Home built CNC
JasonDorie
Posts: 1,930
This isn't related to Parallax, but I didn't know where else to put it.· I've recently finished building a DIY CNC rounter, and posted my first video:
http://www.youtube.com/watch?v=0Birfu8DjQE
I'll be putting some pics online on my blog in the next day or two, but the build was surprisingly easy, and the results are very good for what it cost me.
Jason
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http://www.youtube.com/watch?v=0Birfu8DjQE
I'll be putting some pics online on my blog in the next day or two, but the build was surprisingly easy, and the results are very good for what it cost me.
Jason
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Comments
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Total cost was probably less than $1500, including about $350 in software, and $400 for the stepper motors and controller, but not including the PC to run it. I also bought a drill press and a miter saw, which aren't necessary, but helped a lot. My machine uses Acme Precision Thread drive screws, which were about $20 a foot, and the machine needs 10 feet of those. The plans included suppliers and part numbers for basically everything which made it really easy, and there are adjustment tolerances built in so you don't have to be perfect during construction.
Jason
Public photo links to Facebook (tell me if these work):
http://www.facebook.com/photo.php?pid=2284902&l=a4e6896873&id=671403972· (finished machine)
http://www.facebook.com/album.php?aid=51761&id=671403972&l=7e5e7df977·(full album)
Post Edited (JasonDorie) : 3/24/2009 11:35:00 PM GMT
A real craftsman you are.
Was Bert hand-fed?
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Timothy D. Swieter, E.I.
www.brilldea.com - Prop Blade, LED Painter, RGB LEDs, 3.0" LCD Composite video display, eProto for SunSPOT
www.tdswieter.com
For anyone interested, here's a breakdown of the costs involved:
$400 - Steppers / driver
$200 - Acme precision threaded rods
$100 - Various clamps & flanges
$100 - Router
$200 - Lumber, hardware, parts, belts, pulleys (roughly, I think?)
$350 - Software
$50 - Plans
The steppers, threaded rod, and software can all be done cheaper than I did. Many of the parts could be purchased on EBay for cheaper than I got them for, replaced with cheaper versions, or made by hand, and free software exists as well. You could probably knock a third or more off the cost of this if you were trying.
Jason
Can I ask what software package you are running your machine with?
and
What is the interface to the PC... parallel, serial or usb?
Tim
P.S. Great project, thanks for sharing it.
Jason
Post Edited (JasonDorie) : 3/25/2009 10:46:41 PM GMT
Great Job!! I'm envious!
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Beau Schwabe
IC Layout Engineer
Parallax, Inc.
I asked about it because I work with a guy who is interested in a 4'x4' table like this for 3D foam mold making. I showed him your project this morning and he has already asked if I would be willing to build him a copy.
What are the material working dimensions for your machine for X, Y and Z? If not 4'x4' for X and Y, do you see any reason why it could not be expanded to that size? I can't come up with a reason.
Do you have any idea of the tolerances your machine has or could be able to repeat?
Foam cutting would be a perfect application for this type of machine since the side-loading to the router would be so low.
Tim
The plans I bought included plans for 3 different machines - A small one, a medium one (which I built) and a larger table. The large one has a working area of 48" x 24", but can be easily expanded because it uses racks instead of leadscrew. Even the leadscrew tables can be expanded pretty easily, but pricing for leadscrew is typically in 3 foot lengths, so building a 4 foot table would waste some. With a larger table you may have to use larger diameter screws so they don't flex and whip (think skipping rope).
You also need to be sure that the gantry material won't flex under load. Mine uses 2 x 6 for the Y gantry. For a longer table you might want to reinforce that with some square aluminum tubing or something along those lines, but for a 4' x 4' table that's probably not an issue.
Here's the table I built: http://solsylva.com/cnc/25x25.shtml
The plans state that the table can be expanded easily.
The plans allow for building slop, and include several means to square and align the table once it's complete. I'm not sure what the tolerances of my machine are, but the plans state that with good leadscrews and anti-backlash nuts, 0.001" is possible. My steps are 1/8000", but I'd guess the vibration from the router will move the cutting head more than that. The machine control software includes the ability to set up correction curves, so if the physical machine isn't true you can compensate for it with the software.
As for repeatability, as long as the steppers are strong enough that they never stall or lose steps, the machine will be perfect. For multi-pass cutting it has to be, as each cut traces the same path at a lower depth. Is that what you're asking?
Foam cutting would go very quickly - You could probably just rapid through the material since it's so light. I've been cutting MDF and birch with no problems, but my feed rates are only about 15 - 20 ipm. I'm going to try a more powerful router to see if I can get that up a little.
Jason
Thanks for all the information... this is looking like it may lead to a new project. The guy I work with is pretty excited because he has been looking into a CNC router table purchase for some time now and already has the money set aside for it. He has been running a CNC plasma table for 2-3 years and was considering a modification to that machine to allow for switching back and forth between plasma and routing. His plasma table is busy enough now that he has decided on a stand alone router table so that the two types of work can take place at the same time. He owns a small fabrication business that he runs out of his home shop.
What is the range your Z axis travel?
Again, thank you for your time and help.
Tim
You questions regarding accuracy and resolution are probably better answered here:· http://solsylva.com/cnc/faq.shtml·· He says that accuracy will be between 10/1000" to 3/1000" using all-thread rod, but Acme precision rod and anti-backlash nuts will improve that considerably.
