3D Printed Model Aircraft Stand

What good is a model aircraft if it’s stuck on the ground? Planes are made to be in the air!

Unfortunately in our recent interstate moves the stand for this model aircraft was lost. But as I’ve said many times on this blog, including the previous post, 3D printing to the rescue! Projects like this really tick all the boxes for me:

1. From idea/need to the final solution can be done in a matter of hours.
2. No need to spend a lot of money buying a replacement (if you can even find one). With 3D printing you can make your own for next to nothing.
3. Bring the product back to life. While there was no need to throw this aircraft away now that it had no stand, some products are not so lucky. If you can replace a missing part, you can extend the use and enjoyment of it.
4. Share it – chances are someone, somewhere, may be looking for exactly the same part. Just as I’m doing here, by sharing what you make, you might save one more product from going to landfill.

Having said that, you can freely download and edit this model aircraft stand from your favourite 3D printing platform: Thingiverse, Pinshape, Cults or MyMiniFactory.

It was designed in Autodesk Fusion 360, and features 2 pieces that print nice and flat, making them strong and durable. Fitting them together is tight, you may need to shave off a little plastic with a file or knife depending on your print quality, but this ensures that you won’t need any glue, and it should hold a good amount of weight without wobbling. The critical dimensions you may be interested in are the size of the stand tip that slots into the aircraft: It measures 6.0mm long (front to back direction of aircraft), 2.3mm wide (wing to wing direction), and 6.0mm tall as pictured below.

If you need a different size, please feel free to make modifications to the files uploaded to the various 3D printing platforms, and then re-share them as a remix. I’m not an aircraft collector and don’t know how many different geometries there may be for stands, this was just the one we needed. Hopefully it is useful for someone else.

– Posted by James Novak

3D Printed Flexible Lens Cover

I’ve said it countless times before, and I’ll say it again – some of my favourite 3D printing projects are the ones which are quick, easy, and either add value to an existing product (e.g. see my 3D printed webcam mount or lucky bamboo holder), replace something broken or lost (e.g. my SUP paddle lock),  or in this case, something missing.

I recently bought an old pair of binoculars (or is it just a binocular?) from an antique store. They came in a pretty beaten up case, and were missing two of the protective lens covers, but overall worked nicely with lenses that weren’t scratched. The lens covers that did come with the binocular were cracking and didn’t really stay in place any more, so it was 3D printing to the rescue.

Planning to use some PolyFlex TPU95 filament from Polymaker to create a soft, rubber-like lens cover, I ended up designing the lens covers to be just slightly smaller than the measured diameter of each lens, 0.25mm smaller to be specific, with the intent of creating a secure friction fit, but not so tight they had to be stretched over the lenses. The design is very simple, a couple of extrudes in Fusion 360, before adding the circular pattern detail around the outside (which was not part of the original lens caps!) to add a personal touch. Now that they’re printed they remind me of beer bottle caps, but the intent was just something a bit rugged and easy to grip without spending a long time trying to be too clever in CAD.

These were 3D printed on a Wanaho Duplicator i3 Plus with an upgraded Flexion Extruder. What’s a Flexion Extruder? Well, you can read my whole series documenting early experiments trying to 3D print flexible materials here, but long story short, a Flexion Extruder is the ultimate upgrade for cheap desktop FDM machines that allows you to successfully and reliably 3D print with soft TPU materials. If you don’t have a Flexion, or a good quality system like the Prusa MK3S which has been designed to print a whole range of materials including TPU, chances are you will end up with a tangled mess of filament coming out the side of your extruder, or worse! They’re just too soft to be forced down into the hotend and come out of a tiny nozzle.

The other trick is getting the right settings to print with – you will find loads of different theories and recommendations online, 3D printing TPU is a bit of a dark art and there are many different types of flexible TPU that require different settings. So getting things right will take some time. This is a good general guide to follow, and I’d reiterate that you MUST print extremely slow – I used 20mm/s for the lens caps. Also, follow the recommendations from your filament supplier, this material from Polymaker was printed at 220°C with the build plate at 50°C. Seemed to be about perfect.

