How can I resize only the outer wall thickness?

I have run into a problem with a model and need to make a minor adjustment to the outer wall by making the diameter a few tenths of a mm narrow… See the red arrow here here:

I was thinking that I could select everything and then use scale, but its impossible to select what I want, and deselect what I want, without grabbing stuff on the other side…

What would be the best way to achieve this? Are there tools to just allow me to select the bits I need? Or a better way to make this kind of adjustment.

For now, I have just selected everything and scaled it down by 0.99 and its done what I want… But as its also affecting the INTERNAL faces, its made it a bit tighter than I want… Ideally I want to keep the internal as is… And only reduce the external faces… The rounded tip doens’t matter as long as it stays smooth and the entire length stays the same, so that can be altered too.

I have attached the model in question, and hope someone can give me a bit of advice.

JonHolder.skp (381.4 KB)

You might be able to use Joint Push/Pull for that however it’ll either make a mess at the end or change the length. This is such a simple shape, I’d just redraw that part with the right diamter.

I see a lot of diagonal softene edges which makes me wonder if the thing is right. Should it be cylindrical?

What diameter do you really want that part to have? I reworked it guessing at the diameter. I made the pin 15mm in diameter. Mine is the one in front.

I’m surprised to see you are still working with Length Snapping enabled. I believe there was a discussion about this in one of your threads in the past.

How are you able to do this so easily?? I am in awe… It makes me realise how much a novice I am

The original was an imported STL which I have modified for my application, which is why its has all the extra geometry… Yours is clearly much better and cleaner.

Oh yes… Length Snapping must be on, as I imported this into a new job and never switched it off… Need to remember that!

The original diameter was something like 15.46mm… I guess I want it 15.3mm…

I guess practice. And not relying on imported files.

There are a number of issues with that imported geometry. I used the overall shape as a reference but drew it from scratch using the native drawing tools. I alsso scaled it up and modeled it using meters as the units instead of millimeters. I know we’ve talked about that before.

As for the pin part of this thing I drew a profile and a circle and used Follow Me to create the shape.

So the pin needs to be slightly larger than I guessed.

It was pretty straightforward to erase the pin end and make a new profile with the right outside radius, run Follow Me again, and join it up with the main body of the part.

Before I wrote I had reduced it using SCALE (both internal and external geometry)… But the reduction of 0.15mm wasn’t enough. Its still too tight… So your guess was good as 15mm would probably be better.

I guess I will have a go at re-drawing it… Annoyingly I have 2xPrusa printers and the original design was perfect on my “Mini”… This has only come about as its comes out just a bit “fat” on my MK3…

So the other option is to just use the Mini for it and leave it as is?

Thanks for your help… I just wanted to check if there was an easy way to do what I wanted without re-drawing it.



Some times the easy way is to redraw. This is especially true when the geometry you want to modify is attached to complex geometry that you don’t want to modify. If the model is good and clean to start with, though, you shouldn’t need to redraw it all.

Thanks… My problem in this case is going to be the “follow me”… its a tool that I don’t use much and never get good results… I will need to work out how to use it in this case to maintain the inner shape and tip, but make the outer wall thinner…

If you hadn’t mentioned that… I would probably just draw 2 circles and “pull” it out… And then using a rounding tool on the end… But I need to get the hole in the tip just right…

Probably worth taking a little time to learn to use correctly. It is incredibly useful and you can get good results from it.

I just moved the outer edges of the profile without moving the inner edges.

That’s a good option, too.