#openscad

[louis-sj]

3D printer fist mitts #4

Hollow Ball Rod End by nipnbite

See: https://www.thingiverse.com/thing:3120529

Use 3 M4 X 10mm Button Head Allen bolts and 3 M4 Nuts to hold each mitten together.

OpenSCAD file included.

Hollow Ball Rod End by nipnbite is licensed under the Creative Commons - Attribution license.

[brightgreendandelions]

i finished making the box! it moves even!!

[kickahaota]

This is my new best friend. You may not touch him.

I designed a little stand for him last night.

[kinky-and-cuddly]

Is it chaser-like to add a trans-flag to my room. It'd seems nice given that more than half of my regular partners are trans (cause they are usually friends of other partners). But maybe frightening.

[kitwallace]

Delta Scroll saw

I bought a scroll saw from the Hackspace where it was surplus equipment. There were two in an auction, both quite old and litlle used. I won one of them for £15 and chose the Delta model since it was the heavier and had a dust blower.

The model is 40-430, single speed. There is a manual for it on-line https://www.manualslib.com/manual/590720/Delta-40-530.html

The machine takes pinless blades of which I already had a few. Pinless blades are finer and come in greater variety than pined blades, which are faster to change. There is a custom tool for blade changing, with a long 4mm Allen key attached to a bar which slots into a hole on the blade holder, setting the key in the right position and locking the hinged holder. It was missing and its fiddly to change blades without, so I need to make a substitute.

Surprisingly the blower works - online advice says the bellows is usually perished.The connecting tube is stiff and should realy be replaced.

At first the machine was very rattley until I realized the the three bolts put though the holes in base were only needed if the machine was going to be permanently fixed to a bench. Much better without and its heavy enough to be stable although it would be better with rubber feet.

Once I'd attached a blade and got the tensioning right, I turned it on and it cut fine and true.

The saw was very dusty and hadn't been used in a while. I took it apart, happy to find all fittings were metric.

A few jobs to do:

free up the table so it tilts

lubricate the pivot bolts

remove the rusty table, sand and polish with wax

(x)replace gnarled cover screws

(x)replace worn blade holder socket head bolts

make the blade change tool with long hex 4mm tool (x) and 5mm threaded (x) bar with 3D-printed spacers

add rubber feet 12mm hole eg https://www.ebay.co.uk/itm/133246278952

x Bits ordered 28/01 £12.50

Blade change tool

I designed a spacer in OpenSCAD to align the long Allen key and a threaded guide bar with M5 nuts to hold it in place. Took a few iterations to get the sizing right but it works fine with three spacers, using lock nuts to fix the spacers in place. The OpenSCAD and STL files are on Thingiverse https://www.thingiverse.com/thing:6460819

Anti-vibration feet

Commercial mounts are surprisingly expensive so I made my own. I had a lot of large tap washers in stock so I made up a stack of one dished and two flat washers below the base, two more flat washers and a metal washer above the base, held together with an M8 coach bolt and nut. This works very well and the saw runs pretty quitely now.

The table

I sanded and oiled the table and it's much improved. Car polish is recommended so I'll do that.

Tilt lock handle

Now that the table has been freed up, the locking mechanism comes into play. It is an M6 bolt with a handle moulded onto it, but the moulding has failed so it can't be fully tightened. Fortunately, it also takes a 3mm Allen key and doesnt need to be adjusted quickly.

Looking better

[tsubakicraft]

習うより慣れろ〜余談

同じ結果を得るために複数の方法でやる。理解を深めるのに有効な考え方だと思います。 FreeCADの他にも3Dモデリングができるオープンソースやフリーソフトはいくつかあります。今日は試しにOpenSCADとTinkerCADを触ってみました。人気のFusion…

[practicalsolutions]

Technically the 24 hour modeling challenge doesn't really pan out to 24 hours, because I've been rotating models in my brain for this for the past few months. But...

Time to print.

[debian-official]

aaaaaaaaaaaaaaa my desktop has. debris

[ginmeister]

Because when I think of love, I think of my printer 😬❤️.

[andmaybegayer]

Do you have thoughts/opinions on implicit modeling for CAD? I know Fusion 360 has an implementation of it, but their add-on packages aren't cheap so I haven't gotten to play with it.

I haven't touched much in the way of implicit modelling, the closest I've probably got is some higher tier programmatic primitives based modelling with things like openSCAD or the much weirder ImplicitCAD that one of my acquaintances was working on.

It definitely seems useful! Being able to define and merge shapes with all sorts of interesting boundary-based effects is a great idea, it's like putting shaders into your modelling system to create fillets. If you want to define a complex space-filling load-aware mesh for 3D-printing the inside of a wing or something you definitely want a tool like this instead of doing it by hand.

[brightgreendandelions]

i want to 3d print a box, with this kind of sliding lid, and i'm not sure how to pick my tolerance. the lid is 3mm thick, and will be printed separately.

in hindsight, `lid_margin_bottom` should probably be 0.

