anyone converted a Sherline / desktop lathe/mill to CNC ?

Check the metalworking usegroups. You'll get a broader cross section.
Sherline themselves sell CNC-ready and CNC-equipped models, so if `you
have a Sherline, or plan on getting one, this is one of the best
approaches. Check out http://www.mini-lathe.com/  if you have one of the
cheaper 7x10 lathes that are made in China. Lots of info about using and
converting them.

-- Gordon

    --What he said. Most of the discussion is at rec.crafts.metalworking
and the cnc group (forgot the exact name). Also there are a couple of
publications that have articles on how to do it right. One is "Projects In
Metal" and another is "Home Shop Machinist".

--
        "Steamboat Ed" Haas         :  Why do ears find        
        Hacking the Trailing Edge!  :  earwax necessary?..
                          www.nmpproducts.com
                   ---Decks a-wash in a sea of words---

Thanks to both Steamer and Gordon !


"Projects In

Cool web site - looks like lots of info. Thanks !

I have converted my Sherline to CNC.  It is very doable.
I gave a talk about the subject at the Home Brew Robotics
Club <http://www.hbrobotics.org/>  in April.  My talk "slides"
are on line at:

   <http://gramlich.net/projects/hbrobotics/talks/cnc/index.html>

Warning, the slides are very brief, so they may not be very
meaningful to you.

If you are interested CNC, you should join the following Yahoo
groups (at a minimum):

   SherlineCNC
   Sherline
   CAD_CAM_EDM_DRO
   DIY-CNC
   TaigTools

Also, many CNC people (but not me) hang out at:

   <http://www.cnczone.com/>

The newsgroup:

   rec.crafts.metalworking

occasionaly talks about CNC; heck, let's be generous,
they sometimes talk about metalworking.  (There is
a great deal of off-topic posting on that particular
newsgroup.)

The thing you need to understand about CNC, is that it
is no substitute for knowing your way around the shop.
I still do the majority of my construction using a
drill press (and drill press vice) and a bandsaw.
I break out the CNC when I need the precision and/or I
need a bunch of "identical" parts.  There is a huge
learning curve required to figure out how to use CNC.
Despite the huge learning curve, CNC is a great deal
of fun.

My $.02,

-Wayne

Thanks - I will check those out.


Yep - the most Off Topic group I have ever seen that still gives
good advice! :-) Gordon suggested I look into them a few months ago
and they have been the most helpful to my robotic adventures
besides this group. But *this* group just plain ROCKS!


The one thing I don't have yet is a bandsaw & I am already seeing a
need for one. I keep thinking about getting the Dremel sabre saw
attachment for cutting off small pieces of metal, but it just seems
like it will chatter like crazy - haven't tried it yet. When I get
the Sherline in I hope to be able to make several little
"specialty" parts & in general just have a good time. At this point
I only care about CNC to repeat manufacture several of the same.

Anyway, thanks for the advice!
JCD

[snip]


Amen about this group.  I hope this group never degrades to
even a fraction of the amount of off-topic posts that
rec.crafts.metalworking does.

[snip]


Some people swear by their Dremel motor tools.  I've never
got the hang of using them though.

A number of people are reporting reasonable success with
the Harbor Freight Horizontal/Vertical Band Saw.

   <http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber7151>

Everybody replaces the blade tho'.  My band saw predates
Harbor Freight, so this is all second hand information.
If you don't have the space for the big bruiser above,
the small bench top band saws like (Harbor Freight: 40981-3VGA)
will occupy much less space.  I've never used one tho'

Have fun,

-Wayne

Wayne is correct on the major discussion areas.

I would recommend the Yahoo groups in particular if you follow the
Sherline route...they have the highest traffic for the smaller
machines.

Also check out the Sherline site....they have very good documentation
in place.

As has been pointed out, CNC makes sense if you have multiple parts to
make....and it is REALLY FUN to do. ;<)

Good luck and let us know how it works out.

TMT


Wayne C. Gramlich wrote:

Wayne is correct on the major discussion areas.

I would recommend the Yahoo groups in particular if you follow the
Sherline route...they have the highest traffic for the smaller
machines.

Also check out the Sherline site....they have very good documentation
in place.

As has been pointed out, CNC makes sense if you have multiple parts to
make....and it is REALLY FUN to do. ;<)

Good luck and let us know how it works out.

TMT


Wayne C. Gramlich wrote:

I bought a Sieg mini-mill for that purpose a few months ago.  I've
never used a sherline but the impression I get is that the sherlines
are somewhat more accurate but nowhere near as big and powerful -- the
one I have is about 150lbs, as compared to 30 or so (?) for a sherline.
 I was intending to convert it to CNC but the first thing I did was
attach cheap digital scales to each axis and build a decoder for the
electronic scale protocol -- effectively a really cheap DRO setup.   I
still haven't finished the CNC conversion; I only do one-off parts and
the DRO is all I've needed.  Even with CNC, the DRO is probably worth
it since the grizzly not only has 16tpi screws (argh) but also some
serious backlash.

In general I'd highly recommend getting at least a cheap mill if you're
serious about robotics and can afford to spend about $1k on it.  When
you want to build something, the "machine the exact part you want"
strategy is a lot more fun than the "go to home depot and see if you
can find something sort of close" strategy.

chris

pogo wrote:

want"

Yep! That's exactly why I am asking about this !  :-)

Thanks for the info -
JCD

    True, but it may not be an effective use of your time.

    I know three people with milling machines at home, and
they're all more into machine shop work as an end in itself than
actually turning out useful parts.  For our DARPA Grand
Challenge team, we had a drill press with a manual X/Y table,
a belt sander, a metal bender, and a sheet metal brake.
Anything we couldn't make that way we sent out.  That
worked out OK.  We probably could have used a "mill drill",
a drill press with milling machine grade bearings that
can handle side loads.  But no more than that.

