Machinable Wax, Carvey, and Fusion 360 CAM: A Dream Team for Education or Prototyping

BRIAN JEPSON: Thanks everyone for coming. This is almost the end, right? We're almost done. I can't believe it, because I actually don't want to go home. Well, I do, to be to be honest. So I'm Brian. I'm going to share something I'm really excited about, which is molten wax and what I do to it after it turns into blocks. It's just an awful lot of fun.

So here's what I'm going to try to cover here. I got to get through all these ideas. How do we teach people how to make things, particularly how do we teach people using CAM, a subtractive method where we're going to cut away stuff, because I could do this show of hands. How many people have sat a kid down in front of something like TinkerCAD and then had something come out of a 3D printer and have them have a lot of fun with that? How about with adults? You've done it yourself? You can all-- these same things. Anything that works with a roomful of kids is also going to work for your own prototyping.

And at the end of the day, there are really two things I want to do here. One is stop filling a garbage can full of PLA models that I've printed on my 3D printers. That's actually not true. I'm going to keep 3D printing. I'm not giving up on it. But I do want material that I can reuse. I also want to get to-- I also want to get to an object faster.

So I do want to put a disclaimer out there. I am not an expert modeler. I'm not an expert machinist. In fact, I'm going to show you a stock setup with some clamps. And I think I took the photo before I had a crash into it so you won't see the gouging, but things happen. What I am is somebody who knows things about really cheap and accessible digital fabrication, things with low barrier to entry.

I'm from Rhode Island. I've advised on both equipment as well as approaches to go with that equipment. The Providence Fab Lab, the Newport Fab Lab. Yes, Rhode Island is such a big state we need two Fab Labs. The Rhode Island Mobile Maker Lab and the University of Rhode Island Library Makerspace. So what I want to teach is efficient ways to design and make things.

And at least once a year, sometimes twice a year, I'll do these design make take workshops and I just did one Saturday before I came out here at the Barnes Noble mini Maker Faire in Rhode Island. And what I do is I sit down the participants in front of a CAD program, in this case it was TinkerCAD. And it could be Fusion 360. I'd actually like-- I plan to start doing that. And we get them to the point where they create a design and then I make it appear in the real world. And that's really interesting, because a Barnes & Noble mini Maker Faire, it's not like the big maker fairs where people can go off and spend three hours in some other booth or something.

What happens is they'll come over, the young person or the adult will design something, and then I'll say, well, you're in the queue, maybe come back in an hour. And so they'll either go to the cafe or they'll go shopping and then they'll come back. Now very quickly the queue backs up, because 3D printers can only print so fast. But I have some repeat participants, people that I see come each year. And in fact, on Saturday, I heard a woman say of her daughters say they still have the things they made last year. So that's pretty exciting.

So here's the sort of thing-- here are the numbers that I'm dealing with here, which is somebody could design something in 15 minutes and it's going to take hours to print. I'm picking on the MakerBot print software here, but almost any 3D printer with a 0.4 millimeter nozzle is going to have this problem where things are going to take a long time to print. You can't simply speed everything up because you're just going to get spaghetti on the platform. Now that said, Ultimaker, Printrbot have had wide nozzle printers out for a while-- sorry, wide nozzles that you can add onto your printer for a while. And I'll talk about this later.

At this workshop on Saturday, it was the first time I used a 0.8 millimeter nozzle on the Ultimaker, a 0.75 millimeter nozzle on the Printrbot, and I was able to get things done very quickly. MakerBot recently announced an experimental extruder that'll work with the fifth gen and later lines. And that, I believe, goes up to 0.8 millimeters as well. So you can get things done faster.

But I still like doing-- I still like going down this CAM road here. You know, truth be told, it's not really 3D. You know if we go back to the model that I showed a moment ago, here it is. This is a 3D model. And there are going to be some problems that a CNC has with a model like this. There is certain loss of fidelity.

