TPU Sphere Desk Clock

Hello community!

While time passes among us, clocks of the most diverse variety count the passing of the hours continuously.

Even today hundreds of designers are also looking for them to become decorative objects in a house, office, etc.

Some time ago I decided to create an original and minimalist design, easy to build and assemble.

In this instructable I will describe step by step how to make it using a cheap classic wall clock movement mechanism and 3d printed parts.

If you decide to put together this project (I encourage you to do so) I suggest that you first give it a quick read, and then do it step by step, especially see all the photos, plans, graphs, diagrams where I have added explanatory notes. Do not hesitate to contact me and I will answer you as soon as possible.

If you are intrigued to see how it is installed in a house in different places go to step 10 and take a quick look.

Join this project and enjoy it!

There are very few cheap elements, because I wanted to make the model simple:

• 3D printing filament 1.75 TPU 95a (*)
• 3D printing filament 1.75 PLA (*)
• Quartz Wall Clock Movement Mechanism (shaft long 13/15 mm). https://a.co/d/ei5weW2
• Straight metal hour and minute hands
• Soft Lead Weight.https://a.co/d/1bdWYVq
• Matte spray paint (*)
• Paper tape.
• Contact cement or double sided tape (see step 9).

Tools:

• 3d Printer (or access to one of them).
• 3D Printer Cutting Pliers.
• Flat tip screwdrivers.
• Scissors.
• Ruler.

(*) I did all the Instructable with the colors black for the TPU, yellow for the PLA, and White for hand minutes and hours. Somehow I chose those colors to combine them in my house (I love the yellow, white and black style very used in art), but you will see that I have made a variety of renders with color combinations that I really like a lot and maybe you also like one in particular.

In general, my creative process always begins by making sketches without using CAD.

The first strokes I do away from my desk and PC, scribbling on any paper with pen, pencil and colors.

I share with you the first sketch made on a napkin :D, using a pen and painting with a yellow pencil. I changed those colors later in my final design.

Then I start to shape it better using Rebelle (as in this case) or Photoshop.

After sketching out a few ideas, I designed the entire project using Autodesk Fusion 360 software.

If you don't know this software (or you don't know how to use it), believe me this software is amazing!

In these three steps below I will briefly explain how I design the project.

For greater clarity of this project, these are all the parts:

Main body. It is a truncated hollow sphere, printed on a flexible TPU filament. This piece houses all the others. Why TPU you may wonder?. Firstly, to facilitate assembly and secondly, it is very pleasant to place it on a flat place.

Front piece. On its circular front part it has the clock hands and on the back it houses the Quartz Wall Clock Movement Mechanism.

Counterweight piece. It is also a hollow truncated sphere, which is filled with soft lead weight allowing the clock to be placed on a flat place at a slight angle from the horizontal. It has a top Lid piece to close it.

See that there is a 2D guidance plan (made from the 3D design) where you can see the overall dimensions.

In the 3D design process that is explained in the following steps, I used a lot of printing at one third scale (33%).See photos. This allows you to see how the pieces look during the design and how do they fit together, without having to print in final scale (100%), saving material and printing time. Another technique that I also used was to print partials parts at 100%, for example for the design of the back of the front where the watch is housed. This allowed me to check the tolerances for the fit of the watch, if it could be pushed in and then stay in place, etc.

In the next steps we will see how I designed the 3 previous pieces.

For better follow-through, in the texts below I have used italics to create solids, sketches, or software tools. Likewise, the pieces to be printed will be written with a bold font.

You might be interested only in building this project and not stopping to see how I will design the parts step by step in fusion 360. In that case you could alternatively skip to step 7.

First I made a solid Sphere of Ø140 mm and to make it hollow I made another concentric solid Sphere Ø120 mm using the “Cut” option from the “Edit Feature” contextual menu. Fig.#01 y #02

Next I made a Sketch (Fig.#00) to define the cutting angle of the Ø140 mm hollow Sphere created previously and then I made an auxiliary plane parallel to the inclined line, to then make the cut in the sphere with the "Split Body" tool from the "Modify" menu. Fig.#03 y #04.

In that Sketch there is a closed wedge-shaped surface, which with the "Extrude" function using the "Direction=Simetric" from the “Edit Feature” contextual menu, I create a Body to make later two lateral notches to the Sphere.

With that Body I use the "Translate" function by first Rotating it by an angle of 9.5° and I "Translate" that object downwards overlapping the Sphere and that piece, to make two cuts. Fig.#05, #06 y #07.

The Main Body is completed by making a guide around the entire inside circumference which supports the Front Piece, of thickness 5mm, a height of 5mm, and a distance of 29 mm from the top.

This support guide is made with two concentric Spheres Ø120 mm and Ø115 mm. The second Sphere that with the "Cut" option of the "Edit Feature" context menu allows to have a semi-hollow. Then I made two auxiliary planes to make the cut, which turned out to be a concentric ring to the Main Body and then through the "Modify" menu and the "Combine" option I left the ring attached to the main body. Fig.#08, #09, #010, #11, #12 y #013.

