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A beginner starting in 3D printing with Blender - update May 18th - layers


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Hi there

I'm the person that started the Silhouette thread this time last year that got people using the Silhouette Cameo and Portrait cutters. I'm going to start an LNER D3 soon, and I've recently been thinking about chimneys and domes and such like. To be fair, flat sheets of styrene, no matter how precisely cut, aren't going to produce much of a chimney. With this in mind, and because I would like to dip my toes into the water of 3D printing, I was thinking about using this thread as a diary of a beginner in 3D that will hopefully end up as a step by step guide. Unlike the Silhouette thread, I'm coming at this one as an almost complete beginner. I've read around the subject a bit, watched some tutorials on Youtube, and a couple of years ago managed to put together a couple of things such as the Corner Gas* service station in Sketchup. Oh, and I know my way around a computer.

I'm thinking of using Sketchup as it's free for what I want to do with it, and I've used it before. I've always been told that Blender is much more difficult to learn, and isn't intuitive, but is more powerful once you've got there. Is that true?

Hopefully by the end of this, there will be enough information in this thread to provide other rank beginners with the ability to produce something with quite a complex shape that won't break the bank to have printed out. So, up front I'll try producing a chimney, dome and GNR tender in 4mm scale.

Any advice will be gratefully received, even if it's to tell me I'm going about things the wrong way, or that there is a more efficient way of doing something.

Anyway, hopefully this will bbe of interest to some people.

cheers

Jason

* Corner Gas is a Canadian comedy program from a few years back. Very funny in a "The Smoking Room" or "Early Doors" way.

Edited by JCL
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Hi Jason,

 

Thanks for starting this thread as I am sure there are many out there that will be interested in following your progress. Learning the dark arts of CAD is a some what vertical learning curve and although there are many tutorials online there is not that much about railway modelling that I have come across.

 

Sketchup is a perfectly good beginners application to start off on but it does have it's own limitations. I remember starting to use it when @Last brought it into the world and it was one of the few payware softwares I have owned. Blender on the other hand is a completely different beast and as you say is harder to learn and from my point of view it is to do with the fact that it does use a traditional unit of measuring scheme (although there is a way) However it is a lot more versatile in the long run. I would suggest It might be worth trying your hand at it. The interface and the use of keyboard shortcuts is something you pick up as you go along and gets easier over time there is also a lot of info online like Sketchup.

 

So looking forward to your 3D adventures as sure others will be I will pin this as I think it is a topic that beginners to the group will appreciate finding easily.

 

Go forth Jason

:D

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Hi there

 

OK, I'll have a go with Blender first. A while ago, nexusdj sent me a message that Paul Hobbs has a blender tutorial to building a simple loco on his website here: www.44090digitalmodels.co.uk/tutorials/index.html. The tutorial is for creating a loco in a rail simulator, so I'll have to also take into account that this will be a physical model with wall thicknesses, etc. Also, Paul's document is for version 2.48a, so hopefully there won't be too many differences between that and mine.

 

So then, I've downloaded the 64-bit version 2.72 of Blender from http://www.blender.org/ for my 64 bit Windows 7 laptop. There's a wizard to help setup (there isn't always with open source programs), so that will save a lot of thinking before I really have to!

 

So, here's the opening screen. There's an array of boxes and suchlike, but importantly, there's also a link to the Blender manual here http://wiki.blender.org/index.php/Doc:2.6/Manual .

 

post-14192-0-25646100-1412704280_thumb.png

 

Next I looked around to find some free Blender training videos and found an organisation called Blender Cookie. Their beginner videos are as follows:

  1. Introduction
  2. Downloading and Installing
  3. Interfaced and Navigation
  4. Modelling
  5. Animation
  6. Shading and Lighting
  7. Rendering with Cycles
  8. What's next?

I've watched the first three so far, and they are very accessible, so I'll carry on with the Modelling one in a minute. Obviously I'll not be interested in Animation, but I'll watch them all anyway.

