CNC Bits and Tips

[Guy Mathews]

As the operator and programmer for 3 different CNC machines all with 4th axis systems in place and producing, I am starting this thread to have a place to post video links that help explain some of the mystery of CNC Machines.


http://www.youtube.com/watch?v=m9XSI2ZPwG8


As time permits, I will add more video to youtube. Emails are welcome. If I do not have an answer for you, I will not "BS" you or post you to someone else's work. Questions specific to CAMaster, Shopbot and Fanuc 10 series are welcome. My knowledge comes from my experience on the aforementioned machines and over 3,000 custom programs over the last 3 years. My programming is for woodwork only. I am vaguely familiar with metal cutting so I can only offer a few scenarios where I have cut metal.

I have only had the CAMaster since November of 2008 so I am still trying to decipher any operations that make the CAMaster different from the Shopbot and vice-versa.

Thanks for looking.

P.s. A fellow asked me about my avatar. The skull you see was programmed and produced by me. You can view it at Shopbots website under the Spotlight on Shopbotters section. Of course, my last name is spelled wrong, but what are you going to do? :)

Guy

[Angus Hines]

What sort of programming? Like the stuff I learned from Ryan this weekend which was VB.NET and how to play in the open source SB codes.

[Guy Mathews]

The programming I am referring to has nothing to do with Visual Basic or Linux based systems. I am referring to the G-code programming for the proper tool paths for running 2, 3 and 4 axis programs on my machines. Having drawn, proofed and produced over 3,000 different programs from chair backs to historical reproductions in every species wood imaginable, I have seen enough splintering, shattering, burnt and broken bits, and lack of custom containment fields used in speeding up cycle time, that I can pretty much look at almost any 3D object and generate a tool path strategy in my head.

On a regular basis, I am using Visual Mill 5 and 6, Rhino 3 and 4, Rhino Cam, Rhino Art, Clay Tools, Adobe Photoshop CS2, Parts and Parts Wizard just to name a few.

I have tried to get people to understand that there is no single program on the market that will allow me to reproduce and do the work I do. The salesman at IWF have tried for 2 shows now to convince me there stuff was the best and yet when I created a scenario for them they did not have the answers using their software.

They were able to do the creative stuff, but when forced to deal with a customer that hands them an object and says "Make me 1,000 of them within these tolerances.", they start to stutter.

The same holds true for CNC Operations. There is no magic button that you simply press. The most expensive machine in the world is only as good as the guy that takes the vector art or 3D model and generates a tool path that utilizes the machine and the proper cutting tools in the most profitable and productive way without hurting the machine, the piece or the operator.

This also applies to vector art or a 3D model. It is one thing to take a preexisting file and show it to a customer and say "We can give you this carving on this sign for this amount of dollars."

It is a totally different thing when the customer comes to you and says, "It has to be just like this, if not, you wasted your time and mine."

The latter of the two is what I deal with on a daily basis.

And don't even get me going when it comes to Historical Preservation!!! Talk about having to get it exact!!!!! :eek:

I would give anything to be able to sit around all day and do it the first way, but our name is New Wave Custom Woodworking Inc. Not New Wave Predefined Woodworking Inc. :D

I hope this clarifies your question Angus.

[Angus Hines]

That's what I thought you meant defiantly 2 different animals

So whats a skull turned in blood wood gonna cost me? I'll ship you the blank block.

[Kenneth Hertzog]

Guy

Welcome to the creek
I have 4 machines which all run G Code.
From time to time I have some problems
with the code entries. Maybe we can work them
out together and I can be better educated. :D

ken

[Guy Mathews]

I have 3. We are looking into a 5 axis at IWF 2010 as well as a CNC Bandsaw and CNC Lathe. Will be happy to help when and where I can. One of the things that I did not mention in my earlier post is fixturing. Any one who has ever tried to hold something to a table or indexer for that matter, runs into problems. Be it vacuum, clamps, screws, glue, epoxy or just plain old cussin'! There never seems to be one good all around method for keeping pieces where they belong.

I can honestly say, we are pretty creative when it comes to strapping them down!!!

