Homemade Cnc Thread

[Kammo1]

Hi yep the My CNC forum is a great inspiration and there are some clever guys around there and some nice built DIY machines, I will be making a small one just for basically doing things like inlays etc. I have been custom guitar making for the last 28 years and its come to a time in my life that doing this work by hand is very,very hard and if I work it out per hour and time spent it doesn't work out cost effectively. Therefore a small sized CNC has to be the way to go. I will be using the Mach3 software and Cut 2D as this looks like a superb and very reasonably priced software and best bit about it its based here in the UK in the Midlands not far from me. Have to admit I am still trying to get my head around drawing something in CAD and then scaling it up and then saying to myself how do you put that shape in the required spot ? Maybe the more experienced guys can do a small tutorial on how to draw a shape, dimension it and put it where you want it ? Now that would be cool as I cannot for the life of me see how its done. Anybody ?

[Hank McSpank]

Hey Rob,

Not sure what the conversion is of 100lira? in US dollars I have my first set of leadscrews 1/2"-10 that Im going to sell. a 48", 24" and 12"

for $75.00 plus shipping includes 5 Delrin nuts.

Just a thought.

Mike

Mike,

I'm sorted now, but that seems like an excellent deal for someone who wants to avoid the beginners pitfall of using basic threaded rod - if anyone is starting out Stateside, they should take your hands off!

Have to admit I am still trying to get my head around drawing something in CAD and then scaling it up and then saying to myself how do you put that shape in the required spot ? Maybe the more experienced guys can do a small tutorial on how to draw a shape, dimension it and put it where you want it ? Now that would be cool as I cannot for the life of me see how its done. Anybody ?

It is a massive learning curve...it took me about a month of nights trialing & erroring to get my simple CNC machine built, but then the real time sump arrives - how do I drive this darned thing!! (which means learning a CAD program & the CNC s/w itself...eg Mach3). IMHO, that needs about the same amount of time again to get to a level where things start falling into place.

In the beginning, I too was somewhat intimidated by something as basic as positioning a simple shape & gettting it located in a place that my CNC would know where to go! (I was cacking that my spindle would try to go flying off past one of the Axis extremeties, lol)..you need to start thinking in coordinates & 'origins'.

Additionally, I couldn't get away at all with some CAD programs at all (I tried the AutoCad demo - euuugh). Wrt CAD, once you've got past the basic s/w familiarity hurdle (eg "I just want to create a semi-circle damnit!"), you'll soon realise you've got to start thinking 2.5D & creatively pondering how to achieve the end result in the most efficient (or do-able) way. For example - eg to knock up a proper pickup bobbin on a 3 axis machine - not possible, but if you get creative & start thinking in 2.5D you can use your CNC machine two make two separate identical parts & join them together in the middle (where the copper winding hides the joint!) - I'm now using bits of my grey matter that have lain dormant for years!

In general, I think it's just one of those things where you have to go through the pain of giving yourself a simple intial goal & plodding away & being a pain asking simple questions until you get there...then setting the hurdle a little bit higher - the penny eventually drops & it all becomes real fun after that.

(BTW the CNC Zone is good because there are so many targetted/focused sub forums - so you're almost sure to get an answer to a basic question there).

But it's worth the effort - CNC machines....every man should own one! (it's a birthright )

Re a tutorial ....it would need someone who has your chosen CAD s/w & Cut2D to do that (have you tried the obvious place - youtube ? - there's normally someone gracious enough to take the trouble & upload a video to help others on there). I know Vetric software is considered very good, but I'd think there's a possibility that you might outgrow Cut2D quite quickly - it looks to be ideal for 'easing you in' wrt toolpaths etc, but personally I'd rather go with a more 'integrated' package (by this I mean CAD->Toolpaths->Gcode all in the one application)

Edited February 12, 2010 by Hank McSpank

[MiKro]

Hey Rob,

Not sure what the conversion is of 100lira? in US dollars I have my first set of leadscrews 1/2"-10 that Im going to sell. a 48", 24" and 12"

for $75.00 plus shipping includes 5 Delrin nuts.

Just a thought.

Mike

Mike,

I'm sorted now, but that seems like an excellent deal for someone who wants to avoid the beginners pitfall of using basic threaded rod - if anyone is starting out Stateside, they should take your hands off!

