Try LibreDraw in the LibreOffice suite. You can layer drawings, click to lock the layer, and easily put dimensions on lines. The first layer is set up to be the dimensions. If you have played with lines in PowerPoint, you will find it's pretty easy to use. The user interface is old school pre-Office 2007 so that is a plus. It will also open pdf files and if the lines were drawn in an Adobe program you will be able to manipulate them.
absolutely free CAD type programs
- Thread starter ruben
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Help Support Home Model Engine Machinist Forum:
The process that GreenTwin has described - how to decide which plane to sketch on, etc. - is exactly what MangoJelly has been working through in his series Introduction to FreeCAD 1.0. Even though the videos are specific to that software, the procedures he describes would be universal for nearly any 3d CAD program. For example, he goes through a series of steps; one of them is to note if the object to be modeled forms a rectangle when viewed on any given side. If so, it is a candidate for drawing a sketch and extruding it. If not, then you need to think about other options, such as a rotation. Honestly, I have only skimmed this series, as much of it is more beginner than I am (not that I am any sort of expert whatsoever), but seeing GreenTwin's description of the process called this series to mind. I must stress - no affiliation other than someone who finds many of his videos helpful (especially the ones on more advanced topics).
I had to grow a lot of new brain synapes in order to learn how to use a 3D program.
One of the more frustrating things I have ever learned.
My brother saw my 3D program on my computer, and noted "That looks really complicated".
I told him "No not really, I basically use a handful of commands over again, such sketch, cut, extrude, rotate, shell. Mostly the same thing over and over again".
I started conceptualizing what I was trying to do by looking at a Play Doh extruder.
You basically sketch out the shape you want, in the position you want, and then like the Play Doh extruder, you extrude that shape, then rinse and repeat.
You can also extrude a cut.
Once you figure out the extrusion thing, it starts to make more sense.
It is not like 2D at all, and you have to forget everything you know about 2D (other than perhaps how to make a 2D sketch).
The die (sketch shape) determines what shape comes out of the extruder.
You can also rotate the die around an axis for spherical shapes.
One tricky thing was figuring out exactly where and how to position the die before you start extruding.
Took me a year to get a good feel for the 3D concept.
I gave up many times, but kept coming back for punishment, because more and more people were doing fantastic stuff with 3D.
The 3D boat was setting sail into the 21st Century, and I wanted to be on that boat.
(not my photo)
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One of the more frustrating things I have ever learned.
My brother saw my 3D program on my computer, and noted "That looks really complicated".
I told him "No not really, I basically use a handful of commands over again, such sketch, cut, extrude, rotate, shell. Mostly the same thing over and over again".
I started conceptualizing what I was trying to do by looking at a Play Doh extruder.
You basically sketch out the shape you want, in the position you want, and then like the Play Doh extruder, you extrude that shape, then rinse and repeat.
You can also extrude a cut.
Once you figure out the extrusion thing, it starts to make more sense.
It is not like 2D at all, and you have to forget everything you know about 2D (other than perhaps how to make a 2D sketch).
The die (sketch shape) determines what shape comes out of the extruder.
You can also rotate the die around an axis for spherical shapes.
One tricky thing was figuring out exactly where and how to position the die before you start extruding.
Took me a year to get a good feel for the 3D concept.
I gave up many times, but kept coming back for punishment, because more and more people were doing fantastic stuff with 3D.
The 3D boat was setting sail into the 21st Century, and I wanted to be on that boat.
(not my photo)
.
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I also migrated from 2D which I had used for 30 years to 3D and at first nothing made sense. My biggest problem was that when I wanted to place something I had always entered the X & Y dimensions and with 3D basically you place it in the approximate position and then refine the position. Basically 3D drawing is like they say about making a statue. You start out with a block of marble and carve away everything that does not look like a horse. 3D is like starting out with a block of steel and cutting away everything that does not look like an engine part.
Richard Hed
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Yes, I struggled with Alibre and I already knew AutoCAD 3D. I remember you struggling with Alibre. When yhou kikt the computer, did it kik back?
Granted, I am not the sharpest person, and I am well known as a "slow learner", but I really did not think I was ever going to be able to use a 3D modeling program.
I would watch ytube videos, but I could not find any "Here is how to design a model engine using 3D modeling".
They would draw a shape or something, but no real guidance about an overall strategy for model engine design in 3D.
I finally figured it out, but I pulled out a lot of hair in the process.
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I would watch ytube videos, but I could not find any "Here is how to design a model engine using 3D modeling".
They would draw a shape or something, but no real guidance about an overall strategy for model engine design in 3D.
I finally figured it out, but I pulled out a lot of hair in the process.
.
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I finally have gotten marginally proficient with Alibre. I had used Visual CADD for years and I still wish that a lot of the features of Visual CADD were available in Alibre. I miss being able to enter coordinates manually and being able to enter a command using a two letter command. I still find my self trying to use the two letter command for things. Once you learn the commands it is much faster than searching for the correct drop down menu etc. To be fair I used the 2D about 15-20 hours per week for 30 years and now I make a 3D drawing maybe once every couple of months.
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I hear 3D CAD comments along these same lines quite often. I think well intentioned; trying to provide context or visualization to an outsider with no other point of reference. But analogy's can also complicate or impede understanding if they don't fully apply. Or you need another analogy to footnote the first analogy. This is such a case. No way would you start with a rectangular block & carve out an engine.
