Simple way to nest two rectangular objects such that the air space between them is consistent?
I work a lot with rectangular sheet metal housings that have to nest together. In most cases, there is an airgap or gasket between the two parts. It's very easy to use a concentric constraint to place a cylinder inside another cylinder, but I haven't yet found a convenient way to center a rectangular object within a rectangular cavity. Was hoping someone can tell me the fastest most efficient way to do this.
The attached drawing contains a box and a block. I'd like to drop the block into the box, such that 5 sides of the block are equidistant from 5 walls. Anyone have any idea?
Comments
-
Hi Jim, you forgot the attachment ...
0 -
@Louis Verdonck said:
Hi Jim, you forgot the attachment ...It appears to be posted on my screen... I will try again...
0 -
The forum is telling me I can't upload a second time. Very peculiar.
0 -
Use "MTP" start the move or copy command and select the solid, then when it asks you for a base point type "MTP" (mid two points - you can also use "M2P") and then select two diagonally opposite corners on the top face of the solid, this makes your base point the centre of that face, and then when you are prompted for the second point use "MTP" again and select 2 diagonals on the top opening of the box. Which in this case works out perfectly well, the gap at the bottom is the same as around the edges, but that is possibly more luck than judgement. Otherwise you would probably have to make two placements first use the bottom of the solid and inside bottom of the box and then move the solid up by the distance of the "air gap"
0 -
Mmm, strange, the attachment is now in your original post ...
See attachment for the solution: see the Mechanical Browser panel to see how the constraints and parameters are defined.0 -
I see my post is also published without attachement. It seems uploading attachments takes some time.
0 -
@Steven_g said:
Use "MTP" ...Steven,
That is a good suggestion, for the simplified model I uploaded, but my sheet metal housings make it difficult. They are very large, compared to the thickness of the metal, and they have reliefs in the corners. Nothing to snap to. I will upload another model to show you what I am dealing with. This won't be one of my real housings because I am prohibited by management from uploading them.0 -
Having lots of problems uploading files. This time I got two uploads. How did that happen?
0 -
Not much information on using 3D constraints, Louis. I was able to do what I wanted with "middle of two points", and the geometric center snap. Thanks Steven!
0 -
@Jim Canale you can use the mid point of the long sides opposed to each other, even on the corner curves there is a point at which they meet that would work as diagonals. I can well understand that sometimes it would be different, but "MTP" can help in a lot of cases, another option would be to look at point filters and tracking points
0 -
@Steven_g said:
@Jim Canale you can use the mid point of the long sides opposed to each other, even on the corner curves there is a point at which they meet that would work as diagonals. I can well understand that sometimes it would be different, but "MTP" can help in a lot of cases, another option would be to look at point filters and tracking pointsThanks Steven. Very useful suggestion you made. I tend to forget about MTP. In this case, most of my housing drawings include small bend radii. When this is done on a very large housing, it makes it a bit harder to grab the correct snap. That is why I used the geometric center.
"Point filters and tracking points"? Not familiar with those.
0 -
Point filters are a way to enter just one value at a time. For example, you type ".x" to enter the x value of the coordinates. This permits you to do things like move something horizontally by choosing .y and then just clicking anywhere with the orthographic lock set. Then, perhaps use an object snap to choose an existing object that shows where to move it along the x axis.
Another potential option, that would not work for objects, but only for polygon rectangles, is the center snap. Yes, in BricsCAD, a rectangle has a "center". It is the geometric center of the rectangle.
-Joe
0 -
FYI, there is also a Center snap for 3d entities:
the 'Center of face' snap is one of the snaps controlled by the 3dOsmode setting (see Settings dialog ).
If you activate this flag, it literally becomes 'a snap' to move the box so the center of its top face is aligned with the center of the box bottom face.0 -
@Jim Canale said:
I work a lot with rectangular sheet metal housings that have to nest together. In most cases, there is an airgap or gasket between the two parts. It's very easy to use a concentric constraint to place a cylinder inside another cylinder, but I haven't yet found a convenient way to center a rectangular object within a rectangular cavity. Was hoping someone can tell me the fastest most efficient way to do this.The attached drawing contains a box and a block. I'd like to drop the block into the box, such that 5 sides of the block are equidistant from 5 walls. Anyone have any idea?