[Kenneth Hertzog]

Guy
I have two 4 axis mills one router table and 1 lathe
hard to keep them all going with just a one man shop:D
ken

[Kevin L. Waldron]

Guy,

I'm interested in your techniques that you use to clean up point clouds in Rhino or other. If you scanned an accoustical guitar neck for instance how would you go about cleaning this up or how about a bed post that has both a circular form and several flat sections. I'm not talking about just cutting similiar items directly from the point cloud but having or building parametric files from existing point cloud data.

Thanks,

Kevin Waldron

[Guy Mathews]

Guy,

I'm interested in your techniques that you use to clean up point clouds in Rhino or other. If you scanned an accoustical guitar neck for instance how would you go about cleaning this up or how about a bed post that has both a circular form and several flat sections. I'm not talking about just cutting similiar items directly from the point cloud but having or building parametric files from existing point cloud data.

Thanks,

Kevin Waldron


Kevin, First off, this is kind of off topic and should be in the laser scanning thread, but that's okay.

Here is why you are going to laugh.

I had to look up the definition of parametric file. No, serious. I saw a whole load of calculus equations and nearly fainted. I thought to myself, so' that's what I have been doing!

Kevin, the fact that you used the word parametric file in my presence is blowing me away. Why? Let me explain it this way.

There are 2 types of people. Theoretical and Imperical. The theroetical people consult the barometer, TWC (The Weather Channel) radio, internet, newspaper and satelite photos to determine the amount of rain falling at any given moment during a storm. The imperical guy sticks his head outside and gets wet.
I am the imperical guy. When I started messing with point clouds generated by an LDI Surveyor 3500 Laser Scanner almost 4 years ago on a trial version of Rhino, I was too stupid to know what I was trying was next to impossible. Today, I am still stupid, but I can do what you are asking only because of the experience and the trial and errors over the years.
It is my understanding that Geomagic has a software or is developing a software that will do what you are asking. Polhemus has just released a press release regarding some sort of business venture with Geomagic. In the meantime, I plod along doing what I do because I enjoy it, and my boss pays me to do it. He also pays me to keep that part of my job a secret.

I hope you understand.

I can tell you this though, it is an old joke and should shed some light on the situation for you.

A guy with a violin under his arm walks up to a bum on the streets of New York City and ask him, "Excuse me sir, how do I get to Carnegie Hall?"
The bum cautiously eyes the guy up and down and says. "Practice my friend. Practice."

[Kevin L. Waldron]

Some fly by the seat of their pants others use both.

Enclosed is a laser scanned Dreadnaught point cloud neck and the other is a file produced in Rhino that is scalable and changeable.

Kevin

[Doug Overstreet]

Looks like this will be very informative.

Thanks Guy

[Guy Mathews]

Kevin,

Nice Scan and 3D model. What magic button did you use to clean the scan file?

Looking at the two models I can honestly say that you have already answered your own question. Laser scanners still have a hard time generating that crisp edge we are all looking for, so some good old fashion sit down time is required in a good CAD program to get the edges we are looking for. If you have developed the elusive magic button and the side by side comparison model was made without having to go through the process that I know was probaby involved to make the cleaned model, sell your secrets to the magic button to the highest bidder. If you are using high end software that most small shops do not have enough call for to warrant buying, then you are very fortunate.

When I started our process, I did not have the high end software that I have now. Each has its place in our shop for the particular applications we are doing. As of right now I am still not aware of any one piece of equipment or software that can be the go to guy for every project. Nextengine has a highdef laser scanner but it is not of much use if you have to scan an entire sofa for reference to build a frame inside of it to generate patterns or vectors for part cutting. Polhemus handheld will do that, but high defintion falls off as scanned objects with lots of detail get smaller. Our LDI Surveyor gives us mind blowing detail on small objects, but I can't scan larger objects as fast as I can with the handheld. Plus the Surveyor is limited for solid objects unless we use the rotary to scan. With the rotary, size becomes a factor again. In addition, the LDI scan files are massive because of the level of detail it can give.

Screen shots of the mesh scan and the cleaned model are the true representation of what is actually going on though not renderings. With a screen shot you can tell what is mesh and what is polysurface or nurbs. I have posted in laser threads on 3 different forums asking people to not hide behind smoke and mirrors by posting just one image of their finished work.

The Polhemus Scanner and the RBF software can generate a solid 3D model that is scalable and watertight from scanner to finished product in as little 5 minutes in the hands of a first time user.