Have to admit I am still trying to get my head around drawing something in CAD and then scaling it up and then saying to myself how do you put that shape in the required spot ? Maybe the more experienced guys can do a small tutorial on how to draw a shape, dimension it and put it where you want it ? Now that would be cool as I cannot for the life of me see how its done. Anybody ?

It is a massive learning curve...it took me about a month of nights trialing & erroring to get my simple CNC machine built, but then the real time sump arrives - how do I drive this darned thing!! (which means learning a CAD program & the CNC s/w itself...eg Mach3). IMHO, that needs about the same amount of time again to get to a level where things start falling into place.

In the beginning, I too was somewhat intimidated by something as basic as positioning a simple shape & gettting it located in a place that my CNC would know where to go! (I was cacking that my spindle would try to go flying off past one of the Axis extremeties, lol)..you need to start thinking in coordinates & 'origins'.

Additionally, I couldn't get away at all with some CAD programs at all (I tried the AutoCad demo - euuugh). Wrt CAD, once you've got past the basic s/w familiarity hurdle (eg "I just want to create a semi-circle damnit!"), you'll soon realise you've got to start thinking 2.5D & creatively pondering how to achieve the end result in the most efficient (or do-able) way. For example - eg to knock up a proper pickup bobbin on a 3 axis machine - not possible, but if you get creative & start thinking in 2.5D you can use your CNC machine two make two separate identical parts & join them together in the middle (where the copper winding hides the joint!) - I'm now using bits of my grey matter that have lain dormant for years!

In general, I think it's just one of those things where you have to go through the pain of giving yourself a simple intial goal & plodding away & being a pain asking simple questions until you get there...then setting the hurdle a little bit higher - the penny eventually drops & it all becomes real fun after that.

(BTW the CNC Zone is good because there are so many targetted/focused sub forums - so you're almost sure to get an answer to a basic question there).

But it's worth the effort - CNC machines....every man should own one! (it's a birthright )

Re a tutorial ....it would need someone who has your chosen CAD s/w & Cut2D to do that (have you tried the obvious place - youtube ? - there's normally someone gracious enough to take the trouble & upload a video to help others on there). I know Vetric software is considered very good, but I'd think there's a possibility that you might outgrow Cut2D quite quickly - it looks to be ideal for 'easing you in' wrt toolpaths etc, but personally I'd rather go with a more 'integrated' package (by this I mean CAD->Toolpaths->Gcode all in the one application)

I agree with Hank on this one. The software learning curve is a Beach. My suggestion is not to think like a woodworker. Think like a machinist. you must wrap yourself around the decimal system instead of fractions if you are in the states. otherwise metric is much easier. Also you must clearly understand the X,Y,Z coordinate plotting or you are going to go nowhere fast. Except the wrong direction and a lot of broken bits and wasted wood.

Just my .02cents.

Mike

[Kammo1]

Some sound advice and agree its going to get some serious attention to get me to focus on the software side of things as computers are not my forte. Still I have to start somewhere and did find a easy sort of CAD drawing software called deltacad which is descibed as the easiest CAD software to use in the world so I am fiddling at the moment with this to see if I can get some results. Now what would be an absolute marvel is if anyone can draw some fingerboards in a CAD format in various fret scales and number of frets so we can use them as a template and just drag and drop shapes where you want them and then get it off to Gcode and get cutting now how easy is that LOL!!!! if I do draw some up I will post them for all to share fingers crossed.

[MiKro]

>snip< Now what would be an absolute marvel is if anyone can draw some fingerboards in a CAD format in various fret scales and number of frets so we can use them as a template and just drag and drop shapes where you want them and then get it off to Gcode and get cutting now how easy is that LOL!!!! >snip<

Not as easy as you think. trust me. In order to do the radius you must first understand the YZ or XZ plane in relation to the XY plane using either a G18 or G19 vs a G17, as well as G90 absolute and G91 incremental for arcs. Then you must understand that from G17 to either G18 or G19 that the IJK changes as well. Then add subroutines to this. That's just to do the radius. This does include cutout of the fretboard at the correct taper, in a given length, as well as using a 0.025 end mill to make the fret slots. Now when you get there you should have some fair amount of knowledge at that point and still be learning.

