Turn Toilet Rolls Into Construction Toys

I'm sure I'm not the only one with a large supply of hoarded toilet roll tubes in a scrap box somewhere waiting for the day when they might 'come in handy'.

Well now they can be anything you like!

These 3D printed connectors transform cardboard tubes into modular construction toys to be assembled into forts, robots or cities to be destroyed monster-style.

Supplies

• 3D Printer
• Toilet Rolls
• Hot Glue gun

Step 1: Designing a Modular System

For easier printing, I separated the connectors (grey) and the end pieces (blue) that grip inside the toilet rolls into separate parts.

The toilet rolls I have measure about 40mm in diameter and 100mm long. The length shouldn't matter as long as they are all the same, but the width is important to the design of the corners so the end pieces don't overlap.

The end pieces are the same distance from the centre of the connector in every configuration, meaning that structures built with them will be modular and always able to connect in a neat grid.

Step 2: Files

There are 8 connectors and one end piece.

By combining these, it should be possible to make any rectangular structure.

Step 3: Printing the Pieces

The print settings I used were:

10% infill

Layer height 0.15mm

Support touching buildplate

A brim for build plate adhesion

Step 4: Construction

Use a hot glue gun to attach the end pieces to the connectors.

Squeeze the ends together gently to insert into a toilet roll and it should hold firmly.

Step 5: Build!

Go forth and create cardboard tube empires!

Your only limit is your imagination (and square corners)!

Comments

[DougL2]

fun idea but boy, a 4.5mm square peg is very loose in a 6mm square hole. I would have went for 5.25mm or even 5.5mm pegs.

[snowbiscuit]

Very true! I initially designed it with a much tighter fit, but my printer isn't the best quality and I got tired of shaving pieces off to get them to slot together. I could add a tighter fitting file for people with better printers though.

[DougL2]

oh boy, tuning a 3D printer slicer to produce engineering level prints is a challenge. There is a fine line(pun intended) between a structurally unsound result and a solid object with holes no where close to design specs.

One slicer option I always enable first when doing engineering class objects(things which must fit together) is the External Perimeters First option. It helps to have the 3D printer lay down the plastic which has the correct dimensions first in hopes it'll cool and resist getting pushed out of spec by over extruded inner layers and hopefully forces the error into the infill areas.

I really should have printed just 2 objects first or measured the STL fitment first before plating up 7 hours of printing. :/

I suppose, all that's needed is the correct scaling factor(122%) to get to the correct dimensions on the attaching pieces. No need to post new parts. 122% gets a 5.5mm square peg. But best to recommend a fitment test first before lots of parts are printed.

[snowbiscuit]

Test print is a great suggestion! I have so many iterations of the end pieces and one batch where I had my slicer setting to hollow and it crumpled in on itself as soon as I tried to fit it in a roll :face-palm:
Are most US toilet rolls around 122mm? I can add an updated file so others don't have to feel your pain.

[DougL2]

ah, the 122 was not mm but was a scaling factor(ie 122%). The best measurement I could get was 46.0mm/1.8" inside diameter. But reminding people to test an end cap and a straight section first for fit/function would be helpful. I should have known better.

[snowbiscuit]

Ah of course. 122mm diameter would be one big toilet roll!

[DougL2]

So I had to scaled the end caps to 122 to get a very tight fit on the standard US toiletpaper roll. That meant I had to scale the other pieces to 145 to get the square pegs to fit with just a little bit of play.

That's lots of scaling and way too big for what was originally intended. So will use OpenSCAD and create a plug for the center of the larger end caps but with a square hole size to fit the 4.5mm default connector ends. Seems to be the easiest solution. FYI, in OpenSCAD you can import an STL file and if it's clean and manifold you can do unions, differences, etc on them.

[abogkli]

really goog

[MikeTomk41]

Great idea and super for children. Did you consider making the junction between the adaptors and the end pieces demountable so they are re-useable?
Mike

[snowbiscuit]

Yes, I originally wanted to have them click into place or be a good pressure fit, but I was thwarted by poor printer resolution. I might upload an updated version in the future though for those with better printers!

[jordanat2012]

This is such an awesome idea! I need a 3D printer so I can do these great projects... Thanks for sharing!