In my hands... well, I invite you over to camheads.org to checkout the scan to mill job that I did with the scanner and a CAMaster Recoil Lathe. Better yet, call Polhemus and tell them you need the name of someone to scan some furniture parts or guitar necks and make a file for you to mill on your CNC machine. I am absolutely confident, my name will come up.

Better yet, if someone has an old guitar neck laying around that they don't need, send me an email and I will shoot you a mailing address. I will scan it and post the scan file, the exported file, the Rhino file I used to position it on the correct Axis for milling, the milling toolpaths and either photos or video of the actual milling of the neck.

Later this week I will be doing a Claw foot cabriole leg for a video I am working on. I will carve the finished RBF file on a CAMaster Recoil Lathe. I read in another forum that the cabriole legs could not be done on a CNC 4th axis. It was hard for me to stop laughing. Can't remember where exactly, think it was cnczone. Anyhow, I will post things as they come available in the Laser thread.

Based on your photo, your Rhino work is excellent and I don't know that you really need my help based on that photo. I can see the edges are rounded and I suspect that is the problem you are trying to overcome.

When we use our lasers for scanning parts, we make the edges as crisp as possible. Angles are to exact measurements based on the model we are working on. If the model is 90 degrees, we make the 3D model 90 degrees. If it is rounded or sanded over for finishing as most wood items are, we still make the edge 90 degrees unless the customer wants something different. It is easier to remove the wood edges with sandpaper then it is to scrap an entire finished product. As with any process, having all the right tools does not automatically mean someone can do the job. Knowing when and how to use each of the tools for the speciffic project is what can make or break you.

As for the guitar neck, if someone is willing to send me one that I can have, I will be happy to do a demonstration using the Polhemus Fastscan and RBF software. Will the sharp edges be crisp and angular? Nope. Will the Polhemus RBF scan be really freaking close to the actual object scanned. Yup! Will edges be sharp after I use the process we use to make them sharp. Yup! Will the neck have sharp edges when it comes off my milling machine? Yup? Will it be damn near identical to the sample? It better be, or my boss is not getting his money's worth out of me and he should fire me!

If the 3D modeling process were easy, everyone would be doing it. The fact is, I have done it so often on so many different shaped pieces, that for me it has become easy. But for a while, it was a lot of practice and fly by the seat trial and error.

So I am flying by the seat... let's remember, my seat is flying! :D

Kevin, lets move this to the Sculpting Laser thread. We are getting off the original post.

Nice work, would love to see screenshots and finished work from the machine.

In my opinion, you are at Carnegie Hall when it comes to working with the cloud points in Rhino! :D

[Khalid Khattak]

.....I read in another forum that the cabriole legs could not be done on a CNC 4th axis. It was hard for me to stop laughing. Can't remember where exactly, think it was cnczone. Anyhow, I will post things as they come available in the Laser thread.
:D

I think that was talked on Talkshopbot Forum...It was not the 4th axis issue, that was the software issue ... That software couldn't generate (having no postprocessor ) 4th axis G-code file from 3D object...

Laserscanned Point clouds can easily be converted into 3D object (Nurbs/Splines surfaces)...Just you have to give it time and patience...

Although i don't have a laser scanner , however a cheap setup like David Laser scanner can be enough to create 3D model for woodworking purposes......

The cabriole legs or Corbels can easily be done on 4th axis and if u can see my 4th axis you will laugh on it, but i can do any complex shape on my 4th axis that can be done on 4th axis...... But there are many ways to skin a CAT, when you have some more options and simple techniques available to do 4th axis part on an ordinary 3-axis mill then why to waste the time on 4th axis.. ;)

Truly speaking, I love to have a challenging jobs in my limited resources..... :D:D

[Guy Mathews]

Khalid's work truly is some of the nicest CNC work I have seen. I would love to get him working in our shop.

Keep up the great work Khalid!

[Khalid Khattak]

I would love to get him working in our shop.



Guy..
Thanks for the Job offer to a man who see himself a BILLIONARE in near future ;) (In dreams ;))....I dream to work with the innovative, talented and indigenius Intellectuals Like YOU..........Thanks Guy for the nice informative video...



P.S:
In June-2009, Shell Institute, Netherlands, conducting 05-days course on 'Diagnosis of Mechanical Failure Analysis' . I have been nominated by my company for this course..
Currently Planning to visit the great Europe in 15 days along with my family...:)

[Guy Mathews]

I figured that this project that I am currently working would be a good time to breathe some life back into this thread.