    Actually, the "make drawing and send to a machine shop"
strategy works pretty well.  See "http://www.emachineshop.com"

                John Nagle

Well, that's part of why I want to get into it, too! I've been
writing code for over 20 years, but just recently got the biggest
kick out of simply tapping some threads into some aluminum. What a
blast! I like getting my hands dirty!


I kinda been wanting to try these guys out just to see what I get,
actually.

Hi pogo,

pogo wrote:

I bought my Sherline mill and lathe with CNC stepper mounts and
steppers. I used it manually for about a year, and then hooked up the
CNC.

You can find lots of stuff that I've machined on my web sitem both
robotic and non-robotic. My latest robot is over here:
http://www.davehylands.com/Robotics/Orion/

It has a bunch of CNC machined parts.

Getting your machine to be CNC is only one part of the equation. You'll
also need a decent CAD program, CAM program, and G-Code interpreter.

I use Rhino3D for my CAD, and I like it way better than TurboCAD or
AutoCAD. There are a couple of places you can pick up Rhino3D for
around $600. I bought mine here:
http://www.computersculpture.com/Pages/Index_Modeling.html

I'm currently using SheetCAM (www.sheetcam.com) for doing my CAM work.

I use Mach3 for actuall driving the mill (G-Code interpreter).

I also use a program called CutViewerMill for proofing my G-Code before
machining anything on the mill.

For a larger mill, I've been drooling over the Tormach
(http://www.tormach.com/ ) The only problem with this mill is that it
weighs 1500 lbs, and I'm not sure I have space in my basement.

Dave Hylands
http://www.DaveHylands.com

So Dave, if one has the Sherline to begin with how much does it cost
for all the software?

TMT

dhylands@gmail.com wrote:

Hi TMT,

Too_Many_Tools wrote:

Well, Rhino3D was $580. Although any software that can generate DXF
will do. So TurboCAD, or even Corel can be used.

SheetCAM is $150.
Mach 3 is $160, although the free version will do G-Code files upto
1000 lines long.

You can buy a SheetCAM/Mach3 bundle for $275.

I bought MeshCAM/CutViewerMill/Mach3 bundle - (now $425 - I think it
was around $275 when I got it) and then bought SheetCam seperately.

MeshCAM is a full 3D contouring program for doing complex 3D shapes.

Dave Hylands
http://www.DaveHylands.com

All:

In addition to the dollar cost of purchasing the software,
there is the "cost" of learning how to use the software.
Some software is easier to use than others.  I've never
used any of the software above, so I can't comment on
the number of hours required to learn each of the packages
above.  I suspect that it is tens if not hundreds of
hours, tho'.  Perhaps Dave can comment on the software
learning curve for each package.

Also, all the CAD and CAM programs are constantly being updated,
so you have the constant decision "should I upgrade, or not?".
(This is very similar to the "If I had the Shereline's ABC
attachment, then I could do XYZ" dilema that constantly
crops up.)

Lastly, figuring out how to get all this software to do
what *you* want it to do can actually be a bit challenging.
For people who have been doing it for a while, it is easy.
For the first timer, there is a dizzying array of strategies
where some strategies work better than others.

Let me be a little specific here.  In CNC there is the
concept of "speeds and feeds".  "Speed" means spindle
rotational speed and "feed" means the rate at which
metal is removed.  When you've got a chunk of metal
you've got to figure out both speed and feed values
before you can successfully use your CNC mahcine to cut
the metal.  If you get your speeds and feeds wrong, you
get horrible noises, lousy holes/edges, broken too bits,
etc.  It takes a little while before you figure out what
speeds and feeds work for *your* machine.  If you go to
the Shereline CNC list and ask "What speed and feed should
I use to cut 6061 Aluminum?" you are more likely to get
a lot of hemming and hawing than a straight answer.

Again, I do not want to discourage anybody; CNC is a great
deal of fun and can be wonderful adjunct to doing robotics.
Indeed, I view a CNC machine as a robot that just happens
not to have any mobility.

My $.02,

-Wayne

Agreed. What I find is that many folks think CNC will make make up for
not having machining skills, but this is  plainly not the case. You need
as much -- if not more -- skill to run a CNC rig than running a lathe or
mill manually. The only real difference in the CNC makes part making
fairly repeatable. You still must understand the physical properties of
the material being cut, the affect of feed rates, spindle speeds,
cutting depths, tooling and tooling angles, etc. You must still
understand tolerances, how to draw out and measure parts, and everything
else that goes with traditional machining. CNC makes none of this go
away.

I always recommend first getting a standard lathe or mill that can be
upgraded to CNC. Spend a few years learning how to use it, and *then*
convert to CNC. (I guess you could shorten it to months, if you practice
more or less full time on it.) Otherwise, the learning curve to acquire
machining basics *and* CNC skills is quite formidable. Time and again
I've seen he usual result is discouragement. More tools in the garage
that don't see much use. And these are fairly pricey for that.

-- Gordon

The repeatability is the only reason I want to look into adding on
CNC capability sometime in the future. I've done enough programming
to know that sometimes a good old fashioned pencil and paper is a
lot faster than any spreadsheet or CAD program!

Since I bought my drill press a few months ago, I have realized
that it is not the precision tool I thought it was - just a lot
better than my cordless drill. I'm finding that the most fun I am
having ( now that I am into scratch-built robotics ) is the
physical stuff - the nuts & volts and metal & drilling. So the
lathe / mill comes into play so I can make smaller parts more
precisely ... and *mostly* just because I *want* to !

Well, just had to yak it up a bit ...
JCD