Sorry in advance for the title and certainly description, as I am not sure how I am going to describe this… The question has been going around in my head for days (and before that) and I just need to get words on paper, so please bear with me.
I need to make a little “thing” which will be 3D printed… This:
I need to fit a small ball will fit into the hexagonal section so that its held, but not tight… So like many projects I just increase the hole minutely and re-print until it does what I want.
But I have run into something before that I can’t explain but this time it has now stopped me in my tracks and is causing me a nightmare… let me try and explain.
So I start out with a hole/hex which is too small whihc as you can see from the first picture has a radius of 7mm… And I want to enlarge it by 0.1mm… So I use the move tool and find the “magic” point (blue dotted line) Which allows me to change the size… I grab it… move it outwards with the mouse… And then type 0.1 at the bottom… Like this.
But when I hit return (after entering 0.1) I would expect the radius to be 7.1mm, but its not… The hole got smaller and by much more than 0.1mm.
So I let me try again… This time 0.2mm… This time I found the magic point… Pulled it out so I knew I was going in the right direction… And then typed 0.2mm.
So now I would expect the hole to be 0.2mm bigger… But again its smaller.
So this only happens with minute size adjustments… So just to prove my technique is sound (and I have done this literally 1000s of times on other models)… This time 1mm
And now the hole has grown… By 1mm:
So there is clearly something I am doing wrong with small changes… When even I try to make the hole bigger, it gets smaller by a random amount… I have tried rescaling everything x100 and then making adjustmetns in mms, but I get the same issue…
I have also played with the “precision” settings… But its the same.
I realise there are other ways to achieve what I am doing… But I would like to understand that this little technique stuggles when making tiny adjustments.
Does this make sense? ANyone have any ideas?