Friday, August 14, 2020

How I drew window frames with TinkerCAD for 3D printing

Preamble

Have you ever tried making your own 3D drawings of something you want printed on a 3D printer? I have, and up to now have had limited success. But recently, I came across a great little online app called TinkerCAD and now I will happily turn out 3D drawings which I know can successfully be sliced and printed.
 
Having purchased a very cheap CTC DIY i3 3D printer kit (see How I constructed my 3D printer) and managed to get it working reasonably successfully (see How I set up my 3D printer), I firstly used it to print out models and parts which had been produced by others and posted on the internet (eg see How I constructed a 3D printed diesel loco - pending). However, what I really needed was a way of producing my own bespoke models.

I taught myself to use SketchUp and had a modicum of success. However, when I tried drawing some window frames for my model of the Boneworks, I ran into all sorts of problems. I had no difficulty drawing the window frames in SketchUp, but when I came to transfer them to my slicer software (Cura), it complained that the drawings weren't suitable for printing - they were full of holes and contained planes which were non compliant. The difficulty seems to be, to my mind, that, although SketchUp is a highly sophisticated program, it was developed before 3D printers became available and so it is not designed specifically to produce printable 3D drawings. I therefore investigated other options. Eventually, I tracked-down TinkerCAD. Developed under the auspices of AutoDESK, it has been specifically designed for 3D printing and, furthermore, it is intended to be used with children. This means it is very easy to use (compared with the majority of CAD packages) but also that it has some limitations. However so far, it has readily and successfully produced the parts I have needed.

I found the software very easy to use, almost intuitive, but then I had already been using SketchUp and so it is highly likely that I will have transferred a fair amount of knowledge and know-how into getting to grips with TinkerCAD. However, I am fairly sure that, once the key concepts of the package have been acquired, it is relatively quick and easy to gain a fair degree of mastery of the tools and techniques. Hopefully, this blog-post will contain sufficient information to get you started.

Introduction

Rather than producing a series of generalised tutorials, I will simply take you through how I drew a  window frame which I needed for my model making. I would imagine that most modellers will want to produce their own window frames at some point and so you could follow my processes but simply change the dimensions to meet your own purposes.
 

Getting started

Go to the TinkerCAD website and create an account by clicking Join Now

..... and then Create a Personal Account (unless you are a student or a teacher)


Once you have entered your personal details (or signed-in through Google), you will be taken to your dashboard. In your case, it will be empty and so click on Create new design

Later on, you can choose to load an old design if you want to change it.

You will then be presented with the drawing screen or workplane. Its dimensions default to 200mm x 200mm, but these can be changed at a later date to suit your printer's printbed (by clicking on Edit Grid). But for now we will stay with the default.
Notice that your project will be given a fancy name by the system (top left corner), in my case Brave Jaban. I usually change this early on to something more appropriate.

Click on their default name ......


..... and change it to something more appropriate. In my case, I chose the name small-window.

.
We are now ready to start drawing. You will notice that the only shapes we have are three dimensional ones in the toolbox on the right of the screen. This may seem a bit strange if you are used to conventional 2D drawing packages, but I found I very quickly adapted. It helps to prevent us from making mistakes and producing a drawing which a 3D printer can't handle. After all, a 3D printer can only draw 3D shapes! As we want a window frame, we'll draw it using cuboids. Click on the red cube in the toolbox ......
 

 ...... and drag it on to the workplane - anywhere will do.

Notice that the cube had got 'handles' on its corners and edges to show it has been selected or highlighted and also that the properties of the shape have appeared in a floating pane to the right of the shape. I wanted to turn this cube into the bottom of the my window frame, so I changed its dimensions to 45mm wide, by 5mm long and 4mm high by typing these numbers into the relevant sections of the floating shape properties pane....

There are other ways of changing the dimensions, but more about that later. Click on the relevant values in the shape properties pane, type in the new values and press the enter key to change them. Click anywhere on the workplane and the shape will cease to be highlighted and the shape properties pane will disappear.

To examine our work more closely, we can use the navigation and orientation tools on the left of the screen. Clicking the + button will zoom us in (as will turning the centre scroll wheel on a three button mouse)

The + zoom button zooms in on the centre of the workplane and so our shape has disappeared off the screen - but, by clicking the 'Fit all in view' button .......