Converting the two sheetmetal objects to components allows you to use the component (Block) UCS to constrain with. It requires 3 constraints one for each plane. Attach your example done this way. Move the box and the insert will move with it.
Earlier versions of BricsCAD didn't have WCS/UCS constraint options. You can still do it, but would need to create some dummy (helper) surfaces in the component for each plane, then constrain to those in the assembly,
Regards,
Jason Bourhill
CAD ConceptsCome to the Australasia BricsCAD Conference
0 -
@Joe Dunfee said:
Point filters are a way to enter just one value at a time. For example, you type ".x" to enter the x value of the coordinates. This permits you to do things like move something horizontally by choosing .y and then just clicking anywhere with the orthographic lock set. Then, perhaps use an object snap to choose an existing object that shows where to move it along the x axis.Another potential option, that would not work for objects, but only for polygon rectangles, is the center snap. Yes, in BricsCAD, a rectangle has a "center". It is the geometric center of the rectangle.
-Joe
Thanks Joe.
0 -
@Hans De Backer said:
FYI, there is also a Center snap for 3d entities:
the 'Center of face' snap is one of the snaps controlled by the 3dOsmode setting (see Settings dialog ).
If you activate this flag, it literally becomes 'a snap' to move the box so the center of its top face is aligned with the center of the box bottom face.I will check it out Hans. Thanks
0 -
@Jason Bourhill said:
Converting the two sheetmetal objects to components allows you to use the component (Block) UCS to constrain with. It requires 3 constraints one for each plane. Attach your example done this way. Move the box and the insert will move with it.
Earlier versions of BricsCAD didn't have WCS/UCS constraint options. You can still do it, but would need to create some dummy (helper) surfaces in the component for each plane, then constrain to those in the assembly,
Regards,
Jason BourhillJason,
Thanks for your reply. Opened your assembly and moved the box. The insert did NOT move with the box. I opened the mechanical browser and noticed two coincident constraints marked in RED, whose objects are block / component references. You said I needed THREE constraints, one for each plane. I'm using V17. Perhaps that is the reason why the constraints broke. Also, I don't understand what you said about the component "UCS". How are component references / insertion points specified? Is there a 3D constraint that will work with the UCS origin of a component?
0 -
@Jim Canale said:
Thanks for your reply. Opened your assembly and moved the box. The insert did NOT move with the box. I opened the mechanical browser and noticed two coincident constraints marked in RED, whose objects are block / component references. You said I needed THREE constraints, one for each plane. I'm using V17. Perhaps that is the reason why the constraints broke. Also, I don't understand what you said about the component "UCS". How are component references / insertion points specified? Is there a 3D constraint that will work with the UCS origin of a component?Insert did NOT move with box
I did state that with earlier versions of BricsCAD you needed to use a different method. A limitation on this forum is that users can't state the version of BricsCAD they are using. There are different versions and levels of BricsCAD. User experience will differ depending on what they are using. If you don't state how would I know?Is it possible in V17? Yes, but you must use some helper (Jigs, bucks, what ever you prefer to call them) solids. You use these helper solids to apply your constraints to. With this you can mimic constraining by a plane or axis. Attach examples of both.
You also don't need create components to do this. In the attached Axis example I've used rigid constraints to group and lock the objects to each other, then applied the mating constraints.
You said I needed THREE constraints
My mistake on the V19 example, I omitted one of the constraints, I guess I'm human after all.
Fixed in the attached. I believe you will need V18 as a minimum to work with this one. As you've noted, V17 ignores the applied constraints.UCS terminology won't make sense with V17 or earlier, as it wasn't a feature with constraints then.
Regards,
Jason Bourhill
CAD ConceptsCome to the Australasia BricsCAD Conference
0 -
Thank you Jason. I hope you don't think I was criticizing the work you posted. I simply said it didn't work for me. I know you said earlier versions would not work, and I suspected the issue was with V17.
We are licensed for V19, but I haven't let the network administrator install it yet. V18 failed miserably on my slow machine. Very slow to load, ate resources and crashed all the time. We went through this a couple years ago, when we switched from V14 to V15. Tried to get management to buy me a machine that was upgrade-able, but was not successful.
0
