Solid tools - spiral extrusion not solid

su2021 I have made a square spiral rotated to one complete turn and warped upwards z axis by one thickness - like a spiral spring washer. I want to intersect this with a cylinder but cant get solid tools to accept the spiral as a solid
I have used clean up and made sure the geometry is regular, all faces filled etc but nothing works
i cant see how to insert my skp model here

Have you used Solid Inspector 2 to show you what is preventing it from being solid?

Upload the .skp file so we can see it and help you without having to guess.

i must be dumb didnt see thishelic 30-8 ssu2021-a.skp (32.3 KB)

Even without running Solid Inspector 2 I can see at least one problem. It’s fill of internal faces. You can see them bleeding through the outer surfaces.

And the report from Solid Inspector 2

After fixing it.

A basic rule about solids is that every edge must be shared by exactly two faces. No more and no less. The internal faces violate that rule.

OMG yes I understand that internal faces violate the solids rule, I just didnt see how I could possibly remove them when SU automatically makes them, just one of the many mysteries of SU geometry engine. ive been with su since SU4 at last days, it was a remarkable revelation and pulled me into the 3D world, Thnx 10^6 - I had come to a dead end

Manually you could hide one end face so you can see inside and then delete the internal faces. When you have finished, unhide the end face.

There are ways to do this that don’t create the internal faces. I drew a split washer (which is what I expected to see from the description in your first post) using a helix created by the Curve Maker extension and Eneroth Upright Extruder. Like a real split washer there’s a small gap between the ends and it makes a solid component.

I use the same method for created screw threads. Somewhere there’s a thread with a video I did showing how I model screw threads. I could dig it up if that’s of interest.

FWIW, I think it is definitely worthwhile learning how to do this stuff manually. Once you understand the process, extensions can help speed up the process.

yes indeed thats what I have been trying to do. It all went ok till I wanted to cut flutes in my thread and worse still rotate to make a spiral flute tap
Somehow I expected to find a ready made model of some screwed rod, but it was all clickbait stuff
I want to make a spiral flute tap with whitworth thread form ie 55deg and rounded peaks
Ive been away from SU for a few years and so clearly behind the curve on plugs ins
I would like to see the vid you made - pass me a link pls

Here you go.

Instead of the standard machine threads you could draw the Whitworth profile instead.

I noticed your model has units set to Architectural. I would suggest Decimal–Meters. Treat inches as meters while modeling. So 1 inch is modeled as 1 meter. That helps to avoid issues with tiny faces.

I don’t recall modeling Whitworth threads but here are a few examples of others.

Common machine threads:




Lovely renderings, its never been my bag as I make eng drgs to make things but for info what app did you use?

I finally managed to get my versions of SU loaded up with solid inspector, I have SU8 mr1, 2014, 2017make and am trialling 2021

solid tools is very tempramental. It took me a while to get it to intersect a cylinder. the split tool seems easiest

as you say maybe easiest but laborious to build up a cut out from scratch using the std intersect tool which always seems to work.

I found my copy of 2017 very unreliable and it crashes often for spurious reasons eg using scaling. I have work saved every minute
I even had some crashes with 2021 not reproducible.
thats why I keep my old SU8 which is solid.

unforuntaely my version is 4811 and i havent got a built in “install” extension button and it wants to install RBZ from archive error

I remember it used to be possible to instal extensions manually but I cant find any info ither than telling me to use a non existant install button. I believe this came in with MR2 release. But upgrading has been disabled by big T
Any ideas?
BTW thnx 10^6 I have a work around
will study your screw method tomorrow, I am knakcered.

helic 30-8 ssu2021-b.skp (56.2 KB)

I used Kerkythea to do the rendering for the image of the tap wrench.

The Solid Tools of course requires that the objects be solids to start. It’s possible to create situations where tiny geometry is created in the process and a non-solid is the result. Working at a larger size as I mentioned previously helps to avoid that problem.

I find the Eneroth Solid Tools and BoolTools2 to be better options than the native Solid Tools because they respect components.

Yes, the Install button was added to SU8 with M2. You can still manually install extensions in the older version. Change the file extension from .rbz to .zip. Then open the .zip file being careful not to distrub the file structure inside. Extract the contents to the Plugins folder.

