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Helis and fixed wing

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Wednesday, December 15, 2010

EXI 450 Project: ESC Placement

This was a tougher job than I thought because things never quite fit the way they should, but overall it wasnt that hard to do.

In dry running the placement I found that the ESC is a hair too wide for the frame, so its squished in between the plates.The shrink wrap around the ESC frayed a bit, frustrating only my OCD.  Getting nervous with the tight fit and fraying, I looked for other places it might go, to no avail. It was going to have to go there if I wanted it clean, and inside the frame.  I had to squish them motor wire pins a little to get them to fit into the ESC leads, but they are still lock tight. In pulling the black one off, the pin came off the ESC wire; it was cold soldered... I had to re-solder that and re-shrink wrap it. It then took some time to come up with a way to fold the wires back, keeping the ESC motor wires off the motor pinion as Finless Bob warns, and then getting the wires to fold back on themselves to fit inside the frame. The plastic tie I used to hold the Velcro'd ESC and the ESC wires in place could not go alongside the tight fitting ESC, so I had to slant that down a bit. In the end its a pretty clean install.

In this first pic you can see the battery tray as if hinged forward. The blue ESC motor leads come out of the ESC, and fold over it. The plastic tie can be seen, with a piece of unheated shrink wrap around it to protect the wires underneath from vibration letting the tie cut through them. The motor leads (the red, black and yellow ones) lead back into the frame towards the motor.  The BEC wire to the receiver is the white, red and black one, also going back into the frame.

In this pic looking down through the frame at the motor pinion, you can see the flatehead regular 4M screws I had to use for the motor, which shipped with the wrong screws. You can also see same 3 blue ESC wires folding back into the frame, with the battery tray "hinged" back into place and bolted in. The blue wires are well clear of the pinion, even when the motor gets adjusted for backlash against the main gear later in the build.

Finally, in this pic you can see the ESC below the Velcro on the battery tray, with some clear plastic tape I placed to protect the sides of the ESC, and a bit of the plastic tie holding the ESC in place. You can also see a little blue wire in the front inside of the frame, where they connect to the motor wires that come up as the red, black and yellow wires held together away from the outrunner motor with a yellow plastic tie. the receiver wire is the red, black and white wire that is temporarily spewing out from under the motor.

You can't tell from the pics, but the sides of the frame just below the battery tray (the Velcro) bulge ever so slightly. This is the best place for the ESC, where it is in the Align manual, and where Finless put his. It looks pretty good. I just did not want it hanging off the sides, and there was really no way to situate it so the wires at either end could go where they needed to.

Next I will install the servos. I am still waiting on the batteries from Hobby King in China that I ordered on 11/26. Last night, not wanting to delay the servo set up and the ESC programming any further and having no idea when the batteries would arrive, I ordered a battery from Hobbypartz knowing that in doing so I guaranteed they would arrive the next day. Of course, today an international registered mail package came to the post office, which I suspect has the batteries in it, but it will have ot wait until I can pick it up...

I also ordered another Hobbywing/Volcano ESC programming card from Hobbypartz because I may have fried the one I already have when playing with it (I was bored). I attached a 7.4V battery to it and it got hot at the connection and the lights came on like they were supposed to, but were pretty bright (what is it with me and batteries?).  I thought it would be fine, but I should have remembered that the BEC down regulates the voltage from the 7.4V battery to 5V... so I was not surprised to turn the page of the card's manual to read, "Do not connect to a battery of greater than 5V". So, when I did connect it to a 3.4V battery, only the middle three lights lit up. I then watched a vid on programming the ESC, and the host commented on not connecting a higher voltage battery because  "It might fry it...".  Pretty sure I have fried it and not wanting to delay myself further, as before, I ordered one with the battery.

Oh, the lessons we learn that constitute experience.

1 comment :

  1. Hi, I am visit your blogs and read content. Your services are very nice. I am very impressed from your content and service. I know that Motor esc are run very smoothly.