2.4 Frequency Issues

[PaulP]

Rob
This is a link to the article: http://www.ec12.org/Work_Files/2.4GhZ%20Report.pdf

Paul

[Rick West]

This was good listening, Rob. Thank you for the time. The only comment I will make to these issues is that they occur when someone has a problem and then another pops up. Like I said in another string, we are closing in on it. It is good to hear you take on this.

Paul gave you the link.;

...94

[greerdr]

Bob,
This is why we respect you and your amazing little device(RMG) so much!
Thanks,

R.C.Greer

[Rob Guyatt]

First thing I got to do here is say "what the %$#6*(%$ was I thinking?????" That bit about accidentally changing battery settings is just plain wrong. Can' believe I wrote that. (Michele can. She knows how thick I am).

I said that if the battery is below the detection level it will set a lower level and therefore shut the winch down earlier. WRONG! It <i>will</i> set to lower number of cells for monitoring but the actual effect is to make the winch shutdown at a <b>lower</b> voltage not higher. If you had 6 cells and the winch thinks it's actually 5 cells then the winch will not shutdown until around 5 Volts instead of 6.



Thanks for the article Paul. Very interesting. The Futaba and Spektrum issues are quite fascinating. I (and others over here) have been wondering what will the result be when a large number of skippers turn up at a regatta with 2.4. So far my experience is that the vast majority of problems are caused by inadequate Rx antenna placement in the boat. Only yesterday I solved one skippers range problem at the pond side by getting him to stick the 2.4 GHz Rx to the underside of the deck instead of it just lying in the bilge. Don't need any kind electrical smarts to know that laying the Rx in the bilge is plain dumb!! But apart from the range issue which is always a user fault, it seems large numbers of 2.4 GHz sets on at once is showing up other issues.

If you don't mind I might make a comment or two about the RMG section. All good comment about pot gear slippage. The problem seems to be created by use of lube sprays. The Acetal gear boss seems to swell only a few microns but enough to loosen the grip on the shaft. By all means try a drop of super glue if it is slipping.

There's another way that the gear can slip and that is by the skipper for some reason manually rotating the output shaft and causing the pot gear out of position after the pot has come to its end of travel. Never!!! rotate the output manually unless you know what you are doing. And if you do take great care to feel for the pot end of travel.

On the bit about no winch response at start-up. This part of the article mixes together two different sets of beeps. They are not actually related. I'll deal with each type here so you can quickly identify precisely what happening.

If when turning the winch on, the winch sounds exactly like it does when you turn the winch on without the winch plugged into the Rx then that is simply the winch telling you that the Rx is not talking to to the winch. Most common cause of that (other than Rx just not working) is blackwire corrosion in the winch to Rx lead. It can also be because the Rx has not yet connected to it's bound Tx. Big danger in this case is if the Rx does finally get hold of the Tx right when it's time to enter setup mode. The Pulser will prevent this for D models and earlier. It's not a danger in the new E series.

The other beeps talked about regarding pot fault is the stall signal. This is a two tone (high then low) beep about once every 2 seconds and will go forever until turned off or if it was a stall, the stall corrected.



Rob

[Rick West]

Rob, there is a lot of speculation from many as to issues with the Futabu. Until one has been there it is all speculation.

I am looking into a repositioning of the shaft but in my years of using the RMG I have not seen this. It would only have to be recent. I do not think that antenna positioning is involved either. I do not think there is a battery problem. I do not think there is a range problem.

The people I have talked to, including myself, have had a fully functional system for a year till units nearby had issues at the same time. That is all I know which does not relate to me the same as comments being made.

I have heard nothing about a need to follow the RMG set up procedure re the 2.4 bulletin for DL's and above. I do not hear in these conversations there is an issue with RMG. That leaves it with pilot error of Futaba. As with Futaba it could be that messing with these radios at the lake where all that are on 2.4 are free to rattle away with their systems.

I am not blaming anyone for there is no information to point to anything. We are speculating and in the process confusing all operators.

All I can say beyond this is that I have had a good unit with excellent performance for over a year till someone near me was having a problem. Then again at the next regatta.

Futaba's responses were CYA and not germain to an issue that was functioning well in the same environment for years in other bands...meaning high humidity in the bilge.

Written on the road in Valdosta GA.

...94

[yachtie]

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i><b>The people I have talked to, including myself</b></i><hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Watch out folks - the grand poobah might be loosing the marbles [:D]

Chris
NZL1 Longtack
NZL110 Swept Away NZL128 Ketch me if U Can

[greerdr]

We had 40 plus boats at Ntl's and we did not seem to have any issues.
I suspect the warning not to "bind" at the lake played a positive role.

R.C.Greer

[Rick West]

For what it is worth: 2.4 GHz report from the NCR.