There's a thing called the lollipop end mill. It's exactly what it sounds like. And it can get underneath some things giving you an illusion of actual 3D but not true 3D. And of course, you can flip objects over and mill the other side and get real 3D. But this is about how quickly can we go from idea to something that people hold in their hand.

And the thing about all those chips that are coming out of the end mill there as it cuts, I'm going to vacuum those up. And I'm going to put them in a pot. I'm going to melt them down. I'm going to make another wax block. It's highly reduced waste. And you're thinking machinable wax, this is what I'm using, the expensive stuff that people use when they're doing molds for jewelry and things like that.

And here's a good example. This is a classroom pack of 25 blocks, anywhere between $75 and $240. Right? So yeah, it's that's stuff, but if you buy the bulk stuff, the chips of it, and you don't mind a little fryolater type action, you can make your own blocks and you can keep reusing it. And it has a feel that's very similar to plastic, because it's a combination of paraffin HDPE. So yeah, I'm doing something weird here. I'm using something that would normally be used for mold making, but I'm using it for end use parts, end use parts in the form of trinkets that are created in the educational process.

You know, I was surprised to have that family come in and say they hung onto the stuff they made on a 3D printer in PLA from a year ago, because I don't think-- there's not a lot of stuff except things that I actually make and put into service, which are usually boxes to hold the other stuff that I 3D printed, right. You know I'm just not-- I'm surprised when I hear people hang on to things that they've made.

So I do want to add on the AU 2017 page for this course, I have a handout. It's about 30 pages that has much more detail, step by step, links to where to buy the parts I'm going to talk about it in a minute, and also these slides. These slides that are on the website, they have links to embedded screen cap for the demos that I'm going to do. So you'll be able to go and watch this stuff at your leisure any time. But even though you could be doing this from the comfort of your home, I'm glad you came here to join me.

So this is the machine that I use, the Inventables Carvey. What I like about it is that it's fully enclosed. And when that lid gets lifted, the tool parts itself it shuts itself off. So I can, and I did on Saturday, put this thing in a space with an unpredictable number of children, many under 10, and nobody's-- and that's a heavy, I think, acrylic cover there. So it's very safe. It's designed for classrooms, libraries, and homes.

In addition to that, I use a few different end mills, which are what I'm going to stick into the tool holder and they're going to cut things away, a quarter inch, 2-flute spiral flat end mill. That just means there are two channels that, as it's cutting, material can get ejected out of. Flat end just refers to the shape of the end.

I'll be using the ball-nose end mills later. They give a nice-- they give a much smoother cut. You can mix and match. You don't have to go out and buy tons of end mills. But they're not horribly expensive, unless you're buying really fancy ones. But for these purposes you're doing machinable wax. You're not going to break a lot of end mills unless you crash into the stuff that's holding stuff down. So the lollipop end mill is another optional thing just in case you want to do some under-cutting to give it a little bit of a 3D look.

Here's when something goes wrong. See, I didn't finish the cut here and I hit the stop button. I did want to talk about this a little bit. You really want to make sure that your end mill-- like let's say that your end mill is 1 inch long or 1 and 1/2 inches long and you're cutting 1 inch material, right?

Even though, as you go down the cutting portion of it, where the flutes are can get at the material, if the material cannot escape, it's going to melt. And it's going to stop cutting. And it's going to make a horrible noise and you're going to have to start all over again. So it's really important to pay attention not just to the shape of the end mill. It really is about how long the flutes are, whether you can get that material out.

So when you're casting your blocks initially, and I am going to talk about how to do that, I'd suggest doing them thin. The other downside of using a long flute like this one is you've got more deflection of the tool and you get this vibration and horrible noise. There's just a resonance that happens with the mill because it's so long and it makes quite a racket.

