RE: Building a Dynaflite Super Decathlon
 

Ed,

How many batteries are you running? The weight I have is with two A123, 2300mah on the rx and one 4.8 volt 1650 mah Nimh on the ig. I hope I havn't ruined the ignition battery. I inadvertantly depleted too much power off of it and then to make matters worse I overcharged it. It's got good voltage so I'm going to cycle it about three times with my cycler and see how it looks.

RE: Building a Dynaflite Super Decathlon
 

My zenoah is magneto ignition, so I don't have electronic ignition on it,

I am running 2/ 5 cell nimih batteries. 2000mah each

Hope your battery is still ok.
ED

RE: Building a Dynaflite Super Decathlon
 

To Bill and Ed.
Hi to you both. I have read that you both are using twin battery packs for your receivers. I know that this is probably not the forum where this should be discussed but as a builder of a Dyna SD I value your opinions. My question are,
1. Can you connect the two packs to a "Y" and plug them into the receiver?
2. Should each pack have it's own switch and charge receptacle?
3. What prevents the battery packs from cross feeding to each other?
4. Are there any other concerns that I should be aware of?

I hope you can advise me

All the best


Mike

RE: Building a Dynaflite Super Decathlon
 

Mike,

I think your question is legit since we are running dual bats on our Decaths. Suggestions to your four questions as you asked them:

1) yes but it would be much better to connect the two packs to two separate ports on the rx. I think it would be best to connect one to the bat port and one to a servo port at the opposite end of the rx bus. It may be necessary to use a Y with a servo if you don't have a free servo port to plug into.

2) Yes dual switches and charge ports for redundancy since normally failures occur at connections or switches.

3) they will feed back and forth to some extent in an attempt to equalize so always use the same size and battery chemistries. I think some may have different thoughts on this one but in my opinion, this is safest.

4) Absolutely there are concerns. CAUTION!!! If both packs are connected to the receiver at the same time NEVER charge both batteries simultaneously unless you have one of the bats unplugged from the rx. You can charge one at a time without unplugging one of them. Charging them at the same time causes a common ground issue and can ruin the bats or possibly in rare cases cause a fire. NOTE: Some (very few) changers have built in circuitry to take care of the common ground phenomenon. Safest to charge one at a time. Then you don't. Have to unplug anything.

RE: Building a Dynaflite Super Decathlon
 

Mike

There are more people that visit here more qualified than me on electrical but I have found the above to be safe and sure in my applications. At the same time please note there are some other ways but I don't feel comfortable with them. I hope some of these more knowledgeable folks will jump in here and comment.

RE: Building a Dynaflite Super Decathlon
 

Thanks Bill,
I appreciate that you answered. I'll consider using two batt packs on my new build, a "AMR" ECLIPSE with a DLE 55 on the front.
I'm using all high torque servos and the plane will weigh about 23 lbs. I'm almost finished, just completing the plumbing and electrical but for a big plane, there is little room to spare inside.
Thanks again,

All the best,
Mike

RE: Building a Dynaflite Super Decathlon
 

Mike

Go look at the hangtimes.com site. There is a tremendous amount of info on that site concerning nimh, a123, and some on chargers. I have been purchasing my batteries there for years and IMO he has great quality.
Worth a read even if you get your bats at other sources. He is very knowledgeable.

RE: Building a Dynaflite Super Decathlon
 

I use 2) 5 cell ni mh with a y harness, through one switch, I have used this for several years on different planes.<div>
</div><div>to do this the packs must be identical.</div><div>
</div><div>I use it due to the number of servos and type, to get more mah out of the system</div><div>
</div><div>I have always charged both through the switch charge jack,, and haven't had problems, every fall and spring I take them out and discharge and charge separatly.</div><div>
</div><div>With that being said, I am starting to switch over to the LIFE batteries, they hold their charge better and can fast charge. With these batteries, you would only need one, But you could do dual for redundancy, in that case you would want the dual switch set ups.</div><div>
</div><div>I have the Hitec Aurora, and it tells me the receiver voltage at all times, and I have never had the alarm go off on any set up while flying, So that helps with a piece of mind when flying. When the batteries start to get low, I move both sticks, and can see the voltage drop significantly. then you know to either charge them, or pack it in for the day.</div><div>
</div><div>
</div>

RE: Building a Dynaflite Super Decathlon
 

MIke,
I wanted to chime in on the battery set-up as I done something similair on my Stinson Reliant except I used and Electrodynamic Pow'r Back'r with two heavy duty switches and a "Y" connection. Go to www.electrodynamics,com and check it out. They even have the diagram showing the hook up. I even charged both batteries at the same time with no problem. I was using 2400 mah nicads, two each.
Frank
Washbburn, Me

RE: Building a Dynaflite Super Decathlon
 

The link does not work for me

Zor

RE: Building a Dynaflite Super Decathlon
 

A quick google search for Pow'r Back'r reveals this link which should work http://www.electrodynam.com/rc/EDR-108/index.shtml

RE: Building a Dynaflite Super Decathlon
 

The new URL works fine.
I imagine you knew that having tried it yourself before posting it.

