Getting more throttle resolution from an old RC Controller.

I have been flying my tricopter around lately, and have been getting a bit better at not running it into things. However, one thing in particular has been bugging me about the my controller for the tricopter. The throttle stick resolution has felt really low, especially when compared to a friend's newer and nicer controller. When flying it around at the Makery there was about one notch of difference between it barely skidding around the floor, and heading straight to the ceiling.

So, tonight I took it apart to see what I could do about getting finer control out of it.  It turns out there is just a small spring arm with a bump at the end riding on notches molded on the back of the joystick. I believe this is pretty standard from what I’ve seen online.

This is one of the times where having a 3D printer, and knowing how it works pays off. I needed a very specialized piece with several notches running up a curved surface. This immediately reminded me of the surface that 3D printers make as they lay down each layer of an object. So I took a few measurements, fired up the 3D modeling software and made a “cap” that will sit on top the current notches, so that the spring rides on it instead. You will notice that the 3D model has a perfectly smooth surface, but we get the ridges that it needs by setting the layer height for the printer.  I measured the old notches at .5mm on center, so I set the layer height to .3mm for the first try.

After trying to print one by itself, and having it end up all blobby and malformed, I remembered to turn the “cool” setting on in Slic3r,  and put five of them on a plate to make sure they have time to cool between layers. I also turned the fan on, which I believe is why they all came detached from the build platform halfway through the print. After turning that off and trying it again, 3 out of the 5 finished properly, and I was able to test it out. It worked great! The new piece fit right over the top of the old piece and the spring lined up perfectly on top.

It turned out to be a great improvement over the original. The ridges were smaller and more rounded, which gave it a lighter feel, but the spring was compressed more, so it still felt like it was strong enough to hold position. And most importantly, it had better resolution, and I can fly it around without worrying so much about it running into the ceiling while indoors.

All in all it took about an hour from idea to completion. I would say it’s definitely worth trying this if your controller is like mine.

 

The 3d Printers at Work

Its amazing what you can print these days. We tested out the Mendel Prusa last evening by printing this cool little light bulb sculpture.

If you could make any design in your head come to life, what would it be?

Much of what we can do these days with 3D printing is due to the hard work of Brandon.  Be sure and check out the new RepRap piece he’s making to ensure 3D printing just gets better and better: Vertical X-Axis

Be sure to check out our new “Makery Mendel” channel on Ustream, located in the links to the right.  Whenever the Makery is printing, you can see it happening.

Printer Parts – Heater Tube

Jason notes that I forgot to post a photo of the other Mendel parts I’ve been building for the MakeryMendel.  Below are photos of a stainless steel heater tube (the one that I didn’t ruin by welding a drillbit to the inside) as well as the “order form” that Brandon sent me. His drawings aren’t anything fancy, but we seem to have gotten the job done.  For scale, the bushing in the photo is 1″ OAL, and the threaded rod heater is 1.5″ OAL.  The picture with the fire is a prototype plaster bushing that we were testing.  It’d probably work, but we dried it a bit too fast and it developed a nasty crack.

BrandonSpec (Medium) Plaster Heater