Fusion360: Automatically sized finger-joints

today I'm going to be designing an open-top finger jointed box where the fingers of that box will automatically size themselves based on the dimensions of the box and the number of fingers that I want along any given edge so the first thing I'm going to do is to find some parameters and I will define the length of the box as 150 millimeters the width of the box as 75 millimeters and the height of the box as 30 millimeters now these dimensions are not critical they're just arbitrary numbers here for me to make sure that everything is working correctly but this design is meant to be reusable in other projects so I don't really care right now what the the final dimensions are going to be now in addition to these dimensions I need to define a thickness since I'm expecting that all of the panels for this box will be made out of material that's the same thickness and I am assuming that this thickness will right now be 1/8 of an inch since I'm using metric units for my design I will use three point one seven five millimeters as the thickness next I will define some parameters for the number of fingers that I will have along any given edge and along the length edge I will say five fingers along the width edge I will say three fingers and along with the height edge I will say two fingers now I also need to define the formulas that will calculate the width of the fingers based on the dimensions and it's the same formula for each edge just with different parameters in each one so I will define each of the formulas l finger W for the length W finger W for the width and each finger W for the height and that's it for my parameters right now so I will close this out and then I need to create my bottom panel so I will create a sketch on the XY plane and I will press R on the keyboard and then from the origin point draw out a rectangle and define the width and the length and then I will press e to extrude this panel using the thickness parameter and our bottom panel is created I will go into the body and rename that and the sketch I will rename so with the bottom panel created I will now create the fingers that go across this front edge of the panel now create a sketch I will draw it on the front face of that panel so we'll click on the front face now I will go in and draw a rectangle and I will hover over the bottom edge of the panel to make sure that my rectangle is going to be constrained to that edge I will then drag the rectangle up make sure it's constrained to the other edge and the green X is visible now whatever you do here do not enter measurements or units in in these inputs here because that will for whatever reason break the constraints so click on that edge you'll see the two black dots that show that those corners are constrained to their respective edges and I'll hit escape just to make sure that I'm able to select the constraint that will press D on the keyboard for dimension constraint I will select the top of my rectangle I could do the bottom but I'll select the top drag it up and then enter L finger W as the width of my rectangle I also want to click on the left edge while I'm in the dimension constraint mode click on the left edge of the rectangle click on the left edge at the bottom panel and also say left elf finger W so that the fingers and notches are the same width now I could use the rectangular pattern from the sketch menu and I could select either the rectangular just the left and right lines here to copy them across this edge and I could say L fingers for the quantity and I could do length - L finger W times 3 since I want the this last finger to be one finger width inside and I want to account for the two finger widths on this side here now I could do this and I could click OK and then I could manually extrude these notches and do- thickness to cut into the panel and I have my notches here's the problem with doing it this way if I go up and change the number of fingers for whatever reason I go up and say I want 10 fingers instead of five fusion 360 doesn't know that I want those extra fingers cut or the the extra notches cut into the body even though it drew all of the lines to do that now I could manually go down here to the extrude command that I had done previously a tat feature and then select each one of these to cut the fingers and that's fine but again I want this to be reusable in other projects and the dimensions may change in those projects and I don't want to have to remember to do this and if I accidentally miss one I could end up with a box that doesn't fit correctly or anything like that so instead of doing that I will back out of that sketch so instead of duplicating this rectangle in the sketch I'm going to close out of the sketch with the one rectangle that I drew I'm going to close out of the sketch I'm going to extrude by pressing a and a negative thickness to cut into the panel so I've got my not created fusion 360 calls these features so this combination of faces is a feature I'm going to use the rectangular pattern from the create menu not the rectangular pattern from the sketch menu and I will select this extrusion that I just created this feature that I just created I will select the direction and make sure that the arrow is in the correct orientation here along this edge the distance type is extent that's correct the quantity is l fingers and the distance is because the arrow is pointing the wrong way want the arrow to be pointing this way I'm going to need to use a negative number here so I will do negative length minus elf finger W the width of the finger times three and now we have our fingers so we've got five notches correct correction five notches which is what we've defined now what those notches created I'll go in here and I will rename this sketch so that I keep things organized and now we can create the front panel that will overlap with these fingers and notches here so I will go up and create another sketch this time on the XZ plane and I will use the three-point rectangle I will click on this the origin point again which is the lower left edge of the panel I will click on the lower right edge of the panel and then I will drag up and set height as a height of my rectangle well then press e on the keyboard extrude out the panel the arrow is going in the correct direction so I will type thickness as my distance value and the operation I need to change to new body to create that panel so I will click OK now I've got my front panel that overlaps at the bottom I will rename this body and I will rename this sketch now if you've seen my previous video the configuration video that I have for fusion 360 I've got a custom material define so this is all my laser-cut MDF custom material so I'll press a on the keyboard to bring up the appearance dialog I will change apply to two faces and then under the favorites tab here I already have the fusion 360 default MDF board material I will drag and drop to the large faces on both of these panels and now we can see that there is interference between these two panels because then the fingers on this bottom panel overlap with the front panel and since there are no notches cut in that front panel we've got interference all the way around all the way around there so to fix that I will click on the combine tool under the modify menu I will select the front panel as my target and the bottom