Patrick O'Keefe

This may be obvious to those who have experience with RC stuff, but I figured I would share my experience anyways because I think a couple of people on the forum face the same challenge. The problem with the most popular battery mentioned on the forum (Zippy Lightmax 4000mAh) is that it has bullet plugs for the discharge connectors. Not only that, but there’s one male and one female. Weird.

Google Maps found a hobby store about 35 minutes south of here, and I made the epic journey this afternoon. It’s called Hobby Shop World and the man who owns the place was very helpful. He even gave me 10% off some of the parts! Anyways, I picked up some Deans connectors and four 9 inch servo extension wires. The servo extensions will be used to connect the receiver (after I buy a new one) to the Arduino. Thanks to sumsumdum on the forum for this post.

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So everything was coming along just fine until I just broke the AR500 receiver. I was being a noob and was probing 5 Volts around the pins as if it was no big deal. The LED stopped flickering (which is always bad) and when I touched the receiver, it was extraordinarily hot. I’m pretty sure it is dead to the world.

The good news is that the frame, motors, and props are all assembled. Also, the new XBee shield came in the mail today. The old one was no good because it didn’t allow any room between it and the protoshield. All of that soldering for nothing! The new one (as you can see below) is shaped like an ‘L’ and allows us to mount the IDG300 gyroscope vertically to detect yaw. Sweet.

I just posted on the forum over at RCGroups begging for help with my current problems. Hopefully they will be kind enough to provide some insight to get over this 43 foot speed bump.

I have written code to test the 5DOF and it is working very well. I’ll post screenshots soon if I get it looking pretty.

This was one of those things that needed to be done, but just difficult to get around to. It actually turned out to be much more interesting that I expected. Here’s the problem: the EPP1045 propellers had a hole that was too small in the center. We needed to bore a wider hole so that they could slide onto the brushless motors. What good is a helicopter with no props? José and I went to the machine shop on campus and they were extraordinarily helpful. It turns out the brushless motors had a 10/32″ diameter and the attendant (appropriately named Angel) set us up with a drill press and a special vice and bit. We even went a step further and threaded the inside of the widened hole to match perfectly with the motor’s threading. Quite a learning process. It was very cool to see how the machine shop works, and it is good to know they are very supportive of our project. We’re going to have to go back soon to cut and drill into some carbon fiber. Now we can assemble the props to the motors, mount them on the frame, place the ESCs on the frame, and fire up some test code to see if we can successfully arm the system. Pictures are below. Click on any to enlarge.

Machine Shop

José on the drill press

Threading the props

The 5DOF unit from Sparkfun came in the mail today. Also, the Rx Tx José and I ordered came a couple of days ago. Below are some pictures. Click on any to enlarge. The quarter is just so you can get a sense of scale. I just soldered some headers to the sensors so soon they’ll be attached to the protoshield.

A bunch of parts came in the mail the other day. I also just got news that the only remaining part on backorder (IMU 5DOF) shipped today! Looks like things are coming together. Below you can see the assembled protoshield where the sensors will be mounted. I also took some better pictures of the XBee shield since the last ones were taken with the iPhone.

Below are the frame, the battery, the battery charger, the BESC, and the brushless motors. I’ve already assembled some of this with the team and I’ll post pics soon. The battery charger is a little confusing…but it is one of the many details that will be worked out in the process.

Next up, choosing a Tx Rx and implementing some sensors in code to see how things work.

Parts have finally been ordered to begin the project! They should be arriving within the next week or two.

• Seeeduino – two more ‘Analog In’s than an Arduino
• Protoshield Kit
  
• XBee Shield Kit
• Turnigy Brushless Motors x4
  
• Turnigy Brushless ESC x4
• 4000 mAh LiPoly Battery
  
• MikroKopter Frame
• EPP1045 Propellers
  
• IMU 5 Degrees of Freedom
  
• Dual Axis Gyro IDG300
  

Still no official purchase for receiver/transmitter. As you can guess from above there will be an XBee on board, but will it be just for debugging or will it end up being the main control too?