So this is what it looks like when it arrives at my house. And I spent $50. 10 pounds of wax right there. This is where I buy it. They have a few colors. And I use a kitchen multi-cooker, rectangular soap making mold, bricks and towels. Everybody should know where their towel is and their bricks. And you've got to be careful about the extension cord with anything that has a heater in it, right? Like toaster ovens, space heaters, the longer the cord, you're going to get resistance. The cord's going to heat up. Then you get this loop where eventually things catch on fire. So try not to use an extension corridor if you don't have to.

So you're going to melt the wax and you're going to pour it into these molds. And it's pretty simple. You wear gloves. You should have safety glasses. A shop apron isn't really necessary unless you're either protecting your clothes or you just want to look cool. Class B fire extinguisher. Although it contains paraffin, it does not flash over at as low a temperature as paraffin does, but you it's still-- anytime you're doing something like this you should have a fire extinguisher and common sense and alertness.

For me, I sometimes feel like the gloves might be optional. I spent a year or two after high school cleaning fryolaters in a Burger King. So my fingers are pretty-- without gloves, by the way. My fingers are pretty immune to that kind of thing. So after I pour it, here it is sitting in the-- here it is poured. It's in the molds. Then I put the strip of wood on top of it.

Lately I've been letting it cool just a little bit with a towel on top, because you really want it to cool as slowly as possible or you're going to have bubbles and possibly warping. And then after a peak fidget spinner, I have all these leftover fidget spinner bearings. So they make perfect weights to go on top.

And lately what I've been doing is I put bricks on top after it set a bit and then I've got a lot of insulation, I've got some downward pressure, and it's not as likely to warp. So a couple hours later, I unwrap it. That's an unusually nice pour. Most of my blocks do not look like that. Most of them look a little ragged.

So this is where we get to the problem with the Carvey. In its effort to be a very simple CNC router, it uses a smart clamp, which is over in the lower left there. And it not only assists in holding down the material you're milling, but it also has a probe on top that determines the top of the material.

So the end mill is actually going to go and touch that. It's a button. And when it feels the button, then the machine knows exactly how high it is. Well, actually, it doesn't. It actually just knows where to start. OK. And so what's going to happen is it's going to reckon downward. You're going to tell it like I'm milling an inch of material. And if that estimate was off, it's going to just keep going until it hits an inch and that might go into the waste board.

So you can also reckon from the bottom of the stock. That's not the default mode of the operation for Carvey where you're saying start at zero and then work your way up. It's still cutting downwards. It's just that where it believes the bottom of the board is where it's no longer going to mill into the board. So you do run the risk when you're measuring from here is that you might cut too deep on the first pass. But with machinable wax, it's not really that much of an issue, because it's not like you're cutting a metal or something like that.

So this is what most of my blocks look like. So they're a bit bigger than I want them. And what I do is I clamp them in such a way so that I can face down the whole thing and smooth it out. As long as one side is smooth, I can get a nice smooth block. And this is what I use the quarter inch end mill for. So in this case, the

Smart clamp is completely closed. The probe sensor's at the bottom. I'm using these clamps here to hold it by the side. And then I'm using the clamps that come with the Carvey to hold the clamps down. And so I've got the whole face exposed. I'm sure this voids the warranty. Right? I don't want to let the folks at Inventables ever see this picture, the folks who make it.

So this is-- sorry. I'm going to stop doing that. We're going to do some CAM now. So we're going to use Fusion 360 to take a 3D model. And we're going to cut that 3D model out of wax.

Since I did the handout, I did a little bit of an upgrade to the instructions where we're going to bring a model of that waste board into the design. I was having a problem with the model, because there was a decal of the grid on it that was a bitmap image. And it was warping in some weird ways. So finally just did it as a vector image.

And now I have this nice model that you can download and you can bring in the actual waste board from the Carvey as you place your material precisely on it. And so we're going to-- this is all up on the Autodesk knowledge network and explained in more detail in the handouts that you can download.