First of all, I made a solid sphere of Ø120 mm (inside diameter of Main Body).

Then, taking into account the sketch of the cutting angle of the main piece, I generated two parallel planes separated from each other by 29 mm. Fig.#17.

With these two planes I made two cuts in the sphere with the “Split Body” tool from the “Modify” menu. Fig.#18.

In the main render of the full watch (see step 3) you can see that the Front Piece of the watch is 5mm below the TPU front of the Main Piece. For this reason I created an auxiliary plane and with the cut function I eliminated this portion of the piece, with the “Split Body” tool from the “Modify”, which remains with a height final of 24 mm. Fig.#20.

Then I made a sketch with the necessary dimensions to house the Quartz Wall Clock Movement Mechanism.

These Mechanism have a standard world dimension of 55 x 55 x 16 mm (width, length and thickness).Fig.#19.

In that sketch I put two semi-circles to allow easy placement and removal Quartz Wall Clock Movement Mechanism.

With the "Extrude" tool I made a housing following the shape of the sketch with a depth of 17 mm. Fig.#21, Fig.#22.

Then using the "Extrude" tool I made a Ø8 mm hole to pass the clock axis.Then I made a small milling of a ring Ø14.5 mm and depth 1 mm. Fig.#24, Fig.#25, Fig.#26, Fig.#27.

With the "Fillet" tool I made a curve of the upper perimeter of the housing with a radius of 1 mm. Fig.#23

To try and save filament, then again with the "Extrude" tool I made a larger cavity using the outer perimeter of the clock movement sketch. Fig.#28

As the walls seemed too big to me, I proceeded to further cut the wall. For this I made a solid Ø110 mm sphere. To make it hollow I made another Ø100 mm sphere using the “cut” option from the “Edit Feature” contextual menu. Fig.#30, Fig.#31

I made two planes separated from each other by 17 mm, in such a way that only the part of the hollow sphere remained to be removed from the piece. Fig.#32

Once I had that piece, I used the function "Combine" with the “Cut” function from the context menu, leaving the wall in its final shape. Fig.#34 Fig.#37

In order for the clock mechanism to remain fixed, inside the clock housing I made four solid cylinders of Ø1.5 mm and 10 mm long attached to the wall, using the "Pipe" option in the Create Menu. Fig.#29

Finally, for assembly purposes, I made two notches located on the side of the piece, to accommodate the flat head of a screwdriver. I made a sketch of a rectangular section of 7 mm x 1.75 mm, then with the "Explode" function I gave it volume and inserted it with the "Translate" function inside the walls of the piece. I used the "Combine" function with the "Cut" option to make the two small notches remain.Fig.#38, Fig.#39, Fig.#40, Fig.#41, Fig.#42.

This piece is a truncated and hollow Sphere that allows to house soft lead weight to allow the clock to always remain in the same position.

First of all, I made a solid Sphere of Ø120 mm. Fig.#43

Then I generated a Plane perpendicular to and at a distance of 30 mm from the center. Fig.#45

With that plane I made a "Cut" in the sphere with the “Split body” tool from the “Modify” menu. Fig.#44 Fig.#43

To make that piece hollow I made another solid Sphere Ø112 mm using the “Cut” option from the “Edit Feature” contextual menu. Fig.#47.

Then to support the Lid (which we will create later) I made a mill (4 mm height and 2.05 mm width), using the "Extrude" tool. Fig.#48, Fig.#49

I made the Lid that has a cylinder with a diameter of Ø93 mm and a thickness of 4 mm and a lower part as a "plug" thickness of 1.5 mm so that the lid remains fixed when it is pressed on the truncated sphere once it is filled with material for weight. Fig.#52, Fig.#54

From Fusion360, I exported the STL files and opened them in CURA.

I used the following parameters:

Printer: Creality Ender 3 PRO

Slicer: Ultimaker Cura 4.9.1 version

Main Body TPU 95a:

• Layer height: 0.2 mm
• Printing temperature: 220 °C for hot end, 60 °C for print bed.
• Filling: 20% density. “gyroid” pattern
• Printing speed: 30 mm/s (*)
• Travel speed: 150 mm/s
• Retraction: Speed ​​40 mm/s. Distance 6.5mm. Combed mode: over the fill.
• Supports: Yes Fill 4%. “cross” pattern
• Position in bed: Hollow front against the bed. Upper pole of the sphere upwards.

(*) Printing with TPU is easy, but increasing the speed beyond 30mm/sec is not recommendable.

Front piece PLA:

• Layer height: 0.2 mm
• Printing temperature: 200 °C for hot end, 60 °C for print bed.
• Filling: density 20 %. Pattern “cubic”
• Printing speed: 100 mm/s
• Travel speed: 250 mm/s
• Retraction: Speed ​​25 mm/s. Distance 6.5 mm.
• Supports: NO
• Position in bed: Front of the piece attached to the bed. Back of piece facing up.

