Designing A Sample Part For Our Printers

We stock a large collection of sample parts which can be used to demonstrate different many different things. Due COVID-19 being such a large talking point we chose to design a door opener/button pusher/bottle opener tool.

Brief

The brief specified that the part had to be able to perform all functions, while comfortably sitting in one of the users hands. The part also had to be similar to the previous sample part, in both volume and cost. (13.85mm^3 and £3.60 respectively)

Setting up on the Sindoh

The settings we used for our print are as follows:

Infill Density:

Bed Adhesion:

Support Material:

Wall Thickness:

The Initial Design

The original part fulfilled both brief points coming in at 9.58cm^3 and costing £2.72. One feature of this design is you can open a bottle whilst holding it in the same hand as the bottle opener!

The bottle cap fits into the area at the back and the hook at the front is what’s used to open doors. The hole at the front provides a finger hole for extra grip and the hook at the front is also wide enough to fit a finger in order to help open a bottle.

We tested the part by printing it on a Sindoh 2X in order to get a prototype rapidly before moving over to Markforged. However we ran into a few problems with the part in terms of usability after doing this.

Problems

• The hook at the front is too small to get a secure feeling grip over the door handles.
• The bottle opener at the back is too short to grip over a bottle cap and open it.

To counteract these problems we redesigned the part so that the hook was longer and the bottle opener works. However with those changes we didn’t like the aesthetic of the part and so started anew.

The Updated Design

More ideation was done to come up with a second design for the part that still fulfilled the brief. We produced many variations of this design to make sure the end result was as good as possible. The first of these iterations had a volume of 4.50cm^3 and only cost £0.82 to print! 45 degree chamfers were added all the way round, to stop any support material being needed when printing.

However there’s a glaring issue with this part; the hook is far too weak and would snap under very little force. As a result before we printed this part we added a support beam to help secure the hook.

This model was slightly larger coming in at 5.27cm^3 and costing £1.13 to print. Due to testing with SolidWorks simulation we made sure that it was easily able to open doors without breaking or undergoing plastic deformation. This print was able to open the heavy fire doors in our building with ease! This model was too thin to get a decent looking Solidprint3D logo on it however, so a thicker model was made.

The chamfers on this design were too large, which as a result meant that there were a lot of support beams being produced, ruining the quality of the print. To counteract this we made the chamfers smaller, which also allowed an easier print of the logo and website address on the sides of the print.

Getting ready for Markforged

The final print before moving onto the Markforged tested two things. Firstly how well the text would print and secondly if the part could be printed without support structure. To get rid of the support structure we reduced the size of the chamfers and changed the angle of them to 50 degrees as well as adjusting the size of the chamfers on the bottle opener area so that it could be printed without support. The text on this part was too small to read, so we made it bigger on the next models.

Markforged Prints

After completing test prints on the Sindoh 2X part has eight layers of carbon fibre (4 at the top, 4 at the bottom) to help increase strength.

Due to the higher quality of the print both the text and the logo stood out a lot more and was easily recognisable compared to the Sindoh. This print was almost perfect, however we wanted to see if we could make the part unbreakable. In order to do this we increased the width of the part’s left side.

Consequently by thickening the left side of the part it became a lot stronger to a point where we could not break it. However after the changes we didn’t like the part’s design so reverted it to its previous iteration, changing one aspect.

We swapped round the text and logo because having the long text on the short side looked rather odd. Swapping these parts round made the entire part look a lot cleaner as it allowed for easier centering of the features. After this had been done the sample part was ready for manufacture. Eiger calculated the final volume and cost of manufacture is as follows:

Volume: 9.5cm^3

Cost: £2.72

Extra tip for Additive Manufacture

When adding text and logos to your part, make sure to add them on the side (XY Plane). Printing on the top uses the nozzle width to determine detail whereas printing on the side uses layer height. Consequently by printing on the side, your text/logo will be much better quality.

Below shows an image of the text we printed off on the bottle opener; this detail couldn’t be achieved if you printed on the top (Z plane).

Feel free to check out other blog, that goes into this in more detail:

• How to 3D Print Text, Logos and Fine Detail

Different kinds of Printers

Each printer has its own set of advantages and our part could be produced on any of our printers depending on what we want to showcase.

Sindoh:

Printing on the Sindoh allows up to easily produce prints cheaply with no added hassle. We used this for rapidly testing different models and design choices in the early prototyping.

Ultimaker:

The Ultimaker can produce high quality prints in a range of different materials. We can use this machine to rapidly test the strength of our part in a variety of different materials.

FormLabs:

Formlabs are capable of printing in extremely high quality and detail. We can use these printers if we want to showcase the logo or any other small features on our part.

Conclusion

Looking for a sample part? Here at Solid Print3D we have a large range of sample parts, showcasing many different things. We’re also here to give any advice on designing for additive manufacture! For more information, please call Solid Print3D at 01926 333 777 or email at info@solidprint3d.co.uk