Re: Confusion! (not ELO related)

**Cribbs74** Tue Feb 28, 2012 9:07 am

Surfer_kris wrote:Radical RC has some nice battery backs of different shapes, this one is particularly easy to place in narrow fuselages;

That one is still too big! lol!

Is that a Lipo or Nimh?

I will check out the link Thanks!

fredvon4 Tue Feb 28, 2012 9:37 am

There a quite a LOT of inexpensive multi chemistry charges for our hobby and I think you should invest in one

I have used many of the sub$40 products and if you look closley at most of them you will see that they all use basically the same control board and layout. I have found no advantage to the brands with $78~$145 prices unless you fly giant scale and need to rapidly charge huge packs.

This is only an example...I got a similay unit from Hobby King in Hong Kong for around $28 plus $7 in shipping

http://www.hobbypartz.com/60p-dyc-1003-accharger-blue.html

You asked about servo travel limited mechanically

No it is not OK, from a health of the servo point of view. Transmitter trying to drive the servo past a mechanical stop can destry the feedback POT or strip the gears. IIRC You are using a DX5e with no programing ability. With a more sophisticated radio you could program the end points and not run the risk of killing a servo

The servo chatter is usually from feed back from the control surfaces not being loose and forcing feedback in the neutral position "centered".....OR you battery voltage being too high or too low may be the issue

In my experiance the typical analog micro servos they are real sensitive to ANY push back in the neutral position (centered). So if your control surface has a natural weight (droop) like on a long moment elevator, or a spring up or down (or left~ right) effect from stiff hinges off center, the minute feedback to the uncommanded servo will cause some singing or "chatter"...

On some of mine I can not totally eliminate it and does not seem to effect servo life or usability. On a watt meter I can see the feedback and chatter as higher current draw than a totally neutral,non chattering, servo. BTW this current draw is much too small to worry about until I test a servo that has a LOT of chattering and will not shut up.

In the past I have had to remove tape type hinges where too much Dope or CA caused them to be very stiff and push back on the neutral servo. Once I changed over to Kevlar thread X hinges and zero CA wicked into the thread the chatter disappears.

Other times I decided to try a different servo and it cleared up so I decided that the 5 or 9gr servo I removed was just too sensitive

Hope these hints help

Mark Boesen Tue Feb 28, 2012 9:40 am

Hi Ron,

This is the battery I used in the little Curtis Robin (see chopping balsa, model forum) and yes you don't really need a switch.

http://hobbywireless.com/index.php?main_page=product_info&cPath=15&products_id=552

Mark

proctor Tue Feb 28, 2012 10:11 am

Thanks for pointing me to these quality Hyperion lipo's, realize that there is
no percentage in using cheaper batteries to save a few dollars,
As a matter of interest I find that after the usual three short flights
with my 1/4 A models I am only putting back 30-40mah so in spite
of having reservations about my 130mah batteries not being big enough
I am now quite comfortable using them. I do charge at the field of course
when necessary. john

John Goddard Tue Feb 28, 2012 11:51 am

30X15X8mm

PV Pilot Tue Feb 28, 2012 11:53 am

Some servos chatter, others do not. I have had $200+ digital coreless servos chatter there whole life, they still live to this day.

Servo chatter is usually a servo just trying to find center,,,so long as it is not on a section of bound up linkage as fred posted

I bought 10 of the Hex 9g servo's several years ago. Out of that 10, 6 chattered. I used all 10 of them and they still work.

Did you have the transmitter real close to the reciever Ron?? I have seen personally the high end Spectrum stuff chatter servos until the transmitter was moved several feet away.

Your reciever antenna was away from and not laying directy on a power feed wire?

I take it you just plugged the pack right into the reciver, without a regulator? If so, you might need the voltage buffer circut that is in most if not all lipo regulators.

**Cribbs74** Tue Feb 28, 2012 12:59 pm

PV Pilot wrote:Some servos chatter, others do not. I have had $200+ digital coreless servos chatter there whole life, they still live to this day.

Servo chatter is usually a servo just trying to find center,,,so long as it is not on a section of bound up linkage as fred posted

I bought 10 of the Hex 9g servo's several years ago. Out of that 10, 6 chattered. I used all 10 of them and they still work.

Did you have the transmitter real close to the reciever Ron?? I have seen personally the high end Spectrum stuff chatter servos until the transmitter was moved several feet away.

Your reciever antenna was away from and not laying directy on a power feed wire?

I take it you just plugged the pack right into the reciver, without a regulator? If so, you

might need the voltage buffer circut that is in most if not all lipo regulators.

Yeah,

I was right on top of the plane. So prob no more than a foot away.

I will check for binding and such. Yes I did a direct battery input to the receiver. I was just wanting to check things out. I will be sure to purchase the correct regulator/BEC before I take to the skies.

I have so much info now I don't know what to decide...... I will probably get a smaller 1s lipo for the Spit and run a booster to bring the volts up to 5. For the Hummer I will get a 5-6V reg or battery eliminator and run with the 2s Lipo.

You guys are great thanks for all the help!

PV Pilot Tue Feb 28, 2012 1:53 pm

No problem, don't let it confuse you to much, it's pretty easy stuff once you deal with it a few time.