 

The videos can be found at http://cgcookie.com/blender/cgc-courses/blender-basics-introduction-for-beginners/ .

 

Later, I'll refer to Paul's document once I've got past the basics.

 

cheers

 

Jason

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Great stuff Jason and didn't realise Blender was used for Trainz. As you say although he interface is a lot more different than the 2.4 that Paul uses the techniques are the same. One thing that is pretty important to the progress of learning Blender is memorising the keyboard shortcuts and the can be found on Google with even cut outs able to be printed.

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The one thing that I find a bit frustrating with Blender is that development of the software is pretty quick and that they keep adding new functions (not a problem) or moving functions (a pain in the neck!).

 

Once you get past the initial learning curve of being stumped by the cube, it is remarkably powerful and useful for 3D printing.

 

Cheers, Mike

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I've used Sketchup for my things, mainly becuase it was free and once I got used to it fairly easy to use. Something which I haven't found with my (admittedly limited) use of a few other systems - only problem I am aware of is that it does have a minimum radius (about 1mm - i think) which can cause problems with small items.

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Hi Rovex, I did consider it, but my knowledge of Sketchup isn't that amazing, so I decided to go for broke and start again. I've also been sidetracked by some animation shorts created in Blender; not something I'll be getting into, but there's some amazing stuff out there.

 

Back to my own duffer's diary.

 

I've watched the first four videos now, and I know I'll be watching them again over the next few weeks until I get a hang of the basics. The modelling video shows some of the basic things you can do with cubes and spears such as deleting faces, mushing them up, and intersecting objects. I tend to watch a tutorial all the way through once before starting anything. Then I put the software on one half of the screen, and the video on the other so that I can watch and repeat the actions. Once I'd done that, I thought I'd try to get two cylinders intersecting (I may be using that word incorrectly) in a primitive boiler chimney sort of way.

 

The immediate things that have stayed with me are that right click selects something, left click moves the cursor (the thing that objects can revolve around or the location at which a new object is created), and the mouse's middle wheel (essential) when pressed down will move you around in space (see navigation video).

 

So here are my first steps. I'm assuming you've watch the first four tutorials (or already know what you're doing). I'm not concerned about scales at the moment, and object sizes are arbitrary in this exercise.

 

post-14192-0-65039000-1412784662.png

 

First of all I set up the workspace by

  1. deleting the cube by selecting it, pressing the delete (del) button and left clicking.
  2. Changing the view to orthographic in the bottom left of the screen. (see the image above)

At times I went back to this menu option to reset views.

 

post-14192-0-96765500-1412783048_thumb.png

  1. On the left hand side are some tabs, I clicked on the Create tab to show the objects
  2. Then I clicked on the cylinder which creates a huge vertical 2x2x2 cylinder over the cursor.
  3. I clicked the tiny + button to show the object properties.
  4. I changed the shape of the cylinder by typing new values into the dimensions boxes. (2,2,6)
  5. Then I rotated the cylinder by putting values in the rotation boxes ( 0,90,90)
  6. I finally moved the cylinder over the 0,0,0 location, again by typing in values.

post-14192-0-87998600-1412783424_thumb.png

 

Next, I created another cylinder using the same method as above. This time the changed values were:

Location: 0, -2, 1

Dimensions: .75, .75, 1 (or 1.074 for some reason)

 

Now what I would like to do is delete the horizontal cylinder and leave just the vertical one with a shaped bottom. To do this, I'll have to apply something called a modifier.

 

post-14192-0-83217900-1412784085.png

 

Right click click on the small vertical cylinder to select it

  1. On the right hand side, click on the little spanner button
  2. Click on add modifier and choose Boolean
  3. Change the operation to Difference
  4. Choose the other cylinder
  5. Click on Apply

Finally select the large horizontal cylinder, press the delete key and delete it.

