dgfick

My Feedback: (1)

Hey Wayne, is that because they fly like poo????

When is the second shipment scheduled? If I were to be able to get one it would have to be in 2 or 3 months.

wgeffon

My Feedback: (4)

I'm not sure Dave.
I will find out.

Maudib

My Feedback: (51)

I've got about 4 gallons I guess through it... hover, harrier, elevator, waterfalls, some pretty heavy throttle usage...

I haven't hovered for minutes on end... but hover for 20-30 secs climb hard for a flatspin or waterfall, harrier back around and then hover again...

matus777

Thanks Wayne, just curious is that a NICAD or NIMH? Heard you're going to put skis on yours to do the videos....we all want to know which brand you are going to use?

basmntdweller

My Feedback: (9)

Back on post #620 I commented on my 5645 servos and compared them with a few other servos I had at the time. My Futaba 9152 came in yesterday and my 5945s came in today. I tested the 9152 first on a 4.8v pack even though Futaba says 6v only on these. With my 8" long pointer, There was virtually no error in centering, less than .010 no matter how I approached my mark. That was truly amazing! I have always been surprised at the accuracy of servos in general based on the fact that their position is controlled by such a simple device (the pot). Sorry , I got off subject again. I checked two of the Hitec 5945s just to be surew the first wasn't a fluke. Both centered fairly well but nowhere near the accuracy of any of my Futaba digitals. I'd say on average, they would always be within .050". They were much better than the 5645s on overshoot. They seemed to track nearly as well my Futabas when I moved the stick around fairly fast. They did always miss position coming up short of center when I'd come back to neutral. Comparing them side by side with the Futaba S9152, they were slower responding even though they are rated as a faster servo. I have always suspected Futaba rated their servos from standing start while Hitec rates theirs for 60 degree sweep with the servo at full speed travel. I may be wrong but the speed difference is pretty obvious when you compare the two sitting side by side. slaved from a single TX control.
I am going to keep the Hitecs because they will be just fine for my level of flying. I don't do anything real precision so I likely won't notice their lack of accuracy. I'd almost spend the extra money for Futabas if they had something comparably sized with sufficient torque.

On another servo issue. I have noticed most of the GS planes I have seen use a digital servo for the throttle. Is there a reason for this that I am missing? There's no real need for torque to speak of and throttle precision generally isn't that big an issue. I wouldn't think there is that much difference in failure rates from one servo to the next. I have every intention of using a regular Futaba S148 for throttle on my Yak unless someone can tell me a good reason not to.

Thanks,,,Matt

Bosshossv8

My Feedback: (10)

Skis on a Yak-54..I'd like to see that...and judging by what we are supposed to get here in Chicago...It would be the ONLY way to fly here anytime soon.


i just bought a DA-50R on the market place here, and will want to know if it is the alum or steel rod.

As soon as I get it, I am calling DA and giving them the Serial #. Supposedly it only had 1 1/2 gallons thru it. If you want to see what happens at low altitude , when the engine quits.....


Look here.....[link=http://www.rocha-n-roll.com/images/No%20Gas.MPG]no gas[/link]

or if you don't tighten the prop nut.

look here...[link=http://www.rocha-n-roll.com/images/Tight%20Prop.wmv]loose prop[/link]

wgeffon

My Feedback: (4)

Neither.
Lithium Ion.

No ski's on the Yak. (yet)

Bosshossv8

My Feedback: (10)

I think the reason for using a DIGI on a throttle is for the resolution. Many guys flatten out the response curve in the throttle for better midrange resolution ...the 1024 pcm radios and the digi's give tht fine resolution some guys like. You have to find that sweet spot in the throttle response and then flatten it out with the curve , then you can get more minute deflections in the servo for that "fine tune" feel for hovering and high alpha.

Maudib

My Feedback: (51)

I believe that the "inaccuracy" you seem to have located is not due to the servos inability, but rather a fairly wide deadband. This is to allow some leeway when ganging servos. The deadband can be tightened a good deal using the programmer...

I'm not sure even top notch pilots can detect .05"... an interesting test would be to apply equal tension to the arms... say a strong rubber band to see how they perfromed with the natural tension applied of a surface at neutral.


I've been meaning to perform some tests too using a long pointer and some form of weights...

basmntdweller

My Feedback: (9)

I fly with a Futaba 9C tx. The trims are set for 4 per beep. The amount of centering error is equal to one beep of trim. I don't have a programmer but a friend does. He is quietly following this thread. I'm sure he'll call and offer the use of his programmer sometime soon. I would be interested to play with the deadband settings as well.
Ideally, I would like to get a complete test rig built that hooked up to a PC. I know how I want to build it but I don't have the knowledge to do the PC interface. The PC power supply can generate the power needed to drive the servo and I figure one of the Medusa Watt meters that connect to a PC with logging software can record power consumption. The PC can also generate the pulse required to drive the servo. Once upon a time I could have written the code in basic to create the pulse. My programming days have long since passed, and I'm glad to gete away from it I figured a rotary encoder with 10000 lines would give plenty of resolution for measuring servo movement. The only thing I haven't figured out is a loading method. It needs some way to closely simulate flight loads and the way they vary throughout the travel. Weights can only load in one direction and they are always present. In flight, the load can go from max to nothing.
Sorry off the Yak topic again. This is just something I have been thinking of doing for a long time.
Matt

Maudib

My Feedback: (51)

Well... I hereby relegate that task to you... Since I was only willing to do it because no one else piped up... now you have!