What you are describing is 'subtractive' modelling. Draw a sketch on an existing solid & 'remove' material. A circle becomes a hole, that kind of thing. But it is by no means the only way. Another way is 'additive' modelling. I can draw a circle on a solid, the same circle for arguments sake, extrude it & it becomes a cylindrical solid feature (aka a boss). The circle is just a simple example, it can be any kind of sketch. I can draw a 2D shape & rotate it about an axis and it becomes a solid. I can make a 2D sketch & extrude it along a path; more 'additive' methods. My point is there is no 'one way' in CAD. There is flexibility to use a multitude of different methods to develop the part step by step in whatever makes the most sense.
There are some good video resources out there. Yes, unfortunately more internet grazing when we should be making things. But it wouldn't take many to kind of get an overview feel. Most modelers are similar in their purpose even though the icons & commands are different
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LibreCad is your best bet. Simple intuitive and has plenty of Document tutorials. I have used it for years and I prefer it to fusion 360 sketch as it’s quicker, more location accurate, and simpler. If you use command input it becomes so simple it’s like drawing.
That's more helpful than you can imagine. I have felt dumber than a busted brick trying to figure out how to even start. I've ended up doing minor changes to Thingverse etc. in the darn slicer program just because I could manipulate a basic shape.
[Edit] I'm wrong and don't want to guess again. When I get it right I'll update.
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If I understand you correctly, and I may not, sorry, one of the alleged features of FreeCAD is the ability to manually enter coordinates. No idea about your other requirement, sorry.
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I can get my head around both of those descriptions, and the case for each. And both descriptions are helpful, thanks. I've found the tutorials as important as the application. I'll just stop there without ranting LOL.
I literally downloaded 1.0 after reading through this thread. Inkscape I play in for laser cutting where the medium is flat. Thanks for both tutorial recommendations!Thanks to Stanstocker and others for a thorough review. To add just a bit more from my own experience:
Inkscape is an outstanding vector-graphics program. Highly recommended YouTube tutorials: Logos by Nick
FreeCAD 1.0 is quite usable, but 1.1 is "coming soon" and promises even more significant improvements. Highly recommended YouTube tutorials: MangoJelly
One of the most frustrating issues with cloud-based software is that some of us still live in rural areas with spotty internet.
If you want 3D and free, I use OpenScad. Learning curve is reasonable, documentation is available. Import Stls, DXF and a few others. I find the curves in OpenScad are far better than most 3D programs. You can’t develop dimensioning in it well at the moment. The export function will generate a DXF if it’s done properly and that can be dimensioned. As a programmer I find I can develop something 3D in this far quicker than in most other programs. It has modules that allow multiples of items, massive libraries of objects. Motion, adjustable parameters on the fly. It is my go to for quick 3D , for cad to cam I use Fusion360 and as I said earlier, LibreCad for 2D, love the command line and the plethora of widgets etc. Well worth a look.
It is indeed possible to enter coordinates manually, and FreeCAD 1.0 adds the ability to do so "on the fly" as one sketches. So far, I find the latter capability not to be especially helpful, but that may be because I am so used to setting the coordinates after drawing the shape. I would think just about any 3d CAD program allows manually entering coordinates ... ?
On another point mentioned earlier, it is interesting that FreeCAD incorporates both one-letter and two-letter shortcuts. I wonder if that (especially the two-letter shortcuts) was influenced by AlibreCAD? I haven't really learned the two-letter variants, but I find that the one-letter shortcuts really do speed things up. For example, while sketching, click a line and press V to constrain it vertical; click anything and press D to enter dimensions regardless of what type - it will automatically go with the most appropriate dimension, e.g., linear for straight lines or the distance between two points, diameter for a circle, and so on. The latter is also part of the update to FreeCAD 1.0, and has quickly become something I absolutely love.
As someone who has been programming for 45 years, I love the "programmatic" approach of OpenSCAD. I can imagine that some (many?) will dislike it for the same reason. I have lately been doing some designs in FreeCAD that I formerly did in OpenSCAD, in part to get to know the new "Variable Set" feature. There are a couple of things that OpenSCAD does better, and some that FreeCAD does better. The biggest advantage for OpenSCAD is the ability to create a design with conditional features. I haven't figured out a way to do that in FreeCAD, except to go back and add or delete the features.
That's not how I do it, but then again, I'm lazy. I create a cylinder, and fillet both ends.
Which brings to mind an old CAD joke, I first heard back in the early 1980's:
God commands Noah to build an arc. Noah agrees.
A week later Noah has done nothing. God once again commands him to build the arc.
Another week goes by, Noah has still done nothing.
God, enraged by this, demands to know why Noah has not started construction.
Noah says, "But my Lord, I know not how. After all, there are 11 different ways to insert an arc!"
30 years ago, I started learning 2D CAD (Autocad), and the books said "It is very important to set the limits".
I was not sure about how to do that, and did not see the logic of it, so in 30 years, I have never set the limits on any drawing, and no problems yet.
With 3D modeling, the books said "It is critical that you 'Fully Define' the sketches".
Again, I was not sure about how to do that, so I ignored it.
14 years later, I have never considered whether any sketch is fully defined or not.
I am told that I am doing it by default, but if so, I am not aware of what is happening.
I have never been known to go by the books, generally speaking, with designs.
If it works, and does not cause problems, then that is how I do it.
I guess I would be labeled a "non- conformist" type person.
That is probably a very accurate label.
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