I am currently working on a chair that has hand carving and plastic inlays or appliqués. Our customer wants to have the sample chair reproduced without plastic inlays. They requested the same design, but we were to carve the detail instead of applying it. I have posted a lot more photos over at CAMheads.org, but I figured I would throw a few in here as well.

131741

The above photo is the chair that the customer sent me. I started working on this on Columbus Day. Deadline is tomorrow at COB! Go ahead boss, give the vise on my head another turn!!!!

While this project is being done on the 4th axis, it can also be done using only 3 axis machine with some clever jigs and fixtures.

The 3D models were produced in Rhino 4.0 and Visual Mill 6.0 provided the tool paths however you could just as easily do it with Cut3D, Aspire Art Cam and any other CAM program that generates 3 axis tool paths.

The chair back itself is being milled already assembled.

131717

It will be carved and cut from the 4 pieces of wood that make up the back. Basically, when finished, it will come off of the machine, be set-off on the ends and lightly sanded before being attached to the chair.

The photos below will give you an idea of what can be done with a CNC machine. The pieces are off the machine and had not had any sanding or detail applied by hand. The way you see them in the photos are the way they came off of my 10 spindle machine.

Guy

[Michael Schwartz]

Regarding a universal vacuum table I am trying to figure out what the minimum requirements would be to make one for a 4x8 machine that would be able to handle cabinet panels, doors, drawer parts, etc...

Looking to see what is feasible without 3 phase power and rule out if I can build one or not on my budget.

Also funny you mention ball and claw Cabriole legs, I saw the possibilities of making them when I started looking into 4 axis, and realized there was more to it than just wrapping a drawing around a cylinder, as so many limit themselves to wrapping a drawing around a cylinder.

[Guy Mathews]

Regarding a universal vacuum table I am trying to figure out what the minimum requirements would be to make one for a 4x8 machine that would be able to handle cabinet panels, doors, drawer parts, etc...

Looking to see what is feasible without 3 phase power and rule out if I can build one or not on my budget.

Also funny you mention ball and claw Cabriole legs, I saw the possibilities of making them when I started looking into 4 axis, and realized there was more to it than just wrapping a drawing around a cylinder, as so many limit themselves to wrapping a drawing around a cylinder.

Mike,

Trying using the Search Function for this and other things. There is a lot of info here already on this subject.

http://www.sawmillcreek.org/showthread.php?t=75836&highlight=vacuum+table

http://www.sawmillcreek.org/showthread.php?t=68669&highlight=vacuum+table

More info can be found by using Google

http://www.woodweb.com/knowledge_base/ShopBuilt_CNC_Vacuum_Table.html


I can not be of much help with your question since I stopped using my ShopBot Vacuum system nearly 3 years ago. I found that the vacuum just got in the way when milling small parts. Best to use tabbing features, screws clamps or custom built jigs to hold the parts.

I have most recently started using small vacuum jigs. These are described in a couple of the above links. Small pieces like knife handles or wooden carved rosettes can be milled many at a time by creating a custom jig. You can also make a universal jig that is based on a grid system and map your vectors and toolpaths accordingly.

I recall reading a letter by Bill Glenn over at the CNC Zone regarding vacuum tables as well. Search the CAMaster Threads over there and you should find it. More then likely someone will post the link by COB today.

Good luck.

Guy

[Michael Schwartz]

thanks for the links. The Bill Glen Article is under a thread posted by Jim under his tag cabnet636, and is pretty easy to find in google if you search bill glen cnc zone.

Have to see what I can come up with. I think I could live with jigs and hold downs 75% of the time and possibly make some part specific vacuum jigs. However the reason I would want a universal table would be for processing sheet goods, and cabinet parts.

If I end building cabinets/built ins etc... and making a ton of money off them I would no doubt spend whatever it would take to setup a pro system, but in the meantime I am trying to see what I can do with some redneck ingenuity.

Does anybody know if cabinet parts pro supports tabbing, I have been playing with it and haven't found it yet if it can.

[Nicholas Bukky]

I don't think you can add tabs in CPP but you might ask Ryan.

I think you SB comes with design software Parts wizard or something like that and that is a version of Vectric Vcarve I think.