Yak Man

My Feedback: (1)

How about JR 8611 in the test.
Brown did not come today w/ the DA---hopefully I have talked nice to the rod & bearing
pixys.
8611 are on the way.
If the Carbon Spinner is out of roud I will GO POSTalaaaaL.
Waiting on a SLOW Boat From China.
Do I need A Life?
I Will Head to Kansas to Gas a Pheasant for some relief!

basmntdweller

My Feedback: (9)

I would have loved to compare an 8611 but I don't have any[].
Matt

jrjohn

My Feedback: (24)

This is exactly what I need to do, I thought it had to be done with the radio, I'll buy a digital for my throttle and flatten the curve there. (my radio would not do this) 8103 JR

John

morecashthansense

Hi all,
A quick question to all you large plane flyer's out there,
I have a the Yak coming and will be using the DA 50 running on 5 digital servos and one plain throttle servo, it will be getting quite some abuse in the air so I guess I will be giving the servos a lot of work to do.

The motor is of course getting its own switch and battery.

I have a optical isolator which I have used before and I think was great so wish to use again however it requires a different power and therefore switched power supply to the receiver, I am also running a top of the line JR receiver.

So my choices are for battery choice are;

1 Simple.
Two good (2000mah+) five cell battery packs and two good switches. Cheap to do however not much redundancy, also doubling the risk as both batt's are independent one item fails no radio! oh and heavy

2 Complicated.
Two Lipoly packs of 2s2p of approx 2000 mah each cell for the servo power and possibly 1200 for the receiver and two fail safe regulator type switches. Quite expensive but a good amount of redundancy. presumably lighter than option 1.

3. ???????

any suggestions or help in making up my mind would be appreciated, one other problem I have with the Lipols is despite a very rigid charging routine I have managed to balloon 2 or 3 indoor Lipol' packs where I have never yet managed to wreck any nicadd or nimihs????

I have read Maudib's review of a power box, does anyone think this is an option?

Many Thanks.

going vert

My Feedback: (11)

Here is my recommendation,

Keep it simple and light. No power box and you really don't need all this redudancy.

I'm running a fromeco 2400 li-ion on the ignition with their regulator. I've got their 4800 on the RX with a 6v regulator and fail safe switch. Call Kurt from Fromeco. He is a really good guy and knows his stuff. He explained the purpose of a power box to me and you just don't need one on this plane, especially if you run his 4800 + fail safe regualtor.

morecashthansense

Hi there vert,

I see I can use a big li-poly and regulator/ safe switch however with the opto isolator I now need two switches and li-poly packs although the one for the receiver only need to be small capacity as its not going to do much work. I do like the opto as it vastly increases the range during a aeriel down range check and not one hint of a glitch or Buzz plus the power supply side of the opto has a far greater loading capacity than the tracks on the receiver pcb alone.....

747drvr

My Feedback: (5)

Hi,

This is a good way to get adequate capacity and redundancy . If each battery is plugged into an individual port in the rx through it's own switch , you CAN have the failure of one component and you will still have power.

Marc

going vert

My Feedback: (11)

what is the opto isolator? A kill switch?

If you run the 4800 & failsafe (w/ 2 leads off the reg) you'll have constant 6V, even under heavy loads. You cannot overload the receiver w/ this setup. That battery can only dischard at 8A and the receiver buss can take much more than this (I think 40A, but I could be wrong)

Maudib

My Feedback: (51)

Opto isolator dedicates the power going to servos... he'll have a battery for the servos and a battery for the receiver... the isolator isolates any noise from the servo end from getting to the receiver and dedicates power to just them.

flat spin

Is that really necessary with just five main servos. No one has had any problems with the 68" which although smaller still in many cases is run with the same setup.

going vert

My Feedback: (11)

IMO - it's not necessary. There are a lot of people out there running 40%s w/ 15 digital servos on 2 or 3 - 4400s - no power box, no isolators, etc and the planes run great.

It's just one more thing that can fail - IMO. However, to each his own. If he likes the isolator, run it. I like 14awg wire off the battery. It's not necessary, but I like it so I go with it.

Maudib

My Feedback: (51)

Nope... not necessary at all... at least for me...

But i suppose it's like digital servos, lipos, tuned pipe, aluminum arms, twisted servo extensions, etc....

Whatever gives a person the level of confidence in their build is the right choice for them.

flat spin

a fairer word has never been spoken. I did however speak to Robert at Smart Fly today and he said that running five servos it really isn't necessary. ONe thing he did say which may be of interest to those wanting redundancy is that a regulator with bat share is in the pipeline should be about a month or so away. I won't bother with this myself but if you want to run two packs then it is perfect.

MSP1957

My Feedback: (1)

Any video yet?

Michael