Saturday, February 2, 2019

Building new NiMH Packs...

While shut-in sick over the last few weeks, I took an opportunity to build a batch of 5 cell NiMH 3600 mAh packs for some of my airplanes. They're bonded, soldered, and covered in this heavy-duty heat shrink sleeve. One of these is going in my Kadet Senior first, once I figure out where the fuel tank leak is coming from. 

Monday, January 28, 2019

More battery problems, Kadet Senior...

Wow...I've been working on these airplanes since back in November of 2018. When you stop flying for a few years, everything goes bad. I've repaired my portable glow driver, my power panel, my electric starter, my fuel pump, and pretty much all of the batteries in all of my airplanes. Oh well, at least it's winter and I have time to do it. When I pulled the Sig Kadet Senior down, I discovered a bunch of problems...bad flight battery, leaky fuel tank, and a broken exhaust header on the engine. Here, you'll see the bad battery and the packing from around the fuel tank that shows the evidence of a fuel tank leak. Hopefully, by the time warm weather is here, I'll be all repaired and ready to's a few pics from the tear down of my Senior. 

Tuesday, January 22, 2019

My Sharper Image DX-4 Drone

Debbie got this for me on my birthday, in 2016. I still have it, and it still flies great with the little built-in 3.7vdc 800mah internal battery. This is a basic entry level drone without GPS, but it does have a 3mp camera built in, and streams back to the phone on WiFi. 


It flies about 8-10 minutes on a charge. After poking around a bit, I see where folks are piggy-backing a 12mah 1 cell battery on the bottom and pushing flights out to about 15 minutes. This thing is a blast to fly in the yard. Gotta figure out how to have my phone not disconnect from it and reconnect to the home WiFi when the signal from the drone is a little sketchy. Once I get up near the top of my ham radio tower, it tries to reconnect to the home WiFi and stops recording...trivial, and I haven't put my effort into a fix :-) I guess I could just delete the home WiFi log in stuff from the phone when I'm playing with it...just an idea.


Considering my lame drone flying skills, this sweetie will keep me entertained for a long time. It's easy to fly, hovers nicely, does a few stunts, and is pretty fast. Below are also a few cheesy videos I made with it...


Saturday, December 8, 2018

Building a new flight battery for the Lucky 13...

Wow, I'm still checking and repairing batteries. This is a great time of year for this sort of work, since I'm not real keen on flying in cold weather :-) The Lucky-13 flight battery was shot...a 3000 mAh battery that was checking about 800 mAh...not good! I still have a bunch of cells in a RC car pack that cycle nicely. I set my Accu-Cycle up to test single cells, and test them all, one cell at the time. Here, I chopped out a nice 5 cell pack that tests at about 3500 mAh. I installed the connector from the old pack, slipped it in a piece of sleeve, and shrank it down. Here it is, ready to be reinstalled into it's new home. Once that's in place, I'll move on to the next bird and check it's flight battery. 

Two chunks of 3600 mAh NiMH batteries broken apart, testing each cell, separately.

5 cells, all tacked together. Next, it's time to install the power connector.

 A final test, with all 5 cells in series. It cycled out at about 3500 mAh.

Fresh heat shrink covering installed, ready for installation in the airplane.

Dave AMA119484

Friday, December 7, 2018

Still Repairing Stuff...

Well, I picked a good time of year to decide I was gonna check things over and get back active in the local flying club, since it seems I'll be busy repairing stuff for a while... Things have been "parked" over 2 years, and it's amazing how much goes bad from inactivity. While checking over my flight gear, I discovered my glow driver wasn't working. I opened it up, and found the battery had failed and was leaking. No biggie, I've been chopping up a good 16 cell 3000 NiMH RC car pack for batteries to build more receiver packs for my airplanes, so I pulled a sub-C cell from that and slipped it in. Nothing. I opened it up, and saw the center contact was oxidized black. I grabbed the Dremel tool and a small stone, and removed the oxidation to expose the shiny yellow brass contact. Once reassembled, all was well. Another piece of field gear ready to go!

My broken glow driver...
A 3000 mah NiMH salvaged from the RC car pack...

I removed the outer jacket so it would slide into the glow driver easily...

The center contact in the upper housing was oxidized black, and wouldn't make contact with the battery...

After repairs, all was well and ready to go flying!

Dave AMA119484

Tuesday, November 20, 2018

Hangar 9 Twist Battery Check Out!

I can't believe, that after 2 years in storage, the Tenergy 5 cell 2000 mAH NiMH battery in my Twist actually checks out to be good. It looks like the 'Red Neck' battery maintenance system described in my previous post actually worked. Over 2 years of hitting the battery with approximately 25 mAH of charge per day while in storage, and it cycles as if it were new. 

 It's nice to get lucky every now and again :-) Now, it's time to move on to the next airplane and see how it checks out. 

Dave AMA119484

Saturday, November 17, 2018

More from the Mothballs...

Still getting things ready to go after a 2+ year break... I pulled this 12 year old Hangar 9 Twist .40 down, and put it on the Accu-Cycle. It was stored on my "red-neck" battery maintenance system for the last couple of years... That consists of a conventional 50 mAH charger connected to a Christmas tree timer. I have it come on for 30 minutes/day, and then back off. I never bothered to check it, other than to verify that the charge light was still coming on when the timer was passing power. So far, it looks as if the 5 cell 1500 mAH battery is fine. One more cycle to verify, then on to the next bird. So far, so good!

Dave AMA119484

Friday, November 16, 2018

Checking Flight Batteries...

Well, here we go, after a LONG period of inactivity. It's been about 2 years since I've had any of my birds in the sky, other then little park flyers and such. I installed new batteries in everything about 2-1/2 years ago, flew a few times, and put them up. Now, once again, all of my batteries are shot. I'm trying to cycle them and see if they're worth using, but I have a bad feeling they'll all need to be replaced. In these photos, you'll see an old 16 cell NiMH RC Car pack I've cut open to cycle cell groups to see if I can salvage any of it for use as a 4 or 5 cell flight battery. So far, these cells seem to cycle at about the right mAH rating. Next, to leave them sit a few days and see if they loose any charge from internal leaks...

I use a pair of Hobbico Accu-Cycle units on 12 VDC supplies, and keep them cool by pushing air through their ventilated cases with a small 12 VDC muffin fan. These work pretty good, but Accu-Cycle units will generate a lot of heat in the cycle mode with the discharge rate set to .300 mAh.

Dave AMA119484