 

post-14192-0-59737400-1412784342.png

 

Now, this is still a long way from a chimney, but it is a step closer.

 

Here's a quick question, would the result be a smooth sided cylinder, or do I need to somehow change the number of faces?

 

Like I say, everything I'm doing here is new to me, so if anyone has a better way of doing things, then please fire away!

 

Thanks for looking

 

Jason

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Hi Jason

 

You need to change the number of faces to "smooth out" the cylinder. You can do that when you add a new cylinder - change the number of vertices in the lower LH corner box of your second pic (under Add Cylinder and above radius).

 

I find the number pad invaluable for Blender navigation.

 

Cheers, Mike

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Changing the number of vertices, (or sides) gives me a number of different shapes. As you can see, a 3 sided cylinder is a Toblerone packet, while 90 really smooths out the cylinder into what passes for a curved side.

 

The values in the vertices box for the cylinders are as follows: 3, 4, 5, 6, 15, 90.

 

post-14192-0-87087400-1412797258_thumb.png

 

cheers

 

Jason

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Importing a Background Image

 

So, I have an LNER D2 style chimney in my Isinglass drawing and I'm going to import it into my workspace to try to use it to produce a profile from which I will make something a bit more chimney like than a simple cylinder. I've scanned the drawing into the computer and cut out the bit that I need. I'll import it as a background image and trace around it using the information I've found in this Youtube tutorial.

 

 

The feller's slightly annoying, but gets the job done.

 

post-14192-0-74107300-1412800323_thumb.png

Background image to trace

 

So, to add an image from which you can trace a chimney, you do the following:

  1. Change the view to Orthographic (see post #7), then choose the front view from the same menu.
  2. Press the N key (or that small + button in post #7) to show the properties panel.
  3. Towards the bottom, tick the box that says Background Images.
  4. Click Add Image.
  5. Click the Open button.
  6. Find your image, click on the Open Image button, or press Enter.
  7. Left click at the bottom and in the middle of the chimney to move the cursor to that position.

One thing at this point, while the Open form was visible, I navigated through the folders until I came to my image, then I clicked on Add Bookmark so I can easily go back there in the future.

 

Your image should be displayed now. If it is invisible, you might still be in perspective mode, so make sure you change the view type to Orthographic.

 

If you can't see the numbers in my screen shots, you can view them full size if you click on them.

 

Tracing

 

A couple of things before I start tracing, I need to remain in Orthographic view at all times, so I can't just click the mouse wheel and drag the view around otherwise I'll go into the perspective view. To move around I must hold the shift key down and then drag the mouse until the background image is where I need it on the screen.

 

If the background image disappears it's because I've accidentally come out of orthographic view, so I need to re-enter Ortho view and then select Front to see the drawing again.

 

post-14192-0-55394100-1412803679.png

Button to enter Edit Mode

  1. To start tracing, I make sure I'm in Edit mode, not Object mode by choosing the appropriate setting at the bottom left of the workspace.
  2. Click on the create tab
  3. Click on circle. A circle will be created in the middle of the chimney.
  4. Now we will need to pull the circle up to make a cylinder (extrude) by clicking on the E key, then the Z key to make sure that you only extrude along the Z axis (up/down) and then pulling the mouse upwards.
  5. Press the S button to move the edges of the extrusion in or out. You are aiming for each edge to touch the side of the chimney in the drawing.

The tighter the curve on the side of the chimney, the smaller the extrusion so that you can make so that your circles can easily stay with the edge of the drawing. You can see from each horizontal line how far I extruded each section.  If I'm not describing it well enough, definitely watch the video.

 

post-14192-0-94384800-1412805408.png

Change to wireframe

 

When I finished making the outside of the chimney, I needed to do the interior, so I changed the view to give me a wireframe model instead of a solid one.