Having had radio problems at the two regattas preceding the NCR, a top down review of the system was completed upon arriving at the NCR. Dave Ramos and Tom Germer were involved and it began with a total reset of the system to Futaba's default positions, as the unit came in the box. This then followed with a complete setup of the RMG per the manual and referencing of the winch line between the bow block mount on the board boom and the jib trim servo block. A one inch buffer at close haul and full sheet out was established by referencing close haul sheeting for overrun protection. Length was 18.75 inches for full sheeting run. All wiring was checked for breaks inside the insulation and at the solder points.

Testing was first slow to make sure the settings were established then high speed runs were made to test overrun. TX was verified with a green light and the RX as well when the switch was turned on. This process was also followed on the shoreline during the event with a slower and more methodical timing.

There were no sailing issues with the system during the event. Once the system went into set up mode at turn on for a heat. It was a battery plug issue that was loose. Once the system did not turn onnothing happened during the following power up. All was turned off and restarted with no issues.

It should be noted that the previous offending TX from past regattas was taken to default but not used at the NCR. The backup was used that had never been sailed. The former will now be used as the backup.

An additional note: if one is using end point adjustments close to the end (140%), it is recommended to reference so there is no more than 120%. The RMG, in a full run, can overshoot. While this will reference back, if it exceeds the maximum it could lose the reference point selection to come back to. This could cause hunting. This is not an ding on the RMG but an understanding that processor controlled equipment at our level of use and expense is not a precision device throughout its programmed range.

I am considerable more confident of the 6EX now.

...on the road in Blythe, CA.


...94

[Chuck Luscomb]

Hearing of all the radio issues prior to the NCR, I admit I was a bit worried. Now that the dust has settled a bit I am happy to report that my Spektrum DX6 worked perfectly. Not a single wiggle through out the entire event.

Chuck
#84

[PaulP]

I have done extensive study over the 40+ years I've been involved in the R/C hobbies, both planes and boats.

I've come to the conclusion the biggest problem with the radios is usually a loose nut on the end of the stick [^]

Paul

[Rick West]

Yep, and one of these days I will fall and not be able to get up. [:D]

...94

[Rob Guyatt]

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Rick West</i>

For what it is worth: 2.4 GHz report from the NCR.

An additional note: if one is using end point adjustments close to the end (140%), it is recommended to reference so there is no more than 120%. The RMG, in a full run, can overshoot. While this will reference back, if it exceeds the maximum it could lose the reference point selection to come back to. This could cause hunting.

<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Hi Rick,
I'm not sure what to make of the above. Sorry, perhaps I should have read it before Beer O'Clock [:D].

I have the Futaba 6EX 2.4 GHz myself. I don't see any reason for the Tx end points to have any bearing on the behavior of the winch. As long as Tx end points are not touched once the winch setup mode has been done for winch input limits it doesn't matter what the end points in the Tx were.

You could set the end points in the Tx to 50% both ends then run setup in the winch and the winch will behave the same as if Tx end points were set to 140% then winch setup mode run.

The extent of the Tx EPA % has no effect on winch overshoot. I assume by overshoot you mean the winch goes past the desired stop point a bit then instantly comes back. Sometimes in early models it can oscillate back and forth a few times before settling.

In the D and E models there is very little overshoot if any. No more than a couple of mms. When there is an overshoot it will come back to within a mm of the set point. Earlier models like the C do suffer from a greater overshoot and the even earlier ones with the worm type feedback drive can overshoot by as much as 10 mm but will still come back to the desired point within about 5mm. Quite crude in comparison to the 1 mm accuracy of current models.

I told you I should have read your post before Beer O'Clock. I think I just got what you are saying. You did winch setup at 140% but then backed off to 120% so that the winch doesn't run quite all the way to the end of the feedback pot. Is that right?? If the overshoot hits that actual end of the pot then the pot gear can slip on the shaft and then the actual travel end point (stop point of the boom) will change. There is a buffer in the software that ensures that the winch doesn't actually go right to the end but perhaps that was not a big enough buffer. What model winch is it? Or at least what year (roughly) was it produced? Later models like the D and E's have much better braking and should not go anywhere near the end of the pot. But feedback on this is most welcome.





Rob

[Merv49]

It has been my experience that 99.99% of all RC problems can be traced back to the guy at the end of the transmitter sticks. Im May I attended a large scale RC Giant Airplane event where there were five (5) flying fields on the property and over 800 registered pilots all within a half mile of each other for four days and there were no 2.4 issues that I know of throughout the event. I'm talking multi thousand dollar aircraft of every type and size were being flown all day long and some night flying thrown in and there were no frequency boards.

Seems to me that perhaps our sailing brothers are not as adept at setting up and using the technology as the flyers HAVE to be. It's for sure we don't share nearly the risk involved. I've read plenty about equipment faults and seen pointing of fingers at Manufacturers but no difinitive proof that would lead me to beleve that the problems were anything but pilot error, so to speak.

Just my two cents. [:D]