I don't seem to be able to find one on this forum - Is there one ?

I might be missing something here - But i have tried v2 and v3b but i can not get this to work with Blend. Simple cup exercise where the handle meets the body of the mug. It's a common design need so i must be do something wrong. Any chance of a Blend-->Merge function in V3 ?

Boolean Union handle + Mug
Then select it and Fillet ;)

Hi Martin, for the v3 wishlist post your top 5 wishes on this thread here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3628.1

Then for the Blend, like Pilou mentions you probably want to boolean together those 2 pieces so that they are one object and then you can select edges that are sharp and use Construct > Fillet to round them off.

It looks like you may have cut the handle using the Trim command instead of using booleans? Trim is a surface modeling operation that just cuts surfaces up, while the boolean commands are focused on working on volumes.

So in a case like you had there where you've got 2 solids that you want to combine, use boolean union to do that rather than Trim - they both basically do the same general job of cutting things up, but using Trim is a more "low level" type operation where you will need to manually pick which fragments of the object to discard and then later on use Join to glue the pieces together.

Booleans are sort of like a high level batch mode version of trim that automatically decide which pieces to discard depending on which volume they are contained in and then also automatically join the pieces together, so when you have solids it wraps up a few different steps and tends to be quicker than using Trim. Trim is more to be used for when you are modeling individual surface pieces rather than solids.

You were also asking about Blend - blend is also a kind of lower-level surface modeling operation that will make a new surface that connects between 2 edges of other existing surfaces. It's meant to be used when there is an actual gap of empty space between the pieces you are blending, and then Blend fills in a surface in that empty area. When you have solids that have sharp edges that are touching each other at shared edges where there is no gap between them then you use Fillet for rounding off things like that instead of Blend.

See here for some examples of Blend - notice there how the pieces that are being blended there are apart from one another with empty space between them, and then Blend creates a new surface between them:
http://moi3d.com/2.0/docs/moi_command_reference7.htm#blend


Fillet is in a certain sense a kind of batch mode of doing Trim + blending + joining on solids, because filleting incorporates cutting away some of the material of the edges and then putting in a rounded piece between them.

So if you're working with solids, try to use more of the solid modeling part of the toolset like booleans and filleting rather than trim and blend, and that will help things go faster since it bundles up several steps for you.

Hope this helps, let me know if this does not make sense.

- Michael

Doh!! - Missed the Boolean, I am either too old - too tired or too stupid

Thanks Frenchy

Martin

My background is mainly in 2D and garden design ... 3D is at times a mental block for me, but your post is most helpful but again goes against my modelling teaching. I was taught that Boolean operations are done last, after details have been completed. I know this was a simple exercise but old dog and new tricks best describes :¬)

Many thanks Michael

Martin

Hi Martin, usually in MoI you want to use Booleans more as a primary way to actually construct the model..

Some things like rounding tends to work easiest when there is an edge in the place you want to do the rounding - by doing the Boolean to combine the objects together they get intersected and get an edge formed there, then you can select that edge for filleting...

That's normal to build some pieces as separate objects to start with, but you don't necessarily need to hesitate to boolean things together until later, particularly when you want to do some filleting which will depend on pieces being combined together.

- Michael

Is there a way of doing this that i am missing, or do i need to request an automated process/option on chamfer ?







The side view says that the chamfer is 30 degrees, but since there is no gaurantee that the drawing is actually to scale, one can't precisely say how far down from the corner or how far across the top to start the trimming curve. I am sure many of us here convert 2D drawings to 3D models so the question of how or can we have stands ?

Martin

Hi Martin, you could do something like make the trimming curve be a line that extends far enough, then revolve it into a cutting surface - use the cutting surface in boolean difference to slice the main part:









Hope that helps!

- Michael

Thanks Michael ... It helps, but I still cant see where you know where to place the starting trim line (curve), super sizing the line means you will have multiple intersections as you move up/down or from side to side ... I must be having a stupid moment as you figured it in seconds - Lol

Martin

Hi Martin, I just drew in a line at 30 degrees, mirrrored it, and then placed it in a location that looked close to what you wanted.

I thought that you were focused on the 30 degree angle part. I'm not so sure that drawing you posted has enough information to actually specify where the line should be positioned at.

So since I didn't see that information called out, I just placed it at spot to give the same general appearance as the 3D image there.

- Michael

Hi Martin, now that I go back and read your message again, it seems that was part of your question was how to figure out where to place the line. Sorry I did not quite pick up on that part, I was thinking you were just looking for a way to build it since Chamfer will not do that kind of result itself (it will on a cylinder but not here).

Well, as far as I can tell it's simply not specified in the drawing, so that would seem to me that it's precise placement is not considered all that important.

If placing at some spot that just looks good enough is not a good solution for you, I guess you would need to go back to the source that gave you that drawing and tell them that the drawing is underspecified and that you need more data in order to reproduce the shape properly.