I'm usnig 2-start, 10tpi, 3/8 precision acme rod, and getting rapids of 150 - 200 ipm.· I have resonance damping on the steppers - without it, rapids were around 60 ipm.
My Z axis has about 5.5" of usable depth, but that can be improved by simply raising the frame of the machine above the bed by extending the legs that support it.· You could probably get close to a foot of usable travel by extending the vertical rails a little as well.· To much vertical travel and you'll lose accuracy, since the machine will probably start to flex a little because of the longer lever.
I haven't had a lot of time to play with it yet, but so far I'm very happy with it.· I have practically no shop experience, so I wasn't sure what to expect.· Someone who actually knows what they're doing could probably build it better and in less time.· [noparse]:)[/noparse]
Jason
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I've been reading through a lot of the site information since you provided the link and as I've had time here and there today. I hope to get into more detail with more time tomorrow.
It looks like you've done a fine job with your machine, especially given the fact that you don't have a lot of shop experience! Thanks for the additional details regarding your particular setup... that helps fill in a few gaps in my head as far as the association between lead screw details, feed rates and the results that are achieved. It's good to hear that you're happy with the machine, it is an achievement you should be proud of!
I know that you have not had a lot of time with your machine yet, but I'll be interested to see how you feel about the strength or holding power of those stepper motors for the side-loads involved with hard woods and the like. Can you give us an idea of the motor voltage rating vs. the voltage that you're driving them with? Are they being over driven for quicker response and more power?
Your Z axis travel of 5.5 inches sounds plenty generous enough for most work... I'll have to see what may be needed and desired for the foam application work.
I work with quite a few metal fab folks, so if we go ahead with building a machine, it will be a metal and somewhat more industrialized version of what you've done. Heavy enough to run light production work - such as foam - on a more constant duty pace. Most of the construction would be of various aluminum extrusions with a steel base for stiffness.
Thanks again for your willingness to share your work with the group, it's appreciated!
Tim
With a 10 TPI / 2 start screw, mechanical advantage is about 31 times.· 270 oz-in x 31 = ~523 lbs of force.· Even if you toss half of that away to friction it's still a lot of oomph.· Stronger steppers or lower TPI screws will gain you a lot more.· I've stalled my router a few times already from pushing the feed rate too high, and I've torn wood.· I don't think the side loads will be a problem.· [noparse]:)[/noparse]
I'm using this setup for my steppers: http://www.xylotex.com/Econo3AxSpecial.htm
They're being driven at 24V and will move pretty quick with the 2-start screw I'm using.
Jason
http://www.youtube.com/watch?v=PjenPuxhjyk
·
some have made it 4'x8'
its on cnczone under joes 2006
·my actual cutting· speed is 80 -100 IPM in mdf and maple
have cut a lil aluminum with it and use plastic cutting boards all the time.
his plans are $100, but its all laid out for ya where to buy and such, he also has a forum ( not cnczone ) where you can get answers.
foam would be easy.
i use 425 oz/in motors with a 1/2 inch 2tpi 5 start screw
it's robotics on a large scale
dan
Thanks for posting your new video clip. I like that you included the three stages of drawing, cutting and final part... that makes for a nice complete presentation. Your first CNC cut part looks really good. Planning on mounting a full size router on the machine?? That part looks like a mounting bracket to me.
Dan, (Sawmiller)
Thanks for your input regarding your larger working size machine. It took me quite a while to find it on the CNCZone forum site, but you have a lot of great information there too. You mention that you're running a Joe's hybrid machine and that he has a forum too... do you have links for his plans and forum sites?
Great information guys!
We're still deciding on the many details, but I'm almost sure that we'll be building a router table at this point.
Tim
Jason
I'm continually impressed, you've given me a few ideas for a CNC of my own that I have perpetually been about 25% into before I change my design and/or move onto another project.· Now I've just got to do it.
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Beau Schwabe
IC Layout Engineer
Parallax, Inc.
www.joescnc.com
here's some of the forum at cnc zone http://www.cnczone.com/forums/forumdisplay.php?f=346
also do a search on youtube for joes hybrid,4x4, lots of video's there
dan
I've always been good with software, and I'm becoming passable with hardware, but the missing piece for me has always been the physical side, so that's what I've been working on improving lately. I've had some ideas for physical projects with electronic innards for a while that I'm finally going to be able to execute. I keep thinking of new things I can do with it, and it's incredibly satisfying to just see the thing running. It felt kind of strange holding the mounting clamp in my hands only 15 minutes after drawing it.
If you're thinking of building one, but you're not sure what you'll use it for, trust me - You'll come up with something. [noparse]:)[/noparse]
Jason
Nice Job!!!!
I'm a BIG FAN of REDOAK too.
What ver. of windows are You running the MACH3 on ??? "98,2000,ME,XP etc."
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The Truth is out there············································ BoogerWoods, FL. USA
Thank you for the great CNC links! The Joe's Hybrid machine built with 8020 extrusions looks very close to what this guy will need. He may be willing to invest a little more in a machine that can work more solid materials than just high-density foam. As you said, YouTube videos were plentiful and good information too.
Thanks again,
Tim
Jason