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Hi Mike,
In each case the drill is broken off below the surface and they are
2mm drills, so are quite small. I tried to do the Alum method
advised by an earlier reply. Unfortunately, in the UK, Alum is no
longer readily obtainable "at the local pharmacist". In fact "Boots" -
the countries biggest chemist - is 'out of stock'. I was able to
find an industrial supplier who eventually came back and said they
would supply a minimum of 1Kilo (2.25 lbs) for ?50 ($75) which seems
a bit drastic for the sake of three small broken bits!

My 2nd question is this. There is Chris's terrific 'Little Machine
Shop' in the US - is there anyone in the UK who keeps a similar
supply of 7x12 parts? Chronos have a few items that fit our machines
but nobody, on line, seems to supply a full range of spare parts??
Machine Mart stock parts but you can't order them on line and they
don't keep them 'in store'.

I have a broken cross slide nut (:o( and think while I am it I will
get a few spares of other things (belts fuses gib strips etc) as they
normally go when you need them most.
Regards
Ken


--- In 7x12minilathe@y..., "walsh2002bc" <me.walsh@s...> wrote:

Hi Ken:

I hate it when that happens...I find that deeper holes in aluminum
need to be cleaned out more so they won't bind 'cause it's gummy
stuff. Try putting the workpiece in a vise and tapping the bit

with

a hammer and small drift. Sometimes just working it in different
directions will loosen it off.

mike




--- In 7x12minilathe@y..., "Capt Ken Appleby" <captkenn@m...> wrote:

Hi,
This might sound a bit basic but it has stumped me! While

drilling

on

my lathe, I have broken two 2mm drills in two separate holes in a
steam engine alluminium casting. They have both broken off flush

so

there is nothing to get hold of and there is not a lot of space
around them. I have thought of over-drilling the whole lot out

(if

I

can) and making a screw-in plug and milling it flush.

Is the casting a write-off - Or is there another way?

All help appreciated
Regards
Ken

Hi,
Does "Chris's terrific Little Machine Shop" have a website, Google
can't find the URL.

Thanks,

Jerry

--- In 7x12minilathe@y..., "Capt Ken Appleby" <captkenn@m...> wrote:

Hi Mike,
In each case the drill is broken off below the surface and they are
2mm drills, so are quite small. I tried to do the Alum method
advised by an earlier reply. Unfortunately, in the UK, Alum is no
longer readily obtainable "at the local pharmacist". In fact (snip)

Yup...2mm is a little tough to work around. It reminds me though
Capt. Ken that recently I saw an article on an extremely simple EDM
that was just a vertical slide that lowered an electrode into a bowl
of water. The power was from the mains with two light bulbs on each
phase. The examples showed nice clean small cuts using wire rod with
brazed shapes as electrodes. I've surfed by other edm projects on
the net. If you'd like I'll try to look it up and scan it....It was
in Home Shop Machinist some months ago I think.

I have to confess Ken, I don't have a 7 x 12 but I've had a 7 x 10
for years. Although I'm in Canada I ordered the repair kit from
Little Machine Shop and was more than pleased. It has replacements
for all the driving gears, new driver transistors and belts and cross
slide nut. The price is so low it may be worthwhile ordering from
them and paying the shipping. I'm not aware of any similar supplier
on your side.

My preferance on the nut would be to buy a 10 x 1 mm LH tap and make
my own but then I've never had the trouble.

Give me email off line if you need the scans.

Mike

--- In 7x12minilathe@y..., "Capt Ken Appleby" <captkenn@m...> wrote:
Unfortunately, in the UK, Alum is no

longer readily obtainable "at the local pharmacist.

You might try a taxidermist shop or a garden shop, it has uses in
both activities. I do not know from personal knowledge if potassium
alum or aluminum sulfate give identical results. Seems to me that
both are called alum. If it will save your castings it might be
worth the time to do some web searching.

Al Day

Here it is:



Paul, Central OR


Jerry Smith wrote:

for spare parts i ring the machine mart parts line, pay by switch and take
delivery via post. always had good service and plenty of help
DAVID WILLIAMS
BOLTON
ENGLAND
davidalan@...
l

Hi All,
Thanks for all the help youi gave me on these two matters - I have
resolved the casting problem by getting replacements. Alum is a bit
hard to find here!

I managed to get good service from Machine Mart to put the lathe
right, although a couple of items I asked for (like drive belts) are
out of stock till next year

But at least I am back in business again (:o)
Regards
Ken

--- In 7x12minilathe@y..., "david" <davidalan@l...> wrote:

for spare parts i ring the machine mart parts line, pay by switch

and take

delivery via post. always had good service and plenty of help
DAVID WILLIAMS
BOLTON
ENGLAND
davidalan@l...
l

Here in the USA you can buy alum in the spice section of grocery
stores. It works because it's an acid that attacks the steel but
doesn't harm the aluminum. In horological school we used it all the
time to disolve tiny steel screws that had broken off in brass watch
bridges. It works SLOWLY. Generally it would take a full day of
boiling to disolve one tiny screw. You can speed things up by using
sulfuric acid (available locally in concentrated form from most
hardware stores where it is sold as a drain cleaner). It will work
much quicker than alum and won't harm aluminum. Oddly it will work
quicker if cut 50/50 with distilled water. If you have a steel screw
or bit broken off in brass, I would not recomend using sulfuric acid.
It that case you have to stick with with the slower acting alum.

--- In 7x12minilathe@..., "Capt Ken Appleby"
<captkenn@...> wrote:

Hi All,
Thanks for all the help youi gave me on these two matters - I have
resolved the casting problem by getting replacements. Alum is a bit
hard to find here!

I managed to get good service from Machine Mart to put the lathe
right, although a couple of items I asked for (like drive belts) are
out of stock till next year

But at least I am back in business again (:o)
Regards
Ken

--- In 7x12minilathe@y..., "david" <davidalan@l...> wrote:

for spare parts i ring the machine mart parts line, pay by switch

and take

delivery via post. always had good service and plenty of help
DAVID WILLIAMS
BOLTON
ENGLAND
davidalan@l...
l