Servos??

[Ross Clarkson]

Hi all,

 

I am sure you are all probably getting annoyed with all my different questions lately but i need help once again!!!!

 

As you may be aware, i am getting a Kyosho Calmato 60 Sports 71" model for Xmas along with a DX7.

 

I have sorted the engine out but i have been researching servos and quite frankly, i am stuck!!

 

I need five but i see they range from £15 to £80!!!! All i am after are servos that are reliable, will do the job with ease and quickly but although price isn't really an issue i don't fancy paying £80 each!

 

Any thoughts guys?

[Pete B]

There's always a good range at GC and Servoshop, Ross. Browse for your spec and see what the feedback is like. Much as I'd like top-range everything, we all have to make (sensible) economies

 

Pete

[birdy]

If I were you I would go with Futaba S3003s, or any of that ilk of standard servo.

[Ross Clarkson]

Am i right in saying with Spektrum i can get any servos?

[Robert Bromwich]

Ross

all i buy for the larger models are the digital spekrum standard servos DS821 at only £14 each they are very good /  reliable from here Robotbirds

 

rob

[Frank Skilbeck]

Ross you can use any make of servos with your Spektrum Rx's, the only thing to watch is that some digital servos will only operate on 4.8v (i.e. a 4 cell Rx pack).

[Tim Mackey]

I also find the DS821 excellent.

[Ross Clarkson]

They look just like the job, cheers.

 

Frank, i will have the AR7000 Rx. Do you mean i need to get a 4.8v battery to suit these servos?

[Robert Bromwich]

TBH ive never had any problems with any servos i have put onto the AR7000 

 go for 6v servos there quicker anyway

 

one thing to mention the 2.4g Rx have a voltage of 3.5v to 9.6v so if you are going to ever use a sep Rx battery i wouldnt get anything less then 6v and a good quailty one as well

as you dont want any brownout  

 

Rob

 

Edited By Robert Bromwich on 06/12/2009 07:08:53

[Tim Mackey]

The DS821 are rated for 6V operation no problem.

[Erfolg]

A query?

 

Does the Futaba 2.4 RX use 6v?

 

Erfolg

[Robert Bromwich]

Erfolg

have a look here Futaba 2.4g RX to me looks like they are 4v to 6v

but need to see which is yours and make sure

rob

[simon barr]

Hello Ross. As I said in you very first posting about the Calmato 60, I use Futaba 3004's in mine and they are absolutely fine, and under a tenner, (unless they've gone up). So unless you really want to cough up for some expensive jobs, I would suggest you stick with them.

[Ross Clarkson]

Excellent, cheers guys.

[Erfolg]

My Futaba receivers are 617 from memory.

 

My fear was that the BEC units on my speed controllers would be insufficient for the RX and servos, if the current requirement was a a min.  6v , which I am assuming that the Spektrum needs.

 

With Futaba it would appear they are capable of using Nicads/Nimh with no issues.

 

As for servos, Futaba standards are very cheap days, and in my opinion well suited to even large models, although probably not the very large models.

 

Erfolg

[Ross Clarkson]

Ok, going back to the issue of a Rx battery now.

 

Robert mentions i should be going for 6v which isn't a problem.

 

Should i stick with Nimh or move on to Lipo?

[Ernie]

Hi Ross

It is confoundedly confusing isn't it;

However, it is a lot simpler than it seems. Your 70" sports model is not going to make exceptional demands on servos, so I'd use standard units from a well known manufacturer. Personally I use hitec, because they are cheaper than Futaba, and I've never had any real problems

There are some other issues..

Its a good idea to standardise to one manufacturer, for interchangability of output arms, etc.

Avoid little known makes, I'm sure some are very good, But I wouldn't chance a good airframe with a suspect servo.

You can mix types in one plane, for example for throttle you dont need a lot of power, wheras for rudder you might need something more powerful

Finally, the red multiplex ones look very fine

Finally, finally, installation is really important, I've seen many more problems due to bad workmanship, than to servo failure

ernie

[Ross Clarkson]

Thanks Ernie.

[birdy]

Stick with NiMh - the advantage with lipos is the weight, but that wont be a problem in a model such as yours. And with Lipos you need the regulator to keep things at happy voltages too. Add to that that they are more expensive and more fragile and need special charging equipment... You get the picture - they are more trouble then they are worth as an Rx battery in this case.

And everything Ernie said I would agree with - how many ultra percision servos have you seen which are attacked to the contol serfaces with slop?

 

birdy

[Ross Clarkson]

Cheers Birdy, thats what i thought. I had them in my Heli's and wanted to try and avoid them if at all possible so this is good news.

 

Thanks all for your help. 

[Tom Foreman]

Hi Ross, I try to use Spektrum DS821 for standard servos, Hitec HS-MG85 for mini servos and Hitec HS-65HB for micro servos. I have tried the cheaper Hitec 81 & 55's but they suffer from weak gears and electronics, got fed up of replacing gears or throwing away duff 55's, I even have a dead 55 buried in the fuse of a Blizzard, have had to leave it there and make do without rudder! Just my favourites I'm sure other people have their's

 

The Futaba 2.4Ghz RX work at 6.0v ok.

 

Tom

[Ross Clarkson]

Cheers Tom.

 

I am just about to go online shopping so will let you know how i get on.

 

I really appreciate everyones advice, love this forum.

[Ross Clarkson]

5 x DS821 digital servos bought - £80.

 

1 x 12x8 Graupner G-Sonic prop and 1 x 57mm Alloy spinner also purchased.

 

Just a suitable battery required now.

 

Thanks guys for all the help.

[Tim Mackey]

Hi Ross, have you considered the eneloops or vapex instants - they are good and hold their charge almost as well as Lipo - can be ordered in either 4 or 5 cell packs in various shapes and sizes.

These peeps also have an Ebay shop

Edited By Timbo - Administrator on 07/12/2009 10:28:37

[Ross Clarkson]

Cheers Timbo, i will take a look.