I have been trying to simply lengthen one side of an existing small L-Bracket file that has predefined holes at each leg. When I lengthen one side, it changes the existing hole size into a stretched oval hole. Can you advise how I should be doing this to keep existing hole size?
Also, is there a way in the above example to change the hole size (say if I wanted to have a larger or smaller hole than the predefined one in the file)?
Thank you very very much everyone, my first post and have been learning a bunch from the experts here.
I can only guess what your attempting since you didn’t post an screen grab but it sounds like you’re trying to use the scale feature by scaling one axis. The correct tool is to use a Parametric CAD tool to modify the hole by mathematically changing only the hole diameter. Slicers are not that tool. When you scale you scale the hole model. The slicer doesn’t know the difference between the hole or the surrounding material.
There are many free CAD programs out there so money is not the issue. However, if you have a model that you wish to modify using the Slicer and all you want to do is change the dimension in one area, you could cut the model, then stretch a piece of it then reattach the center piece and then merge the pieces into one model again.
Here’s an example. Please note that this is a very time consuming process that would otherwise be done in seconds in CAD. There are probably other ways to do this but this is the way I used to do it, wasting hours, before I started using CAD.
Step 1 - Cut the object twice along a solid boundary that can be lengthened without changing the geometry of the entire bracket.
Huge thank you for the very detailed reply and instructions @Olias , very much appreciated… wow, that is a ton of work as you say using the slicer. Any time I spend on this should be getting more proficient at CAD based software.
PS: This was the file I was trying to change and of course the oval hole result:
MeshMixer is maybe a little easier to master if you have no CAD skills, and it can be used to modify geometry the way you want. Download a copy of “MeshMixer”, load your STL, select the polygons that includes the hole and the end of the bracket, and then move them however far you need them to be moved.
MeshMixer is owned by Autodesk, the AutoCAD company. There are lots of YT tutorials. You need to watch the one on selecting parts of an object and the one on the use of the transform tool. Maybe 5 minutes of viewing. 30 seconds to make the changes you want once you’ve figured out how to do it.
Also, those brackets will need supports to print the way you’ve oriented them. I would take the “gusset” (the triangle in the inside corner of the bracket) and use Meshmixer to move the up/down facing faces to be aligned with their respective bracket edges. The triangle will be as wide as the bracket. So it won’t need supports. Bonus, the bracket will be stronger.
You don’t need full CAD software to hack this together, you can use organic design tools like tinkercad/3d builder/meshmixer. (mild warning on tinkercad’s export - low res, bad for organic curves, but not noticable for simple stuff like this bracket example)
0.1) Measure the holes size, or determine the size you want to have in the end product
Add some cubes, scale them so that they fill in the holes, group/combine these objects together.
Scale this solidified object to your desired size.
Recreate screw holes as cylinders / cylinders-with-a-cone-on-top, sized as you want. Make these a negative object.
Place them as you want, group/combine the object to cut the holes.
To show you how it can be done, here is the file. Admittedly, this has some rough edges but this is what I can do in 10 minutes. In CAD it would be seconds.
Since your dimensions were conveniently 40mm and you wanted to grow it to 80 mm. These are the steps to do it. Just cut out a middle section and lengthen it to desired dimension then glue the pieces back together. The bug drawback in this approach which CAD would remedy is that your angle brace didn’t scale in this example. I supposed one could just stretch it and it would scale accordingly like this: Right+Angle+Bracket added height modified long angle.3mf (483.0 KB)
