Bryant330L

My Feedback: (126)

I just bought my first Gas airplane and I am having problems. I bought a Dave Patrick Extra330 w/Brison 3.2 and Hitec 5645 digital servos. The fellow I bought it from flew it with a Futaba 10x radio system. I installed my trusty old JR 642. Went to range check it with the radio on and it had some pretty major glitches at random times and from random distances. I am not sure of the reciever model but I think it is what came with the 642 when it was new. So, I took out the 642 (ch.42) and put in my 622 system (ch31). Went out to fly and it checked out great. Flew it once and everything was fine. Then I go back tonight and it is glitching just like the first night. I don't know what to do. Some of the guys tell me I should get a PCM reciever for my 642 and some say I should not have to do that. I really don't know what to try next. The antenna comes out the side of the fuse and is banded to a T pin in the verticle fin. I am running a 6v 2100 mAh battery. The engine has a restricted spark plug in it. I am new to gas and new to digital servos and I am lost. Any advise you could give would be great because I spent big $$ on this plane and I don't want to lose it from radio trouble. Thanks a lot!!!

Giant Scale

I'll try and provide you with some help. Does the radio glitch with the engine off as well as on? Are you getting glitches at your house or at the field or both? A radio will glitch for a number of reasons, one possibility is ignition noise interfering with the radio signal. Another is a "hit" from another radio on the same frequency or some other outside source. I'm sure there are other sources of interference. In the first case you need to make sure that the radio equipment(servo's,battery,receiver..etc) are located at least 12-14" away from the engine, engine,ignition and battery. Make sure to also use a non-metallic pushrod to connect the throttle. Have you ruled out a faulty radio component such as a receiver or servo? Check all your wires and connections. Start the engine and see if you get glitches. It is difficult to diagnose problems like this without seeing the plane. Perhaps there is someone at your club who has experience with gas models. Since you purchased the plane second hand you really need to spend some time and go over each area of the plane and thoroughly check everything. I use a PCM receiver( which has some advantanges over PPM) but PCM is not a cure for glitches. You must find the problem and correct it. Until you have confidence that the radio and all it's components are working properly DON'T fly the plane. You risk injuring yourself as well as others. You may also find it helpful to report your finding back to this forum as you go along your problem solving journey. I'm sure other member will be glad to give their 2 cents worth. Hope I have pointed you in the right direction.

Ed_Moorman

My Feedback: (1)

I agree with moving all radio components away from the engine. Move the ignition battery and switch, too. There is a tendency to place both switches, radio & ignition, close to each other. Don't.

Another thing to consider is the pull-pull cables. If they are metal cables, they can cause glitching. They have in my planes in the past.

I also agree with the previous reply about PCM. It does not cure glitches, it only masks them. They are still there and if they happen to last longer than the preset time, your radio goes into fail-safe.

jlmaviation

My Feedback: (54)

I have 80" ws One design. Balsa sheeted foam wings, balsa ply fuse covered in ultracote. The engine is a OS BGX1 (glow) using a firewall mount with a Bison muffler and a Carbon fiber prop.
I have:
2 JR 8101 servos for the ailerons with buffered extensions.
2 JR 8101 servos for the elevators with buffered extensions.
1 JR 507 for the throttle (no extension)
1 Hitech servo for the rudder (no extension) hooked to a plastic coated metal pull /pull wire.

When I turn the TX on and walk around the plane it goes beserk, with the engine on or off it is the same, and with a range check it is the same. It is on Ch 37 FM.

I have unplugged the wings and it still does it. I removed the pull/pull cable and it still does it. I removed the sw harness and plugged the battery direct and it still does it. I used a hitech Rx no luck. I used someone else's JR RX & TX on ch 44 FM and it still does it. I'v tried many other things and still no luck.

HELP!!!!!!!!!!!! ME!!! I'm losing my mind!

My next thing is to go all Futaba on this beast.

If that doesn't work than my only answer is the Ultracote covering which it is covered 90% in the neon colors. Is there someting in the Neon pigment?

Another thing is the JR rx's that I tried are single coversion and my Futaba's are duel conversion.

What do you think?

Any suggestions would be helpfull.

JohnVH

My Feedback: (38)

What are you guys running for batteries? 6v? try 4.8 and see if that helps.

jlmaviation

My Feedback: (54)

4 cell 4.8 volts is what I have. Tried the 6v also, either way the problem is still there.

JohnVH

My Feedback: (38)

try a different RX

jlmaviation

My Feedback: (54)

I did. 4 times on 2 different channels with different tx's

jlmaviation

My Feedback: (54)

The rx's and tx's that I used are in other planes now flying perfectly. I even used someone else's tx & rx that is in fine working condition and still the same problem.