Counterweight piece PLA & Lid piece PLA

• Layer height: 0.2 mm
• Printing temperature: 200 °C for hot end, 60 °C for print bed.
• Filling: density 20 %. Pattern “cubic”
• Printing speed: 100 mm/s
• Travel speed: 250 mm/s
• Retraction: Speed ​​25 mm/s. Distance 6.5 mm.
• Supports: Yes. Fill 5 %. Pattern “Zig Zag”
• Position in bed: Hollow front looking up bed. Pole of the truncated sphere touching the bed.

For the design I chose metal minute and hour hands with straight lines.

Usually the Quartz Wall Clock Movement Mechanism come with the hands included, you just have to choose a type similar to the one found in the photos, with a width of 3 mm for the minutes and 5 mm for the hours.

 As these mechanisms are generally for use in wall clocks, either for craftsmen to make a new one or to repair existing ones, the size of the hands is longer than necessary in this project.

In my case the hands were aluminum painted black, so I measured with a ruler, I made a mark on each one with the final dimensions from the axis to the tip of the needle: 30 mm in the case of the hours and 40 mm in the case of minutes.

Once marked, with scissors you can make the cut to the final size that I indicate as seen in the photos.

In this design I also chose the white color to contrast with the yellow on the front.

For this I used matte white spray paint.

It's very easy to paint them, just put a little tape under the needles to keep them from moving when you spray.

The most awaited moment has arrived: the assembly :)

The first thing we will do is fill the Counterweight Piece with the small spheres of lead or steel (depending on what you get). Fill in such a way that it is completely flush and allows the Lid Piece to be placed without it coming out. If you want, you can apply a few small drops of contact cement to allow this piece permanently closed.

Once the previous step is ready, we will place this piece inside the Main Body piece of TPU, with a position and an angle similar to that seen in the Fig. #58. Previously, you should place contact cement on the inside of the TPU so that when placing the piece it remains glued. If you are not sure and want to test the final position, you can leave it temporarily taped with double-sided tape.

The next thing will be to place the clock mechanism inside the Front Piece on the back as seen in the video/photos. Apply a little pressure so that the mechanism is perfectly attached. The orientation of the mechanism be such that the batteries are facing down.

Depending on the type of mechanism, it could happen that the mechanism is somewhat loose or that it is difficult to enter. If you already have the parts printed, in case there was some more slack, you can apply some masking tape. If it is too tight, you can carefully use a cutting tool or sandpaper to remove any excess plastic that is impeding the installation of Clock Movement Mechanism.

Once the above is done, take the hands of the clock and place first the one for the hours, exerting a slight pressure on the plastic axis, then do the same with the one for the minutes, doing the same on the respective axis. You must avoid by all means that the minute and hour hands are inclined with respect to the plane of the front, in order to avoid touch each other during the course.

As the clock does not have any type of hour mark on the front (minimalist design) on one of the sides of this piece, you will see one small notch in the lateral that mark the "12:00". (See Fig.#56 and Fig.#57). Turn the hands by hand (not with back clock adjustment) to 12:00. Once it marks twelve, with the rear plastic dial of the mechanism, check the operation and set the clock on time.

Once the above is ready, tilt the front as indicated in the video and/or photos and with the help of flat-head screwdrivers open the upper rubber mouth of the watch, taking advantage of the fact that the TPU is flexible and also the two notches sides allow this process to be carried out. You will see that the PLA plastic piece on the side has two small notches that allow you to accommodate the tip of the screwdriver to disassemble the clock and adjust the time or change the batteries (See especially the photos that I have added, where the disassembly for the change of batteries is shown using this last procedure)

Once inside the TPU piece, the Front Piece will be at a distance 5 mm below the top level.

Now all you have to do is arrange the clock so that it matches the inclination of the design, and place it anywhere in your home, office or wherever you like.

Now I had to locate the clock somewhere in my house.

I realized that it goes very well on desks and also in living rooms.

I took some inspiring photos.

I am sure that depending on the color you choose you will be able to find a dream place for what you do.

Finally, see how the clock rotates when you try to change its natural angle of location from the horizontal. Since the TPU is soft, it doesn't make any noise and it's addictive :D

Enjoy!

Here I share, some general design considerations:

SECONDS HAND

In my original design I didn't put seconds, but Quartz Wall Clock Movement Mechanism always come with a seconds hand, so you could add it if you want.

LINES/NUMBERS ON FRONT INDICATING HOURS

As the design is "minimalist" I simply did not want to add lines indicating hours, minutes, or numbers. Maybe in some future upgrade of this Instructable I will add some fronts that have "negative" numbers or stripes without affecting the original design.

.....

And finally that's all for this project.

We have created an original desk clock with a very low cost.

I hope you enjoyed this Instructable as much as I have enjoyed it.

If you have any question ask them in the comments below!

I would also love to hear what you think about the project.

Happy making!

cfb70 - Instagram @cfb70ok

PS1: if you like the project, please choose it as a favorite ♥️ == THANKS

PS2: If you want to see my other works on instructables look here:

https://www.instructables.com/member/cfb70/instructables

PS3 / Credits: Image by jcomp on Freepik - www.freepik.es