I am looking around a bit at CNC milling systems mainly for carving
wax models of CAD designs made in Matrix.
Has anyone tried the Sherline CNC mill? At $3,000 or less new it
looks like a pretty good value.
Also the fact that it doesn’t look like a huge space eater is nice
but since I don’t have any CAM experience (some limited CAD
experience) I wonder what others think and what is important in this
kind of system?
I noticed that the RPMs look like they are 2800 max as opposed to
the gemvision machine which looks like a 20,000 or 30,000rpm
machine. So that doesn’t look as good for the sherline system
relatively.
Has anyone tried the Sherline CNC mill? At $3,000 or less new it
looks like a pretty good value.
I have a Sherline mill that I performed my own CNC conversion on.
The Sherline system uses EMC as the control software, whereas I’m
using Mach3. My drive is made by Xylotex, I don’t recall who makes
the drive for the Sherline machine. As for the mill itself, I’ve
found it works extremely well. It’s small, but is very high
precision. There are optional high speed spindle upgrades that can be
purchased.
EMC is good software, though you will probably want some CAM
software to go with it. EMC interprets the G-code and moves the
motors as commanded. Rhino3D and an appropriate CAM plugin is
probably the cheapest way to go. I mostly make steam engine parts
with the machine, so I use BobCAD. It works pretty well for my needs.
The question is really “How much time do you want to spend figuring
it out before you start to make money”
The answer to that is the Gemvision Revo C
The fact that you can make money your first day with the Revo and it
can do all the complex shapes you can design answers your question.
I have used the Sherline, Roland, and a home built machine. I also
worked for Gemvision and dealt with quite a few customers who made
good money from day one.
I am looking around a bit at CNC milling systems mainly for
carving wax models of CAD designs made in Matrix. Has anyone tried
the Sherline CNC mill? At $3,000 or less new it looks like a pretty
good value.
I have a Taig mill like the microproto only with a self built
controller (if I can make it I can fix it) A bit larger than a
sherline and a 10K spindle. Also a very weird little home built mill
in another corner. The Taig is a very nice mill, slightly larger than
a sherline but around the same price point. Little monster in the
corner only 2/3 as fast but maybe 1/5 the price.
Hardware is easy, even if you build it mainly from local hardware
store parts. In my experience the software is going to eat major $$$
and learning curve time. Hardware can be a pain to tune but once done
it is good for years until muck with it. It is the software is what
makes all the magic work.
Don’t get me wrong, it is one of the neatest and most powerful tools
I use, but you are contemplating jumping into the deep end of a pool
filled with sharks. Keep smiling and don’t panic, only some of them
bite
jeffD
P.S. My sometimes miss guided help always available here ( and there
are some really smarter cookie monsters here too)
From what I hear, the Sherline is fine. They have a lot of
accessories too. If you ever want to to anything heavier duty than
wax or wood, the Taig is perhaps a bit sturdier. The Microproto
system you mentioned is a Taig mill incorporated into an OEM system.
I have the Taig, with my own pc, limit switches, accessories. I got
it on Ebay for around $1800 (mill, controller box, and stepper
motors).The 2800 max rpm you mentioned seems a bit low. The stock
taig does 11,000. Are you sure that’s not the motor speed, as opposed
to the actual spindle speed? If you want higher there is a company
called Wolfgang Engineering that sells a high speed spindle on Ebay
that will do 24,000 or more (and costs a lot less than an NSK spindle
too!).
For what it’s worth, I’m the proud owner of a Taig 2019 ER/CR CNC
milling machine which I purchased second-hand and which I am still
happy with five years later.
I find them less expensive than Sherlines, all other things being
equal. They are also of much sturdier construction than a Sherline,
allowing you to work with materials harder than aluminum.
If you want to just focus on jewelry making, go ahead and buy the
Sherline. But if you want a slightly more general purpose machine
capable of creating other tools and fixtures for you to make jewelry
with, then you should buy a Taig.
From what I hear, the Sherline is fine. They have a lot of
accessories too. If you ever want to to anything heavier duty than
wax or wood, the Taig is perhaps a bit sturdier. The Microproto
system you mentioned is a Taig mill incorporated into an OEM
system. I have the Taig, with my own pc, limit switches,
accessories. I got it on Ebay for around $1800 (mill, controller
box, and stepper motors).The 2800 max rpm you mentioned seems a bit
low. The stock taig does 11,000. Are you sure that's not the motor
speed, as opposed to the actual spindle speed? If you want higher
there is a company called Wolfgang Engineering that sells a high
speed spindle on Ebay that will do 24,000 or more (and costs a lot
less than an NSK spindle too!).