..... our shape or drawing is brought back into view. The orientation cube in the top left of the screen can now be used to view our efforts from various different perspectives. Clicking on each of the sides of the cube will give us the views labelled, whilst clicking on a corner, holding the left mouse or track-pad button down and dragging the cube around enables us to manipulate the view to best suits our needs.


It's worth playing around with these tools for a while to become more familiar with how they work. The 'Home' button (shaped like a house) will always return you to the default view.

Now I wanted to create one of the sides of the window frame. I dragged another box on to the workplane.
 This time, I re-sized it by firstly dragging the black square ' handles' on the edges of the cube. Firstly I dragged the left hand side inwards (notice that the 'handle' on bottom left of the new cube shape is now red, showing that it is 'active'.

NOTE: The black handles change the dimensions in one direction (eg left/right for width) while the white handles change the dimensions in two directions (eg left/right and backwards/forwards).
It is possible to drag the handle carefully until the dimension has changed to what you want, but it's a bit of a fiddle. In this case, I wanted the width to be 4mm and the length to be 45mm.
A more precise way, is to click on the handle, click on the dimension number shown beside it and then type the required size in from the keyboard. In this case, I want the height to be 4mm so I typed 4 and then pressed the return/enter key on the keyboard.

I now needed to move the two window frame sections together. The first thing I did was to view them from the Top, by clicking "TOP" on the orientation cube in the top left of the screen.
 
 then switched to "Flat View" or "Orthographic" by clicking on the button on the left of the screen, which makes it a lot easier to see when parts are adjacent to each other.
 
I moved the side frame so it was touching the base frame piece. To do this, I clicked on any part of the side piece making sure I avoided clicking on any of the handles. With the left mouse button (or left track pad button) held down, I dragged the side piece so it was overlapping the bottom piece with the two corners aligned. There is another way of aligning piece of a drawing which we'll explore later.
 
I was now ready to draw the opposite side of the frame. Rather than doing this from scratch, I decided to duplicate the existing side piece. I clicked on the side piece to highlight/select it and then clicked on the "Duplicate and repeat" button in the top left corner of the screen.
 
At first, it looks as if nothing has happened because the new duplicated piece is superimposed over the old one. So, I dragged the new piece up to the other end of the bottom frame member and made sure the corners were aligned.

 NOTE: Another way to align two shapes is to use the Align Tool
 
 Select or highlight the two shapes which need to be aligned and then click on the Align tool button in the top right corner of the screen.

Lines with black blobs appear around the outline of the two shapes. Click on the blob indicating one of the axes you want the shapes to align with. In the screenshot below, I have already clicked on the lower horizontal blob (now shown in grey) and am just clicking on the left vertical blob (shown in red)

The two shapes are now perfectly aligned along the two chosen (ie greyed-out) axes.


 I now duplicated and moved the bottom piece to make the top of the frame.

To better admire my handiwork, I then clicked on the "Home View" button on the left of the screen ......

.... which presented me with the default view of the workplane - ie the view you see when first starting a drawing.

However, as you can see it looks very distant, so a quick way to zoom in on the window frame is to click the "Fit all in view" button on the left of the screen.

I then clicked on one corner of the orientation cube (in the top left corner of the screen) and dragged it around to see what the frame looked like from different perspectives.

I was now ready to link all the pieces together into one unit. This helps to avoid accidentally moving one or more of the component pieces when making additions to the drawing. Firstly, gave myself a Top / Orthogonal view of the frame. I then highlighted all the pieces of the frame by positioning the mouse pointer to the left and above the frame and dragging the selection box (the dotty red box) to the diagonally opposite side of the frame. In this way the whole frame was now highlighted.

Another way to highlight all the pieces of a drawing is to click on one piece, then hold down the SHIFT key on the keyboard and click on the other pieces.


With all the pieces highlighted, I then clicked on the "Group" button in the top right corner of the screen.

This turns all the separate pieces into one unified piece. If you look closely, you can see that the lines in the corners of the frame which showed where the separate pieces were overlapping have now disappeared - the frame is one solid piece.

If you needed to go back and change one of the pieces, the frame can be 'Ungrouped' by clicking on it and then clicking the "Ungroup" button in the tip right corner of the screen (next to the "Group" button).