Bryant330L

My Feedback: (126)

Wow, I am not the only one huh? My plane meets most of the criteria mentioned above as far as battery location and so forth. I have not changed any of that stuff since I bought it and it was fine before. Like the other fellow above I have chanced tx and rx with the same problem. A fellow suggested wrapping my rx in aluminum foil and tieing it into the ground wire on my battery to eliminate false signals. I will try that and see how it goes. My pull pull cables are lined with plastic so I don't think that would be it.

I need to try it without the engine running... I have only tested it with the engine on. Could this lead to something?

On the 2nd night this plane had no trouble at all... I don't understand that. I would think that the trouble would be constant. I know nobody else at out fied even had their radio on during my range checking.

Thanks for all of your help. Hopefully together we can find this thing. If not, is there a service that I can send this thing to? I know horizon will tune my radio but who will work with the whole package if I can't find it?

JohnVH

My Feedback: (38)

I feel for you, I am going through the same problems on my jet in the jets forum

Bryant330L

My Feedback: (126)

JohnVh,,,,

Do you have a PCM rx in your jet? I posted this in the JR customer support thread and he heavily recommended I get a PCM rx. If all else fails I may have to try.... what else am I going to do? I have too much $$ in this thing to quit on it.

thomasb

JLM,
problems like yours on a glow model are curable. Something has been missed, but it sure sounds like you have done a good job trying to isolate the problem.

Since you have tried a Hitec DC Rx and the JR 610, going to Futaba is not expected to gain you much. BTW, is there anything else installed (gyro, battery monitor, etc.)?

My thoughts are that this one will be either an antenna routing problem, metal-to-metal issue, servo troubles, or weak battery pack. Of course there are other noise sources.

Time to get back to basics:

Perform a range test with just the Rx, JR517 throttle servo, and fully charged battery pack. Remove these from the model. Do not connect anything else, including the charge harness -- direct connections only. Do not use servo extensions. Be sure to disconnect the pushrod from the servo arm. Lastly, string the Rx antenna out and away from everything.

If the glitch is present with this scaled down installation then you may have a weak cell in the pack or the connected servo is defective.

Continue this methodology as you plug each additional servo in, one at a time. Be sure that the pushrods are not connected. Remove the prior servo as you move forward. It will be necessary to remove the servos from the wing in order to avoid using extensions cables.

If you get this far without a glitch then start installing the servo AND its extension, one at a time. If that is OK, then start installing ALL the servos (with extensions) into the Rx. Test the range as each servo is added.

Next, install the pushrods, one at a time. Range test each time, all the while twiddling the sticks.

At some point you should get glitches. Back up a step or two to isolate the culprit.

Assuming that this is not a environmental interference issue, the problem will be identified during the course of your troubleshooting. I suspect a metal-to-metal problem, but Murphy often makes these very interesting exercises. Don't worry, you will find the culprit.

JohnVH

My Feedback: (38)

I do have PCM in it, BUT, pcm doesnt stop glitches, you will get them with both.

I have a G62 powered stinger, and I run PPM in it. Not a glitch, not a problem, and I have flown it a LONG ways away.

Bryant330L

My Feedback: (126)

ThomasB,,,,,,,

Something you just wrote struck home with me..... Two things actually.....

1. This plane has a I4C LED readout on it for battery voltage.. But... the next thing might be something to think about...

2 The previous owner of this plane told me that I could not charge this big battery with a wall charger. I forgot about that. Here is my question.. I have been charging this thing with my wall charger and when I take it off it reads 6.9 to 7.2 volts BUT, am I getting this battery charged enough to work? The mention of a weak battery reminded me of this. I think first thing I will try is to replace my battery with one of my NIMH 6v 1200 mah packs. It says in the directions that you CAN fully charge these with a standard wall charger. I am also going to remove the I4C unit and see what that does.

If I got a better charge on the one succesfull outing I had with this plane (2nd time) that would explain why it worked fine that time. That would be about the only thing I am doing different than the original owner. He had a high power charger for the big battery. He routed his antenna down a tube in the fuse and I ran mine out the side and back to the fin. Those are the only changes I made to the plane besides the radio tx and rx themselves.

What do you guys think about the battery issue? Can a battery read that it has plenty of charge but still be undercharges? I would think that a weak battery could and would cause the problem I am having. I will report back after I try a few more things............

Giant Scale

LovemyEdge,
It has been my experience that high capacity nimh packs need to be charged with a charger that causes the battery pack to get warm. I have a 4500mah pack that if you charge it with a 50mah charger overnight it will show full charge(~7 volts) . However, the batteries will not hold the charge for very long. I also tried a charger that charged at 150mah but it did the same thing. I finally got a charger that can charge batteries from a trickle to 4amp rate. This caused the pack to warm up and really hold the charge. The 50mah chargers are fine for standard 600mah 4 cell batteries or radio batteries, but for large capacity packs you really need more amps.

Bob Pastorello

My Feedback: (198)

Lovemyedge - Having LOST my Edge 540 last year due to a unplugging of a battery, I now am VERY sensitive to ground checking and glitches...BEFORE I put it in, it was "warning" me, and I ignored it.