Zor

RE: Building a Dynaflite Super Decathlon
 

Sorry about the goof on the Electrodynamics site. Glad you figured it out though.
Frank

RE: Building a Dynaflite Super Decathlon
 

I was flying my new Calypso yesterday and the thought hit me about putting an electric motor vs a 35cc gasser in my SD. This is all new territory for me. I've never had electric - always nitro or gas.
IF and I say IF I wanted to go electric, where do I begin in sorting out the motor, speed control, battery etc?
What sizeswould I need? Is it too costly for this big bird?
My Dynaflight SD is just getting to my bench, so nothing has been started yet.

Yes I am "Old School" when it comes to my building and flying. I don't do any 3D - airplanes don't fly like that... period.
So, any Good Advice?

RE: Building a Dynaflite Super Decathlon
 

Thanks All,
I now have enough info about running twin NiMh packs. The system that I will use is
1. Twin identical 5 cell 2200 mAh NiMh receiver packs
2. Separate switches and charge receptacles
3. A Single 4 cell 2200 mAh NiMh ignition pack
Frank, thanks for the link and info about Electrodynamics. They sure have a lot of neat stuff but it seems a little pricy for me at this time. I have two friends who have had bad experiences with “Bat Share Circuits” so for me, I’ll stay with the simple setup that I have proposed above, however I am open to any and all suggestions and can change my mind if someone convinces me with logic and Price.

All the Best

Mike

RE: Building a Dynaflite Super Decathlon
 

Plane is completed, Still have to check the balance and set the fail safe in my A9. Worked all day on the engine Saturday. Could not get it to run. I tore down the carb and discovered the pump check valve gasket was sticking to the carb housing. This engine although new has apparently set on the shelf awhile. Reassembled the carb. and the engine started up after about 8 or 9 flips. Ater running a few minutes, It shut, (I thought), due to having to low an idle. Then I could not restart for anything. finally I tore the carb down again checking all the gaskets and DUH! I had installed the pump gasket backwards due to my inatentiveness. the check flaps had to travel over the gasket side rather than being flush against the carb base surface so they did not lay over the fuel passages properly. I'm surprised it even ran at all. I flipped the gasket/flap assy over and reassembled. The first start, the engine started in four flips. The next two starts after cool down, the engine started 2nd flip both times and man does this thing pull hard. It is making scary power. I will definitely have to use throttle management.

RE: Building a Dynaflite Super Decathlon
 

Forgot to post a pic of my carb adj access.

RE: Building a Dynaflite Super Decathlon
 

Sounds good, I know my G38 is way too much also. But there is a throttle servo, So good luck with the maiden, Are you using a 9  channel receiver with the A9?  i was just wondering, I also use the A9 and chose the 9 channel due to two receiver leads, as opposed to the single lead in the 6 and 7 channel receivers.<div>ED</div>

RE: Building a Dynaflite Super Decathlon
 

Ed,

I use 9 channel in everything now due to it having two antenna leads. I do have a couple of seven channels in a couple of SPADS which as you may have guessed are no big deal if you crash one.
Whether true or perception, I don't know. I just feel more secure with the Optima 9 and it's dual leads, like you. I also like the ability to plug a battery in to each end of the rx bus.

Thanks,

RE: Building a Dynaflite Super Decathlon
 

I have used the 6 and 7 channels for 3 years, and haven't had a radio issue with them, All have been on glow powered, I just felt better on a gas with ignition to use the 9 channel<div>
</div><div>Probably doesn't matter, but we do what we do:)</div><div>ED</div>

RE: Building a Dynaflite Super Decathlon
 

I hope to maiden next weekend but the long range forcast doesn't look promising at this point. Time will tell. The one good day during the week that they predict, I'm having to work.[:o]

RE: Building a Dynaflite Super Decathlon
 

Well guys,

I have an issue. The CG is supposed to be 3 3/8 from leading edge give or take a 1/2 inch. Mine comes in at 4 inches an 1/8 inch past the Max allowable. I thought with the gas engine this would not be an issue.

Has anyone flown this plane with the CG this far back. Don't really have anything left to move forward. Don't want to but I'll add two or three once's of lead to the nose if I have to. I normally end up setting my planes a little tale heavy but, not on the maiden flight.

I'll read some of the earlier posts to see if anyone else published their cg but I don't remember anyone being past 3 1/2.
Thanks

RE: Building a Dynaflite Super Decathlon
 

Mine came out slightly nose heavy, I was able to put the battery packs back by the servos, Mine was right on the recommended. Hope some one else chimes in.<div>ED</div>

RE: Building a Dynaflite Super Decathlon
 

Mine was tail heavy, and I added about 8 oz to the nose to balance it out. If Ihad the chance, Iwould move the elevator and rudder servos forward to the cabin instead of their default location. Also, I'd hollow out those terribly heavy wing tips - something I knew better about when Iput them on but blew off out of ignorant disregard. The plane isn't too unstable when tail heavy (I flew mine tail heavy many flights before adding the 8 oz), but it flys much better when balanced.
</p>

RE: Building a Dynaflite Super Decathlon
 

Now that I remember, I couldn't put those bricks out on the wing tip, I cut one in half, and put one half on each wing. I personally don't like a lot of weight out on a tip.<div>Ed</div>