Improving Fusion 360 3D Toolpaths! FF115

hi folks what can we do to improve the tool pass for machining the 3d surfacing on this part let's dive through both some tips and tricks but also some general methodologies and tools that you can think about in improving your surface finishes welcome to another fusion Friday [Music] so the customer sent this file in with an existing camp set up they have a 3d adaptive the quarter inch end mill then they were coming through and doing a ramping operation with a 3/16 ball end mil and then a parallel operation to cover the top of the surfacing also with the same 3/16 end mill so I give them a lot of credit one of the things Fusion does a really good job of is explaining what some of these 3d operations and surfacing operations can be good for and again for the folks out there that have done surfacing machining for mold and die shops this is probably going to be boring and you should probably close this video but for the rest of us that are trying to learn from scratch or start or figure out how to do stuff this is awesome and this is really helpful understanding things like the ramp tool path is better for steep walls or that parallel is a really commonly used finishing strategy that's actually helpful to understand and really I wouldn't say there's anything that's done wrong here but let's talk through some changes I would make now because we didn't specifically say what they were going for here I believe they're looking for what most of us are looking for which is really good service finishes on parts that's not always the most important thing other things that can matter our cycle time you know how long are you allowed to take to make the part how long do you need your tools to last right you know is tool life and issue do you have the ability to use multiple tools or tool changes some people want to do more with the same tool so that they can let it run even lights out so that being said there are limitations based on the tools you have at your disposal here's what I would recommend I'm gonna duplicate their operation and we're going to do NYC C&C and we were spend some time playing around with this ahead of time which is why we've got this pre video test I'm gonna leave their original adaptive I'm gonna change one thing on it which is I'm going to increase the stock to leave say 240 thousands of an inch click ok and we're going to delete the rest the operations the thought here is actually going back to Rob Lockwood's Autodesk University presentation on great service finishes which is that when you do your final surfacing operation you really want to present the tool with a consistent amount of and the problem with the first version of this tool path is if we walk through the simulation we finish the adaptive with a set of stairs so as we start our parallel operation and we walk through it that tool is going to see a very different amount of material as it walks up and down this part and interacts with the stairs that we created so I want to try to get away from that so we start again with an adaptive what we're then gonna do is duplicate that we're gonna switch to a new tool I've modeled it up here as tool 101 which is a quarter inch in the middle I love running quarter inch tools especially on the tormach machines but the difference is instead of it being a square shouldered end mill we've got a corner radius of forty-five thousandths of an inch we've actually been playing around with these lately in our shop for some different projects and they've been working out quite well we'll put a link in but here is an example of a quarter inch tool where you can purchase it with different corner radii on the second tab geometry will check rest machining change it from stock setup to previous operations and will reduce the stock to leave to 20,000 I wasn't expecting was why if it's a rest machining why is it machining all of this material down here on the floor well here's why we changed the amount of axial stock to leave on the first operation it was four teeth out she want to keep it that way because axial isn't just the floor of the part it's also all the axial stock to leave along the surface apart and here we've changed it to 20 thousands is that when we're done with this first operation we've left that much material and we step down to the next tool we've machined a little deeper awesome way to fix that let's hop into a browser if you go to the library on NYC C&C and you type expressions we'll get a post up with all of the cam expressions in fusion 360 so I'm just going to hit ctrl F to search I'm gonna type axial stock to leave so there is the fusion 360 variable I'm going to right click copy for axial stock to leave I copy it because it's case sensitive and the V is lower case but the s T and L are upper case so I don't want to deal with typing it in so what we're gonna do again we're in the first adaptive edit Heights under bottom height I'm gonna change it from zero offset of Model bottom to negative and then paste in that value that's going to lower the lowest point that part can machine and that's good thing because what's gonna happen is now that first operation is gonna go all the way to the bottom now one quick note if you go back in and you look at what that value is it looks like fusion changed it to a hard-coded value of negative forty thousands it didn't it kept it as a variable and you can check that by right clicking edit expression and you can see it's now listed as negative vertical shock relief I like this you know maybe overkill for a one-off job but I like this because if we went in and changed the stock to leave here to say point O five it's gonna flow through it's just smart stuff and frankly it's pretty cool I think perfect I love it the benefit is now that this regenerates our second rest machining adaptive with the bullnose tool isn't cutting all that extra material here on the floor so let's take a look at what that simulation looks like so when we finish the first adaptive we've got those stairs so now what we're going to come into is the rest machining adaptive with the bull nose and I'll just go ahead and fast-forward to the end and you can see we've gotten rid of a lot of those stair steps it's not perfect and what we could do is reduce the maximum step down to say 0.25 and that reduces the fine step down to 25 foul and that's just going to give us again a little bit