Parts that fit odd shaped objects - 3D design for 3D printing pt4

To get the best out of 3D printing, it helps if you can design your own parts. In this tutorial series, we will learn to use a free 3D CAD program to do just that.

In this episode, we model a printed part that must match an obscure object perfectly. To achieve this, we use a combination of measurements and a reference photo to generate accurate geometry. We also examine why small print undersized with three potential fixes, and learn how to split parts into two.

0:00 Introduction

0:40 What we are designing

1:16 Taking measurements and reference photos

2:21 Importing reference image

3:50 Rotating the reference image

5:00 Scaling the reference image

5:57 Sketching, constraints and dimensions

6:46 Prototype for testing accuracy

7:56 Why do we have undersized holes?

9:00 Solution 1: Drill out hole

9:12 Solution 2: Adjust CAD dimensions

9:58 Solution 3: Slicer compensation

10:30 Finishing the design

11:32 3D printing design considerations

12:07 Split tool using a plane

13:13 Split tool using a sketch and surface

14:07 Finished part

Get Quality Resins from 3D Printers Online. 5% off storewide for Teaching Tech subscribers [Code: tech5]

Take a look around and if you like what you see, please subscribe.

[basicmods]

New teaching tech video? Don't need to watch, instant thumbs up.

[caloroga]

I think you scaled the photo the hard way. An easier way is to draw the construction line on the ruler and then dimension the construction line based on the span of the ruler it covers. If this is the first dimension placed on the sketch, it automatically scales the image too, keeping the construction line in the same place on the ruler.

[timnicholls]

Hey Michael!

Thanks for this series - it's exactly what I need to help me make the mental shift from years of doing arty CAD for subtractive manufacturing (Vectric Aspire) to thinking in a way that works for additive. I was struggling with the concept as a whole, but you've helped enormously.

You're an absolute rock star!

Thanks again,

Tim

[JamesMossR]

Been using Onshape for at least a couple of years and you've already taught me loads of useful tips. It's super useful to see how other people approach problems too. Absolute gold, thanks!

[MaheerKibria]

There is a really easy way to get dimensionally accurate outlines. It's super old school technique which is probably why i guess younger people don't use it. You take a piece of paper or masking tape. Then rub with a graphite or charcoal stick. and voila you have a 100% accurate representation of what you are trying to model. It's also great for transfering scroll work on wood. Then attach to a piece of paper since those tend to be rather dimensionally accurate and scan said piece of paper put it in your modeling software as a reference and scale it properly. It has the added advantage of not having lens distortion. It won't work for the car engine bay but since you don't have any mating surfaces it would probably be fine

[birddroppings]

This whole series is immensely valuable for getting my foot into the 3D world - Thanks for your effort!

[zenw]

amazing! These tutorials are exactly the kinds of frustrating problems I find myself 3d modeling/printing for. This is by far the most applicable tutorial series on 3d modeling I have come across.

[RobertD_]

This series has been the push I needed to venture out beyond tinkercad. I've been wanting to learn a proper cad software for a while head a really hard time following along with freecad tutorials. I've been passively watching/listening in advance while doing other things and sitting down later and following along making my own similar variations of the model in the tutorial. I've made a couple of basic parts that I'm pleased to say came from my own head and am learning a new skill that recently seemed kinda insurmountable. Thanks for the series, you are indeed a great tech "teacher"!

[automaticprojects]

Love this series. I’ve been using Fusion for years but really impressed with OnShape because of this.

[notice_fpv]

I was blown away (I'm still pretty new) seeing how easy it is to get accurate dimensions from a reference drawing. That will definitely come in handy someday.

[LibertyEver]

I print engineering prototypes, useful mechanical parts I create to solve daily problems as shown in this video, and products that I sell. This was a GREAT video. It's a very good example of how OnShape is used as a fairly easy and intuitive but full featured 3D CAD tool. I recently bought a 4WD Hijet Japanese mini truck and I'm slowly remaking it in 3D printed parts. Tonight - a rubbery TPU mounting adapter for a universal replacement fuel pump.

[gmo]

G'day Michael
I've been using Onshape for years, taught myself through trial and error. Only just stumbled on these videos and have learnt things I wish I knew earlier. Thanks!

[JustTony]

One thing to note when taking and using reference images is to always use the longest edge on the item you can to reduce extrapolation effects. Airways more accurate interpolating. When scaling a reference image use as much of the ruler as visible to reduce camera distortion effects on scales.

[dcf]

This is why I always paste links to you here when I'm on social media sites, make it easier for fellow printer peeps! You teach in an easy to understand way, guess that's why you are a teacher 😊👍you're good at what you do. Thanks heaps for making these how too vids, got me keen to try and make some ideas I've had.

[draskuul]

I wouldn't have thought so much of splitting it the way you did, but the advantage of making that part in TPU is definitely a good one. I'd probably have considered adding a glue or silicone to help join the two parts. My route would probably have been to loft/extreme filet the hose end to the mounting plate, allowing it to be printed hose-end-down without additional supports (and adding a little more strength to the part).

[gizmobowen]

This series is the missing link to making 3D printers useful tools and not just something for printing trinkets. Don't get me wrong, I have a shelf full of fun trinkets but I'd rather use my printers as tools. Knowing how to make your own part for your specific application is the key to unlocking the full potential of a 3D printer. Combine this with some nice engineering materials, like carbon fiber filled nylon and the sky's the limit. Thank you Michael for putting this very useful series of videos together.

[ericcsuf]

I frequently split parts like this to avoid supports or just to get a cleaner print, then CA the printed parts together. The seam is invisible and stronger than the original. However, I REALLY like your idea of printing the parts from different materials where useful. In your example, the lowere half becomes a useful gasket. It would still be useful in some applications to glue the TPU and PLA parts together leaving a part with an integral "gasket". Incredible versatility.

BTW, I've been a Fusion 360 user for nearly 3 years. Once you know one major program like this, you can usually follow tutorials like yours which use a different program. It's like word processing. Once you understand what one is capable of, it's just a matter of learning how that particular function is done in the new program. I've had no difficulty following your last 4 videos as design exercises instead of software tutorials.

Excellent video as always.

[LelandPD]

This is EXACTLY the kind of bracket that I needed to design for the extendable legs on my drafting table (the ancient plastic ones have cracked and crumbled away). Currently printing my first prototype now. I'm so happy that I'm starting to understand how to make parametric dimensions that allow parts to be updated and modified as needed. Such a huge step in the journey of designing my own parts! Thanks so much for this series.

[stvcolwill]

OUTSTANDING VIDEO!!!! thanks so much. I've been following you for years now, and this is the best series by far. Kudos!

[Jimmy___]

These tutorials are so great and succinct.