But what we do here is the first thing we do is we create a new design in Fusion 360, new design from file, and we choose the waste board model as the source of that. And so now that's in there and it's conveniently sitting underneath our plane. So it's going to be out of the way. You know, it's off the radar in some ways for the milling.

So the next thing we're going to do is then create two blocks that are the same size as the wax block that I cast. One of them is going to have the height that I measured as it came out of the mold. And if you have a variable height, you should pick the highest point. The second model is going to be the width and length of the block, but it's going to be the height that I want to mill it down to. And so that's coming in there.

And then the other thing that I do is I align both blocks to the origin so they're sitting on the baseboard exactly how I would like them. So here comes the second box. And this one's going to be the same shape and size. And so the nice thing about this is then you actually have a pretty good realistic view of what's going to happen.

You have the block as it is measured, as it came out of the model, sitting on the board, and then you have what you want to mill down to. And the other thing I do is, towards the end, I'm going to set the opacity of one of the models, usually I do it for the stock, to make it just at like 80%, 60%, so I can tell which one is which.

And again, we're taking that second block, aligning it to the origin, and there I am sitting the opacity of one of them. And finally, I move them. Remember that photo that we saw where I had it in the middle with the clamps. I move it to exactly where I put the block on the waste board. And being able to do this with the waste board view is just incredibly helpful, because I still measure, but it just ends up making things feel a lot more intuitive.

So now in order to do the work of having the mill go and make all these cuts, we have to do a few things in Fusion 360. We have to create a set up and we have to create the tool operations. So the first thing that we do is we switch over to the CAM workspace in Fusion and create a new set up. And that set up is going to specify where the origin is in the work coordinate system for this operation.

I'm going to start by specifying the material, the stock material that we're going to mill, which is going to be that wax block that measures as it came out of the mold. And over here I'm going to set the origin so it's going to be right in the corner there of where the waste board is. And then finally, I go in there and I make sure that I've selected that piece as the model, the piece that I want to cut down to.

After that, I create a 2D facing operation. And if this is your first time through it, you're going to need to define a tool. So I bring up the tool interface. I make it a flat end mill. I make sure it's-- I set it to the material type, carbide, and tell it that it has two flutes and give it a name, give it something descriptive.

Because you're going to also specify the feed and speed, you know how fast it's spinning, how fast it's moving across the material, I give it the name of the material I'm cutting too so I'm going to call this quarter inch machinable wax. And then you go through and set all the parameters, the diameter of the end mill, the length of the flute, shoulder length. And if you don't have that on a piece of paper somewhere, you can get out your calipers and measure it.

And then this is where I put the speeds in. I do 12,000 RPM. That's about the max of the Carvey. And then I'm going to do 90 inches per minute. I turn off the coolant. There's no coolant on the Carvey so there's really no point. And then that part is done.

And so we're still defining the facing operation here. So the next thing we're going to do is make sure the outline of the model is selected, because that's how it's going to decide what it's going to cut. And then we do multiple depths, so it doesn't just try to go down and blow it away all at once. And I'm doing 0.06 inches you can experiment with this, maybe be more aggressive. There are tons of speed calculators online if you want to try to get it just perfect.

And then that's it. And then that's going to create the tool path there. And we're going to zoom in and just take a look it. You can see all the step down there. So it's three or four passes that it's going to make on there. And when that's done, I export it.

Now this is very important. Because I'm measuring from the origin, and because it's not the default mode of the Carvey software to run things, I actually have to tell it to raise the tool up off of the material with a z-axis move. And that's also in the handout so you won't forget to do that. So I just want it to hop up and over the stock so it doesn't collide into it on its way to making the cut.

So next step is to import into Easel. Easel is the software that comes along with the Carvey. it's of a 2D design tool, but it runs jobs as well. So it's sort of a lightweight CAD/CAM. And this all important thing is that travel red line there that you see where it goes up and then over. If I had not done that extra z operation, you'd see it start below there and then just crash into the material. Because I'm closing the smart clamp and starting the origin at the bottom, it just confuses the software a little bit. And then here it is in action.

