stevens4x

Hi. I have just bought a DX9 Black and had an issue tonight maybe someone can help me with. I'm setting it up to a Spektrum AR6210 rx, elevator Hitec HS-645MG, throttle and rudder- JR NES-537 and the battery is a JR 4N1100. Wings weren't plugged in.

I was using the Accu-Throw to set the throws and dual rates probably for over 20 minutes on the elevator alone. All the servos went haywire briefly then the elevator went full up and I lost power. I measured the volts then at about 4.3. I had not charged beforehand- is this a cutoff level of sorts? Did I reach a fail safe level? ..or could it have been something else? I've been out of airplanes a good while as you can tell by my equipment. Oh, I've since charged and now the battery reads 5.36 volts on my x1 Touch charger. (This all happened on my workbench not in the air) If you need more info please let me know. Thank you.

Aerocal

If your using a 4cell NiMh 1100mah pack the voltage is going to be somewhat marginal to begin with.
It may be 5.3 off the charger but is going to settle back to around 4.8 rather quickly. The problem is that just because the pack has 4.8 volts doesnt mean that voltage is going to be maintained after it travels through the lead,switch and connectors which all have some measure of resistance. The cells themselves also have internal resistance and the pack voltage will fall some under load. As a general rule the most current you can reliably expect from AA NiMh cells is 2C. For an 1100mah cell that would be 2.2 amps and that may be generous before voltage drops under load. Most digital servos with a reasonable load will draw 1 amp each give or take. You can easily see where a voltage issue can easily come into play. At an absolute minimum you want to start with a 5cell pack at 6volt.Good leads,switch and clean tight connectors. If the voltage at the Rx bus falls below 3.5volts you risk it shutting down and rebooting(brownout). Just because your pack is charged and starting out at 6 volt doesnt guarantee the voltage cant fall below safe levels by the time a full servo load is applied. Resistance in the form of small wires,weak switch contacts,loose or dirty connectors will all contribute to voltage being lost along the way from the pack to the Rx bus where its needed.
You have the capability in your Tx to check and Monitor voltage at the Rx bus not only during setup but also inflight. This is what Telemetry is for. I suggest getting a TM module. During setup you can power everything up and physically put a reasonable load on all servos while observing voltage at the Rx in realtime. If it is dropping(and it always will drop some)more then 1-1.5 volts from resting it may indicate a potential problem. You never want it to drop below 4.5 at the Rx bus to maintain a margin above where you may be in danger of brownout. Its hard to know exactly how much load the servos will pull inflight so its a good idea to have Telemetry attached at least for first flights to get an idea how your voltage delivery setup is working. You can set an alarm in the Tx for 4.5volts to alert of a impending problem inflight. It will also show what the minimum was even if there is no alarm so you can track its health. Very valuable info IMO. You also get Flightlog data numbers to analyze how well your antennas and Rx are performing during Low Power/Range tests and inflight. Alot better than go-no go alone. Again it also can notify you of a developing problem before it becomes a total failure.
Many of us have gone to using a 2cell LiFe Rx pack. Much less internal resistance and will hold voltage at the pack under heavy load alot better than NiMh type cells and they are about half the weight for the same capacity. For many sport applications a 5cell NiMh pack is perfectly adequate for moderate loads. Either way you need to confirm it is actually adequate without simply guessing.
The results of guessing wrong usually arent pretty.
Over time connectors get loose and or dirty and switch contacts age.Whats good today may not stay good over time. I lost count of how many times someone says "I dont know what happened.Its been fine for a long time and alot of flights and now it just quit.It must be a radio problem". Voltage issues dont generally just happen. They develop over time as components age and wear.

Aerocal

You say you have been out of the hobby for awhile. I dont know how long that would be but Im kind of assuming you were flying back when we were mostly using 72mhz equip that was for the most part analog type stuff. The 2.4 stuff we use now is more in the realm of pure digital. The Rxs are basically a small computer.We used to be able to get away with marginal voltage and temporary drops. Its all a bit different now. When a Rx no longer has enough power to function it reboots.When a reconnection is made and all the servos come back to life it may momentarily need a surge of current to stay alive. If voltage drops again it will reboot again. It can get into an endless cycle of current rush,voltage drop,reboot,repeat if voltage is not maintained at an adequate level. Newer digital servos are alot hungrier than what we had a few years back. The signal instead of being like an FM radio station or TV where you might see or hear some fuzz now and then are gone. Its like a WiFi connection. You are connected or you arent. Instead of having an analog signal we have data sent in packets(frames). You can lose a few here and there and still soldier on but if you lose enough in a row the Rx can no longer know what to do and it goes into Hold/Failsafe until it gets good solid packets again. This is the part you learn to understand when looking at Flightlog data. Antenna fades,Frame losses and Holds.
They all mean something. The antennas need to be line of sight to the Tx and get easily get hidden behind solid objects like motors,engines, batteries or even fuel tanks will absorb them.Carbon fiber is popular now and it pretty much blocks all 2.4 from passing through. Paper,wood,fiberglass,most plastic are invisible to 2.4. This is part of the reason for using multiple antennas and or Rxs. Positioned correctly at least one should always have line of sight to the Tx.