  1. Across the top, I pressed the E and Z key again, but didn't move the mouse, then I pressed the S key to resize the circle so that it corresponds to the inside of the chimney.
  2. Then I simply extruded down until I was at the same level as the outside.
  3. The bottom of the chimney isn't finished because I haven't put in the bottom face. To do this, in the bottom left of the workspace I chose Select, and then Non-manifold to select the inside and outside edge of the bottom.
  4. Finally, I chose the Mesh menu option next to Edit Mode, and then Faces and Fill to create the bottom ring.

post-14192-0-93513000-1412807385.png

 

Above is the selected chimney superimposed over the top of the drawing. You can see each of the extrusions as horizontal lines, and I have highlighted the inner edge using a red line. You can see the same edge on the other side as a boundary between two different levels of transparency. If this item were to be printed, I'd make sure that the walls were thick enough for the printer.

 

Here are the different view types I used

post-14192-0-85520600-1412807046_thumb.png

 

Finally, if this were "in best" I'd make sure I've the right number of vertices on the circle before I draw it as using the subdivide modifier seems to "melt" the bits that are supposed to be sharp.

 

Next I'll do the same thing, but using Paul Hobbs' method of drawing a profile and rotating it on an axis. It'll be an interesting comparison.

 

cheers

 

Jason

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Paul's way of creating the chimney appears to use a tool called "spin". Using this tool, you create a profile and rotate it around an axis, extruding as you go.

 

Create the Profile

 

post-14192-0-83242000-1412813732_thumb.png

Creating the profile

  1. You start off the same way as last time, that is, change the view to Orthographic, and Front.
  2. Left click where the bottom inside point will be.
  3. Click on Add, then Mesh, then Plane.
  4. Change mode from Object to Edit.
  5. Click on Mesh -> Vertices -> Merge -> At Centre to create a single point
  6. Press the E key and the X key to extrude a line to the bottom outside edge of the chimney.
  7. Now press E and Z to extrude a line vertically.
  8. Now pressing E and click on a point on the edge of the chimney until you have got all of the way around and back to the point created in step 2. If you want to create more vertical or horizontal faces don't forget to press E & X or E & Z.
  9. I then selected the first point I created in step 2 and noted the coordinates before selecting the last point I created and typing those coordinates in. Hopefully this is accurate enough to make things watertight.

Creating the Chimney

 

post-14192-0-11213400-1412814600_thumb.png

The Chimney

  1. Left click on the centreline for the chimney to place the cursor there.
  2. Choose the View menu and click on Top. The profile will become a single line with dots on it.
  3. Choose the Tools tab on the top right, then "Spin" in the add section.
  4. When you first use this option, the spin will create a 90 degree spin. Use the the spin options in the bottom left to change the angle to 360 degrees and increase the number of steps. I've used 90 in this example.
  5. I then changed from wireframe to solid to see the chimney as a solid object.

That's basically it. You can then use the centre mouse button to move around the new chimney and see if from different angles as below:

post-14192-0-49728200-1412814626_thumb.png

From a different Angle

 

post-14192-0-77698000-1412814651_thumb.png

As a solid

 

This method definitely seems to be faster than the first one.

 

Now I've got to sort out the bottom of the chimney so that it follows the smokebox and the flange so that it is the same all around the chimney. Hopefully this will work using the same method as in Post #7. I think Page 40 on Paul's PDF file will help me there.

 

I've been at this for a few hours as you can tell! If I'm on the right track, then I'm pretty pleased with the progress so far on this exercise, and I hope all of this makes sense.

 

cheers

 

Jason

Edited by JCL
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  • RMweb Gold

What a useful thread Jason! Already I feel less intimidated by this. It's exactly because you are learning yourself that it is accessible and understandable for the rest of us. Many thanks for taking the time to document it  :)  

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Thank you very much. I've been putting this off for a long time thinking it's witchcraft, and I've heard things about Blender, but I'm finding it less onerous than I imagined. Since putting up the posts I've managed to sort out scaling of objects, and I've even had a go at uploading the test chimney to Shapeways to see how much it would cost (apparently it's $1.84 US for white flexible or $500 in platinum!). I'll put up my scaling notes in the next day or two, but at the moment I'm going to try to work out the following:

  • How many steps I should have in my chimney when extruding - too few and it'll look ridged.
  • How to make the flange fit to the rounded top of the boiler - too many and it'd look awful if I resized the flange manually.

