Gyro/rudder servo recomendations

[AOW Lusetti]

Hey Guys,
I have been learning a lot reading these threads. Any recomendations on a Gyro/tail rudder servo for a blade 400. I was thinking of upgrading to a digital servo and eventualy a better gyro. Please advise. Why the heck did E-flight supply a Digital Gyro w/o a Digital rudder that works with its gyro. :arggg:

[Heli Jim]

Well, yeah, it's a digital servo but it can't handle the frequency that a TRUE digital
servo does so you have to run the stock gyro in analog mode, which is the way it
comes set up from the factory.

I just swapped out all my servos for a JR mini helicopter performance pack which has
three ds285's for the cyclic, and they just drop right in....exact fit.

The tail servo is a 3400G which is a true digital tail servo so you can set the gyro to "DS"
mode.

I REALLY like the new servos.....much more solid feeling and the tail is SOLID!!!

If you don't want to spring for the whole Gyro AND servo combos right now, the 3400G
is a good choice and you might want to consider the perf. pack and upgrade ALL your
servos. From what I've read, and I now believe, the servos are definately the 'weakest link'

[AOW Lusetti]

thanks ! I have stripped a few sevo gears on this puppy already with my newbieness:YeaBaby:
I may just bite the bullet and go for the pack. Where can I find the pack at a reasonable price ?

[GreenBar0n]

Just google:

JRPF300H

I bought mine at Ready Heli, came to $139.99 after adding to cart, looks like they are out of stock ATM.

http://www.readyheli.com/JRPF300H_Mini_Heli_Performance_Servo_Set_p/jrpf300h.htm

[sokal]

thanks ! I have stripped a few sevo gears on this puppy already with my newbieness:YeaBaby:
I may just bite the bullet and go for the pack. Where can I find the pack at a reasonable price ?
its about $160 for the heli pack at horizon much better than buying seprate
but if you wana buy slowly i would recomend the GY401 and JR3400G first
the 3400G dosent work to well with the stock gyro just because the 3400g has a huge throw with out a limit it will over run your tail slider and bent rod

i fave the same setup as Heli Jim and it is a night and day upgrade

also ebay and towerhobbies have the GY401 priced nicley:clappp

[sokal]

Just google:

JRPF300H

I bought mine at Ready Heli, came to $139.99 after adding to cart, looks like they are out of stock ATM.

http://www.readyheli.com/JRPF300H_Mini_Heli_Performance_Servo_Set_p/jrpf300h.htm
:arggg:thats cheap WOW!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:badair:

[LockMD]

I'll chime in to 3rd the JR pack, as I did the same and LOVE it!

[skigolfmike]

My 401 was $139.99 too. No 3400 for now, I have a DSP75 on the tail programmed with the Spektrum servo programmer as a TR servo. It holds great. I did have a problem with the piro rate, which I think I have figured out. When in doubt RTFM.

[rudderman]

I bought a GY401 and a 9257 tail servo and its rock solid.My best upgrade up to date along with my hs65mg cycling servo's.Try the classified there are usually good deals there.I bought my 401 for 75.00 in the classified here.Couple weeks back.

[brookshay]

Is the servo programmer required to do this? I was thinking of adding a DSP75 for my tail and don't have a programmer.

My 401 was $139.99 too. No 3400 for now, I have a DSP75 on the tail programmed with the Spektrum servo programmer as a TR servo. It holds great. I did have a problem with the piro rate, which I think I have figured out. When in doubt RTFM.

[skigolfmike]

Is the servo programmer required to do this? I was thinking of adding a DSP75 for my tail and don't have a programmer

No, you don't need the programmer. I think the DSP75 will work fine out of the box. The default program is airplane mode, the throws are 45* each direction. (90* servo) Basically, you'd setup the servo like the folks using 3400s or 9257s. The only difference is I would be leery of setting the gyro to digital mode. In the default "airplane" mode the servo gain is lower and I don't know if it can handle digital pulses, so, in this case, I would use analog mode.