stevens4x

Wow, what a great reply. Thank you very much for such a detailed answer.

So here's the full story: I bought a used H9 Taylorcraft with a G26 (the 80" bnf). It's right up my alley for now since I've flown so little in the past 8 or 9 years. The airplane I'm asking for help on is the Sig 4*60 ARF and it's been sitting in the garage for 5 or more years. I got it running and it flew great last weekend but on FM, hence the DX9. And it's old, in great shape, but I imagine the wood has dried out and no longer has the strength it once had so I'm realistically not expecting it to last too long.

I don't know for sure when the battery was last replaced. I'd say maybe 3 years ago when I thought I'd have time to start flying again. I cycled it a bunch and it's holding a charge and seems ok but I agree with everything you said. I recently purchased a 6.0v nimh from the lhs not remembering it has a 4.8 in it. I guess my question through all of this, is will these old servos, I'm pretty sure they're not digital, be able to handle the 6v system? Will I burn them up? I don't care enough about this plane to stick too much more money into it. I'd like to get good with the giant scale TC and then go even bigger.

...and thank you for telling me about the telemetry. I'll definitely put it into the TC. If you could maybe give me a part number or a little hint at what I'd need I'd really appreciate that too.

Thank you!!

stevens4x

Well you replied as I was. Thank you again for the great info. I worried about the antennas as I installed the rx and the "satellite?" receiver. I can't boot up the pc and wake my wife to post a pic (I will in the morning) but the main receiver is in between the servos and fuel tank with the antennas running towards each end of the fuselage. The "satellite" rx is mounted behind the servos and its antennas run toward each wing tip.

stevens4x

I checked the manufacturer's websites and they list 4.8 and 6.0 for the JRs and the Hitec, but real-life is sometimes different. Adding in the 2 aileron servos (I believe they're the JR 537s also) do you think I'm safe to run a 6.0v battery?

Gizmo-RCU

My Feedback: (27)

I would throw that battery away, now!
I now only use Life Battery's and for me they are the best choice. They are a constant 6.5 volt and hold a lot of power with a short charge time. You will need a proper charger and there are quite a few out there for a reasonable price.

stevens4x

I figured as much and was thinking I should. Thank you.

...I'm good on chargers now thank you for the suggestion. I bought the Hitec 4 battery charger. X4+ I think. Plus the single battery touch screen.

stevens4x

Please let me know if you see anything I should change before I clean it up and get ready. Thank you.

Gizmo-RCU

My Feedback: (27)

Might try and clean up the wires a little and secure them. Check the glue/epoxy on the control rods looks brittle to me and they need to be very secure. As the plane has set for quite a while just check glue joints and do so after a days flying........

Good to go, have fun

Aerocal

I didnt look at the specs specifically for those servos but there are very few servos that are rated for 4.8 only unless very old. When you do look at specs if they list speed and torque for both 4.8 and 6 your good to go with 6. LiFe generally runs a few tenths more than 6 but thats not a problem. A 5cell NiMh will be a bit over 6 for quite awhile fully charged. 6volt rating isnt absolute.
Its a nominal round figure.

The telemetry modules available are the TM1100 and TM1000. TM1100 is for shorter range and only has basic Rx volt,FL data,Flightpack voltage,temp and rpm. The TM1000 is what your looking for. Longer antennna lead for optimizing location of the active portion away from where it is actually mounted and it has XBus input for optional sensors.