If your swinging your control surfaces till they stop there complete throw and the servos buzzes hard,,let them return to neutral immediately. If that happens you are stalling that servo at the end of the throw and the heat is building in the case expotentially. Very hard on circuts and such in the servo as max volts/amps are achieved and passed thru it all.

Read up on the servo endpoint adjustment and adjust accordingly before moving forward.

**Cribbs74** Tue Feb 28, 2012 2:34 pm

PV Pilot wrote:No problem, don't let it confuse you to much, it's pretty easy stuff once you deal with it a few time.

If your swinging your control surfaces till they stop there complete throw and the servos buzzes hard,,let them return to neutral immediately. If that happens you are stalling that servo at the end of the throw and the heat is building in the case expotentially. Very hard on circuts and such in the servo as max volts/amps are achieved and passed thru it all.

Read up on the servo endpoint adjustment and adjust accordingly before moving forward.

Thanks PV,

My servos are stopping before they complete a full swing. Basically the servo is stopped by the linkage before it comes to the servo endpoint. No buzzing is heard.

fredvon4 Tue Feb 28, 2012 3:09 pm

Just to be clear the stalling of a servo before it reaches it's intended internal limit is a bad thing that forces high volt and current draw and is hard on the position sensing potentiometer and gear train. Mechanicall fix, electroniocally fix (not possible with DX5e) or make sure you never thrown TX sticks to full up, down, left, or right for more than a fraction of a second

Lets say your mechanical throttle fully opened at 50% of micro servo travel throw. You fly and take off at full throttle driving the servo into a stall condition...during climb out you concentrateon leveling wings and establishing a right hand turn then you decide to throttle back, now you get NO response to the reduced throttle input...you have killed a servo either electronically or mechanically and must fly at full throttle until fuel exhausted and land dead stick

andrew Tue Feb 28, 2012 3:48 pm

cribbs74 wrote:

My servos are stopping before they complete a full swing. Basically the servo is stopped by the linkage before it comes to the servo endpoint. No buzzing is heard.

You cannot drive your servos to a stall position and expect much of a lifetime from the geartrain. Secondly, current consumption goes way up when the servo is stalled --- many times the smaller servos will have high stall currents. The DX5e does not have an adjustment for endpoints so you will either need to allow your surfaces more movement or reduce your control throws. You can do this by choosing the innermost hole on the servo arm and outermost hole on the surfaces controlhorn. Even with these changes, you may find that the servo still stalls near the endpoints.

There are also servo savers available that spring load the servo arm so when the surface reaches its mechanical stop the servo can continue to rotate. I'll see if I can get a picture of how I set a servo up to allow some over rotation movement.

EDIT: Some of the info was posted while typing.

John Goddard Tue Feb 28, 2012 4:14 pm

IMO...
It's good practice to have the servo arm hole the same distance from the pivot as the hole on the control surface horn is from
the hinge point. Slop and surface flutter are but 2 of the reasons.
Also set up throws etc mechanically first before fine tuning with the radio.
Have we all managed to frighten you off yet Ron?
lol!

**Cribbs74** Tue Feb 28, 2012 4:17 pm

Good info PV and Andrew.

I think tonight I am going to spend some time with my wife as I am pushing my luck already.

Andrew are you refering to the ball socket setup? The pivot ball snaps onto the servo control arm and the socket on the control rod?

If so do they make them in park flier size?

**Cribbs74** Tue Feb 28, 2012 9:06 pm

John Goddard wrote:IMO...
It's good practice to have the servo arm hole the same distance from the pivot as the hole on the control surface horn is from
the hinge point. Slop and surface flutter are but 2 of the reasons.
Also set up throws etc mechanically first before fine tuning with the radio.
Have we all managed to frighten you off yet Ron?

Not yet John!

They grey matter is soaking it all in. Of course I'm more of a tactile learner lol!

**Cribbs74** Thu Mar 01, 2012 8:18 am

Good folks,

I am headed to Hobbytown USA today. I don't like going there but, my local LHS people are not overly concerned with helping me fly antique glow planes. Plus the prices are stupid there.

I have fixed my linkages in the Spit and it's ready to go once I install a volt booster. My Hummer is better but, the throttle servo is still hanging up so I need to come up with options.

The chatter is what was mentioned the servo's are having a tough time centering. I used Sig easy hinges on both planes so the control
Surfaces are a tad stiff. Perhaps they will loosen up after a while.

I am am almost there guys and I am excited. I hope to call on my experienced friend and do some maidening.

I will keep you posted. I passed out rep points all around for all the good answers.

**Cribbs74** Fri Mar 02, 2012 8:58 pm

Finished! Time to maiden.

The hummer hums and the Spit, spits fire!

Servo travel fixed, battery voltage levels fixed. Thanks in no small part to all the help I received here.

Onward and upward!!!!!!

John Goddard Sat Mar 03, 2012 3:30 am

Can't wait Ron
I hope you've got a camera holder
Very Happy

PV Pilot Sat Mar 03, 2012 6:20 am

Good luck Ron. Let us know how it went.

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Confusion! (not ELO related)