I'm going to have a look for an add-on that will create a rounded corner between two object no matter what the two intersecting surfaces look like - I know Sketchup has one. :-/

 

Any thoughts would be very welcome.

 

cheers

 

Jason

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The one thing that I find a bit frustrating with Blender is that development of the software is pretty quick and that they keep adding new functions (not a problem) or moving functions (a pain in the neck!).

 

 

Hi Mike, that's why I've decided not to buy a manual. I get the feeling that it would be out of date fairly quickly.

 

One thing that is pretty important to the progress of learning Blender is memorising the keyboard shortcuts and the can be found on Google with even cut outs able to be printed.

 

I'm starting to realise that Blender is short-cut heavy! There's loads of them.

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Jason,

 

You seem to have a natural talent for writing these sort of guides.

 

The chimney is looking good, although you need to 'sit' it on a correct sized smokebox, so that you can get the shape of the bottom flange correct so that that sits on the top correctly, because at the minute it is just a block, and will not sit.

 

The cost of the part is quite cheep too, this is looking good! (So how much platinum are you going to be ordering?)

 

Andy g

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Cheers Andy. I'm trying to work that out as I speak - well it's getting late, so I'll look tomorrow. I've had a quick look at a thread here on RMWeb which may be able to help http://www.rmweb.co.uk/community/index.php?/topic/77750-drawing-a-loco-steam-dome-how-to-get-the-varing-flare/ , along with the stuff I was doing in post #7. I think the interface might be the most difficult part of the exercise so far.

 

Yep, it's not as much as I expected, so I'm wondering how much a chimney, dome and smokebox door will cost. I might forgo the platinum I don't want to look ostentatious.

 

cheers

 

Jason

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Hi Jason

 

You're really getting the hang of this quickly.  A few Blender tips you might (or might not!) find useful:

 

- build things out of re-usable sub-assemblies to save time

- think about how you can create "tools" to modify objects eg if you need lots of holes of a certain diameter create a cylinder for the correct diameter and use the boolean difference modifier to remove material

- save versions of your work regularly so you can go back and fault find if necessary (beyond Blender's Undo function)

- check your objects are manifold (watertight) regularly. 3D printing requires the objects to be watertight and it can be easy to inadvertently create something which is no longer watertight. In edit mode pick vertices (or edges) and make sure nothing is selected (you can toggle between all or nothing selected using the shortcut A). Then Select Non Manifold (CTRL + Shift + Alt + M) - the top RH corner dialogue will tell you if any vertices, edges or faces are non-manifold.

- when on the main window pressing space brings up a search bar which you can type for commands

 

Cheers, Mike

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Thanks Mike, I'll bear those points in mind - I can see the sub assemblies being useful for axle boxes,, that sort to thing. Thinking about it, can these sub assemblies be put into a library so they can be reused on different projects?

 

I have a question, how do I project a circle onto the curved side of a cylinder, then cut away the cylinder, only leaving a curve that looks like a Pringle? If I can do that, I might be able to extrude the circle, plonk the chimney on top, and then try to make the flange/rounded corner/fillet between the two using the Bevel tool.

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You can use the append function to move any object from one Blender file to another.

 

I'm not sure I can conceptualise correctly (my fault not your's!) what you want to do but a boolean difference modifier between two cylinders might have the outcome you are after.

 

Cheers, Mike

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Thanks everyone. I've changed the title to make it more obvious that I'm using Blender now.

