So here’s something new and different… This is a gadget I designed and made with a 3D printer. I wanted to think of a really snazzy name for it but just settled on “The Party Hat”. It’s a party in your mouth? No. It’s a party in your pants? No. It’s a party in your pyramid! YES! Wait, what?! This piece of kit allows for an alternate way to set up your pyramid shelter with an A-Frame pitch (two trekking poles). Since 3D printers are relatively easy to access now, you can find this project offered here as an open source for making your own. This post contains the model(s), tips, and information you need to print your own Party Hat, as well as some background on 3D printing. Let the Party People rejoice!
The Party Hat
What is it? A small and light plastic hub that will make for a cleaner A-Frame pitch on your pyramid shelter. The weight is 0.9 oz (26g) which can vary by material/print quality/printer used.
What problems does it solve? Rather than having criss-crossed handles in the apex of your pyramid, you get a nice symmetrically rounded wedge that nests snugly into place. This eliminates hot spots on the shelter material, evenly distributes stresses, and makes for a less wobbly pitch. Locus Gear uses a similar approach, the DPTE, which inspired this idea because I felt there was room to improve on that design. The benefits over the DPTE are mostly the same, and the Party Hat eliminates the fuss of having the pole jacks slip out of the DPTE while setting up a pitch.
How to use it? (1) Insert two pole jacks into the Party Hat. (2) Insert one trekking pole tip into one of the pole jacks. (3) Slip the assembly through the door of the shelter with the Party Hat going up into the top of the shelter and the trekking pole at the far side of the shelter (4) assemble the second trekking pole into the other pole jack to complete the pitch. For extra security you may choose to have a pre-measured piece of lightweight guyline to tie the pole handles together (to keep them from spreading apart/stressing the tips); or wedge them against a rock, or extra tent stake.
Need some more detail? The shape is designed to match the shape of a specific shelter(s) and to achieve the proper pole angles/spacing – so it’s not a one-size-fits-all design. Right now the models for the MLD Duomid are available, these also fit the Locus Gear Khufu. A Solomid version will be available soon and also one for the previous Solomid “XL”. Each model comes with two options – Inch and Metric. The “Inch” version is designed for 5/8″ diameter pole jacks (the ones MLD and others offer). The “Metric” version is designed for 18mm pole jacks (the ones Locus Gear and others offer). It’s important to download the model for the shelter and pole jacks that you own. If you have another shelter and would like a Party Hat designed for it, check out the “Spec Drawing” below, set up your shelter, and send us the A, B, and C measurements.
Unknowns?At the time of publishing this article, there are only a couple of these in the wild, aside from the prototypes I’ve been testing – so there are a few unknowns. The first is, how will this work while using various inners, we will have some answers to that soon, at least with the MLD inners (both Solo and Duo). I will also take a look at the Locus Gear inner since I own it, but have not dug it out of the gear closet yet. The next two questions are somewhat related, in the sense that the material choice will affect the answer. First, how well will the Party Hat handle freezing temperatures, the next being how will it hold up to exposure to stress, UV, and moisture over time. Feedback from others over time will help answer these.
Use one of the links below to download the model you need for your shelter and pole jack combination. The model is an “.STL” file. It’s ready for printing and can be viewed with any .STL viewer (such as viewSTL.com).
Inch versions (MLD style pole jacks):
- Duomid / Khufu – inch
- Solomid – inch (coming soon…)
Metric versions (Locus Gear style pole jacks):
- Duomid / Khufu – inch
- Solomid – inch (coming soon…)
Tips For Printing Your Own
It’s not difficult to print a part, but here are some tips/info that you would probably want to consider and/or pass along to whomever you work with…
- Find a Printer: Obvious, yes, but in case you don’t know where to begin, this should help.
- Shapeways: These folks are an over-the-web business. They’ve been the forerunner in outsourced 3D printing for some time and offer a full line of services.
- UPS Store: Yes, UPS has gotten in on the game. More and more of the brick and mortar UPS stores are offering 3D printing services. Check your local branch out.