Mike

[Prostheta]

From what I could make out, a lot of the more fully-featured packages can take the Gcode and run a 3D simulation on the "result" without putting tool to wood. Do you find there is a difference in the virtual modelled output and the actual toolpath results?

I have done lots of work in my time in Lightwave, so the ability to model a 3D item in a package that is familiar to me and export that to a CAM package for translation into Gcode for whatever tools and CNC is available would be very exciting for me....

[MiKro]

From what I could make out, a lot of the more fully-featured packages can take the Gcode and run a 3D simulation on the "result" without putting tool to wood. Do you find there is a difference in the virtual modelled output and the actual toolpath results?

I have done lots of work in my time in Lightwave, so the ability to model a 3D item in a package that is familiar to me and export that to a CAM package for translation into Gcode for whatever tools and CNC is available would be very exciting for me....

Yes you are correct most do have a simulation of the modeled product, and yes there is a difference between what you see and what you get.

It also depends on the tool type you choose as well as the specs for depth of cut, step over and feed rate. All of these combined change the real world. As well as settings in your controller software, such as settings like, Exact stop vs, constant velocity.

Then you have the problem of step resolution and what your setup can handle as well as the accuracy of the equipment. Backlash, or flex in an axis can be a problem.

Also you should measure each Bit or tool. As a 1/4" bit can range from .240 to .255 or more or less. These affect the overall outcome as well.

So if I'm doing an inlay,and I know that a specific tool is a 0.124 diameter. I will set up 2 tool paths, one for the pocket using that exact diameter to get the tool offset and remove the inside.

Now for the inlay I will edit the tool specs and tell it(the software) that the tool is 0.120 this will give me a 0.004 interference cut and the inlay will be a thumb press fit, since I will profile the outside of the inlay thus removing and extra 0.004.

MK

[jaydawg]

>snip< Now what would be an absolute marvel is if anyone can draw some fingerboards in a CAD format in various fret scales and number of frets so we can use them as a template and just drag and drop shapes where you want them and then get it off to Gcode and get cutting now how easy is that LOL!!!! >snip<

Not as easy as you think. trust me. In order to do the radius you must first understand the YZ or XZ plane in relation to the XY plane using either a G18 or G19 vs a G17, as well as G90 absolute and G91 incremental for arcs. Then you must understand that from G17 to either G18 or G19 that the IJK changes as well. Then add subroutines to this. That's just to do the radius. This does include cutout of the fretboard at the correct taper, in a given length, as well as using a 0.025 end mill to make the fret slots. Now when you get there you should have some fair amount of knowledge at that point and still be learning.

Mike

Or you could just use a CAM program like everyone else.

Yes and then you cannot troubleshoot the 40000+ lines of code when it screws up, whereas learning and using it as pure Gcode will only use maybe 100 lines of code vs a Cam Modeling software. I use Cam as well but I will say if you take the time to learn Gcode when all hell breaks loose you will be able to find it and correct it. Just my observation so far, I have used Cut2D, Cut3d, VCarve Pro, ArtCam Pro, RhinoCad/Cam, BobCad/Cam, just to name a few, which I either own or have at my disposal through my machinists friends as well and I will say they don't work flawlessly.

MK

I agree completely Mike. I was just being a wiseass.

I program and operate a 5'x12' Onsure router and have been using MasterCam for almost 5 years now. I couldn't count the number of times I've been able to quickly track down a program issue by being able to scan through the Gcode and find the problem. It's generaly much faster then going back to the CAM program and tring to find the one little box you forgot to check off or that funky number you put in by acident.

[MiKro]

>snip< Now what would be an absolute marvel is if anyone can draw some fingerboards in a CAD format in various fret scales and number of frets so we can use them as a template and just drag and drop shapes where you want them and then get it off to Gcode and get cutting now how easy is that LOL!!!! >snip<

Not as easy as you think. trust me. In order to do the radius you must first understand the YZ or XZ plane in relation to the XY plane using either a G18 or G19 vs a G17, as well as G90 absolute and G91 incremental for arcs. Then you must understand that from G17 to either G18 or G19 that the IJK changes as well. Then add subroutines to this. That's just to do the radius. This does include cutout of the fretboard at the correct taper, in a given length, as well as using a 0.025 end mill to make the fret slots. Now when you get there you should have some fair amount of knowledge at that point and still be learning.