less scalping there's really no limit to how far you can take this with the caveat that one of the things that I've learned is that the key to good surface finish is you actually need to leave enough stock to let the next tool take a cut in other words running everything down to 2,000 Eve at every point in time isn't actually going to always help you nevertheless if we take a look at this simulation not bad you can start to see and sand is the next tool the ball end mil surfaces over this it's going to have less stair-step intersections that are going to cause it to change and deflect everything to flex that's one of things I've learned there's tool pressure on a soft material like aluminum even in a rigid machine with a big heavy-duty carbide end mill it deflects to a pressure matters next up let's do some surfacing I have really found that scallop is a pretty awesome tool back to at least try or start with it's a little bit of a one-size-fits-all and if you want to click to a card here Rob Lockwood talks through what's the ultimate tool path and it kind of gets into some of the nitty-gritty and understanding how to think about what the tool bats do or how they're created with scallop I'm gonna select my tool and I'm gonna step up to a 3/8 inch ball end mil now here's the thing carbide is not cheap and I'm conscious of that and I also love quarter-inch tools most the time the reason I want to step up to a 3/8 inch tool here is for two reasons one it is going to be a lot stiffer and we've got some stick out here and then the second reason is that the larger the diameter here the larger a radius we've got which means the bigger we can increase our step over and with less scalloping meaning when we go in to edit our scallop let's start with a step over of say 50 foul now let's duplicate this and let's compare what that looks like if we also did that same tool path with a 3/16 ball end mil the 3/16 Paul and Bill would simulate to looking like this with the $50,000 with a 3/8 inch tool which has double the diameter or double the radius is going to look all that much finer one of the things I like to do especially with surfacing tool passes leave the step over relatively big at first this isn't how we're going to run it in the end but it generates more quickly and it lets us worry about what I care about right now which is let's look at the tool path and understand how do I want this tool path to move so the first thing I noticed is that we want to cut from the bottom up the reason is that nothing happens at the very bottom center of a ball end mil there's less chip evacuation there's less gullet the grind I think changes a little depending on the tool and most of all you've got no service footage as you approach the exact center I have a tool I would rather do all my cutting up here on the side the best way I found was scallop to do that is ironically not to change the up/down milling but rather to change inside outside in this case to go outside in what that'll do is machine from the outside in which has the effect of walking up the part from the outside the except for that first little move right there next thing I'm going to do right click duplicate I'm going to call this the copy now my main one I'm going to go to simulate and turn on show points every point is a line of G code or a new motion control command and what I've seen here is effectively going to be a lot of jerkiness and here's the irony if we reduce the number of points your part is going to be slightly less accurate because again instead of making a curve here and then a curve here we're gonna make one curve between these two and that's gonna change the technical accuracy or the technical geometry of your part however accuracy is not the same as surface finish and what I want the machine to do is move in this really nice fluid motion and not have this jerkiness where it's making small Myer adjustments to the motion control every so often so by duplicating it let's just give us a quick comparison I'm gonna edit that scalloped turn on smoothing and we'll set the smoothing say that eight tenths which is double the tolerance click OK eight tenths is eight ten thousandths of an inch or about point zero two millimeters so quite as quite a small amount now simulate that and show the points and compare that to that it's actually not as different as I expected so let's try changing the tolerance to 1000 the smoothing - to simulate show points now we're starting to get fewer points now I don't have the answer for you here I'm not sure that there always isn't answer but it's something I want you to at least be aware of our conscious of and when you are done we can reduce that step over I would probably try running this tool with a twenty thousands of an inch step over there's always going to be some experimenting the answers for surface finish aren't just in the cam here two things that come to mind one making sure you've got a really high quality tool with very little tool run out card here to our that when we did the Lego mold and we were measuring tool run out to make sure we minimize that the other thing which I don't hear talked about very often is your coolant your coolant needs to not only be at the right Brix concentration to have the optimal surface finish but it needs to be clean if you've got debris or sediment even micro particles in your coolant that's going to turn into a form of abrasive or sandpaper or something that's going to Mar your surface finish and finally material there's a big difference in where your material is source and if you want a really good surface finish on an aluminum part consider buying it from a supplier that's able to give you a certification that shows that it's made from a reputable aluminum company you know Kaiser would be a brand or a manufacturer of aluminum that comes to mind is a high quality reputable that's also made in the United States so folks with that I hope you learned something I hope you enjoyed again this video is as much about understanding some of the tools and tricks as it is the actual answers to surface finish take care see you next Friday [Music] you

Channel: NYC CNC

Views: 34,453

Keywords: tormach, fusion 360, how to, cnc, machine shop, nyc cnc, DIY, machining, milling, CAD, cnc machining, cnc milling, toolpaths, 3D Surfacing, CAM Expressions

Id: CxFfcCoKTXQ

Length: 13min 13sec (793 seconds)

Published: Thu Jan 18 2018