this solid object can't be trimmed or boolean subtracted, nothing works. seems like a legal file to me.

any thoughts anyone?

thanks
wim

edited: oops, wrong file attached

Looks like the shopping cart of the future!

nothing seems to work today...
I tried another approach, starting with a u shaped line, offset it a few mm, extrude it, then try to trim it. trimming does not work....
rgds
wim

Hi Wim, re: cannot_trim2.3dm - try doing boolean difference and pick the objects in the Front view, if I remember right (I'm away from my main computer for a bit so I can't double check at the moment) picking in a view that has a grid aligned to the lines will help disambiguate which direction lines will be projected out to when cutting planes are generated from them.

Over here doing that with boolean difference seems to work ok, I've attached the result.

Other things that may be generally problematic with your objects is the rather small numeric size of some of the features, like you've got a fillet with a radius of 0.002 units in there. I know that it may not seem to be a small value since you are using meters as the units but really the unit system doesn't really make any difference, things are considered "small" by the geometry engine if they have a lot of decimal places just in the numeric values that are used. There are some areas of MoI that can be sensitive when processing geometry that is close to the default fitting tolerance of 0.001 units. So it can be generally better to avoid making things that are small in numeric size like that, maybe use cm or mm for your units for things of that size rather than meters.

- Michael

Hi Wim, and re: first cannot trim attachment, that also looks related to the same kind of "small numeric size around default fitting tolerance" type thing that I was describing above, that one has even smaller features in it, like the thin surface in there has a width of 0.0002 units.

Things will work better for you if you make these things have a larger scale, try to build things around sizes not much smaller than 0.01 units or so and these same cases will probably work better for you.

For example in your case there I switched units from meters to centimeters so the object didn't have such numerically small features and then trimming that same object with a few drawn lines seemed to go ok.

There are some areas of MoI that are less sensitive to small objects than others, I'm on a general path of trying to make more things work better with small objects by using an "adaptive tolerance" which is when fitting functions use a fraction of the object's size as the accuracy for the fitting operation rather than just a hard coded value of 0.001, but there are still areas that use 0.001 accuracy right now so just in general things will work more smoothly if you don't create things with such small numeric values in them. Try building them at 10x or 100x size or better yet use a unit system that will let you put in numbers in a range more like 100 to 0.1 rather than something like 0.0001

- Michael

Thanks Michael, same remarks as with the sweep problem. I'll use the smaller units. works fine now!

Wim