Mike

Or you could just use a CAM program like everyone else.

Yes and then you cannot troubleshoot the 40000+ lines of code when it screws up, whereas learning and using it as pure Gcode will only use maybe 100 lines of code vs a Cam Modeling software. I use Cam as well but I will say if you take the time to learn Gcode when all hell breaks loose you will be able to find it and correct it. Just my observation so far, I have used Cut2D, Cut3d, VCarve Pro, ArtCam Pro, RhinoCad/Cam, BobCad/Cam, just to name a few, which I either own or have at my disposal through my machinists friends as well and I will say they don't work flawlessly.

MK

I agree completely Mike. I was just being a wiseass.

I program and operate a 5'x12' Onsure router and have been using MasterCam for almost 5 years now. I couldn't count the number of times I've been able to quickly track down a program issue by being able to scan through the Gcode and find the problem. It's generaly much faster then going back to the CAM program and tring to find the one little box you forgot to check off or that funky number you put in by acident.

I understand JD.

Like I said though as you are well aware learning to use Gcode will make things easier.

I have a link to a text file that shows the G code I generated from Artcam for a 7" radius sanding block 3" wide and 8" long. it is somewhere around 1754 lines,

at the bottom of that text file is a hand written Gcode version that I wrote that is 33 lines of code that is for a 3.25" wide 7" radius and 12" long. It also has the ability to alter width, length and radius with a few minor numeric changes.

one other thing as well is that the Cam version is based on X0,Y0 being the bottom left hand corner, whereas the the Hand written code is based on X0, Y0 being X is the left edge and Y is the center of the left edge. Had the cam program been set this way the code generated would have been much longer.

link to gcode

enjoy

Mike

[MiKro]

Some info for any of you using limit switches and Estop switches with Mach3.

After I added the switches I started experiencing problems with them triggering out of the blue while cutting. Setting the debounce in M3 did not help. I am using well shielded cables also.

I put a scope on it and found intermittent spikes.

Solution is to add an individual 0.1 Uf / mfd film type capacitor on each set of wires, bridging as close to the breakout board as possible. This acts as an Rf filter and the problem should be resolved. I have since run a few million lines of code and have had no problems at all.

Note: DO NOT USE AN ELECTROLYTIC Cap for this

Just some advice while you are building.

Happy CNC

Mike

[Woodenspoke]

Some info for any of you using limit switches and Estop switches with Mach3.

After I added the switches I started experiencing problems with them triggering out of the blue while cutting. Setting the debounce in M3 did not help. I am using well shielded cables also.

I put a scope on it and found intermittent spikes.

Solution is to add an individual 0.1 Uf / mfd film type capacitor on each set of wires, bridging as close to the breakout board as possible. This acts as an Rf filter and the problem should be resolved. I have since run a few million lines of code and have had no problems at all.

Note: DO NOT USE AN ELECTROLYTIC Cap for this

Just some advice while you are building.

Happy CNC

Mike

I added a breakout box before the controller and ran all my limit switches too that.. I Still need to put in a stop switch..its been 3 years..LOL

[MiKro]

Some info for any of you using limit switches and Estop switches with Mach3.

After I added the switches I started experiencing problems with them triggering out of the blue while cutting. Setting the debounce in M3 did not help. I am using well shielded cables also.

I put a scope on it and found intermittent spikes.

Solution is to add an individual 0.1 Uf / mfd film type capacitor on each set of wires, bridging as close to the breakout board as possible. This acts as an Rf filter and the problem should be resolved. I have since run a few million lines of code and have had no problems at all.

Note: DO NOT USE AN ELECTROLYTIC Cap for this

Just some advice while you are building.

Happy CNC

Mike

I added a breakout box before the controller and ran all my limit switches too that.. I Still need to put in a stop switch..its been 3 years..LOL

What no Estop?