panel as my tool make sure that the operation is set the cut and that keep tools is enabled otherwise the bottom panel will disappear when I execute this operation so we'll click on OK and now we can clear clearly you see that the interference has gone away and the fingers are now cut in my front panel now with the fingers along the front edge of my box I need to add fingers to the left edge of this front panel so again I will create a sketch this time on the left face of that front panel and once again I will draw a rectangle I will constrain it to that edge we'll make sure it's constrained to the other edge and I will click again all it escape to make sure I'm in the right mode here and then I will press d2 add a dimension constraint to the finger width and I'm using each finger W as my width here and then one more dimension constraint from the bottom of that rectangle to the bottom of the panel again with each finger width and I can close that sketch out again I'll extrude a cut into this panel with negative thickness and then I will use the rectangular pattern from the create menu select that last feature that I just extruded change the direction to make sure it's going in the right direction the distance type is extent that's correct the quantity is H fingers and the distance is height minus H finger W times 3 click on OK and I've got the notches on that panel on the left hand side I will rename that sketch and then I need to copy this panel to the back so I will hover over it so we can see the profile of the sketch I'll press E because I can use that face as my reference profile and change the start point from profile plane to from object and now I can specify where I want my new extrusion to start from and I want it to start from this back face of the bottom panel and the arrow points out from the bottom panel but I want to have this back panel overlap with the bottom of the box so I will enter minus thickness and I want to make sure that I have a separate body here so I will change the operation from join to new body because I need separate bodies for me to be able to set up the job on the laser cutter I will click on ok and now I've got that back panel the back panel has the same profile shape as the front panel however the bottom panel does not have any notches in it so to fix that I will go up to the combine menu again I will select the bottom panel as my target and the back panel is my tool and we can see that the fingers from the back panel will cut the notches into the bottom panel again making sure operation is cut and keep tools as enabled click on OK and now we've got our notches in the back of the bottom panel I will rename this panel and I will press a to bring up the appearance change the faces and I will drag and drop my MDF board material to those faces and now I can move on to the left panel so I'll create another sketch this time on the Y Z plane I want to make sure that I'm not accidentally drawing on one of these faces so I'm on the Y Z plane again I will use a three-point rectangle I will click on the bottom edge of the box in the back I'll click on the front edge of the box which also happens to be the origin point and then I will click on the top front edge of the box so that this left panel will resize as the width of this box changes now I can close this sketch again press E select the profile and then the arrows going in the correct direction so it will type thickness make sure that the operation is set to new body and click OK and then I'll press a bring up the appearance again select the apply to his faces and drag and drop to each of those two faces and once again we see interference here so I will go up to the combine tool I will select now my left panel as my target and then the back panel the bottom panel and the front panel and before I do that I realized that I forgot something here so I'll cancel out of that and I will just turn off that left panel I need to draw the fingers in this bottom panel so I'm going to create another sketch here this time on the left face of the bottom panel and draw a rectangle make sure it's constrained to both edges press D and then set the width of the knotch and then another dimension constraint here to make sure that it is offset from the edge correctly stop that sketch press e to extrude select the rectangle and the arrows go in the wrong way so I will do - thickness to cut that notch use the rectangular pattern again select that feature select the direction the arrow is pointing forward and I wanted to go back which means I will do at W fingers as my quantity but I need to do a negative in the distance so do negative with minus W finger W times three and then hit okay so now I've got my notches in this bottom panel so I can turn this panel back on and now I can go up to the combine menu select the target as the left panel select the tool in the back the bottom and the front now all of my fingers are correct again make sure operation and keep tools are correct hit OK and everything's created there and we rename this panel and rename this sketch and you name the sketch now keep in mind I always use sketch at the end of my sketch names and the reason for that is if you ever go into the change parameters dialog you need to look for model parameters I find it easier to find the sketches by having sketch in the name so that's why I do that now with the left panel created it's very easy to create our right panel I will just press e on the keyboard extrude again this time I will select the left panel you can see the the profile for the left panel is highlighted I will click on that again change the start point from profile plane to from object I will select the right face of the bottom panel and the arrow is going the wrong way so I want to extrude over whoops it would help if I could type I will do negative thickness and change the operation to new body I'll apply the appearance by pressing a change apply to two faces and drag and drop over those two main phases and again we see appearance there are interference and the reason for that is that the fingers on my right panel are correct but there are no notches in the other panels so I will use the combine tool again this time select the front as the target and the right is the tool operation cut and cheap tools enabled do the same thing for the bottom and then do the same thing for the back now we've got all of our notches cut so I will rename this panel and our box is done if we resize this box so if I change this the width and the length we can see that the fingers that the number of fingers stays the same but the size of the fingers changes if I go up and change the number of fingers then we will see the size of the fingers change so the problem with this design if you want your fingers to be consistent in width this design is not going to work for you because of the the fact that that the finger widths are actually defined by the dimensions and the number of fingers so in the next video I will show you the design that I typically use which ensures consistent width of all of your fingers and I find that slightly more aesthetically appealing I hope this video was useful for you please leave feedback or quick

Channel: Hobbyist Maker

Views: 48,453

Keywords: Glowforge, Fusion360, Parametric Design, Laser Cutter

Id: 9U2JPfkQpsE

Length: 22min 55sec (1375 seconds)

Published: Fri Feb 09 2018