thin or did you mean into
rather than through?

and is attached by a small nut on the underside of the piston.

When you say 'attached' do you mean locked or does the rod go right
though the piston ... or is the piston rod threaded into the bottom of
the piston (blind hole) and the nut just locking the two together?

We are talking approx a 2 inch stroke and 1 inch dia piston.

Ok.

The piston stroke is fractionally too long so the piston hits the bottom
of the cylinder so I need to sink the nut in to the brass by 3 mm.

Hmm, I think a 'picture might speak 1000 words' here but is it the
piston or nut that is hitting? If you sink the nut into the underside
of the piston, will you still be able to do it up (is the 10mm OD hole
you mentioned allowing access for a box driver etc) or if the nut was
say 6mm thick could you use a thinner (half) nut?

Sounds interesting though. ;-)

Cheers, T i m

On 04/01/2017 10:35, T i m wrote:
Hmm, I think a 'picture might speak 1000 words' here but is it the
piston or nut that is hitting?

It is the nut that is hitting.

Image:

Ahh! It's a lathe you need to produce a counter bore in the piston. If there is enough thread on the piston shaft that will allow the nut to screw down further but looking at the photo the shaft is level with the top of the nut so that will start to hit the top of the cylinder so it will need shortening. Alternatively if the other end of the shaft length protruding out of the cylinder is not critical than a few washers on the underside of the piston will pull the shaft down enough on the piston to avoid shortening and as Tim suggested a locknut which is about half the height of a standard nut might avoid the need to counter bore.

Richard

On 04/01/2017 11:12, ss wrote:
On 04/01/2017 10:35, T i m wrote:
Hmm, I think a 'picture might speak 1000 words' here but is it the
piston or nut that is hitting?

It is the nut that is hitting.

Image:


Some thoughts:
- You could use a thick gasket to solve the problem but would lose the
centring action of the step on the top plate ... probably not too
important. Whether a non-metallic gasket is viable depends on whether
the engine is single or double acting and the pressures.
- I presume the piston tightens onto a shoulder so you could file that
back 3mm
- Could you reduce the stroke by moving the fulcrum or changing the beam
length?
- You could enlarge part of the hole with a jobber drill and accept that
the nut tightens onto a sloping surface, or you could make a suitable washer
- Could you bore a recess in the cylinder end?

Finally, if all you have is a hacksaw, and no mates with a pillar drill,
drill stand or lathe, then I suppose you could saw a few mm off the
piston as a last resort.

On 1/4/2017 12:09 AM, T i m wrote:
On Tue, 3 Jan 2017 23:53:51 -0000, "bm" wrote:


"ss" wrote in message
...
On 03/01/2017 23:30, Andy Wade wrote:
On 03/01/2017 23:22, T i m wrote:
[...]
with a non centre cutting end mill)?

That would be a slot drill.

So could I use a slot drill in an electric drill.
I dont have a pillar drill.

No chance.

+1 ;-(

Cheers, T i m

+ another 1

On Wed, 4 Jan 2017 11:12:24 +0000, ss wrote:

On 04/01/2017 10:35, T i m wrote:
Hmm, I think a 'picture might speak 1000 words' here but is it the
piston or nut that is hitting?

It is the nut that is hitting.

Image:


Ah. ;-)

As others have said there are several solutions, especially if you
have access to a lathe or mill.

One that you could do yourself is as has been mentioned is to create a
counterbore with a std drill (ideally in a press) and then shape a nut
accordingly to match the taper of the drill. If you knew the thread
and nuts were available (it's probably an imperial size) I could do
the nut bit on my lathe and stick it in the post to you?

Is the piston shaft screwed into the piston and the nut just acts as a
locknut or is there a shoulder on the piston rod (the rod looks like
it could be slightly bigger diameter than the thread).

Is the threaded portion of the rod deep enough to allow the nut to be
recessed?

Has the thing previously worked OOI (has something else been changed
that has impacted this issue)?

Cheers, T i m

On 04/01/2017 19:32, T i m wrote:

" Has the thing previously worked OOI (has something else been changed
that has impacted this issue)?"


Thanks for the offer Tim (the nut), I have resolved the problem by
filing making the nut slightly thinner, that has cured the problem.

The piston shaft is screwed in to the piston and then the nut to lock
it. No shoulder on the piston rod.
Has it previously worked I do not know, I have had for 40 years stored
in the attic. I have taken apart now and cleaned up the bearings etc and
it turns very smoothly, it was just this last part of the piston
bottoming out I had to resolve. I believe it was an apprentices model
of a Stuart vertical steam engine.(it came from an engineering works) I
never paid much attention to it years ago, I have a very vaque memory of
slackening the pivot bolt on the connecting rod so the flywheel would
turn when my kids played with it years back so maybe back then it was
bottoming out.

On Wed, 4 Jan 2017 21:03:18 +0000, ss wrote:

On 04/01/2017 19:32, T i m wrote:

" Has the thing previously worked OOI (has something else been changed
that has impacted this issue)?"


Thanks for the offer Tim (the nut),

You are welcome. I could also have counterbored the piston (Myford
ML10) if stage 1 (or any alternatives) hadn't worked. ;-)

I have resolved the problem by
filing making the nut slightly thinner, that has cured the problem.

Yeah, sometimes the difference of just a few thou is all it needs.

The piston shaft is screwed in to the piston and then the nut to lock
it. No shoulder on the piston rod.

Ok.

Has it previously worked I do not know, I have had for 40 years stored
in the attic. I have taken apart now and cleaned up the bearings etc and
it turns very smoothly, it was just this last part of the piston
bottoming out I had to resolve. I believe it was an apprentices model
of a Stuart vertical steam engine.(it came from an engineering works) I
never paid much attention to it years ago, I have a very vaque memory of
slackening the pivot bolt on the connecting rod so the flywheel would
turn when my kids played with it years back so maybe back then it was
bottoming out.