I was now ready to draw the cross members of the frame/ I dragged another cube on to the workplane ......

..... and re-sized it to 2mm (Length), 45mm (Width) and 4mm (Height).


 I then changed to a Top Orthogonal view and dragged the main frame so that the bottom left inside corner was aligned with the thicker grid lines on the workplane. This makes the accurate positioning of the cross members a lot easier.

I then dragged the cross member down so it was aligned with the bottom inside edge of the frame.

I then changed the Snap Grid steps from 1mm to 0.5mm. When an object is dragged, you may have noticed that it was moving in steps of 1mm. To ensure the cross member is exactly in the centre of the frame, we need to be able to move it in 0.5mm steps.

I then moved the cross member up the screen 18.5mm. This can either be done by clicking and dragging or by using the up arrow key on the keyboard - or, of course, a combination of both.

BTW - using the arrow keys to fine tune the position of an object on the screen is called 'nudging'.

Notice that the amount of offset from the object's original position is shown on the screen - which greatly assists the positioning of objects.

To make the vertical cross member, I firstly highlighted the horizontal member and then duplicated it.


I then clicked on the 'Rotate' handle (the curved double ended arrow) to the left of the highlighted cross member. As you can see, this brought up the protractor.

I could have dragged one of the handles round until the duplicated cross member was vertical but instead, chose to type '90' into the value box beside the rotate handle.

Pressing the 'Enter' (or 'Return') key on the keyboard instantly rotated the piece by 90 degrees.

I then highlighted the whole window frame .......

..... and 'Grouped' it, before I accidentally undid any of my good work.


I now admired my handiwork from various angles and decided that I needed to recess the centre of the frame by 2mm to make it more realistic.This is where TinkerCAD's unique "Hole" shape feature comes to the fore.

I dragged a "Hole" box on to the workplane (it's the ghostly looking box shape at the top of the Basic Shapes toolbox)

(NOTE: any shape can be turned into a "Hole" by clicking the "Hole" button in that shape's properties pane)

I then re-sized it so it was 41mm by 41mm (leaving the height at 10mm)

I then moved my Hole Box up so it was floating 2mm above the workplane - by clicking and dragging the cone shaped handle above the shape (shown in red below).

 
I then changed to the Orthogonal Top view and dragged my Hole Box so it was centred on the window frame

Next, I highlighted both the frame and my Hole Box by dragging the selection box around them (I could have held shift and clicked on the Hole Box and then the frame).

Now here comes the clever bit! By clicking the "Group" button, we are instructing TinkerCAD to combine the frame with the hole. Or, to put it another way, the hole buries itself into the frame.

And here we see the frame with the hole cut out of its centre.

You may have noticed that the drawing automatically saves itself after each change and so the only thing needed now is to export it as .obj or a .stl drawing which can be recognised by the 3D printer's slicing software. I clicked on the "Export" button in the top right corner of the screen, clicked on the .STL button and then saved my drawing in a folder where I knew I could find it again.


After slicing, I loaded the .gcode file into my 3D printer and was able to produce as many window frames as I needed.

Incidentally, I used a brim with a width of two strokes as my cheapo printer takes a while before the filament starts flowing
 
Clicking on the TinkerCAD logo in the top left corner of the workplane window takes us back to the Dashboard where all our drawings are saved and displayed ready for re-tinkering or re-exporting at a later date

To my mind, TinkerCAD is by far the easiest 3D drawing application I have found. In this mini-tutorial, I have only touched upon some of its many features. I strongly urge you to watch the video tutorials produced by Promo Ambitions. They are very well presented and take you through many more features and short-cuts.

Enjoy!
 

4 comments:

Anonymous said...

The ruler in TinkerCAD is very handy, The first step I do is add one to the workplane.

GE Rik said...

Sounds like a good idea, thanks

Rik

Unknown said...

Thank you kindly for linking to our Tinkercad tutorials, wonderful blog piece...keep creating : ).

GE Rik said...

Thanks. As long as I keep doing and learning new stuff, I'll keep on posting in the hope some of it might be useful to someone, somewhere. It's feedback like yours that keeps me going. Thanks again 🤗

Rik