mini CNC routers/mills

I got a late start today in the shop. I's still working on the necklace for the cameo project, but I stayed up until 3am the night before getting the CAM ready for it. I also wrote CAM for the match boxes so I'm excited to go into mini production run mode on those. Today I started the necklace milling and while that job was running, I started work on a mini CNC router that I'm building for when I teach workshops on CNC and need to travel. This CNC is built with 3D printed parts and basic hardware. It's a simple little machine that will be good for milling foam and plastic molds and parts. I did decide to put an aluminum plate bed on it. It should turn this thing into a little tank. As I was making it I was thinking that most of the printed parts could/should be built in metal. 

Anyway as I was making this one, I started scrounging for some parts and came across a bunch of linear motion parts that I had along with some aluminum extrusion. I decided to start making an even smaller but super heavy duty version of my larger CNC router table but completely out of metal and with NEMA 23 steppers. I already have a Gecko G540  box to run it and I even have some ball screws that I can incorporate. The last picture is a teaser photo of the spoil board for the heavy duty CNC. I decided to give it a grab handle for carrying vertically. Stay tuned for more pics of these machines as they come together.

Again, it feels really good to just be doing manual layout and building on the fly. I'll CNC mill the parts I need to, but for now this allows me to build while my CNC cuts other things.

goliath cnc

kickstarter

spoil board resurfacing

I spent some time last week resurfacing the CNC router in the DCRL. I think this is the third or forth time I've done this. I'll be needing a new spoil board as I think this is the last time we can do this on this particular sheet. The router was used a ton this semester. My students created a lot of work with it. They also learned a lot about it's use. I like to have a little fun with them about "leaving their mark". I hate for things to get messed up, but then again I think I've learned a lot from my mistakes. As long as their mistakes aren't catastrophic I can live with a few mistakes.

tank

I need a tank...

clear irons game board

Yesterday the fellas from Clear Irons (Eric and Robby) came up to Milwaukee so I could assist them in cutting a large walnut game board table. Clear Irons just purchased a new Laguna 4'x8' CNC router and so they visited the studio to learn about setup on the router. Eric wrote some code using HSMWorks and then we worked through the use of this code on my router that uses Mach3. The piece required two sided machining so I went through that with them. We had a couple glitches due to warped wood, but things worked out. It was really good to meet Robby and see Eric again and to share a little time chatting about design, ambition, business, and future plans while the router was running. It had been over a year since Eric and I had gotten together for some studio time so it was a long time coming.

Clear Irons is as busy as ever, and Eric's business is doing really well (thus the reason I don't see him much). I can tell Robby is a valuable asset to the company and that he is continually growing in all of the roles that he fulfills there. Their business capabilities are growing, as their shop is very well equipped to do everything from ideation, working prototypes, to production ready drawings. 

Design work and prototyping is the bread and butter but recently the fellas also made an attempt to create some awesome side projects after-hours, that allow them to play and have fun. Go check out their etsy site and see their awesome wallets and sketchbook covers and tell them that Frankie sent you. I've been using my Eric Larson designed wallet for six years and I'm happy to say that it's aging well and getting better with time. You won't need another wallet or sketchbook cover once you invest in some of their goods.

dcrl/carthage partnership

Some of the work that the DCRL is facilitating with our partners at Carthage College. Chad Bridgewater is doing a great job using the knowledge he acquired at UWM and passing it on to his own students. Keep up the great work, Chad!

See how Chad is combining 3D scanning with plaster casting as his students create 3D self portraits.

123d make leg

Three weeks into the semester and the students have some things happening; good to see. I'm trying to push them a little to work a bit faster. Calvin just cut out  and assembled this leg: made from a 3D scan, sliced in 123D Make, cut on our CNC router with code that he generated with RhinoCAM. This will be a wood "buck" that he'll use to create a leg covering.

resurfaced

Hugo and I resurfaced the router today. We also emptied the dust collector and proceeded to fill it up again. We've been having some issues with the CNC controller not working, but we made it through this job with only a couple glitches. We have a smooth and level bed now. After this job ran, I had trouble getting the machine to move again. I don't know if something is getting too hot or what the deal is. Strange issues for certain.