A couple of things - First, it is ABSOLUTELY essential to determine if the glitches happen "engine Off" or not. If the radio is solid with engine off, then you will be chasing ignition interference. You didn't say where the throttle servo is located, or what kind of pushrod connection to the carb you have, or type of pushrod. Those are each potential serious "glitch inducers". If those things are okay, then start looking for SOMETHING - ANYTHING that is metal to metal, bouncing when the motor is running - THAT for sure would cause glitches.

If glitching occurs engine off - I'd pop in a 4 cell battery just for ground checking. I have had situations where a similar setup to yours did NOT like unregulated 5-cell packs.

As others have said - I also don't "believe in" PCM "solving" glitches - that system is just IGNORING the glitches that are STILL THERE!!!! Fix them, my friend!!!

thomasb

The standard wall wart charger that came with your R/C system is a marginal choice to charge a five cell pack, regardless of chemistry (NiMH or NiCD).

Also, in your situation you should stick with 4-cell packs until the mystery glitch issue is solved. In a few reported cases, a 5-cell pack, fresh off the charger, has caused some glitching.

What mAH capacity is your "Big" 4-cell pack? What charge current does your wall charger's Rx side provide (per its label)? How long are you charging?

Can you borrow a charged pack from a buddy? All you will need is a 600mAH size NiCD for the glitch tests.

BTW, the voltage you read on a battery, even right off the charger, does NOT tell you if the pack is fully charged. All we can determine is that, with a proper C/5 load, when the pack is too tired to use again without another charge. That occurs at about 1.18V per cell. But using the voltage to determine any other charge state is not practical.

But having said that, if your 4-cell pack is NiCD and higher than 6.5 volts during charging, then you are going to damage it. Although the charge process involves current, rather than volts, the terminal voltage should stay below 1.6V per cell in order to reduce metal migration issues. Overcharging tends to drive the terminal voltage too high. Also, defective cells tend to gain higher than normal voltages when charged, but not loaded.

Why not discuss the particulars about your 4-cell pack and the charger. Perhaps we can come up with a way to make what you got work better. With luck, it may solve the glitches too, but I have a feeling you may have other problems as well. Need to sort them all out, is all.

thomasb

lovemyedge,

Please see "RC-CAM's" post: http://discussion.rcairport.com/show...&threadid=1475

Bryant330L

My Feedback: (126)

After doing some checking today I found out that my problem is not engine related. It was twitching with the engine off as well as on. I tried several things but I think I may have fixed it. I took the antenna out of the side of the fuse and routed it out the top behind the canopy, then back to the top of the tail. This SEEMED to fix it. Not sure why, don't really care why, as long as it is fixed. I will range test it again when I go flying next and I will report back. Thanks to all that is helping me on this, I have learned a ton about radio interference in the last 3 days.

Rodney

If moving your antenna seemed to cure the problem, I'd be very suspicious that you have a break in the antenna wire itself that is well camoflaged by the insulation. Be sure to check the continuity of it from the tip to the circuit board while you are putting mild strain on the antenna (gently pulling on it), as it is doubtful that just moving the antenna (with no engine running) would cure the problem.

thomasb

This also is a typical fix if the antenna routing is close to an offending EMI/RFI noise source. This can be innocent looking metal-to-metal (eg, metal pushrod into metal throttle arm), a servo that is goofy, or other equally frustrating sources.

It is best to spend the time to determine the exact trouble source. Then you will be able to best judge if it is safe to ignore and continue with a simple antenna position change. For sure, antenna routing is an important element in promoting reliable R/C range, so the fix may be fine as-is. However, I would encourage you to poke around a bit more to make sure of this.

Bryant330L

My Feedback: (126)

You guys were right.... that did not fix my problem. I range tested extensively on the ground and all was well, but the trouble came back while in the air. I have checked everything mentioned on this thread and nothing has fixed it. I am at a loss to tell the truth. No metal to metal, antenna routed different places..... this stinks. I guess my next and last move will be to buy a PCM radio system and see if that works. That is the only thing that is different between myself and the last owner of this plane. I saw him fly it and he has never had glitch problems with it. If the pcm don't fix it I will have to sell it and buy another big plane. I hate to but I seem to have exhausted all I know to do. Thanks for your ongoing help. Take care

jlmaviation

My Feedback: (54)

Hey Thomasb. The batteries I used were good as I have tried several different packs. The RX ant. was routed in all directions and that did not matter. The thottle servo alone is not a problem. When I add additional servos the problem comes back.

I was talking to a club member this weekend and he mentioned that he has a couple of JR 8101 servos in the elevator of his DP Extra and his plane twitches on the grond also. I will try replacing those servos just to see if the problem goes away.

thomasb

jlm, do the twitches show up when a servo that has an extension cable is connected? That is a common issue that is solved with buffered extension cables or high quality passive types.