Mounting location for both main and remote Rxs can be a kind of art. Its always best to get the antennas away from other components as far as possible and practical. Getting both sets of antennas oriented 90 degrees to each other is also good. There really isnt a magic one location or orientation fits all when it comes to antennas. You pick the best locations,mount them and do some real good Low Power/Range testing in all orientations while observing FL data. If it looks questionable(very high fades or alot of Frame losses) then moving them to a slightly different orientation and/or location will usually make the data look alot better.
If you do have a marginal signal problem related to antenna location you generally will see a momentary Hold at maybe a certain orientation to the Tx. Anytime your getting a Hold its not good thing. I found that if you monitor and set a Telemetry alarm for 1 Hold you will get a Hold warning while maneuvering without ever noticing any kind of control glitch. 99% of signal issues Ive had are due to a failing remote connector cable. They are kind of fragile.Treat them with care. Dont unplug by pulling on wires. Most of us also use silicone or tool dip and make a little rubber boot kind of thing where the wires come out of the connector to provide strain relief. Also make sure you tie the loose lead down and dont let it flop around with g-loading. A little extra care with remote connectors goes a long way towards reliability in the long run.
Also if your mounting Rxs in a gasser you want to use some kind of foam or foam tape like for mounting gyros to isolate them from the harsh vibes a gas motor can put into an airframe.Heavy vibes can hurt Rxs.

stevens4x

Thanks again- y'all have been super.

I've been thinking since Gizmo's comment and think I'm going to go ahead and do a little makeover on the 4*60- redo all control rods and linkages. They are very brittle as you suggested and it's super cheap to replace them. This plane is fun and worth a little investment to make it last alap and be safe.

...so now I'm on to the Taylorcraft and mounting the 9020 with 2 satellites and purchasing the telemetry. For the remote connector cable, that's a great suggestion and I wondered about it because they come unplugged rather easy. Where exactly do you add the silicone? Do you unplug the cable and then apply to the wires and connector on the cable only or do you keep it plugged in and apply getting two strengths- the above I just wrote plus add some so it doesn't come unplugged? If possible please post a pic. I'd appreciate it. Thanks again.

Also, do I only need the TM1000 and the Flight Log? I've done a lot of Traxxas cars and you have to add sensors for everything. ...I think all I'll want is the antenna stuff plus the ability to see receiver battery voltage on the remote. Thank you.

Gizmo-RCU

My Feedback: (27)

You can use servo safety clips or shrink tube over the connectors. I use shrink for connections on those I don't take apart and the clips on aileron connections. The clips can be found on ebay for cheap.

rgburrill

Personally I would never use a NiMH as a receiver/servo battery, especially a 4 cell one. I wouldn't go so far as a LIFE - I used NiCds. Voltage curves on NiMhs drop off way too quickly especially with surges caused by servo movement. And as someone else said above those surges can cause your digital receivers to reset.
NiMhs served a purpose before the Lithium batteries started coming around as power sources for electric motors in cars and boats. But I would never put one in the air then and won't even consider them for anything now.

Aerocal

For remote cables they will stay in the socket fine if you snap them in completely and tie or stick the loose lead down so it cant pull on the connector by flopping back and forth with g-loading.
For the silicone or tool dip I start with a new cable. Just put material where the wires come out of the backside of the connector body. I use a toothpick and kind of poke it down around between the wire exit and connector body being careful not to get any on the sides or front where it plugs into the Rx. The same as many cables have a rubber boot where the wires exit the back of the connector. I kind of get some goop back up the wires about half inch. Keeps them from bending and stressing right where they enter the connector body.
They do actually stayed plugged in pretty well if you seat them fully. You will find this out when you try to unplug one. Like I said before dont pull on the wires to unplug. The plug body is a tiny bugger with not much to grab.I have a tiny pair of needle nose pliers I can grab the connector body itself without pulling on the wires. In a pinch if my pliers arent handy an xacto on edge you can kind of lever it out from each side without touching the wires themselves.
Again you would be surprised how much loose wires bend back and forth with g-forces inflight. This is probably the #1 cause of problems(next to pulling on wires to unplug) if they arent tied down. The problem with the bending back and forth is the wire breaks but the insulation is still intact. Usually happens right where the pin is crimped on.The goop back there and up the wires a bit relieves most stress in that one spot.
I had my share of problems with them when I first used them. Since I exercised the extra care religiously my connector cable issues are pretty much zero.