Ok and thanks. So (I don't know much about steam engines as such) but
I wonder if the distance from any crankshaft to the cylinder could
have changed or is it all pretty well defined when bolted up?

e.g. Is the piston running around the centre of travel, eg, not too
near the bottom and further away from the top (at the extremes of the
stroke). If it is and if the assembly allows, you might be able to
pack the 'crankshaft' (or whatever determines that dimension) away
from the cylinder a touch?

If it were mine (and especially if you were going to get it running,
even if only with compressed air) I might like to know all was
symmetrical, or there was a reasonable space under the piston (nut) at
full stroke etc.

Cheers, T i m

On Tuesday, 3 January 2017 22:41:13 UTC, ss wrote:
I need to drill out a 10mm diameter hole to a depth of 3mm in a piece of
brass.
I want a `flat` hole not conical as a normal drill bit would give me .
I am looking for something like the fostner drill bits but something
that would drill brass.
Not sure if it is possible, any suggestions.

Grind to, or buy, a flat-bottomed twist bit.

On 04/01/2017 21:32, T i m wrote:
Cheers, T i m

“So (I don't know much about steam engines as such) but
I wonder if the distance from any crankshaft to the cylinder could
have changed or is it all pretty well defined when bolted up?”

Everything is fixed and not adjustable apart from the bolts that fix
the pivot on the piston rod but tried minor adjustments and it then
either bottoms out or tops out. So the issue was inside the cylinder
which I have now resolved.

“If it were mine (and especially if you were going to get it running,”

It does not have the inlet/outlet valves but someone with an
interest should be able to convert it.

This is part of a bigger plan, the model is worth at least £100+ as it
stands and I have other items ...clocks/plate cameras/carbide
lamps/paraffin irons/old scales and other stuff that has been in the
attic for 40+ years and a load of other stuff that my children are not
interested in so as I have recently retired I will sell it off and I
intend to get a high quality working steam model of a beam engine with
the proceeds.

This is almost identical to the model I have:
https://www.youtube.com/watch?v=B_unVRB4UKw

This is what I want or something similar:
https://www.youtube.com/watch?v=3Wb_AAKMXGQ

On Wed, 4 Jan 2017 23:49:23 +0000, ss wrote:

On 04/01/2017 21:32, T i m wrote:
Cheers, T i m

“So (I don't know much about steam engines as such) but
I wonder if the distance from any crankshaft to the cylinder could
have changed or is it all pretty well defined when bolted up?”

Everything is fixed and not adjustable apart from the bolts that fix
the pivot on the piston rod but tried minor adjustments and it then
either bottoms out or tops out.

Understood. I was thinking more likes shims that 'adjustment' as such
but the latter part of your reply makes that irrelevant in any case.
;-)

So the issue was inside the cylinder
which I have now resolved.

Understood.

“If it were mine (and especially if you were going to get it running,”

It does not have the inlet/outlet valves

Ah.

but someone with an
interest should be able to convert it.

Ok.

This is part of a bigger plan, the model is worth at least £100+ as it
stands and I have other items ...clocks/plate cameras/carbide
lamps/paraffin irons/old scales and other stuff that has been in the
attic for 40+ years and a load of other stuff that my children are not
interested in

I have recently been given a Drummond lathe and other workshop tools
on the same basis. ;-(

so as I have recently retired I will sell it off and I
intend to get a high quality working steam model of a beam engine with
the proceeds.

This is almost identical to the model I have:
https://www.youtube.com/watch?v=B_unVRB4UKw

Ah, even better idea of what we were talking about. ;-)

This is what I want or something similar:
https://www.youtube.com/watch?v=3Wb_AAKMXGQ

I can see the appeal as I love all things mechanical bit it looks a
bit big for the mantelpiece (well, mine anyway). ;-)

Cheers, T i m

newshound wrote:
On 1/4/2017 12:09 AM, T i m wrote:
On Tue, 3 Jan 2017 23:53:51 -0000, "bm" wrote:


"ss" wrote in message
...
On 03/01/2017 23:30, Andy Wade wrote:
On 03/01/2017 23:22, T i m wrote:
[...]
with a non centre cutting end mill)?

That would be a slot drill.

So could I use a slot drill in an electric drill.
I dont have a pillar drill.

No chance.

+1 ;-(

Cheers, T i m

+ another 1
There are several ways a proper DIYer can use a slot drill for finishing
a dead hole with hand tools with out a pillar drill or mill.

On 03/01/2017 22:41, ss wrote:
I need to drill out a 10mm diameter hole to a depth of 3mm in a piece of
brass.
I want a `flat` hole not conical as a normal drill bit would give me .
I am looking for something like the fostner drill bits but something
that would drill brass.
Not sure if it is possible, any suggestions.


Drill hole with a 10mm HSS bit
Then use a 10mm forstner bit to flatten the bottom, use it slowly and
with good cutting lube and it should be fine.

Alternatively buy a 10mm end mill and finish hole with that

On Thursday, 5 January 2017 18:13:51 UTC, rick wrote:
On 03/01/2017 22:41, ss wrote:

I need to drill out a 10mm diameter hole to a depth of 3mm in a piece of
brass.
I want a `flat` hole not conical as a normal drill bit would give me .
I am looking for something like the fostner drill bits but something
that would drill brass.
Not sure if it is possible, any suggestions.


Drill hole with a 10mm HSS bit

that would get you about a 3mm wide hole.

Then use a 10mm forstner bit to flatten the bottom, use it slowly and
with good cutting lube and it should be fine.

Alternatively buy a 10mm end mill and finish hole with that

NT