[nostalgebraist]

could i fine-tune an llm to generate svgs? or openscad files?

Totally.

As a proof of concept, GPT-3.5 and GPT-4 are already pretty good at generating SVGs zero-shot. There are some examples here.

[hackernewsrobot]

OpenSCAD: The Programmer's Solid 3D CAD Modeller

https://openscad.org/

[trainsinanime]

I love OpenSCAD, but I also wish there was some type of, I dunno, OpenScad 2 or similar. Just like OpenSCAD, but good.

The concept is awesome, sure. Or perhaps more accurately, it fits the way I work and think really well. But it’s so damn limited everywhere. There is no official standard library, just lots you can and have to download, but then there’s no package manager or namespacing to make that easy. I had to implement my own bezier curves. (I probably didn’t have to, I could have downloaded some module that did that, but they’re still not part of the core thing). There is no truly useful way to add bevels and fillets anywhere. In fact, there is no real underlying concept of curves, so you have to write $fn everywhere. Any complex geometry has to be built out of extrusions and transformed cubes and cylinders and spheres. Gears and screws? You’re fully reliant on third party libraries even though these are some very obvious use cases.

It’s cool that I can use modular code to define my functional 3D models for 3D printing, but in practice, everything about it is a goddamn ordeal. Maybe I should go back to try and learn blender, or perhaps FreeCAD.

[kitwallace]

The 'Spectre' monotile

The recently discovered Hat and Turtle monotiles needed to use a reflected version of the tile in aperiodic tiling and this seemed a bit untidy. Although I had used OpenScad to generate the continuum of tiles from Comet to Chevron via Hat, I hadn't appreciated that 'Turtle' lay in the continuum and created a separate continuum for that tile with a different perimeter. Doh!

In my parametrisation, the continuum is generated by varying the kite semi-angle A from 0 to 90, with the two side lengths respectively a=cos(A) and b=sin(A) .

This OpenSCAD function generates the tile perimeter for a given angle A:

function monotile(r,A) = // r is the radius of the base hexagon // returns perimeter as a sequence of [side,internal angle] let (a = r * cos(A) ,b = r * sin(A) ) [[a,180],[a,120],[a,270],[b,120],[b,90],[a,120],[a,270],[b,120], [b,90],[a,240],[a,90],[b,240],[b,90],[a,120]];

where these are the special case (together with the Smith et al parameterisation)

A=0 : Chevron Tile(0,1)

A=30 : Hat Tile(1, sqrt(3))

A=45 : Equilateral Tile (1,1)

A=60 : Turtle Tile(sqrt(3),1)

A=90: Comet Tile(1,0)

It turns out (that phrase covers a huge amount of work described in the most recent paper) that the Equilateral tile (A=45) is quasi-aperiodic in that it is aperiodic only if reflections are forbidden.

To modify the tile to prevent reflections, one approach is to replace the straight sides with arcs which alternate left and right. Since the tile is equilateral (noting that the long side is composed of two co-lateral short sides) , a common arc angle yields arcs of common curvature

It's easy to see how the resultant tile got its nickname 'Spectre'

although we might be calling it 'Elephant' if the arcs had been oriented in the opposite direction:

This version of the tile was generated from the perimeter by a JavaScript tool developed for ceramic design which uses a form of Turtle language. It's the 'Spectre' function in the list of functions. The Arc angle here is 90 degrees.

OpenSCAD

The online tool generates the perimeter as a sequence of points, intended for copying into the Fottery tool to create the Gcode to print ceramic objects. The sequence is in the same format as that used to define a polygon in OpenSCAD so a minimal script looks like:

thickness=4; perimeter = {paste the sequence here }; linear_extrude(height=thickness)   offset(delta=-1)     polygon(perimeter);

[I should really implement this version of the Turtle language in OpenSCAD so resolution is determined in the OpenSCAD script]

The negative offset here allows for slightly excess filament width in a 3D printed part. (you still have to clean off any 'elephants foot'). Offset would be positive for laser-cutting to allow for the kerf.

Diversion

The JavaScript tool also generates arced versions of the other tiles in the continuum from Comet to Chevron. These two periodic tiles are also equilateral so all sides have the same curvature. These are rather pleasing shapes to use for tesselation:

The number of sides is 8 for the Comet, 6 for the Chevron, corresponding to the 8 a sides and 6 b sides in the common perimeter.

Further reading

'A chiral aperiodic monotile' David Smith, Joseph Samuel Myers, Craig S. Kaplan, Chaim Goodman-Strauss https://arxiv.org/abs/2305.17743

Aperiodical : Now that's what I call an aperiodic monotile

Craig Kaplan -Mastodon Thread

Craig Kaplan : Blog

[tsubakicraft]

習うより慣れろ〜余談

同じ結果を得るために複数の方法でやる。理解を深めるのに有効な考え方だと思います。 FreeCADの他にも3Dモデリングができるオープンソースやフリーソフトはいくつかあります。今日は試しにOpenSCADとTinkerCADを触ってみました。人気のFusion…