Wall Clock Part 3: Hands and assembly

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Let's start our last part of our series on how to design for 3D printing with Shapr3D. So this is the last part where we are dealing with details and check the results of our 3D print and see if we have to change anything and adapt sizes or diameters and fix possible issues. But first

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while our main body is printing we can try and create our clock hands. So let's do a bit of housekeeping. So we have the clock motor or mechanism in here which we will need in a bit. What we also have is this pattern of the indicators so I'll call them indicators.

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we have some sketches and planes and our two main bodies so this one is the wall mount and then we have a main clock body and so what I'm gonna do is create a new folder for all the sketches and then I'll select all of the sketches and move them into here so now we did a bit of a bit of housekeeping and we have the main

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main parts visible. So now we can just hide all these parts that we currently don't need and let's see what we need to do. So just for just a recap we have two separate pieces of this mechanism. The bigger outside one and the smaller inside one and technically there's even a smaller one for the seconds hand but we're not going to

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build a hand for the seconds, I think it will look better if we're just using hours and minutes. So we need to create a sleeve that will be snapped in place here onto those two different diameter signatures. And both of them have small little ridges and I believe they are made in order to create tension and make the hands snap in place.

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So we really need to take advantage of this ridge and see how we can make the hands snap in place as well. Another thing we can or we need to consider is if we unhide the main body, we will have some sort of fastener showing up here. So either if we want to hide them, we need to figure out a way to hide the fasteners. Or I think what I'm going to do is

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create a sleeve that goes over this whole section here and around where the fastness will be and that way it will be most likely hidden out of view. And one more thing I'm going to show you is a little different from what you might expect and let's discuss this in a minute. We are hiding the main clock

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body for now and let us create a new sketch and for that I think I'm going to use this top surface as a sketching plane so let's create our sketch here. Alright let's start with a classic offset of this edge and we are giving us 0.1

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millimeter of offset and that is classically a way to give us a press fit so 0.1 millimeters gives us 0.2 millimeter overall and that should create a snug fit another thing we need to do is create our outside diameter so again I'm gonna use an offset and let's do that for

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Let's see, 1.5 millimeters for now. And that's how this looks. Now what I want to do is basically create a way in order to create this snap fit. So let's push this down all the way up to this surface here. So I'm going to go into the extrusion and then extend up to the object. And we're going to click on fix, select this object and or this

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surface. Now our cylinder will be going all the way up to that surface. So if we go to the side view or front view section view, you will see this is how it looks. And my theory is that you see here we have now a zero gap and that's on purpose. But as mentioned before, it will be hard to go over that hump.

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with that zero gap so we need to do a few things. Let's first hide our clock motor and the first thing we can do is basically create a chamfer and that depends on the the size depends on testing and we can play with different dimensions but let's go for 0.4 and when we unhide the clock motor

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Now we see that it didn't impede anything, it didn't change anything, but it basically creates a ramp in order for that edge to go over this ridge. So that already makes it much more likely to be able to cross that threshold and be snapped in place. Another thing we can do is again go into our top surface or the surface that we created here and create a new sketch. And then

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I'm going to use a center rectangle and create a small slot and that could be one millimeter wide that looks good and let's use 7.5 millimeters of uh length and now let's use these two areas and just go through this whole section so basically not to the motor so don't push into the motor

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or this cylinder, but just cut through our new body. And to make sure that there is nothing subtracted, check the subtract from and you see that only subtracts from our new body, which is correct. Now we need to, the idea is to have those relief or stress relief slots and basically be able to

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make use of the 3D printing material in order to bend this a little bit and make it um snap or go over the ridge and then snap in place. What's important is we never want these sharp edges for any relief slots so make sure to select those and over here as well and then give them a fillet, a full fillet usually is a good idea because otherwise

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those edges would create stress points where this piece or this element might crack. So I think those look great. And we can test different sizes or for example also different sizes of chamfers in order to get the best fit. But this is my best guess for now and we'll see how it works in the end.

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So now that we created this, I'm going to actually go back into our original sketch. So this is this one. Gonna increase that dimension. So this offset to two millimeters. And I think that gives us enough space to create a small uh additional sleeve that runs down the length of that outer cylinder. So I'm going to create a new sketch, offset that edge inwards.