I think my RF problems arise from the fact that I am in the flight path of Southwest Airlines passing over at 2000ft. I'm about 6 miles out from the North end of Love Field. Not much noise, but I believe it is the source of RF interference I get. Then again I am also close to a major highway and we do get our share of the truckers with linear amps on the CB blasting away as well.

mk

[Vinny]

I can see it now, crossed signals in the air:

"Control Tower to Flight 84, - you're clear to land on an 8 inch long sanding board with 12 inch radius, your coordinates are X=0 and Y=0, Over "

Pilot: "Control Tower, PLEASE Repeat that "

-Vinny

[Woodenspoke]

maybe you should consider shielding the case and running some Braid over all your wiring. The Parallel cable is shielded most everything else is not. It could also be the electrical outlet not putting out clean power, a UPS may help that side or a box which cleans up the line voltage.

It could also be a bad controller Board or power supply

[MiKro]

maybe you should consider shielding the case and running some Braid over all your wiring. The Parallel cable is shielded most everything else is not. It could also be the electrical outlet not putting out clean power, a UPS may help that side or a box which cleans up the line voltage.

It could also be a bad controller Board or power supply

No it's outside interference. I have shielded cable, a good case and I know it's clean power as the power filter I have is one I used in networks for a large company It's an anomaly that does effect some as I have found others that have this problem since finding reference on the Mach forum, CncZone as well as the manufacturer of my boards. It's not as uncommon as one would think. I happened to be blessed with this additional problem which is now gone

See ya.

MK

[DC Ross]

There's a section in the current Make magazine on 3D manufacturing at home if anyone's interested. It's a great magazine in general as well.

Edited March 14, 2010 by DC Ross

[MiKro]

AH HA! I found my Phantom RF spike. I was getting a static discharge from the vacuum hose when it touched the frame usually somewhere in mid table area. The hose may touch the upper gantry at various stages of XYZ location. The ground wire was broken for this hose.

I'll leave the caps on though.

Mike

[factory5150]

Just a quick update...

I got my router last week from George..

Quality and construction is superb. It wasn't quite worth the 4 month wait, but close. The cost compared to a k2 router is not even in the same league. A 24x24ish router from K2 is 1400 plus motors and electronics. So I got a machine double the size for the same money and for that I am a happy camper. I hope to have it running in the next few weeks.

[Vinny]

Thats lookin nice, I assume the strat body in the pic is full size? Then that means your cut area is REALLY HUGE. A big plus for making more stuff is a big cutting area. Is it up and running yet ? -Vinny

[factory5150]

Yeah the strat body is full size. I should be able to fit 3 bodies side by side to cut them in one setup. My gecko g540 should be here any day now and then it will be up and running. I am still waiting on the aluminum tabletop but I will use MDF as a temporary fix. I cant wait to make dust with this thing!

[Vinny]

Wow, thats a sweet set-up. Geez I gotta get my work finished so I can get back to my CNC build. -Vinny

[DC Ross]

Has anyone built a machine from the book "Build Your Own CNC" and the site www.buildyourcnc.com?

Edited March 26, 2010 by DC Ross

[Vinny]

HuntingDoug mentioned this a while back, its worth looking at again:

With the guitar builders on here using/making CNC machines, I believe that this will spin off into a New Topic Section eventually. And I also hope see our members sharing files that they created with each other in a download area.

Last I counted 8 members here with CNC's or are building one:

Vinny

HankMcSpank

HuntinDoug

Mikro

Spoke

JpMarsh

Factory5150

Mattia

What's your thoughts on this? -Vinny

[Mattia]

HuntingDoug mentioned this a while back, its worth looking at again:

With the guitar builders on here using/making CNC machines, I believe that this will spin off into a New Topic Section eventually. And I also hope see our members sharing files that they created with each other in a download area.

Last I counted 8 members here with CNC's or are building one:

Vinny

HankMcSpank

HuntinDoug

Mikro

Spoke

JpMarsh

Factory5150

Mattia

What's your thoughts on this? -Vinny

I'm all for it. Luthiersforum.com has a CNC section that's pretty cool, but focussed mostly on acoustics, and this place may draw more people out. I'm also all for the free exchange of models and ideas, although in terms of 3D models only within reason; if I make a custom shape with a custom carved top, model it, it's not something I'll likely want to publish openly on the interwebs. A standard Tele or Strat or similar, sure, why not?

[RestorationAD]

I'm in. Looks like June before I start on mine. But I am going mechanical...