123D make foam routing

Hugo and I cut some foam triangles for Chris Willey today. Chris was going to hire Pete to help him do this, but their schedules didn't match up so I showed Chris and his student assistant how to create the RhinoCAM files for these 123D Make low poly wolves. Chris is making this for an exhibition. I ended up cutting this sheet today while Chis was in a meeting. I was glad to have Hugo here to help as he's willing to be there to help, learn, and get his hands dirty. He's a good guy. Only 10 more to go...

alu-panel trash receptical

It's nearing the end of the semester. That means students are trying to finish their projects and I get requests from students that I'm not teaching to assist them is making their projects for their other courses. Eric from DVC was in a class that I taught while I was on sabbatical and he is completing his capstone course for Design and Visual Communication. Eric asked for some advice about his Graphic Design showcase project for a trash receptacle. He already had a design in mind, so I told him about alu-panel and told him I would help him cut it on the CNC router. I set him up on one of my "days off" from teaching. We were able to get everything scored and cut and then we bent it into shape. After seeing the material properties and the process, I think he realized that he could have come up with a much better form, but he learned something regardless. Helping these kinds of students that are outside my courses is rewarding, but I just don't have the time to do this as much as I would like.

zero your cnc machine

I came across this web article a few days ago. This post by Beatty Robots is just too good not to re-post. I'm sure my CNC friends will find it very interesting and useful in zeroing their machines. Enjoy and make sure to go check out Beatty Robots.

 zeroing a cnc

We enjoy machining custom aluminum robot parts on our CNC Mill. One of the best things about a CNC is that it can cut precise parts by following the geometry of a CAD drawing. We measure the precision and repeatability of our CNC in thousandths of an inch (0.001). But one of the challenges of using a CNC is to to get the raw material setup properly and make sure the spindle starts at exactly the right position. The CNC can only hold a precise position from its starting point. For example, let’s say you want to cut a pocket that is .050″ deep. That’s easy to do, but you need to start the CNC at the exact surface of the raw material so that it knows how far down along the Z-axis to move the spindle. Or let’s say you need to drill a precise hole pattern in a square sheet of aluminum. That’s easy to do, but you need to start the CNC at the exact corner of the square or your pattern will be way off. Finding the exact starting point is called “zeroing” the CNC. There are whole books written on the subject and a whole sub-industry of gizmos for handling this challenging problem. It took us a while to figure out, but this is what we’ve found to be the best solution for us:

1. When it comes to zeroing out the X and Y position of the CNC at the beginning of a job, we have tried a number of approaches, including eye-balling (not very accurate), mechanical edge finders (don’t like these), and even a laser edge finder (not as accurate and cool as you’d think). For our solution, we installed a super-cool USB camera microscope from our friends at Adafruit onto the frame of our spindle. We mounted the camera using a small aluminum bracket that we designed in SolidWorks and machined on our CNC. We secure the camera bracket to the spindle frame using a 4-40 threaded hole that we tapped for that purpose. The microscope camera points downward toward the raw material. It displays a large, magnified image on the computer screen, including crosshairs. When we want to set the X and Y zero point, we turn on the camera and then move the spindle until the crosshairs line up exactly with the corner of the raw material (or whatever position we want to identify as the zero point). Because it’s a microscope, it’s very precise. We then press the Mach3 “REF ALL HOME” button, which we’ve re-purposed and re-programmed to set the X=0 and Y=0 based on the offset distance between the camera crosshairs and the spindle position. This allows us to quickly and easily zero out the X and Y axis to the exact point we need to.

The microscope camera is the tall, tube-shape thing clamped to the edge of the spindle mount. It has a built-in ring of LED lights to illuminate the subject area.

Close-up of the custom bracket we made to hold the tube-shpaed camera to the spindle frame

In this situation, we are using the crosshairs of the microscope to zero the CNC to the center of a tiny hole. The macro will set this as X=0, Y=0.

2. The Z-axis, which is the vertical position of the spindle, is by far the most important axis to zero out properly. For this, we rigged up a very cool solution that works great. We cut a piece of copper-clad circuit board (about 1″ x 1″) and soldered it to a long wire that we ran back to one of the 5 volt inputs on our controller. We ran another wire from the base of the CNC. These two wires, combined with the CNC and the end mill (which are both conductive), become like the leads of a voltmeter that is setup to test conductivity. We then wrote a macro in the BASIC language that runs when we press the “Auto Zero Tool” button on the Mach3 interface. When we want to zero-out the z-axis, we place the copper plate on the top of the raw material and press the button. The CNC moves the spindle slowly down toward the plate. The instant the tip of the end mill touches the copper plate the electrical circuit is closed. The macro instantly stops the spindle, sets the Z-axis zero point (by subtracting the .063″ thickness of the plate), and then moves up .125″ so that the copper plate can be removed. The whole process only takes a few seconds to complete. And the result is that the CNC determines exactly where the top surface of the material is and sets it as Z = 0.

The zero plate is placed on top of the raw material. The macro automatically moves the spindle down until the end mill touches the plate and closes the electrical circuit, which signals the CNC to zero the z-axis. Note the wire soldered to the copper plate.

These two techniques have really helped improve our setup time and accuracy.

article by Beatty Robots