- Michael

Thanks Michael, i have figured out your way, and yes it had to be done by eye, but at least it works. It's not a clients drawing, it's just one plucked off the net for what i thought would be simple a simple task for MoI, which it as long as you have all the data to translate, is there any way you could add something like a lathe option/tool. It would certainly come in handy here at times.

Martin

Hi Martin, could you describe a bit about how you would want the lathe tool to operate? How would it be different than doing a revolve like I showed above?

- Michael

It's a bit difficult to put into words, but I'll have a go .... two starting curves to converge as a cutting point, which can then be rotated around a given path or radius, to cut into the target solid object to a given depth and to give the resulting cut the equivalent to a boolean merge.

I hope that makes sense. I just might have to do an example ;)

Martin

Hi Martin, yup an example would definitely help!

But in your own description there you say: "give the resulting cut the equivalent to a boolean merge." ..... So if you want a result that's the equivalent of boolean merge, can't you use boolean merge to do that right now?

What I mean is - doesn't doing a revolve plus a boolean give you the same result that you're looking for with Lathe?

If that's not the case and you're asking for something that you cannot do currently with Revolve + boolean, then that would definitely help to get more explanation.

If you can get the same result using revolve + boolean, then that's the method to use for doing your "lathe" right there - I usually don't like to put in a totally new tool that replicates functionality that is already easily obtained by using a couple of existing tools in combination with each other. Having tons of specialty tools tends to lead to a complex and "bloated" UI which then causes problems for people just trying to find any particular tool to use during regular operation... The main way to have specialized tools like that would be to do it as a plug-in at some point so that it would not clog up the regular UI.

- Michael

Ok here is what i mean. It takes a whole heap of messing about to produce the shapes, and then the boolean results wont unite back again, and the solid don't behave as a solid, it behaves as a skin with no real density/mass. If it's this difficult using the tools provided step by step, then I am seriously flawed in my methodology, yes it can be achieved with profiling and revolve etc, but if all i want to do is to add some patterning to an object some way along the line, without thinking about it at the time of construction, then i would have to restart that part over to add the pattern.

Now i can see how much of a pain it could be programmatically and understand the complexity it could add, it's perhaps because of the way the "Solids" don't behave like solids that i find it frustrating and just too much darned work when all i am doing at the moment is learning and playing with MoI. So in reality i guess my wish is for solids to behave as solids, if that's possible ?

Martin

Hello,

The great thing about creating models in this way is that there are multiple ways to get it done. I find that sometimes it is easier to scribble out an idea and think of commands I'd like to use before I sit down and work in MoI to make an object. If you'd like to see one way I make screw threads Michael posted a link in the Resources page on this site. Here is an M6 nut. It also helpful to have those core cutting profiles so you can make an infinite number of types of nuts and bolts while being able to make it look believable.

Looks good OSTexo - I will get there .... slowly. Moving from 2d pen and paper to 3d is a hard journey for me.

Martin

Hi Martin, the result that you have at the end there is not a solid - it's a bunch of separate surface pieces. So that's why it's not behaving like a solid, because it is indeed not one...

It looks like your original sweep in this case is done with an open curve:




It can be ok in some situations to use a surface as a cutting object, but only if it fully divides the solid - your cutting surface in this case does not fully divide the solid at the very top and bottom spots I don't think. So it would be better to form a solid as the cutting object in this case instead.

You can make a solid for the cutting object by drawing in a line segment on the ends of that open "V" curve and then select the V and the line and use Join to make a closed triangle profile curve. Then the sweep result of that will be a solid.


Also you'll probably be better off making the cylinder be slightly shorter than the cutting object rather than having the cutting object stop right where you have it currently since that makes a sort of teeny little notch at the end.

See the attached 3DM file for an example - here I've shortened the cylinder so that the cutting object runs cleanly off the end, if you wanted the same sized cylinder as before you would probably instead want to make the helix path slightly longer instead.


At some point in the future I could see making a "helix cut" type plug-in that would automate this particular type of thread type stuff, but that probably won't happen anytime too soon though.

You can probably find a lot of various premade standard parts like this in IGES or STEP format so that you wouldn't need to model it at all though - I'd recommend checking out http://grabcad.com, and also see the links here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=1826.1
http://moi3d.com/forum/index.php?webtag=MOI&msg=3505.3

- Michael

Hi Martin, also the screw threads tutorial on the Resources page that OSTexo mentions above will take you to his video tutorial here: http://vimeo.com/30765016

And also some previous discussions here on the forum:

http://moi3d.com/forum/index.php?webtag=MOI&msg=4623.1
http://moi3d.com/forum/index.php?webtag=MOI&msg=767.2
http://moi3d.com/forum/index.php?webtag=MOI&msg=490.36

- Michael