- Public Library: Many libraries are jumping on board with this technology as a way to remain relevant in the electronic age. You shouldn’t need an excuse to visit the library, but if you do…
- Choose the right Material: ABS would probably be the best choice for the Party Hat due to its low moisture absorption and resistance to UV, however PLA seems to be a common material and so far has not presented any problems.
- Orientation Matters: This part should be printed with the apex pointing upward (in the Z-direction). This will give the part much better strength.
- Use Support: When the part is printed in the vertical orientation (see previous note) you’ll want to tell the printer to “use support”, sometimes called “rafts”. These are lightweight support features that can be easily trimmed or sanded off the finished part. The printer software can automatically calculate where supports are needed.
- Verify the Size: Before printing, when the model is imported into the printer software, it may appear very small. If this happens you’ll need to scale it up by a factor of 25.4 (conversion from mm to in).
- Sanding: The bottom surfaces (where the supports will be added during printing) will be a little rough after removing the support material. Using a sheet of 120 grit sand paper will clean them up. Just lay the sand paper on a flat surface and hold it while moving the Party Hat back and forth. The sockets for the pole jacks will also need a very light sand most likely. Check the fit before sanding the sockets. It should be a little tight and the part is designed to expand a small amount, but if you have to really force it they’ll need to be sanded. Wrapping some sand paper around something like a marker pen and doing a light sanding inside the socket should do the trick. Don’t over-do it otherwise the fit will become loose and not hold the pole jacks in place!
- Print Quality May Vary: My point of reference is the Ultimaker 2.0. These are nice machines. I have been using the “normal” setting which produces a very nice result (it takes about 6 hours to print). Varying the in-fill and shell thickness settings will affect the quality as well. I have been working with the default values and have not seen a need to adjust these settings (yet); the parts appear to have good strength, and are still very light! You may need to experiment with the settings. Feedback (comments/email) on your experiences are welcomed!
This design as undergone testing and revisions. The current revision will always be in the file name (currently “40”, meaning 4.0). If any future changes are made the revision history will be posted here.
A Primer on 3D Printing… For the Curious
I have to thank the Marin City Library for making a 3D printing program possible. It’s great to see libraries evolving to stay relevant and providing exposure to technology that will inspire the current generation to take interest in science, engineering, and design.
3D Printing allows designs to brought to life relatively quickly with a variety of plastic (and other) materials. With 3D printing, material is added layer by layer, like thin slices being stacked on top of each other. This can have it’s challenges, printing areas with open space below them for example – but it also has advantages. With 3D printing it’s possible to create designs with complex internal geometry; this is not possible with other manufacturing methods, even casting and injection molding have their limitations when it comes to design complexity. The process is not suited to mass manufacturing, however it’s a great tool for making one-off designs and prototypes.
For those who have never seen a 3D printer in action, solid material, which is on a spool, gets fed into a heated nozzle that melts and extrudes it out as a very fine filament. The nozzle size determines the diameter of the extruded material, and thus will determine how “fine” of a finish a printer can produce. The print head moves in the X and Y directions simultaneously and moves upward in the Z direction when a layer is completed. The printer software automatically calculates how to print the part when the model is loaded into it. Print settings can be adjusted from the software as well (temperature, feed rate, travel speed, shell thickness, infill percentage, etc…) in order to get the best results for any given part. There is definitely some learning curve associated with diving into the settings, but thankfully printers come pre-configured with reliable default settings.
As far as creating models goes, there are a range of programs out there. Tools like Google Sketchup are not a bad introduction, but they fall short on features. If you are very creative, and don’t mind spending potentially a lot of time working on a design, it’s possible to model up parts with a bit of complexity. The paid versions offer more features but at the point of spending money it might be worthwhile looking into an application such as Autodesk Fusion. It’s a broad topic, needless to say there is learning curve here as well, but much of the software now is very intuitive, putting your ideas potentially only a few hours away from concept to complete. Pretty cool!
That’s all we got! If you print your own please let us know how it works out! If you have questions, please use the comment form below! Party On and… Hike It. Like It.