And it's just going to go piece by piece. This is actual speed. You probably could go faster. At this point, it's not really hitting much of the material, because it's not really-- it's not uniform thickness. That's why I'm doing this operation. So towards the back you'll see it end up hitting the material.

And once you've done that, you've got a block that you can work with. Now if you had a band saw, you could make short work of this, or any number of other tools. But this is also a good fun first tool path project for folks who haven't done a lot of CAM.

So now I'm going to go back to the smart clamp, because now I have a piece of material that's uniform. I am going to have this area near the smart clamp that I can't machine. So although the instructions very clearly tell you to measure the material when you run a cut with Carvey, I don't. I clamp it down and then I measure the gap between the smart clamp top and bottom. Because what I'm really trying to do-- and you know what, if you don't care about that, you always could put something between-- if you don't care about your waste board, you could always put something between the wax and the waste board.

But the reason I do care about the waste board is I want to vacuum that wax back up and I don't want MDF mixed in with it. I don't want a lot of junk in there. So this is to make sure that the height of the smart clamp and the height that I'm going to put into Fusion, everything matches up.

So here I've got a model of the finished shaved down wax block as it would be oriented under the block-- sorry, under the smart clamp. So what I do now is I insert a base feature in Fusion. This is a neat little thing that-- you know, I'm going to just pause that for a second here.

The neat thing about the base feature is it won't be recorded in the design history. And that's important because I'm going to do something, I'm doing it right now in fact, to the STL import. I'm going to convert it to a boundary representation, a BREP. In order to do that, you either have to turn off design history or you have to use a base feature.

And again, this is all-- all of these steps-- you can use the handout as a checklist if you're trying to do this stuff. This will be in there. So let's see. So this will start from the beginning, which is good. So we create a base feature. We insert the mesh. Then we place the mesh. We turn it into a BREP, finish the base feature. Now we're going back to capturing design history. Everything else has design history. The base feature itself is outside of that.

And then next thing I want to do is scale the model. I don't know if this is the best way. Maybe somebody knows a good trick in Fusion 360. What I do is I find out the current dimension, such as the length, which in this case was something like 79. And I do the desired length, 2.5 inches, divided by 79, and then click OK. And then I align it to the origin.

Once I've done that, so I start there at that corner, align at the origin. And that's going to place it right on the waste board. And there we are. So now we're going to do another CAM set up, because things have changed a little bit, orientation of things. But it's basically very similar to the operation we did before.

First thing I'm going to do is move this model out of the way of the smart clamps. It wants something like 0.8 inches. So I want to just get it away from it. It actually wants more than the smart clamps are. It overcompensates a little bit, because the last thing it wants you doing is crashing that tool into the smart clamps and calling with warranty problems.

And then I create a set up with the wax block as the stock, the CAM origin in the corner there, and then I set the model that we imported and scaled as the target model. So here we're setting the stock material, setting-- oh wait. Most important is the one thing I'm doing differently this time is instead of setting the box point at the bottom here, I'm setting it at the top. That's because that's where I put the smart clamp. That's where the Carvey's going to come down, press that button, and determine where the top of the material is.

So it looks like it's going to go back to the beginning there. And so here we are positioning it precisely. There's no pause button on this. It just keeps replaying. Switching to CAM, creating a set up, setting the stock as the wax block. Setting the origin to that part up there, and setting the model to the body that we imported. So now that set up is ready to go.

Now next step is I'm going to create three tool paths to clear this out. I'm going to start passing this object around, and one 3D printed version and one that was done on a mill. On the side you'll see that I use a lollipop mill to undercut but you also see that I had a place where the wax started melting to the blade and collided into the stock. Made a yucky cut, but I like other people to learn from my mistakes.