Above you can see just how flexible the end result is, the lens caps easily bend and squash without permanent deformation. If you’ve got any settings you’ve found are reliable, or just general tips and tricks for 3D printing TPU, please comment below to build up some resources for others to find.

Happy 3D printing.

– Posted by James Novak

Is That A Clogged Nozzle, or…

No it’s just a clogged 3D printer nozzle, thanks for asking!

2017 seems to be my year for repairs on the Cocoon Create 3D printer, it was only a few months ago I wrote a big post about repairing and replacing the PTFE tube after it got seriously clogged. I did some research and found out exactly what the tube is for, and bought a roll of spare tube for future repairs (click here to read more).

Lucky I did! This seems to be the same sort of problem, however instead of the PTFE tube just getting clogged, when I opened up the nozzle the tube had become melted and broke off inside, completely stuck as you can see in the photo. I wonder if the spare PTFE tube I had installed was made from dodgy materials, allowing it to melt? Or maybe the ABS filament had just found a way around the outside of the tube and caused it to clog. Either way it’s getting a bit frustrating to have the same issue.

Luckily this wasn’t too difficult to fix (although I did jump straight on Ebay and buy a couple of spare brass nozzles – just search for RepRap MK10 0.4mm nozzle since the Cocoon Create is based on the RepRap Prusa i3). Using a drill and holding the nozzle with some pliers, I gradually worked my way up from a 2mm to 4mm diameter, clearing out the clogged material. 4mm is almost exactly the same as the internal nozzle diameter, so it cleared everything out nicely.

With some new PTFE tube installed, I’m back up and running again and the first print is coming out nicely (stay tuned to see what it is). Let’s see how long it lasts this time…

– Posted by James Novak

New Year 3D Printer Repairs

After something like 150 hours of 3D printing leading up to Christmas it’s no wonder that my Cocoon Create decided to extend its holiday with some down time to kick off 2017. There have been 2 problems to do with extrusion that I’ve come across, and thought they might be handy to know how to fix for others with this printer, or indeed any of the many derivatives of the original RepRep Prusa i3 which this printer is based off.

The top image shows the first problem which I noticed after some jamming and issues swapping out filaments – basically a build-up of filament “powder” over time from the gear grinding it when it’s been jammed. This one’s a nice easy fix, just a cleanup and a reminder to open up the extruder occasionally to keep things clean. If you’ve never opened the extruder before it’s nothing scary, just 2 bolts on the left where the fan is mounted to the heat-sink which opens the whole thing up as shown above. You might be surprised how simple the whole mechanism is.

After fixing this problem and doing a couple of prints, I then noticed the filament was getting jammed again and I couldn’t push filament through the nozzle no matter what I did. Opening the extruder (same process as before except now removing the small screw on the right of the metal block to release the actual nozzle) the problem was pretty clear – a clog in the PTFE tube which you can see above. A lot of people are surprised to open their extruder and find a plastic tube inside, and this is the first time I’ve really had a problem with it. This tube is made from PTFE, basically Teflon like in your non-stick frypan, and seems to serve a couple of functions from what I’ve read online:

1. it stops heat from the nozzle climbing too high into the extruder and prematurely melting the filament, which would cause serious clogs.
2. being non-stick, it helps the filament keep sliding smoothly down to the nozzle without sticking as it gets warm.

A very cheap, simple part that has a lot of responsibility. Mine must’ve gotten worn out or slightly dislodged during my last attempt at fixing the extruder. Thankfully my printer came with 1 replacement, which I cut to size (make sure both ends are nice and square so that there are no gaps for filament to get caught in) and now I’m up and printing again with no problems. Also I’ve jumped onto Ebay and ordered a 2m length of PTFE tube (inside diameter 2mm, outside diameter 4mm) from China for $2.50 – I recommend anyone who has a 3D printer with this part order some PTFE tube as backup, it’s very cheap but if you need to buy something locally in a 3D printing emergency, prices look at least 10 times higher. For a couple of dollars it might just help keep you sane.