Either the Taig or the Sherline CNC mills will work well for wax
carving. The Taig is a bit bigger and more rigid, while the Sherline
has a nice variable-speed DC motor. Both can be fitted with a 4th
axis rotary table (made by Sherline) that makes it possible to carve
the periphery of rings, etc. The Sherline CNC system comes with EMC
(the Enhanced Machine Controller CNC software) that takes advantage
of the real-time capabilities of Linux, and requires that operating
system in order to work. The Taig CNC system (provided by
Microproto, their sister company) includes Mach3, which runs under
the 32-bit versions of Windows 2000, XP, Vista or 7. If you buy
either machine “CNC-ready”, you can equip it with whatever control
system and software you want. Spindle speeds are about the same with
both systems, although you need to specify the 10k rpm pulley set
when ordering the Sherline if you want it to spin that fast.
It’s not hard to fit either mill with a 3rd-party spindle assembly,
but I’d be hesitant to recommend the “Wolfgang”, which is basically a
tiny RC airplane motor attached to a collet assembly through a couple
of bearings. Comparing it to a NSK spindle is like comparing a
go-cart to a Ferrari, IMHO. Here’s a continuing discussion about it
on CNCZone (a good forum for matters CNC):
I ordered one myself to check it out, and when I tried to contact the
ebay seller (they are sold only through E-bay, as far as I know) I
got the same non-response about the issues I encountered with it
noted by others in the aforementioned thread. On the other hand,
it’s certainly inexpensive, and seems to work for some people, at
least for a while…
The 2800 max rpm you mentioned seems a bit low. The stock taig does
11,000. Are you sure that's not the motor speed, as opposed to the
actual spindle speed?
That is correct for the stock Sherline. They do offer an option to
get a 10,000 rpm pulley set…
Thanks to all who have responded so far to my inquiries about the
Sherline or Taig/ Microproto mills.
I already have Matrix and although I have not used it in a while I
used to be fairly proficient in it. (A cool program!)
In the experience of those who use them how smooth a wax model do
the sherline (possibly with a high speed spindle attachment) or taig
produce relative to the jewelry specific units?
Do they require lots of hand cleanup?
From what I gather, once I finish the model in Matrix I would need
to output to another program (CAM) that would generate the
toolpaths etc to run the mill. Is that correct?
I see that the Sherline runs on Linux so what are the best options
in either Windows or Linux for CAM software?
I notice the sherline site talks about many major CAD programs
generating “G-Code” and then this needs to be inputted into the CAM
software I assume? It looks like the Sherline comes with a CAM
software called EMC2 if I understand it right. (Info from this page
here: http://www.sherline.com/8540pg.htm )
I notice the sherline site talks about many major CAD programs
generating "G-Code" and then this needs to be inputted into the
CAM software I assume? It looks like the Sherline comes with a CAM
software called EMC2 if I understand it right.
Most CAD packages do not generate G code. CAD packages generate an
output file like STL or a DXF file that is a series of points in XYZ
space connected by lines or arcs that describe a 3D surface model.
CAM packages take CAD output and create G code that tells the machine
how to cut the surface. A CAM program will take the model from the
CAD package and input from the user like stock size, tool
configurations, material properties, speeds and feeds etc and combine
all this into a set of tool paths, speed and feed instructions for a
specific machine via what is called a post processor that takes
generic instructions and makes them match the specific version of G
code for a particular machine. The machine tool has a CNC processor
that takes its particular G code dialect and converts it to direct
commands to the servos or steppers that control the axis and spindle
movement on the tool. You do not need a CAM package to run a CNC tool
but it takes a fair amount of skill to directly program in G code,
however many machinist do just that and think CAM packages are for
people who don’t know hot to run a CNC machine. EMC is a machine
control package or CNC processor that drives the tool but it is not a
CAM package. Some CNC processors have some limited CAM capability but
they are not a true full featured CAM system.
So for example Rhino or Matrix are CAD programs that output a file
that is sent to BobCAM or Gibbs or Visualmill or some other CAM
package that generates a G code file configured for an EMC
controller running a Sherline mill or A Revo Mill or what ever
specific machine tool you are running. Some CAM packages are
available as plugins for a CAD package like RhinoCAM or Proto Wizard
are called from inside Rhino. But they are still separate programs
that are just accessed from inside the CAD package.
