I give up!

[Chris Bott - Moderator]

Doug we had/have something very similar at our field. On odd occasions a tiny part of the sky has glitches in it, they were always very brief so unnerving rather than dangerous. Thankfully they seem to be there less and less often these days. In fact I don't remember a mention this year at all. But they never chased a model right down to the ground with total loss of control. The absolute fix for them last year was definitely 2.4Ghz. On the odd day we did suffer, we managed to pretty much prove that 2.4Ghz cured our problem. Whatever it was.

[Martin McIntosh]

Martin R, you only really have a couple or so of prop sizes per ic motor, so go with the manufactures recommended size except for Japanese products which will state a rediculousely large prop to keep the noise beow their level, ie OS 91FX - recommended 14x10 to 14x11. Actual - 14x6. MM.

[Tim Mackey]

Martin Roberts wrote (see)

Hey there Timbo, not sure where to put this ......no don't be rude!!!!!!

I note in the review section for motors there is only for 2 stroke or 4 stroke..... but its not a review section for IC engines, so where should one post reviews for electric motors.

Also a lot of newbies would not know what size props for ICs, or what revs the particular IC would pull with a given prop, maybe the vet IC flyers could set up a forum/thread with results of IC type/size, fuel, glow plug?, prop size, and measured (not guessed) revs obtained.

Maybe start with the oldies like Cox 0.49 and 0.25 as they easily relate to small park size models.

Marty

We will contact the techie guys and see what can be done

[Martin Roberts]

Hey Martin, thanks for the input, but the idea of the post was so that the newbies and the guys who start with electrics can make comparisons, I only have electrics, gave up on ICs many years ago cos they wont run for me, in fact I had so much trouble with them that I gave the sport away for over 20 years, I came back to electrics cos I can turn on a switch.

That said I am no dummy, and I have a very good mechanical knowledge and electrical background, I can pull apart almost any machine and rebuild it and it will work, but a small 2 stroke like a lawn mower - forget it, even that has to be 4 stroke, no matter what 2 strokes and I don't work.

Ok you can all laugh at me but, plug in switch on and go flying, throw it in the back seat - no clean up...... whose laugh now.... even some of our old timers have been converted by me

Marty

[Martin Roberts]

Ooops,

so if a newbie or someone with DC wants to build a bigger plane they can for example, pick a plan, see what IC is recommended, figure the probable prop size, find out what DC motor would push that prop, at the rev range and amps that are suitable, so people dont have to waste money on bad experiments and end under powering a project, or build a ballistic plane by accident....

Marty

[Chris Bott - Moderator]

Guys haven't we gone just a tad off topic here? I thought this topic was about Shauns two losses of control.

[Martin Roberts]

Chris, you are correct this topic is about Shauns losses, and what caused them.

If you go back just a smidge you will note that I had put it to Timbo, that it might not be the correct place post re: motor size/prop size/revs, but also sought his advise as I have never started a new thread.

I think that the causal issue of Shaun losses has been discussed but not yet resolved other than to say that the fault is either in the Rx or possibly that sight, even though some of us flying 2.4 (various systems) experience similar problems, although I must say that I have put my Cessna in (pilot error) and my Stryker (oops numb thumbs again) but have managed to save from what I thought was a huge glitch (using DX6) which happened in exactly the same place and altitude (within reason) as glitches that previously affected my Hitec Optic 6 system whether using Hitec micro Rx or full size. The same place affects guys with top line Jrs and Futabas. 

A theory is that particular kvs may cause a harmonic fail safe to occur.

Sometimes you can not win, therefore my planes are by-lined with I don't have a problem with center of gravity - they know exactly where the center of the earth is and hed there.

Marty

[Tim Mackey]

Martin Roberts said -

"If the Ubec was a problem it would be because you use a 5 volt bec with 6 volt servo's, and I imagine that is not the case but worth a check, e.g. pulling more volts than supply".

 This is completely innacurate.

Using a 5V supply ( of any type - UBEC -ESC BEC or simply a battery ) on the very many servos designed for either 5V or 6V supplys is perfectly acceptable. Put simply, almost every servo I know of is designed to work perfectly well on 5V, and if its specification allows the use of 6V then it will simply work a little faster with higher torque - at the small cost of very slightly higher current consumption. To say that the load ( servo ) will "pull more volts than supply" is a statement of impossibility - the supply is the supply is the supply - and NOTHING can make it any higher than it is!

As stated by Chris, the other discussions about reviewing electric motors and missing relevant sections for same is completely off topic, and I have answered your post accordingly - we will look into the point you have made.

I think most of us have - by now - ( including Shaun himself ) pretty much exhausted the post mortem of his incident, and concluded that it was either....

1) Signal loss caused by any one of several potential scenarios which we shall probably knever know for sure

2) An overheating BEC which suddenly stopped supplying power to the receiver which in turn shut down the motor and radio went dead with servos obviously staying in last known position.

I remain convinced that it was not simply a "brown out" in the normal sense whereby the power supply itself fails to maintain the critical low votage required, as this almost always immediately recovers back, and the QC of the receiver would then restore control immediately.

I think this thread has run its course.

[Martin McIntosh]

Not quite Timbo! I hate to keep saying this but the cause of many failures is due to the totally crappy servo connectors we now have to put up with. They simply do not snap in and lock together properly and individual pins are prone to being pushed out giving an intermittent connection. Manufacturers please take note.