Duct.shapr (9.1 MB) Hi,
I’m attempting to glue these two stl bodies into one, it says either boolean failed or invalid results. Would you take a look at the two files and tell me what a workaround would be?
Oh, a function suggestion for the future - when boolean goes wrong or invalid results come up, when possible, for the Shapr3d to highlight where the problematic area is. (for the cases where it is visible)
Thank you again.
Just tried merging(union) the bodies on a Laptop software, and the software I tried it with required the mesh bodies to be converted to other format first and then merged - problem is that the bigger part had too many triangles in it and the pricess was aborted. Maybe I should try it again with lower resolution stl - but it’d have to be quite crude quality I’m afraid, unless I make the design into a more square-ish one.
There are mesh sculpting apps and softwares - which one would allow merging multiple mesh bodies, rather than sculpting a single object at a time?
P.S. I’m rather new to CAD programs - any insight/pointers appreciated. I’m guessing mesh is in general/in comparison a resource guzzler when compared to parametric…
I tried moving the Top Body down toward the Bottom Body in increments of 0.1mm at a time.
At 0.5mm the Boolean Operation was successful.
The Top Body mating face could be further extruded to compensate for this discrepancy?
Ooops! Just realised that this is not possible with this Object.
However the Top is fairly easy to replicate by Sketching, either directly on the Bottom mating face or using available dimensions on a separate Construction Plane then moving it into position afterwards.
On completion of the hollow rectangle it can be extruded/pulled up as described below.
The following is not completely straightforward dependent on skill level, hopefully someone will be able to chime in with a simple solution?
As you want the two Bodies to become one perhaps it is worth considering this:
If the Top does need to be separate, note that it cannot be separated after Union other than by an immediate Undo, Sketch on a Construction Plane based on 2 above Offsetting appropriately.
Starting working life as an Apprentice to the Refrigeration and Air-conditioning Trade I became intrigued by the tiny size of this duct. Because my Designs are created entirely using S3D it seemed reasonable to verify my suggestion(s).
Working with the Bottom portion of the duct revealed slight discrepancies in the profile of the mating face, so my attention was shifted to the Top portion of the Duct.
In the attached shapr. File Sketch 01 was created on the Top mating face and after completion the Top was moved 20mm in the [upward] Z direction and hidden so as not to impede the following actions.
To avoid the result becoming two separate Bodies both areas either side of Sketch 01 ‘dividing’ line were pulled downward by the same distance, then each area was pulled upward by the differing distances, deliberately exaggerated so that the heights could be adjusted to match the original.
The Top was unhidden and the resultant single Body [New Top] was Moved upward so that it nested inside the original Top.
The differing heights were adjusted to match the original and the Sloping faces were also manipulated [highlight the appropriate Edge of the Body and Move it into position] to match the Sloping Faces. Of course it would be better moving the Edges by precise measurements.
Highlight either the Top or New Top and Move them apart.
Lastly it seemed reasonable to see if the desired end result was possible? I.e., creating Union between the two Bodies.
The optimum MO would have been to keep the Bottom, Top and New stacked neatly by only Moving along the Z axis. Move Object(s) by distances that you record or can remember, it makes for simplicity when returning them to original positions.
I chose in this instance to displace the Top sideways before creating Sketch 01 and the New Top, it will simplify the task by not making unnecessary displacement sideways. Simply Hide anything that obstructs your work area.
However moving the New Top into its position on the Bottom, then performing the Union routine, worked first time.
I have used this opportunity to increase my knowledge regarding the capabilities of S3D. Doing is a great way of learning?
Duct T.shapr (4.7 MB)
Hi, Gelphyn.
Thanks for the thorough testing on this subject.
Drawing a general rule/workflow from a repeated success or error is a logical thing to do, but can be time consuming and frustrating,
Thanks for the pointers on the fix! I’ve been working around by adding extra pieces in between the two un-joinable bodies as ‘bridge’, this works sometimes, sometimes it won’t, case by case.
Slight discrepancies seems to be a problem quite often, but not always. Sometimes the bodies would join just fine with these minor gaps that come from sketching a mesh body onto parametric surface, but sometimes it’d be a problem. It’d be nice if S3D can point out which region of the body is giving it a trouble when there’s error.
I’m designing a new duct and running into a similar issue, one more iteration inbetween the one in topic and the newest worked just fine, this new one I’ll try approaching with your workflow in mind.
P.S. without joining the two bodies, I overlapped them and exported them as STL and it seems to export them as one mesh body. This could be a trick!
I think your approach
duct finished.shapr (2.0 MB)
Again, thank you for the duct top, very nice drawing, I only had to add the mounting tap, and a mating surface on the upper rim of the duct.
Lovely to see the finished Design, if you are happy with it that’s great news.
You could avoid discrepancies by using S3D for the complete project, Lofting objects like the Bottom Duct and then adding objects direct onto an appropriate face.
Of course if you are using existing Designs it may not be viable to start from scratch every time.
Thanks for presenting the challenge of the day, I thoroughly enjoyed it.
Thorough enjoyment for some involves going through a lot of pain. 
I guess labour or love is a great expression for that, as we’re not focusing on the pain, but the flow, creativity, mastery, whatever the name is.
Since you mentioned that you’re working on refrigeration devices - and the duct’s small dimension - I’m modifying a 3D printer to run in my hot, so-cal desert summer garage. I don’t have a feasible space for the printer otherwise at the moment, and taking the crowded hot end assembly apart and placing them with more ventilation in mind for the parts that need extra cooling, is what I’m designing this little duct for.
Hope you’re applying your knowledge on AC onto yourself for your own summer well-being!
Thanks again!
I am truly thrilled to learn that the Duct is component that will actually be doing something. During my Model Making days I gained a lot of satisfaction from the long hours of work but that was/is equaled by making a useful special purpose bracket for a bike [bicycle] in less than a couple of hours.
I have spent a few years working in the Sahara and West African Tropics, and humidity dictated how most coped during the most oppressive seasons. This is being typed now, early hours of the morning, to avoid the heat and humidity. Fortunately I fair better now than I did as a youngster. I can only guess that your climate is drier but obviously still problematic on occasions?
S3D is a means for me to keep mentally active, I scan the Forum and when something appropriate crops up have the urge to learn. Not everything triggers a full response but anything of substance is investigated to the best of my abilities.
At present I have no plans to venture into 3D Printing, there is a ‘queue’ for the cash and a lack of space, However printing Screw Threads is of interest and ‘feelers’ are out seeking information and experiences from anyone who has anything on the subject to share.
I have just started a ‘Thread’ about Screw Threads in case you are interested: