--- marp: true theme: default html: true --- # Design for the printer Design and print · Designing for the printer --- ## Today **We are learning to** a printer builds in layers: an overhang more than about 45° from vertical needs supports, and a part is weakest across its layer lines. Choose the way up that needs no supports and runs the layers along the load. - I can tell when a part needs supports. - I can choose a print orientation so the load runs along the layers. --- ## Why it matters > Two brackets, same file, same printer, same plastic. One holds a shelf of books; the other snaps the first day. The only difference is which way up they were printed. --- 💬 Discussion ## Predict **An L-shaped bracket will hold up a shelf. Which way should it be printed to be strongest?** - Upside down - It makes no difference - Flat on its side - Foot down, arm up --- ✍️ Activity ## Try it {{embed: https://studio.learningwaypoints.com/tutorials/_playground-board/index.html?id=deck%2Fengineering%2Fcad%2Forient%2Fstep-2&code=widget%3A+fab%0Amode%3A+orient%0A&fresh=1}} [Open this step in the tutorial](https://studio.learningwaypoints.com/tutorials/engineering/cad/orient/?full=step-2#step-2) --- ✅ Check ## What happened? * Flat on its side: no supports, and every layer runs along both arms, so the load pulls along the layers, not across them. --- 💬 Discussion ## Overhang, then load Now try a hook. $$\text{overhang} > 45^\circ \Rightarrow \text{supports}$$ 1) $\text{layers across the load} \Rightarrow \text{weak}$ — Layers bond less well to each other. 2) $\text{bracket: flat on its side}$ — No overhangs, and the layers run along both arms. 3) $\text{check both, every part}$ — Supports cost plastic and finish; weak layers cost the part. --- ✅ Check ## Overhang, then load **A hook will hang a bag from its curved end. The load pulls down the hook's length. Which way up should it be printed?** - Standing up, curve at the bottom - Flat, so the layers run along the hook - Standing up, curve at the top - It makes no difference * Answer: Flat, so the layers run along the hook --- ✅ Check ## Find the mistake **Sam's bracket snaps across the arm the first day. Click the line where Sam's reasoning first goes wrong.** ``` 1 Sam prints the shelf bracket foot down, arm up. 2 It needs no supports, and it looks perfect. 3 The plastic is the same all the way through, so it is equally strong every way. 4 So it will hold the shelf. ``` * Answer: line 3 --- ✍️ Activity ## Make it in the slicer --- ✅ Check ## Which way? **Which of these need supports printed as described?** Groups: Needs supports · No supports A letter T standing up, its bar at the top · A letter T lying flat · A pyramid standing on its base · A pyramid standing on its point · A cube with a round hole straight through, top to bottom * Answer: A letter T standing up, its bar at the top → Needs supports; A letter T lying flat → No supports; A pyramid standing on its base → No supports; A pyramid standing on its point → Needs supports; A cube with a round hole straight through, top to bottom → No supports --- ✍️ Activity ## Make: choose and justify - **A phone stand:** - **My part:** --- ✅ Check ## Exit ticket **Give two reasons to choose a print orientation.** * To avoid overhangs that need supports, and so the load runs along the layers rather than across them.