I notice the sherline site talks about many major CAD programs
generating "G-Code" and then this needs to be inputted into the
CAM software I assume? It looks like the Sherline comes with a CAM
software called EMC2 if I understand it right.
A couple quick definitions:
CAD - Computer Aided Drafting. The more modern systems are solids
based, so you create a 3d model of the part.
CAM - Computer Aided Machining. CAM software takes the model
produced by the CAD software and converts it into g-code.
G-code - So-called because most of the instructions start with the
letter G. Very old, goes all the way back to the early days of
numeric control. These are the instructions that machine controller
understands. They tell it positions to move to. For example: G01 Z0
Y-.5 X-.5
Tells the controller to move the machine the zero coordinate on the
z axis, -.5 on the y and -.5 on the x. Since they are both specified
on the same G01 line, it will “interpolate”. It will move in an
angle. There are commands to move in a circle or an arc. Some are
canned cycles, my machine has G89 - drill w/peck. It will drill a
certain depth, retract to clear chips, then drill further, then
retract, and drill until it reaches the intended depth.
The workflow goes like this:
SolidWorks → CAM SOFTWARE → Mach3/EMC
Mach3 and EMC communicate with the drive that controls the steppers.
They interpret the g-code.
CAD … program to do the drawing (your case rhino and matrix)
CAM … program to generate tool paths for the mill (some cad
programs have plugins but an independent program might be more
versatile)
CONTROLLER … program to run the mill (emc, mach, turbocnc,
cncpro etc. different prices and operating systems and computer
requirements and graphics) Usually on a different computer than your
design one.
DRIVER … hardware which converts low voltage signals from
computer to rather wicked ones the motors like.
Some packages might contain a few of these steps in one interface but
you are actually doing all of them in sequence.
Re: clean-up… that is your choice, high resolution with small
finish tools and lots of time or quick with big tools. Other than
absolute physical limits (ie undercuts and min tool size etc) You
have control of almost all the variables. Do exactly what you want
or shoot yourself in the foot, your choice.
In the experience of those who use them how smooth a wax model do
the sherline (possibly with a high speed spindle attachment) or
taig produce relative to the jewelry specific units? Do they require
lots of hand cleanup?
Surface smoothness mostly depends on how closely-spaced the passes
of the tool are, and the size of the tool used. Larger ball-end tools
will not need to be spaced as closely as smaller ones, since the
“cusps” (the ridges formed where the tool passes overlap) that they
make will be shallower. But you often need a very small tool to get
maximum detail, and that’s where the faster spindles come in handy.
But I don’t think the jewelry-specific mills will produce a
significantly smoother model, although a mill with a faster spindle
will produce it quicker. If you construct your toolpaths correctly,
the only places you’ll need to clean up the wax by hand will be
places where the tool couldn’t reach, such as undercuts.
From what I gather, once I finish the model in Matrix I would need
to output to another program (CAM) that would generate the
toolpaths etc to run the mill. Is that correct?
Yes, that’s basically correct, but the toolpaths don’t actually run
the mill; the CNC control software does that by running a G-code
program that is based on the toolpaths.
I see that the Sherline runs on Linux so what are the best options
in either Windows or Linux for CAM software? I notice the sherline
site talks about many major CAD programs generating "G-Code" and
then this needs to be inputted into the CAM software I assume? It
looks like the Sherline comes with a CAM software called EMC2 if I
understand it right. (Info from this page heRe:
http://www.sherline.com/8540pg.htm )
It sounds like you’ve got this slightly mixed up. CAD software is
what you use to create your model; Matrix is one example. CAM
software is the next step; it takes your model (often in the form of
a DXF or STL file) and plots out a toolpath based on it, considering
what tool you plan to use, how closely-spaced the passes are, how
fast you want to run, etc. and produces a G-code file, which is
basically a text file with directional commands. Deskproto is one
example of a Windows CAM software package; VisualMill is another
good one. I don’t know of any that run under Linux. EMC2 is CNC
control software; it doesn’t write the G-code, but it runs it,
sending pulses to the motors, allowing them to execute the G-code
program. You generally need all three types of program: CAD, CAM, and
CNC, in order to make a part using this process.
I am keeping a file on all the responses to refer to in the future.
I am going to be AWOL for a while because Tucson is upon me but if
anyone has anything further to say I will get it later when I get
time to check the Orchid emails that will have accumulated.
My forum participation will probably be very limited for a while
though.