Some good forums discussing PTFE tube issues:

• https://groups.google.com/forum/#!msg/flashforge/8RBXZhlggvM/C8wP4w6hzlYJ
• https://www.reddit.com/r/3Dprinting/comments/2hca7w/ptfe_teflon_tube_in_hot_end_what_does_it_do_is_it/
• https://groups.google.com/forum/#!topic/flashforge/8RBXZhlggvM/discussion

I’ve previously written about another type of clog where filament breaks off inside the extrusion tube as you’re retracting it, and you can’t force a new piece in – check out the post here if this sounds like what you’re experiencing.

Happy 3D printing, happy new year.

– Posted by James Novak

Repairing 3D Prints with a 3D Pen

It’s been a while since I last played with my 3Doodler Pen to repair a broken 3D print – the results were pretty cool, although it takes some practice to get reasonable results. Check out the post and images here. Some people make pretty amazing sculptures with the pen, however I find the real value in using the pen to fill gaps created by warped 3D prints and fix other cosmetic problems.

One of my latest projects is assembled from 16 separate pieces printed on my Cocoon Create 3D printer (60 hours worth of printing!), and inevitably with such large pieces printed using desktop FDM technology, there are some gaps caused by print warping. Most of them are reasonably small, but some like the ones shown above and below are quite large. Unfortunately the 3Doodler uses 3mm filament, meaning that I couldn’t use the same 1.75mm filament used to print the parts to begin with, but given that this project doesn’t need to be cosmetically pretty (prototype only), a different shade of yellow that came in the box will do.

The first step is of course to use the pen to extrude material into the cavity, ensuring to move slowly and use the hot nozzle to bond the new plastic with the original. It can get a bit messy and smelly (do it in a well ventilated area – I had a fan blowing to keep a lot of the fumes moving away, but there were times my eyes were stinging), and as shown in image 2 above, might look a bit rough, but that’s OK. You can go back over some of the rough patches using the side of the hot nozzle to try and smooth them out, not extruding any material but using the nozzle like a hot rolling pin. This technique is also great for blending some of the sharp edges or smaller gaps that don’t really need to be filled. The final step is to use a metal file to clean things up, giving a much smoother finish.

Admittedly this process wasn’t all smooth sailing, my 3Doodler kept getting clogged despite me taking it apart and cleaning it out – I have a feeling it might be the material quality and/or the temperature of the nozzle not being quite as hot as it needs to be, so a lot of time was wasted trying to manually push the filament through the pen and get a steady flow. I did notice that when I pushed the hot nozzle into my original print (the darker yellow plastic) it melted much quicker than the 3Doodler filament, despite them both being ABS. So material quality is likely the cause. But the final result is worth the pain, gaps are cleaned up nicely and the surface is nice and smooth. Time for some testing!

– Posted by James Novak

When Layer Orientation Matters

Often when you are 3D printing the main thing you think about is how much support material your print will have, and you orient your print to minimise this – reducing material waste, print time and any manual post-processing to clean up the print. However sometimes the best print orientation for these reasons is not the best for mechanical strength, and I’ve just discovered this with one of the parts for the InMoov robotic arm I’m currently building (see the first collection of 3D prints in my previous post).

The “RobServoBedV6” part is where the 5 servo’s connect that control the individual finger movements, using screws to fix them in place. However some of the stands are splitting as I screw into them as shown in the photo above due to the layer orientation. Yes I could use super glue to fix them, but the split will just happen  somewhere else. So I’m going to completely cut the stands away from the part, and re-print just these stands in a different orientation to improve their strength. This is where the free program Meshmixer comes in very handy, and I’ve previously published a few examples of how to use it for my friends at Pinshape – just click here to find out more.

