Re: I GOT A PROBLEM

Hi Arne,

Whilst my machine isn't up and running yet, I know pretty much what I want
to do with it (let it take over from jobs I currently do by long winded hand
methods). These centre around two areas - watch and small clock making and
making parts for musical instruments. To take the latter first, this is both
milling 3D parts (finger keys for wind instruments etc.) from the solid
which I currently fabricate and file out by hand, and drilling or milling
precise sized holes and exact diameters in tube. This will involve being
able to rotate the tube between drillings and so I will have a dividing head
and tailstock mounted on the bed.
As to watchmaking, this will be the machine's main purpose and I want to be
able to make any part of a watch or small clock on it (but some parts may be
better made on a wire EDM machine when someone comes up with enough details
to enable me to design one). The basic work on watch and clock movements is
milling different depth pockets and circular recesses in plates, drilling
through holes to precise positions and dimensions and engraving on the flat
surfaces. Cutting gear wheels and pinions is a series of simple repetetive
tasks, milling out the blanks to make the spokes and cutting the teeth on a
stack of blanks using a dividing head and a series of cutters. A more
interesting possibility I want to explore is the cutting of the odd shaped
escape wheels and cam-type parts by generation - using a simple 'slitting
saw' and moving the dividing head, cutter height and slide positions
together to form complex shapes on the edge of the wheel disc. A number of
the jobs I get involve replacing missing levers and such like made out of
flat stock. These are comlicated shapes which have to fit and interact
exactly with the remainder of the mechanism and making them by hand often
involves a number of tries before I get things exactly right. What I am
considering here is photographing the part of the watch which the lever is
missing from using a digital camera, using this image as a scale background
in a CAD programme (as you can in AutoCad), designing the new part over
this - animating it if necessary to see that it will work correctly - and
then using the resulting file to produce the new part. Watch dials, of
course, involve basic engraving and 'rose turning' ( A rose engine is just
like a lathe except that the headstock is pivoted parallel to the bed,
sprung to one side, and has a system of knobbly cams and a fixed follower
which make the whole headstock rattle backwards and forwards as the spindle
rotates. When you have a fixed tool in the toolpost and keep moving this out
on diameter after each revolution, you get the fancy patterns we call
'engine turning'. There is a variant of this often used on watch and clock
dials called 'straight line engraving' in which the work is held on a
vertical slide which descends past a tool and which vibrates against a fixed
vertical 'rack' as it does so, thus producing a series of wavy vertical
lines.). Watch cases are more interesting and come more into the sphere of
what Andrew is hoping to achieve also in 3D carving - the ultimate
difficulty here being the ability to engine turn the design on the outside
of a curved case back. Occasionally I have to make helical gears and other
such obscure parts. I think it is fair to say that, once my initial machine
is up and running, its abilities will be pushed to their limits!!!
As to programs, I use Autocad and Rhino (which I like better) and have tried
Flashcut and Bobcad (which I don't find particularly easy to get on with)
for conversion to G-code. What I would like to see is a program with the
capabilities of Rhino CAD, able to also use graphic files as backgrounds
like Autocad 14 and which will produce G-code output in a 3D format with
multipass tool feed - not much to ask for surely ;o) Oh, and it should be
GPL for Linux!
Has anyone looked at the screen interface for WinPCNC, it seems to be very
nicely designed with everything there, perhaps EMC's future versions could
develop along these lines?

Ian
--
Ian W. Wright
Sheffield UK

> "Arne Chr. Jorgensen" wrote:
>
> > Is it possible for a number of you to write about the way you would
> > go by this ? ( In simple terms I and other could understand ?
> > ( I don't even know what a rose machine looks like )