Not quite sure what you are actually trying to model in your latest one.

that model was a half spring washer which i intersected (split( with a cylinder) It was quite difficult to get them both recognised as solids and eventually it worked and they split.
will try the other two exts tomorrow

got EDT and Boob2 loaded up, noted the Dave method of scaling up 1000x so as to avoid small lines and faces. i never knew that su struggled with 2D intersections, i thought inferencing was supposed to be its strong point and that you needed to be very accurate about selecting an intersection point
its odd that you cant draw a perp to clamp onto an axis (xyz) accurately, i find i have to draw a line in axis hghlight along that axis first to be sure i am actually perp on the axis is 2021 any better at this?
boob2 need a fee of $29 but I dont mind if it works ok the author seems to know the details of the problem

correction 3D intersections

The problem comes in when vertices are created extremely close together; closer than SketchUp’s tolerances will allow. It does pretty good for a primarily architectural application, though.

I’m not quite sure what you are trying to do but I expect you can do what you want. There is more inferencing options in 2021.

BoolTools2 is very good. So is Eneroth Solid Stools. I tend to use them both depending on what I’m doing.

If you were modeling for 3D printing, you might conisder just modeling in meters as I described before and not scaling down. there’s no need to scale down if you are exporting .stl files, anyway.

yes indeed this is all new stuff to me
Sometimes, Boolean operations result in VERY tiny edges which SketchUp does not like. In fact, SketchUp will try to clean these edges up whenever you save your model. The problem is that when SketchUp ‘cleans’ or deletes these edges, tiny holes get created in your model and it is no longer a solid.

BoolTools 2 can detect when SketchUp wants to ‘fix’ your model and then stop it from messing up your printable solid models. By applying a special scaling technique, BoolTools 2 can prevent SketchUp from creating these holes in your model.
from Boob2 FAQ - that explains a mystery
Well SU was primarily an architects toy, but Ruby fellas got hold of it and did wonderful things way beyond its remit.

I dont do 3D printing but I can appreciate the problem dodgy solids might cause some expensive time consuming crashes.

Are there not 3D modellers more suited to this printing app?

There are other 3D modelers but I don’t know that they are any better or worse for 3D printing. I expect it’s mostly up to the user.

another modeller i chat with uses

Alibre Atom 3D £260 (subs ? rather opaque about what you get

it seems gear toward 3D printing. the art work he shows is impressive, but then its all glossy stuff to me

I know quite a few SketchUp users who do 3D printing from models created in it. I do sometimes have things printed that I’ve modeled. It works just fine and I don’t ever wish for anything else.

Yes the Boobtools is a much better solid boolean, no question I managed a model after more sweat

its not a complete spiral flute tap but enough for my purposes. tried Kerkythea and it reminded me of many years ago why i didnt pursue graphics rendering - the process can take forever

thnx for all the tips, Id never have got here otherwise, learnt many new things

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I finally got where I wanted to be in my model but only thanks to Booltool which i shall definitely buy, native solid tools would be useless here.
My model has become large ca 7500 edges, 3500 faces. A lot of calcs involved.

Is there any link to how SU works
I mean we start from the basic 2D vertices and vector drg, then SU perfected making a face from shapes that were determined as coplanar in 3D, then making inferences that were perp to this surface and hence the patent extrusion process.
But then it starts to get iffy when drawing lines to meet other lines particularly if not perp and so on. microscopic errors can creep in and ultimately be your undoing. (you still cant draw a line from an axis - no inference - you have to draw a line on the axis first - why?)
It all boils down to the rounding off of 13 digits native to the windows calc engine.
And it appears that SU does some nifty secret fudges to fill up gaps, combine close vertices but this often results in faces that wont fill - as we all know

Also we get to a stage where part of the model starts disappearing from screen? never got to the bottom of this, mostly solved by view extents

Before long you are in suck it and see territory not knowing what you are doing.

So I would like to have a better understanding of what su limitations are and know when I am getting too close, eg when are lines, angles, faces too small. What processes are unhealthy for SU etc.
I daresay architect draffies never run into these geometric queries, although i do wonder if contour creation has its problems - i found that area frustrating - probably using wrong tools and too many exts want you to hype you to pay

so bottom line - how do i become a savvy user of su geometry