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3D Printed Anti Vibration Mount

Posted On: 17:15:13 - 06/12/2014 - Viewed: 1641

By GuyMcCaldin with the original Blog article here: http://diydrones.com/profiles/blogs/3d-printed-anti-vibration-mount

 

Over the last few weeks, I've been prototyping different anti vibration mount designs using an Up Mini 3D printer. I wanted something that performed well, using affordable and readily available components.

 

 

The first design started with anti vibration dampeners in a simple vertical configuration. This suffered from too much play in the horizontal plane, which might have caused instability in quick accelerations. The next design rotated the dampeners 45°, which resulted in much more even resistance across the horizontal and vertical planes.

 

The large rubber dampeners provide outstanding isolation. Too much in fact. The ideal anti vibration mount isolates the controller from high frequency vibrations, but conducts lower frequency vibrations that might represent small changes in attitude. For the next design, I moved to smaller and slightly stiffer dampeners available from Hobby King.

 

 

I've been testing them on a Turnigy Talon tricopter, using an APM 2.5. The GPS is mounted to the top of the APM to increase the moving weight, which assists slightly in reducing higher frequency vibrations.

 

The results so far suggest that it's working very well:

 

The above graph is taken from a two minute hover in loiter mode. All axes are below ±1g, which exceeds the specifications set out in Arducopter guidelines.

 

Using a tool (link) that Forrest Frantz developed, we can see these results from another perspective:

 

The Acceleration results are still excellent, but the pitch and roll stability shows a bit of oscillation. I'm using default PID values which would definitely benefit from tuning, and flying in slightly windy conditions. I'm also new to rotary wing flight, so I'm still honing my flying skills. I'm able to keep the tricopter in a 1m x 1m x 1m cube, but it slowly drifts around if there is a change in wind.

 

These are the most likely causes, but in the interests of full disclosure, I wanted to mention that it could be caused by the APM not responding to small changes in attitude if the mount is creating too much isolation. It certainly doesn't appear to be affecting flying performance, the tricopter is impressively stable in loiter mode. I won't know if it's an issue or not until more people try Forrest's tool out, so I have more data to compare my results to (you can find the forum thread here)

 

If you have access to a 3D printer, you can download the STL files here:

Omnimac APM Mount v1.5.stl

 

Alternatively, I've uploaded the design to Shapeways. You can purchase it starting from $22.92 depending on material:

Shapeways Omnimac APM Mount v1.5

I've include a 30% margin in the price (~$5) that will go towards a trip to Africa in November, where I'll be donating time and resources using 3DR powered UAS in wildlife research and conservation.

 

To complete the mount, you'll need these dampers which cost $1.20 from Hobby King:

General Purpose Anti-Vibration Rubber w/M3 x 11mm Screw and M3 Nylo...

 

The mount can be installed using double sided tape, or M3 screws spaced at 45mm x 45mm. If you'd like me to modify the file to suit the mounting options of your airframe, just let me know.

 

The logfile that was used to produce the results shown above can be downloaded from here:

Turnigy Talon 2min Loiter (default PIDs)

 

Update, 30th of April 2014

Earlier this year, Bob Moore approached me and asked if he could become a distributer for the Omnimac series of mounts. I'm pleased to announce his site is now live, and can be viewed at:

 

http://www.readymade3d.com/

 

Purchasing through Bob will continue to fund my wildlife conservation and research projects in Africa, as well as the development of new 3D printed products for the community. You will also get a complete mount (including dampeners) at a cheaper price than Shapeways, that has been printed using FDM technology. Any queries regarding Bob's products should be directed to his contact page, which can be found here: Contact Us


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