 

Hi Mike, not a problem, I'm not explaining it correctly. I think I might have the solution, so I'll give it a go then report back.

 

cheers

 

Jason

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Good guide this and a good start. Once you get this part mastered everything else on a steam loco is pretty easy. The one thing to remember from the first is to design to the limitations of the printing material/machine and not just draw the prototype. This is my rule no.1: will it print, will it be strong enough, is it the most cost effective way to represent that part.

 

Cheers Andy. I'm trying to work that out as I speak - well it's getting late, so I'll look tomorrow. I've had a quick look at a thread here on RMWeb which may be able to help http://www.rmweb.co.uk/community/index.php?/topic/77750-drawing-a-loco-steam-dome-how-to-get-the-varing-flare/ , along with the stuff I was doing in post #7. I think the interface might be the most difficult part of the exercise so far.

 

Yep, it's not as much as I expected, so I'm wondering how much a chimney, dome and smokebox door will cost. I might forgo the platinum I don't want to look ostentatious.

 

cheers

 

Jason

 

 

Thanks Mike, I'll bear those points in mind - I can see the sub assemblies being useful for axle boxes,, that sort to thing. Thinking about it, can these sub assemblies be put into a library so they can be reused on different projects?

I have a question, how do I project a circle onto the curved side of a cylinder, then cut away the cylinder, only leaving a curve that looks like a Pringle? If I can do that, I might be able to extrude the circle, plonk the chimney on top, and then try to make the flange/rounded corner/fillet between the two using the Bevel tool.

 

Thanks for reminding me of that post. For anyone using AutoCAD I discovered a much quicker and better way of creating the 'pringle'. I don't know Blender so don't know if it will help but I'll write it up here shortly: http://www.rmweb.co.uk/community/index.php?/topic/77750-drawing-a-loco-steam-dome-how-to-get-the-varing-flare/

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That's great, thankyou for doing that. I did learn this when I tried uploading that exercise to Shapeways. My wall thickness was about .65mm.

 

In the meantime, here's my Pringle, or base for my chimney. A little warning, it might be a dead end, I don't know yet, but may come in useful at some point.

 

Step 1 - Create a horizontal cylinder to represent the boiler. Create a smaller vertical one that is the same diameter as the maximum width of the flange and position centrally in the boiler. I've been using the Location boxes and type in the location numbers - you can see them in the screen shot. Create a copy of the boiler. In Windows I use Ctrl-V and Ctrl-C and then drag the copy out of the way.

 

post-14192-0-44756300-1412950028_thumb.png

 

Step 2 - Here, I selected the boiler by right-clicking on it, then clicked on that little spanner on the right, and added a boolean modifier (see previous post) using the intersect operation.

 

post-14192-0-52327300-1412950207_thumb.png

 

Step 3 - I selected the chimney at the top and dragged it out the way and deleted it. This leaves the smaller chimney behind it.

 

post-14192-0-20648900-1412950374_thumb.png

 

Step 4 - Reposition the cut down chimney into the middle of the boiler copy but slightly proud - this will be the height of the flange.

 

post-14192-0-14532300-1412950493_thumb.png

 

Step 5 - I clicked on that little spanner on the right again, and added a boolean modifier, this time using the difference operation.

 

post-14192-0-71789200-1412950652_thumb.png

 

Step 6 - I dragged the boiler out the way and I've got a pringle.

 

post-14192-0-64048900-1412950799_thumb.png

 

Step - 7 Finally I created another cylinder the diameter of the top of the chimney base. So I currently have a top hat, but no chimney yet. Now I've got to work out how to use a bevel or similar to make that curve. Hopefully it'll go from the top of the cylinder to the outside top of the flange.

 

post-14192-0-18993200-1412950847_thumb.png

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  • RMweb Gold

Cracking work. Must admit I tried sketchup but gave up after a few hours and moved to Blender, felt much more comfortable. I learned in Maya originally but it costs so much to buy!

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