June 13, 2010

I performed surgery on my T-Rex 250 this morning. It was flying great so I hope I didn't goof up a good thing. I moved the elevator servo from the location hsown in the owner's manual to the opposite side of the frame. The reason for doing so was to try to balance the helicopter a little better. Both the tail servo and the elevator servo were hanging off the same side of the frame. By moving one of them there are now two servos on each side of the frame. This should help the model hover a fly a little better with less trim. The fact that you might want to do this seems obvious but I didn't think of it until I read about it on the T-Rex 250 forum on the Helifreak.com. Afterwards I went out for a quick hover. Some trim changes and a mechanical adjustment were needed. I think this will be a change for the good. It was worth the time I spent on it.

June 12, 2010

I decided to replace the head on my T-Rex 450XL / HK 450 with the head that shipped with the HK 450. There was a lot of slop in the old plastic XL head. I was interested in seeing how much better it might fly with the HK head. I disassembled most of the HK head. I applied CA on all of the metal to plastic screws and blue Loctite on all of the metal to metal screws. I had some trouble getting the links adjusted like I wanted and finally decided I was close enough and brought it out for a quick hover. There were no surprises. I am looking forward to flying it after I charge up some flight packs.

I also performed some maintenance on a couple of lithium battery packs. After about eight charges on one of my new Flightmax 3S 800mAh packs one of the cells puffed up big time. I used it a couple of times like that but it was losing it charge quick. Rather than tossing the pack I removed the damaged cell and turned it into a 2S 800 pack. Since it wasn't the middle cell of the pack that went bad the modification was pretty easy. I just needed a rotary tool and a soldering iron. It works fine now!

I also had a 3S 1350 ThunderPower pack that went "bad" because I could no longer balance charge it with my FMA CellPro charger. It turns out that the cells were fine. This pack shipped with a glider I bought on RC Groups and I later found that it really was a 2S pack that the owner changed to a 3S pack. It looks like the wire he added for the balance tap wasn't soldered into the pack and it came loose.Because of that the CellPro could not charge it. I soldered the loose wire to the appropriate tab and now its like new again. Now I have two packs I can use on my Radian and Slow Stik.