So the first thing I'm going to do is I'm going to mill around those towers. And by the way, this is the model that a kid did at one of my workshops about a year ago. So for this, this is where I'm going to switch to the ball-nose end mill. So I'm going to create a 2D contour. And I'm going to define a ball-nose, because it just gives a nice finish on these.

I also changed the tool number in the post processor to one, because there's a bug in the Easel post processor where it doesn't properly set the speed if you have a number of tool paths that you export together. So again we're going to do the diameter. You know, we're just defining the tool. In this case, this is a one eighth. Actually, this is the one quarter. Oh no. This is the one eighth. OK. So this is the one eighth inch ball-nose. So it's going to get a little finer detail than you might get with quarter.

In fact, I'm going to pass around Gale Crater on Mars. Similar operations, but it was done with a one quarter inch ball-nose, which I got just before I flew out here. I had just enough time to try it out.

So in this case, I set the contour as the-- all four of the tower like where the roof comes to an end there. And now that's not where I want to stop milling of course. I want to mill past that because I have these towers here.

So the next thing I'm going to do is go to the-- set the bottom height, and I'm going to choose just some face on that there. I have to hide everything because it's a little-- there we go. So we got it. And that's where it's going to stop-- enable them again.

And then enable them so you can see them again. And then we're going to do multiple depths so it doesn't just try to cut it all-- that amount of material all at once. And then we're going to get what you would expect. That's going to be the first pass with the ball nuts.

So the next one, we've got this path, now I'm going to do a 3D pocket clearing tool path. There is this thing called adaptive clearing that's hyper-aggressive and uses as much of the tool length as possible, but I'm just chicken. But I think when I get home, I'm going to get over it and try it. It actually might help with some of the vibration and noise because a lot of that may come from the fact that you've just got the tip of the endmill colliding into the stock. So I sent the-- in this case, I go through and I set the boundary.

I tell it just to work around the model-- the body of the model. I make a couple of changes. I set-- I add a manual step over. Fusion suggest-- strongly suggests that. That's the amount that it changes within each pass as it goes over. And I sent that a little high, higher than you might normally for other types if you wanted a nice surface finish. So I'm actually stepping-- setting the manual step over to 0.1 with a tool that's 0.125 actually you're holding in your hand right now.

And the other thing is if you want a nice surface finish, get a heat gun. Just blast these things with a heat gun when you're done and it's going to look really nice. So that's the clearing. I'm open to advice from people with more cam experience on faster ways to clear this material. It goes pretty fast. I'm pretty happy with it.

Final thing is another contour, and this is now-- allow me to remove this model from the stock. This is going to mill around it. It's going to leave some tabs, so we're going to define some tabs. And you'll see those when the tool path is generated.

And here I am. I'm selecting the bottom contour of the object. That's the target shape that we want to mill with this. The reason I want to have tabs there is so it doesn't fly out and have little bits of it knocked out while it's bouncing around the endmill as it flies out of the object-- flies out of the stock. And so I'm just setting the tab heights here.

Because this is a 2D operation and I want to go through this pretty far, I'm going to again do multiple taps. And I've been changing the default from 0.04 inches 0.06 inches for multiple depths. I probably could go even more aggressive than that and clear things faster. And there you can see at the bottom of the tool paths there are the tabs.

So we're actually getting very close to the finale here. So we're going to export to Easel. This time when we do the post-processing step, we're not going to add that z move because we're using the smart clamp and it's got to be positioned over the material before it starts cutting. And the great thing is after you've done all this, if you import it into Easel to run the cut, it's going to complain at you if it thinks you're going to hit the smart clamp.

In this case, it doesn't because I did everything right for once. And those are all three of those operations combined together. And then it runs it. And so these are the results in terms of time. And so on an Ultimaker 2 with a fairly normal 0.4 millimeter nozzle at a 0.2 millimeter layer height, this was before I did some upgrades to it. You could probably see some ringing in it if it needed a few things tightened. It took 41 minutes.