Aerocal

And once you start getting a feel for FL data you will get an idea of how many fades you see on the various antennas.You will see some.100s arent out of the ordinary. If you get in the habit of glancing at them on the display at the end of flights you will spot a inflight connector problem right away. fades on that one will be way up if not ---- that indicates they are beyond the max display number(9999).On many installations with only a main and one remote if a connector or remote itself is having a problem inflight you might get a momentary Hold and never notice a loss of control or glitch but the Hold will register when the one functioning antenna remaining in the main gets momentarily shadowed in a specific orientation while maneuvering. If this happens you will likely see the runaway fades like I mentioned. If your not keeping tabs on the data there is no way to know there is an impending problem until it turns into an extended Hold and loss of control. I set an alarm for 1 Hold and Ive been warned several times to fix something before loss of control. same with low rx voltage. Knock on wood Ive never lost a model in 1000s of flights to a signal failure or brownout. Ive definitely had my share of warnings.
This is also true with BECs. They generally dont just fail out of the blue.they get weaker and weaker until they shut off. If you get your warning set correctly 1 or 2 tenths below its healthy min
you will be alerted to an impending problem developing before it turns into a failure.

stevens4x

Thank you. I actually have a bunch of these clips now and stocked up on heat shrink yesterday. I do the same on connections I don't take apart.

stevens4x

Great info again, thank you.
I was confused by the tm1000- I thought you'd get the basic telemetry without having to purchase the module. Anyhow, the lhs is out of stock so I'll have to order one which is a bummer cause I have an instructor scheduled tomorrow to help me out in case I have trouble getting my bird down.
I noticed the satellite cables do snap in well, I think my cable wasn't pushed in well from the factory. ..Trying to mount the satellite rx's has been a bugger.
Headed to the store in a bit to get some silicone, I'm happy to take every safety precaution. Thanks again.

stevens4x

Man am I frustrated. I can not bind to my Rx. When I plug in the battery and bind plug, the receivers (Rx + 2 satellites) do not flash their lights. I tried with 2 different fully charged batteries. One a nimh, one a life, I even bypassed the switch and plugged the battery straight into the Rx.

I fab'd a piece to hold the satellite and it's kind of a one time deal and will be a ton of work to pull the satellite if needed.

Any ideas of what to try? Thank you.

Aerocal

Well thats a big bummer. IIRC the 6210 has a Bind/Data port. The Bind plug needs to be plugged in to the Bind port before you apply power. You should be able to apply the power to any other port. Even if the remote
isnt plugged in correctly the main should do the fastblink/Bindmode indication.
Do you have all the servos plugged in already? Possibly one of the servos has a problem and is pulling the whole system down.If your sure your connections are not in backwards try unplugging the servos and Binding with just Bindplug and power only.
The other possiblity is that you have the power lead upsidedown/backwards.
Where did the 6210 come from? If it from your LHS and they are an authorized HH dealer its fairly safe to say it is genuine and not a counterfeit.If it came from ebay or another supplier that sells them cheap there is definitely a big ?. The 6210 is a common target for counterfeit and Ive heard of more than one that dont function correctly.
Its always possible the Rx(genuine) is dead out of the box but not real likely.
With the Bindplug inserted then power applied does the orange led(on main or remote) even flash momentarily or do anything at all?

stevens4x

It's the 9020. I binded OK to the 6210. For the 9020, I never had any servos plugged in, just the bind then the batt. The only light I get is 1 flash on 1 satellite as I plug the battery in. ....I'm thinking it was doa. ...I bought the whole dx9 black which included the 9020 from my lhs. I was standing right there as he ordered it from HH so I'm not worried about counterfeit. ....I also had issues with the tx. I called Horizon, waited an hour and 15 for the call back. The gentleman was super nice and we tried for over 30 minutes to simulate and fix my tx. He hung up with me as he was going to program and try to get the same problem to happen on a dx9 there at support. He took my number and I waited 2 hours to make sure I didn't miss the phone call but he never called back.
...so I think both the tx and Rx were basically doa. I hope their support is good, that was my only experience with them and I wasn't impressed with not getting a phone call back.
...would you agree I probably just need to swap it all out? Thank you.

Ok. I just watched this video... I think I was using the wrong port. Gonna go try and then I'll report in.

http://youtu.be/XJcjcuvyRi8

Yep...I goofed. Thought the label for the plugs meant one side but they were the other side. Everything binded and working fine so far now.

Len Todd

Signal wires to the center and the label is miss-leading as to the location of the bind port. Take a look at the attachment.

stevens4x

Awesome. Thank you. It's definitely confusing until you know. Seems like the first row of labels should go to the nearest ports, not the opposite side.

...anyone know any builders in the Houston area?