In the top right image you can see the first step of using Meshmixer to edit the STL file. I have used the Plane Cut tool to slice away the bottom plate, and then repeat the process to remove the other 2 segments which seem to be strong enough for the screws at the moment. This leaves me with the 2 stands that I’m having issues with. These can now be exported as STL’s ready to 3D print (orientation is not important here, this will be set in my 3D print software).

I’m printing these parts as we speak on my Cocoon Create 3D printer, and have used Cura to prepare the parts and get the G-code. As you can see to the left, I have oriented the parts so that the layers are perpendicular to the original orientation, meaning that when I screw into them, the force from the screw will not pull the layers apart. Super glue will hold these replacements onto the original part really well as they are printed in ABS.

If you are designing your own parts from scratch in CAD and intend to screw directly into them, keep this issue in mind. However if you’re downloading a STL where modification isn’t as easy, knowing this simple trick in Meshmixer can really help you repair and improve a part rather than trying to re-print it from scratch and potentially use a lot of support material in a different orientation.

– Posted by James Novak

Drawing in 3D – First Attempt

If you follow 3D printing at all, chances are you’ve at least heard about 3D printing pens like the 3Doodler and others, with the 3Doodler originally funded through Kickstarter and now a successful brand. While I’ve seen people make some really interesting things like the Eiffel Tower and Golden Gate Bridge, I have to admit the pens have never really interested me. I can see the fun for kids because they are so easy to pick up and begin using, much like a hot glue gun, and there are templates you literally trace over to construct your object. However the models are really only visual, it would be almost impossible to make anything accurate or functional in the same way you can with an actual 3D printer.

However I was given a 3Doodler, and have been looking for an excuse to try it out. Well, one broken 3D print off my Cocoon Create (who by the way have their own 3D Pen which was sold through Aldi for $79) and I finally had my chance! The benefit I see of such pens is the ability to repair and weld details on a regular 3D printed part – in this case a Voronoi Tealight Candle Holder available on Thingiverse. You can see the before and after photos above.

I have to admit the process wasn’t nearly as easy as I thought. The slowest speed of the pen is still quite fast, and once the plastic starts coming out of the nozzle you really need to get moving! The easiest repairs were the little ones near the bottom of the design, just a quick squirt and it was done. The larger distances were much more messy because of the speed of extrusion, but adhere well to the existing design especially if you use the nozzle to melt some of it to begin with and fuse the new material. I found that once I had roughed out the repair, I could use the hot nozzle to go back and “smooth” the outside surfaces like putty (although the result is far from smooth). This could be further improved with acetone (you can see some of my previous experiments cleaning surfaces with acetone here) but for an experiment like this, I’m happy to leave it as is.

The kit comes with both ABS and PLA filaments, with 2 temperature settings on the pen to match. However it would definitely be interesting to experiment with some different materials – I see on the 3Doodler website they also sell a Flexy Material in numerous colours. I wonder if you could put a conductive filament through to draw electronic circuits? Hmm that’s not a bad idea, perhaps there is more use to this pen than I first thought…

– Posted by James Novak

Cocoon Create Extruder Fix

After yesterday’s exciting successes with my new Cocoon Create 3D printer from Aldi, today there have been some hiccups – namely I tried to change filaments and could not load any new filament into the extruder. The filament would start to load, and after about 5mm there would be a “clunk, clunk, clunk” sound as the motor was grinding the filament but not pushing it any further down. Being jammed, there were 2 possibilities; either the filament was not able to find its way down towards the nozzle because something was misaligned, or there was some old filament jammed in there. So after only 24 hours of ownership, it was time to hack at it and take apart the extruder. It’s actually very easy, and I’ve used the photos above to try and illustrate how to fix a jam.