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about 0.8 we can also use this so this cylinder and create a 0.2 offset that gives us this area which we can pull down and now it's important to again unhide the main clock body in order to see how far we need to push it so I'm deciding for 3 millimeters and this should give us enough space for the washer and the nut

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fit in here. If not we can always push this up. As a last step we need to create the hand itself. So for that again I'm going into that top surface creating a new sketch and basically I'm reuse this top surface and I'm going to create a circle all the way to the right somewhere along the x-axis and then make this and that outer surface

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and that outer edge be the same diameter. So now we can connect those with some straight lines. And you already see that they are green. So what's not green is just a distance. And we can just create a distance here with that length. So 75 or 80 I think is a good dimension. The minute hand will be a little longer.

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What we also need is to project this surface. Make sure it's a linked sketch. Hit done. Now we have this full selection or full area selected and we can push up in order to create our hand. And I'm going for two millimeters and that gives us a nice opportunity to give it a small chamfer as well. So now you might be wondering why I

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I did a completely straight hand without any consideration of the three dimensionality of the whole product and I'm going to explain that in a second. So we are designing for 3D printing and that means we have to also consider strength and printing processes and the best way in order to or the fastest way to print certain parts.

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And the fastest way is to have as little space in the z-axis as possible. And also we could print this completely flat and have the best strength and adhesion that the 3D print can get us. If we are going in a three-dimensional space, we really need to figure out the way the handle is placed on the print plate. You can see that...

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The lines go vertically and that creates weak points. So the adhesion on this part is really really bad. If we turn it another way, for example like this, you will be able to see the steps that are quite ugly and we are trying to avoid completely. So this also is not the best way to print this part.

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So we're going to take advantage of the material. And what I'm trying to do is we are going to print those hands completely flat, heat them up, and bend them to shape. And we are going to create a small little device in order to help us bend them into the correct shape in the end. So for now, we are going to design or model those hands.

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both of them completely flat and in a minute we are going to create our mold to give us the correct shape. So that being said, let's create our minute hand as well. So let's hide our body as well. Again, we're gonna do the same thing a little smaller. Since we already did the same procedure for the hour handle, let's fast forward this process since it's

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the same idea just with different dimensions and diameters. Very much the same process, just a little longer. So now we have two separate pieces. If we go into our section mode, we'll be able to see that we created this intricate solution to connect the pieces to the movement. And we...

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are able to adjust everything once we print it and test it in the real world. So now the last step is really to create these molds that we need in order to make this nice curvature for the clock hands. And the good thing is we already have our first sketch. So that we did here, sketch 07. And from that we can

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derive our mold. So let's create a new sketch on the same side and just click on this arc over here which we need and click project and click done. Now what I want is an offset because these shouldn't scrape on the surface of our clock. Give it a nice rather big offset of

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millimeters. The next thing we need is to create a volume so let's create a line. Start from this endpoint I'm gonna go down all the way to the x-axis then go along the x-axis a bit further than our center go up and then all the way to the right to intersect this new arc. Now we need to make sure that these two lines

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are these two lines are intersecting. So basically we can take this endpoint and put it along this line to make that coincident. And this way we already have our base surface where we then are pushing up to create the required curvature. For the minute handle, which we can create in the same way, we can offset the same edge a little bit further.

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So the same distance between the lower edge and the lower edge of the minute handle and the lower edge of the hour handle. So we can just create a line quickly in order to check the distance. So 3.4 millimeters. And I'm going just type that in here, 3.4. And we can, of course, make that a variable if you really want to make it bulletproof. But I think for now that should be sufficient.

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and another line to go up and then to the right until it intersects and this should be vertical and we can take the same point and put that onto the lower edge of the minute handle to make that coincident I think now we can trim all the unnecessary pieces and I'm going to make that projected

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curve a construction line close the gap here that should give us two separate areas one on top and one on the bottom and this is our start of the mold all right let's unhide this original sketch because it has done its job and we can start with the first mold which is the hour so let's

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Unhide, no, let's hide the minute handle and select this lower part of the sketch. And we're going to extrude symmetrically. So both directions. Let's go for 10 millimeters, but create a new body. Think we can go less, so we don't need that much space. Let's go for six or seven. So that now created our initial volume. And if we look into our

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X-ray mode we can see that we have a necessary space we can get rid of so I'm gonna just make that smaller in order to also save some space in this direction and then also I'm gonna go up and then save some space in this way as well. Now let's create a socket in order for that our handle to be installed.

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And think the easiest way is to go into that lower surface, create a sketch on there and then go into either X-ray mode or show hidden edges. Select this outer edge and project it onto our surface. And we can now offset this a little bit. And this doesn't need to be very precise. So I think 0.2 creates us a

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overall 0.4 millimeter gap which is plenty for a loose fit. So again we'll make the inner one a construction line and that gives us a nice area to push through the part. Again we need to make sure that the extrusion is only subtracting from the correct body so just delete the one that we don't want.