Now on the Printrbot Simple where their 1 millimeter nozzle at a 0.6 millimeter layer height, which is why you got all that spaghetti there, that was 13 minutes. That's pretty good. That's fine.

And then the next lower left, you've got the Carvey with a 1/8 inch endmill. This is just profile and a roughing pass. And that's 8 minutes, 52 seconds. That's pretty good.

And then finally, the last one there shows-- the last one shows an operation that I didn't include in the demo, which was a spiral contour. And that'll just go over the surface and give it a nice final finish. So I actually brought the Carvey to the workshop on Saturday at Barnes & Noble. And I learned something really fast, which was running a CNC router requires a lot more attention than a 3D printer.

So there were a couple of models-- I'm going to pass one around. In order to keep the identity of the young woman secret, I took her name off of it, so it just said hello on the heart. But originally had her name on it.

So I-- most of the objects that we printed were done on the 3D printers, and the structure of the workshop that I did at the Barnes & Noble Minimaker Fair was kids sit down, make anything you want. My stepson joined me. He helped them make sure the models were at least together, printable to some extent. But in a workshop where there's more-- where you directed people towards a specific activity with some degree of improvisation where there's some constraint than you can do-- for example, if we're doing these heart things with lettering on them, running a CNC router would be fine.

So we'll take some questions in a moment, but I actually have some cool stuff to share with you. So I work at LinkedIn Learning also known as Lynda.com, and we just made a whole bunch of courses free-- 42 Autodesk-related technology courses. You don't even need to be LinkedIn Premium member or Lynda member. I'll give you time to copy that down, or you can just-- honestly you could just go to LinkedIn Learning or Lynda.com and click play, and they'll just start playing. And the this link is also in the slides.

Cameras mean we don't have to jot anything down. You get OCR, too. Click the link.

And I also-- Tom Tremblay, who just finished these courses, these are really close to the stuff that we're working on-- that I showed you. And in fact the smart-- he's better at this than me. So he just came out with these two, and I had those unlocked until next Friday-- so at least until Thursday.

So that's it for me. We do have a landing page with a little bit more information. And one more thing, I have a whole bunch-- this is like Christmas here, man. I have a whole bunch of three-month gift codes that will give you 90 days of Lynda.com so you can go in and learn better-- this is all to make up for the fact that-- like I said earlier, I'm not an expert machinist. I'm an expert modeler, so you can go and watch these courses and learn how to do things the right way. So any questions, comments, suggestions, advice? Yes.

AUDIENCE: So I know you can use machinable wax, and I want to know were there other materials that you found [INAUDIBLE]?

BRIAN JEPSON: You know I haven't-- so the question is I'm using machinable wax. Are there other materials I've used that have given me the same machining time? Definitely 3D printers with those wider nozzles. Now all of the printers-- I like Printrbot, Makerbot, Ultimaker all have optional nozzles. If you have an Ultimaker 2, the Ultimaker 2 to 2+ upgrade kit gives you three new nozzles including one that goes to 0.8. When I learned that, I spent $300 or $400 and bought it. It was-- took like an afternoon to upgrade because I know there's a lot of Ultimaker 2s

No. Part of the reason I didn't-- well, actually it's not true. I did try another material. I tried homemade machinable wax. And what you do is-- and this-- I don't recommend this at all-- paraffin and grocery store bags. And you melt them together, and you pour them into blocks. And they look disgusting. They look like silly putty, and they're really brittle.

So you could-- there are some machinable foams out there if anybody knows of any favorite materials for doing fast milling. For me, one of the criteria was reuse. That was the key-- that was a actually really-- that was equal with speed, but there are definitely plenty of things out there that can machine things really fast. Anybody else?

AUDIENCE: [INAUDIBLE]

BRIAN JEPSON: So faking the distance on the smart clamp. No, but I think about that all the time. Yes. Yeah, so have you done that?

AUDIENCE: Yeah, I have.