1. Use an allen key to remove the 2 screws on the left side of the extruder – be careful as these hold the entire extruder together, so you want to catch the parts rather than let them drop. Also make sure your nozzle is nice and cool!
2. The fan can just hang from its wires, but the heat-sink and 2 white spacers can be removed, leaving the motor and feeder as shown in the second photo. This is what feeds the filament down into the nozzle (entering from where my thumb is). Check for any loose material in here and clean (mine was fine).
3. As circled in photo 3, this little piece of the remaining first filament is the culprit of my jamming. It wasn’t enough to grab with pliers, so I just turned on the printer, heated the nozzle, and then used a small allen key to push all the material down through the extruder, leaving a large opening for the new material to enter.
4. Done. Just re-assemble and make sure all the little wire connections are firmly attached.

This quick process solved the problem and new material loaded without any further problems. After looking on the Cocoon Create website it seems that there is almost no support or FAQ as yet, so I hope this helps anyone stuck.

– Posted by James Novak

How to Repair STL Files

My first blog article for the new year for my friends at Pinshape is now available, and walks step-by-step through a number of common repairs you may need to make to your files prior to 3D printing – just click this link to read all about it and follow along. The main things covered are:

1. How to repair holes and gaps in surfaces
2. How to delete or trim unwanted surfaces, particularly useful for 3D scan data
3. How to add thickness to surface geometry, turning it into a solid
4. How to reduce file size

All of the tutorials use the freely available software Meshmixer from Autodesk, as it’s by far been the most user friendly tool I’ve found for working with .stl files, however you should have similar success using other free software like MeshLab or netfabb Basic. This tutorial builds upon another similar tutorial I wrote for Pinshape in 2015 called How to Modify an STL File: A Beginner’s Guide which shows you how to take a downloaded .stl (or one of your own) and begin customising it for your own needs, for example adding text onto the design.

I hope it helps improve your designs and your 3D printing success rate 🙂

– Posted by James Novak

1/2/2016 UPDATE: A new version of Meshmixer has just been released – Makezine has just posted a really good summary of some of the exciting new features http://makezine.com/2016/01/30/autodesk-releases-meshmixer-3/

UPDATE 30/03/2016: With the sad news that Pinshape has closed down (read more here), you can now read this article in the PDF below.

Click here to open the PDF

3D Printed SUP Paddle Lock

With plenty of my designs available for you to download and make yourself on Thingiverse and Pinshape, this is officially the first product I’ve created through additive manufacturing for retail sale!

My local surf shop, Surf Connect, approached me with a unique problem: popular Stand Up Paddle (SUP) brand Ozoboard uses a snap-fit locking mechanism to allow for adjustment of the paddle length, but many customers have been losing them into the ocean. While it seems securely locked with the snap details onto the paddle shaft, somehow people just keep knocking them off, I guess because it is close to where people may be gripping the paddle with their hands. This is the grey part pictured in the middle image on the left.

A replacement part costs around $20 to buy, and to make things worse, the company making them is no longer able to supply them. So there are people stuck with paddles they can’t use because of this one small part. Well, as anyone who knows me would say, I’m up for any excuse to 3D print something new!

Some digital calipers, some Solidworks CAD software, and an hour or so of time is all it took to reverse engineer the lock details. The only trick is the metal pin which has been moulded into the original part, and takes all the forces of the 2 paddle shafts when they are locked in place. To do this as simply as possible I just used a screw with a matching diameter (a M6 x 12mm in 316 stainless steel) as shown in the top left image, gluing this with Araldite into place and concealing with a little cap. Other than the extra bulge to accommodate this, the 2 parts are identical.

Both parts were 3D printed on an Up! Plus 2 in about 50 minutes, and as you can see in the top right image, fits perfectly! Even I’m surprised that a) it fits first time, and b) it didn’t snap when popping around the paddle! The only thing yet to be seen is how well it holds up to use out on the water…

I will now be supplying these to Surf Connect exclusively to sell, since there is a genuine demand for them and no other way for people to get them. As a keen kitesurfer (and now SUPer with one of these Ozoboard paddles), I can imagine how annoying it is to be stuck on land when it’s perfect summer weather! If you need one, please get in touch. You can also download the design from Pinshape by clicking here.

– Posted by James Novak