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Alright and now for the fun part because we can now decide on how smooth the hand will transition onto that arc here so now we can create a nice soft radius in order to make a really soft S-curve that it will follow. Alright now we can tidy up a little bit, make that, give that a small radius just to make

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make it look nice and also for 3D printing it's also good practice to have a little radius on the edges so it won't have a sharp plastic edge or corner. Alright, this is our first mold and now for the second mold it's very easy to do because what we can do is just copy this part give it a one up one down and or to copy it in place

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We're going to hide our initial or first mold. I'm going to unhide the handle. And what we're going to try and do is push this surface up until we reach the 3.4 millimeters that are required. So this updates nicely. What we also need to do is push this forward until we reach the threshold.

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should be around 29. Let's double check with the X-ray. Yeah, that's enough space. We need to push in this diameter as well. And I really don't want or need to be very precise here. Just make sure that there is a little bit of distance or gap between the cylinder and the cutout. All right, and that's the second mold done.

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And we didn't even need the sketch that we made beforehand but it's good to just double check so we can go into the front and we see that it's following nicely the same curvature. So this way we can double check and see if we did the right or correct thing. Um So yep, that looks great and we can export those two molds as well as the hands for 3D printing. After exporting

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Here you find the parts in the slicer, the molds as well as the hands. And for those intricate parts I used a layer lines for the front surface. Very much the same process, just a little longer. So now we have two separate pieces. If we go into our section mode, we'll be able to see that we created this intricate solution to connect the pieces to the movement. And we...

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are able to adjust everything once we print it and test it in the real world. So now the last step is really to create these molds that we need in order to make this nice curvature for the clock hands. And the good thing is we already have our first sketch. So that we did here, sketch 07. And from that we can

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derive our mold. So let's create a new sketch on the same side and just click on this arc over here which we need and click project and click done. Now what I want is an offset because these shouldn't scrape on the surface of our clock. So give it a nice rather big offset of

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because of imperfections, we can always go into our sketch and increase that dimension here. So while we are here in the section view, I can just quickly talk about uh something that's different from designing for manufacturing in a traditional sense and designing for manufacturing for 3D printing or rapid prototyping. So you will be able to see that we have a body

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which has a varied wall thickness, so indicated by this green area. And this is usually not easy to replicate in any other material except maybe CNC machining. Because if that part is injection molded plastic, we need to ensure that the wall of the material is uniformly the same.

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Because we are creating something for 3D printing, we really don't need to worry about this and can take advantage of this technology. So all these green areas are going to be infilled by a pattern and therefore we are saving a lot of material and are still able to create the desired shape. So really this technology allows you to be very creative and think

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outside the usual restrictions. All right, let's finish our shape by selecting this edge. We are going to create a fillet as promised. So just pull out as far as you would like. I think I'm going to use a 50 millimeter radius. Right. So we now finished our main clock body, but there are a few things that we need to add in order to make it

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course the clock hands but we'll just keep that for the next step and for now we are trying to finish the clock body itself. Alright just a quick jump in time we have added most of the details such as the indicators and the wall mount. I have opted for a twist lock mechanism on this on the wall mount if you prefer a easier

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solution you can opt for a keyhole that is made for wall nails and not screws. This option is just a little bit more secure but both options work. All right now that we have added all these details that the clock body needed we are now ready to export.

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I'm gonna hide the motor and then go to file, export and export, which allows me to click on 3D printing and it already has preselected the 3MF file format. And what I'm gonna do is include or save the different items separately. So all these elements that we created, the wall mount, the main body and the inserts.

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are exported separately. All right, so now we are inside our 3D printing software. This might change according to your printer and settings and preferences. But I'm here in Bambu Studio and I have a few tips on how to get this printed correctly. So first you already see that I tilted the main body a little bit to the back.

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and that gives us the best layer lines for the front surface. Then I use a tree support which is automatically populated for all these little overhangs. And the last thing I want to do is I will click on the model and then I'm going to seam painting. Just go to the back here and then use a fairly big brush size and just try to

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Put all the seams at least here on the top, here in the back of the model and then maybe same here on the underside. That should avoid seams on the front of the clock. So let's check if that works. All right, perfect. No seams visible on the front. So all the seams are stored neatly in the back. No...

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disturbance in the layers of the front surface. So this will take around seven hours to print and I'm gonna send that off and during that time we're going to continue with our modeling.