3D Printed Pumpkins, Spool Holders and NinjaFlex

by Jason King on November 14, 2014

3D Printed PumpkinsDuring the run up to Halloween I naturally decided to check out Thingiverse to see if there were any pumpkins I could 3D print.

After my recent delivery of Dutch Orange ColorFabb filament I though an orange pumpkin or two would be a great addition to the Celtic Skulls I already printed for Halloween.

That’s when I found the Makies Jack-O-Lantern. Don’t ask me why they called it this, maybe it’s an American thing but to us here in the UK, it’s just a plain old pumpkin.

I started with a low resolution (0.3mm layer height) small orange pumpkin to see how it turned out. I was so impressed I printed a much larger version (200%, so eight times the volume), again in low res.

I didn’t feel the need to print in higher resolution because pumpkins don’t exactly need to be high precision. Besides, I was too impatient to wait any longer than the 5 and a half hours it already took to print the big one.

For my third and final pumpkin attempt I 3D printed a little glow in the dark one using ColorFabbs glowFill filament. It’s a shame my night time photography isn’t very good, because it glowed really well after being charged under a lamp for a while. Unlike my glowFill Swampy, I also managed to charge it without melting it on the light bulb.

RoboSavvy Universal Spool Holder

Universal Spool HolderOne thing that’s been on my ‘to do’ list for months is to buy some NinjaFlex (rubbery) filament. More on this later, but while I was browsing the RoboSavvy website to find some I spotted a Universal Spool Holder Kit.

As much as I love my Broom Handle Spool Holder which does work very well, I have to remember it is only temporary and a better more compact spool holder solution is needed.

The great things about the RoboSavvy spool holder are as follows:

  • It can be adjusted to hold two spools of almost any size
  • The spools run on metal bearings so it’s very smooth and low friction
  • The metal parts are delivered but they email you the files to 3D print the plastic parts
  • After printing the plastic parts and building the kit, you really feel you’ve made it yourself

I only have a few small issues with it, all of which I solved easily:

  • Four hex nuts were missing from the kit
  • The holes in the plastic parts I printed were a bit too small
  • The holder tended to slide easily and moved while printing

Don’t get me wrong, these are very minor gripes which I solved as follows. I tweeted @RoboSavvy who will hopefully be sending me the missing hex nuts. In the mean time I designed and 3D printed my own (4 minutes to print 4 hex nuts) which work really well.

The holes can be made slightly bigger by putting a screwdriver in there and milling them out a little. This only took a minute or so.

Now for my favourite solution. The plastic feet slide too easily on the smooth surface I placed the stand on, so I simply added “rubber stick on feet” to my shopping list… then I looked at the NinjaFlex I’d also had delivered in the same order and scrubbed the feet off my shopping list.

NinjaFlex First Impressions

So, I need some rubber feet and I’ve just had some NinjaFlex delivered. I guess you can work out where this is heading. Out came Tinkercad and I designed a prototype foot. After a few measurements with my vernia caliper, 5 minutes designing and 5 minutes printing I had my prototype plastic foot.

It was slightly too small, which was good because when printed in NinjaFlex it should stretch a little and fit snugly.

Out came the NinjaFlex and I swapped the filament over. The first thing I noticed is that being rubbery, the NinjaFlex wouldn’t feed into the cool end of the extruder. This is because the filament is gripped quite tightly but being rubber, it’s not possible to push it in so the stepper motor gear grabs it.

NinjaFlex FeetThat’s easy to solve though as on the Replicator 2 there’s a lever at the side of the extruder which opens up the hole and allows you to push in the filament easily. After doing this and releasing the spring loaded lever the filament was being fed though the hot end and was being extruded cleanly.

The settings I used for this first attempt were standard PLA defaults using 210 degrees. This was fine for the first layer but after that it failed to extrude. What I noticed is that the first layer always extrudes slowly (on any print) and then it speeds up the extrusion for subsequent layers.

A quick Google search confirmed that the default 90 mm/s extrusion speed after the first layer is too fast for NinjaFlex. Just remember we’re pushing thin rubber though the hot end. It’s like playing snooker with a piece of rope, it’s quite tricky.

I slowed down the extrusion speed to 30 mm/s (a basic setting in the MakerWare slicer software) and upped the temperature to 230 degrees. For many this might seem too hot, but for me it worked perfectly. The first rubber foot turned out perfectly so I printed the other three in one go and they worked great.

The new spool holder is complete, works great and thanks to NinjaFlex no longer slides around on the smooth surface I stand it on. Goodbye old broom handle spool holder, our time together was good but you were always only temporary 🙂

NinjaFlex KeyringAfter this success with NinjaFlex I remembered a keyring I’d made for someone, who had managed to trap it in his house door and break it within a few days. Maybe a flexible rubbery keyring would be a good solution. The keyrings I make are far more detailed than the simple rubber feet I just made, so I was curious how NinjaFlex would cope with this.

The keyring printed without failure, but due to the number of areas where the filament needed to retract for the extruder to bridge an empty gap, it resulted in quite a stringy print, with thin stringy bits between all the open spaces. I can certainly improve on this, buy tweaking temperatures, speeds, retraction distance etc, so I’m not too worried.

Over all my first NinjaFlex experience has been good. It prints pretty well and is very strong and flexible, making one of the most useful materials I’ve printed with so far.

Photo Sweep Stand

In my quest to improve my photography a little, I found a Photo Sweep Stand on Thingiverse. I’ve been using white A4 paper as a background for my small item photos for a long time, but this stand allows you to hold an A4 sheet in a smooth curve creating a great background for your photos.

Photo Sweep StandDue to the fairly large long and flat parts (there are six parts in all for both sides of the stand) it warped a little but using a raft would have prevented that. It is still fully functional and works just great, so if you take your own photos of small items then I can highly recommend downloading, 3D printing and making this stand.

Just before I go, there’s a couple more things. I have been working on a process for turning 2D drawings in black pen on white paper into 3D prints. With the help of a few free tools I have managed to do it, but I wanted to improve the process before I wrote about it here.

I’d like to write an article dedicated just to this 2D to 3D process so I think that’s what I’ll do. The reason I like the idea of this technique so much is that a major barrier to 3D printing is that designing intricate and complex objects using CAD packages is a little beyond most people.

The idea of being able to draw an intricate detailed shape on paper using a plain old black pen is something even a child can manage… and I can now turn those into 3D prints. I posted a very simple example on Twitter the other week, but I want to produce some better examples before I write about the process. I even managed to convert a single photo into a 3D print, but that process does still need more work.

Finally this week, I created a new 3D Printing Resources Page on my website where I intend to share all the products, services and information sources which I find most useful and can recommend. There’s about ten things on there already but I’ll continually to add more as time goes on. Follow the link above and feel free to have a browse.

Thanks for reading and if you’d like to Share and Like this article that would be great. Also feel free to leave a Comment if you have any questions or suggestions.

Happy 3D printing…

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