How to 3D Print Using Flexible Filaments Like NinjaFlex

by Jason King on March 16, 2016

3D Printed Custom ChocolatesIf you’ve followed my work for a little while you’ll know that I 3D print quite a few things in NinjaFlex.

Most of the time I design and 3D print RC Car Tyres but I’m not just a one trick pony and I’ve been experimenting with other stuff recently.

One of the biggest issues with NinjaFlex is that people who are used to PLA or ABS have trouble loading and 3D printing with it.

This is mostly because it’s flexible so can be tricky to load and to extrude smoothly to complete an entire print job without clogging or becoming tangled inside the extruder.

I thought it was about time I attempted to address this issue by showing you how I use NinjaFlex myself.

There’s a little story behind this though. I was intending to write an epic blog post, a bit like my Cost Calculation post which has been extremely popular, but I thought I’d try a different approach.

3D Printed Chocolate Moulds

Recently I’ve been experimenting with some new screen capture and video editing software and I love it, so why not make a YouTube video instead? One of my latest NinjaFlex ideas has been to design and 3D print moulds to make custom chocolates.

This would make a good example to use in my video, so what I’ve done is briefly explain how I designed the mould in OpenSCAD and demonstrated the settings (temperature, extrusion speed, etc) I use in my slicer to 3D print using NinjaFlex.

What I do next is literally film myself unloading the old PLA from my 3D printer, loading the NinjaFlex and starting to 3D print the mould.

The video is just under 12 minutes, but if you’re interested in OpenSCAD, 3D printing in NinjaFlex, or you just like chocolate then it’s worth watching

So, what do you think? As much as I’d love to own a Choc Edge 3D Printer I’m not sure I need one now.

There’s a couple of points to mention about the video and the process. I haven’t explained every single detail, especially about the OpenSCAD design, else the video would be 12 hours long, not 12 minutes. However, the main point is this…

The Obvious Food Safety Question

At some point, someone is bound to ask about NinjaFlex not being Food Safe and FDA Approved. What I’ll say about this is that there’s no known toxins in NinjaFlex, but as far as I’m aware it isn’t certified as food safe.

VW Chocolate MouldWhat this means is that in practice if you make and eat a few chocolates this way it’s likely to be quite safe, but I wouldn’t start selling such chocolates on any kind of scale without seeking further advice.

I did have a search around for food safe flexible filaments but didn’t find any. Surely some exist so if you find one I’d be really happy to hear about it. If it doesn’t exist, it’s potentially a big gap in the market.

This reminds me of when I made a Shamrock Shot Glass out of ColorFabb PLA. Someone asked me the same question about being FDA approved. I was happy to point out that what you put in the shot glass to drink is very likely to be far more toxic than the plastic itself.

Anyway, if this blog post and video turn out to be popular (you never know) then I’d be happy to write a long, detailed, epic blog post about 3D printing using flexible filaments as there is far more to cover.

If you want to learn more about doing this kind of stuff yourself then you can download my Beginners Guide to 3D Printing at Home eBook and join my 3D Printing Facebook Group.

Feel free to Like and Share this article too, if you found it interesting.

Happy 3D printing and go easy on that chocolate.

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{ 2 comments… read them below or add one }

John March 19, 2016 at 1:10 am

Good video explanation Jason.
I think you’ve upgraded the build plate for you makerbot and I’m guessing it was because the stock plates warp and heat unevenly.
Anyway I was wondering if you could respond to that and let me know where you got yours and what the cost was.
I am just fed up with with my 2x and ready to buy a different brand.


Jason King March 19, 2016 at 12:17 pm

Hi John,

I wrote about the replacement build plate in this blog post…

I purchased it because the original wasn’t really very flat. I didn’t recommend this glass build plate though for a start, as it was costly to ship to the UK and a very very tight fit. It’s much better now though after some use.

I have heard bad reviews of the 2X, I think Makerbot tried to add too many new features in one go, which is just asking for trouble.

Best regards,


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