BRIAN JEPSON: So when you do that are you faking the distance and then putting your material in the middle?

AUDIENCE: Well, some of the time [INAUDIBLE]

BRIAN JEPSON: Oh, OK. Yeah. Yeah, that's totally legit. Just put a piece of material that's equal to the height of the material you're milling under the smart clamp and then use some of the other clamps. You may have noticed that I don't have a way to tell the Easel software where all of the fixtures are. You could do that easily in Fusion.

And it won't automatically avoid them, but when you go to simulate the cam operation, it'll warn you about collisions. So you can do that. I don't think you can have it automatically avoid them. But yeah, yeah, I have often thought about faking out the smart plan. Anybody else? Yes.

AUDIENCE: If you bought your 10 pounds of machinable wax, would you consider cutting it with a pound of paraffin?

BRIAN JEPSON: So the question is-- I'm repeating it because this is being recorded-- would I consider cutting it-- cutting the machinable wax with paraffin. I have many times. The bag of paraffin that I'm not using is sitting there. But what I think I'm going to do that paraffin is get some old newspapers and make some fire starters for the firepit in the backyard.

I don't want to do that for two reasons. I definitely would not do that in the classroom because your safety data sheet is going to be calibrated to the original mix for one. And adding paraffin is going to lower the flashpoint. And anybody who's ever had-- I have witnessed flaming wax. It's not fun.

But you could, and if you have a way-- if you have the expertise, which I do not, to determine the flashpoint based on the paraffin you added, then sure. Go for it. But I would worry about the flashpoint because I think the paraffin flashpoint is 300 or 400. It's pretty low. So that would scare me a little bit. Got a-- yep?

AUDIENCE: Are you doing this in context with the Fab Labs?

BRIAN JEPSON: At the moment-- the question is am I doing it in the context of the Fab Labs? At the moment, I'm-- this is-- I feel like as of Saturday, I've reached the point where I can more definitively recommend this path. I have recommended to the mobile maker lab that they use machinable wax.

They have the Carveys now. They have two Carveys in the mobile maker lab. They have not yet taken the machinable wax step, but I am-- yeah, I am advising that, and this was really my first test with children on Saturday.

So I feel like the one thing I learned is that I can't just do a freeform workshop. I can't say just go model anything. It really has to be done in the context of a curriculum. So I do intend to now-- now that I know more. Yes?

AUDIENCE: [INAUDIBLE] question. Have you explored other ways of actually melting machinable wax before you put it into molds? Because for me, using the kitchen cooker, I [INAUDIBLE] scenarios that [INAUDIBLE].

BRIAN JEPSON: Yeah. The question is have I looked at different scenarios for melting it? So one thing that I do-- I feel that the melting part is probably something best that an instructor or an adult does outside of the kids because I don't think the kid should be involved with it. You really should treat it like it's a turkey fryer, which you could if you had an oven, that certainly-- if you had an oven that you're maybe not going to put food in, that would probably work.

You might want to look into using a loaf pan for bread or cake. And I have tried loaf pans, but they always are-- have a little bit of a slope to them, which is annoying. But that's something that you can solve with a table saw. So, yeah, I think other ways of melting and so like a kiln that gets hot enough or an oven.

Yeah, I would definitely suggest looking into other ways because you've got this pot of wax, and somebody knocks it over. Fortunately, these days they make them-- the cords have these little magnetic things. If somebody trips over it, the cord comes out, but that still doesn't eliminate all the safety concerns. Anybody else? Yes.

AUDIENCE: I missed it. What post-processor did you select?

BRIAN JEPSON: So the post-processor-- so that-- the good news is-- I knew somebody was going to ask me about it. The good news is that I tell you where to get it in the handout. And also when you go to import models into Easel, Easel tells you where to go get the post-processor. So it's a post-processor that Inventables, the maker of Carvey and the people who do Easel, it's a post-processor that they've created and they've shared.