The advantage the programmer gives you is is setting the endpoints in the servo so it can't bind and matching the servo mode to the intended use. With the programmer it's a versatile servo. OTOH, it's never going to be as good as a specialized TR servo.

[brookshay]

What's a good option for price / performance for a decent TR servo?

[sokal]

the specilized TR servos are your best bet
i herd of people using others and works fine
true preformance for tail is speed and torque
i recommend the 3400G will set u back 70 or so but well worth it
but its up to u bud

[Wolfpackin]

Mike,

I've been using the DSP75, not reprogrammed, in digital mode.
I finally got the stock gyro to hold pretty darn good with it and I was able to turn my gain from 67% up to 78%.

Is there any way we can find out for sure if the out of box DSP75's can handle the digital pulse?

If I have to switch the gyro back to analog will I have to lower my gain?

Thanks.

[skigolfmike]

I've been using the DSP75, not reprogrammed, in digital mode.
I finally got the stock gyro to hold pretty darn good with it and I was able to turn my gain from 67% up to 78%.


I got the DSP75 servo/ 110 gyro combination to hold OK. I had the servo programmed as a TR servo and I had the gyro in digital mode. I never could get the gain above 66% though.

Is there any way we can find out for sure if the out of box DSP75's can handle the digital pulse?

I think you are the guinea pig. If it doesn't burn up the servo, you're probably OK. Specs on Spektrum website don't really say.


If I have to switch the gyro back to analog will I have to lower my gain?


I doubt it, I bet you'd have to increase it. When I was checking the gyro reaction on the bench, the difference in servo reaction between analog and digital mode was dramatic. In digital mode the servo moved farther and faster for comparable tail movements.

I would bet if you got a Spektrum programmer and programmed the servo in TR mode it would work a little better. I also bet you'd have to turn you gain down some.

[brlowe]

Does the tail rotor servo for a blade 400 really need 40 oz of torque like the 3400 has? I was looking at putting a futaba S3154 servo on the tail of mine. It is the same speed as the 3400 but only has 21 oz of torque. Only costs $30. The 3154 is also drop in on the blade for mounting.

[sokal]

not sure if all the torque is needed but damb does she do the job
and its also drop in
http://www.helifreak.com/attachment.php?attachmentid=40644&d=1204506988

[skigolfmike]

I got in a quick hover flight and got a chance to check if I fixed the piro rate problems with the DSP75. I have insane piro rate now. Good thing I learned to hover nose in.;) So, I would say 19 oz. of torque is probably enough.

However, I have quite a bit of rebound now when I stop a piro, which means I need to start adding delay to the 401. Since the guys flying 3400s and 9257s don't have to use any delay, that tells me those servos are more suited to the task than the DSP75 for the tail rotor. When I feel I need one to get my flying to the next level, I upgrade too.

[carlo_the_wonder_frog]

adjusting your rudder channel endpoints will adjust your piro speed.

[Wolfpackin]

adjusting your rudder channel endpoints will adjust your piro speed.


Doesn't it do that by limiting how far the servo can move the tail slider?
I never quite understood that.

[skigolfmike]

It's because the gyro actually flies the tail. Since it figures out how to move the tail from your input, you are just the voting member in the system. The gyro can, and will, move the servo to the limit of it's travel. Turning the rate down in the TX will slow the piro because the gyro sees it as less throw. You vote, the gyro decides.

[Wolfpackin]

Mike,

Very well stated.
Bravo, and thanks.

Ray

[glassier]

The B400 manual says that although the DS75H is a digital servo it is not designed to accept a pulse rate of 275Hz:arggg:. So you will have better results in analog. Page 26 of manual. I'm flying stock with great results in std mode.:Bang

[skigolfmike]

We're not talking about the same servo. We are using the Spektrum DSP75, not the E-Flite DS75H. Same case, same gears, not similar performance. The DSP75 is a much better servo. Also, I believe the B400 manual states you can use the DSP75 on the tail with the 110 gyro in digital mode. Works better than stock IMHO

[glassier]

My mistake:oops:. I should have looked at the number more closely.
Does the other servo by spektrum really make that much difference?