You can tab in that program (VCARVE) so I assume the same for part wizard.

You will have to ask SB if that is part of your package.

Nick

[james mcgrew]

you can save the dxf in cpp import to aspire or vcarve (it preseves layers) when you toolpath there you can use tabs, it is an extra step but saves a lot of money on initial software.

jim

[Guy Mathews]

thanks for the links. The Bill Glen Article is under a thread posted by Jim under his tag cabnet636, and is pretty easy to find in google if you search bill glen cnc zone.

Have to see what I can come up with. I think I could live with jigs and hold downs 75% of the time and possibly make some part specific vacuum jigs. However the reason I would want a universal table would be for processing sheet goods, and cabinet parts.

If I end building cabinets/built ins etc... and making a ton of money off them I would no doubt spend whatever it would take to setup a pro system, but in the meantime I am trying to see what I can do with some redneck ingenuity.

Does anybody know if cabinet parts pro supports tabbing, I have been playing with it and haven't found it yet if it can.

Mike,

When you go to run your program on the ShopBot you will be able to use the tabbing feature that comes with there software. When using the tabbing feature you will just input the length of the tab, the height of the tab and how far apart you want them. There are many other features that come with the ShopBot software. This is not to be confused with Parts Wizard. The tabbing feature is part of the ShopBot Controller Software. No extra money for software needed. Just generate your toolpaths in Parts Wizard and setup the tabs at the ShopBot computer.

Take some time with the manual and by all means, get yourself on the ShopBot Forum. Ed Lang and Brady Watson are the go to guys over there

Guy

[Guy Mathews]

Well here they are. I posted more photos over at CAMheads. Here are a few of the finished chairs and some of the detail. The front legs were turned on the lathe from a pattern that I produced that would allow to just carve the detail needed. The rest of the chair parts were made using a computer and CNC machine. The one exception is the little piece of wood that acts as a back support for the back's top and bottom rails. Other then that, machine made.

[Robert Alexander]

Regarding a universal vacuum table I am trying to figure out what the minimum requirements would be to make one for a 4x8 machine that would be able to handle cabinet panels, doors, drawer parts, etc...

Looking to see what is feasible without 3 phase power and rule out if I can build one or not on my budget.


Michael,
I am putting together a (build it yourself)110 volt vacuum clam set up for my machine. I got the stuff at Joe Woodworker. The prices are very reasonable. The setup uses vacuum clamps that can be placed anywhere on the cnc table. I got this particular setup so I can do large metal sheets 4 x 10. The all ready made systems that I looked at other websites using the same system was around $2000.00. And this system was 1/4 the cost.

[Nicholas Bukky]

Very Nice!

Were the backs curved before you put them on the 10 spot cnc?

I bet the customer will be glad to have that in wood instead of that pretty plastic!

Nick

[Guy Mathews]

Very Nice!

Were the backs curved before you put them on the 10 spot cnc?

I bet the customer will be glad to have that in wood instead of that pretty plastic!

Nick


Nick,

If you can get a chance follow the photos over at CAMheads from start to ending. The backs were carved out of glued up over-sized assemblies that were made from a pattern of a 3D model that I created in the computer. That 3D model is the used as the STOCK in the CAM software. This process cuts machine time and allows me to cut glue up and finishing times in our Finishing and Assembly Divisions because they do not have to line up joints or hand carve details where seams come together. That is all done before hand in the computer and by the machines. While I might add, a good machine makes all the difference, as I have said before, it is just a dumb piece of metal and electronics that needs to be told what to do by a person who is experienced, and not afraid to try something outside of the ordinary.

Guy

[George Brown]

Nick,

If you can get a chance follow the photos over at CAMheads from start to ending. The backs were carved out of glued up over-sized assemblies that were made from a pattern of a 3D model that I created in the computer. That 3D model is the used as the STOCK in the CAM software. This process cuts machine time and allows me to cut glue up and finishing times in our Finishing and Assembly Divisions because they do not have to line up joints or hand carve details where seams come together. That is all done before hand in the computer and by the machines. While I might add, a good machine makes all the difference, as I have said before, it is just a dumb piece of metal and electronics that needs to be told what to do by a person who is experienced, and not afraid to try something outside of the ordinary.

Guy

Really neat, like your approach to get the job done in the most efficient manner!