bachynski

My Feedback: (1)

Just got back into rc after an absence for about 15 years. Boy have things changed! Have a question about my Futaba 7C 2.4 GHZ Tx with R617FS Rx. Can I use both analog and digital servos with this system. I would like to use some of my older analog servos to avoid the cost of switching all servos to digital right now. I notice that Futaba sells this Tx/Rx package with S3004 servos (analog) or S3152 servos (digital) which implies that you can use both servos with this receiver. I've heard that analog servos will overheat, make lots of noise and eventual malfunction. I've noticed with FASST compatible Rx ( Orange, FrSky, and Corona) they mention that the Rx mode must be changed to accommodate the analog servos. I even fired off an email to Futaba support and they told me I could use both type on one receiver provided they are not plugged into the same channel, If that's the case the Futaba Rx must be quite a versatile Rx compared to the rest. In either case, I'm confused and would really appreciate any light cast on this issue.

landeck

My Feedback: (1)

I am using analog servos on all of my Fasst receivers (7, 8, and 14 channel) without any problems. Some of them are 25 years old (S148). I am not currently using any of the China clones but I would be surprised if there is a problem with using analog servos with them.

Bruce

aghost

My Feedback: (13)

I have the 7C 2.4 TX, 617FS RX, and the FrSky futaba compatible RX. All I use are analog servos (Futaba, JR, Hitec, Hobbico) with both RXs. The FrSky RX does have two modes. One should only use high speed digital servos in the FrSky High Speed (HS) mode. Use the FrSky FS mode for other servos, otherwise the servo may heat heat up and burn out.

pilotpete2

+1.
All good stuff here. I'd just like to add that the HS mode (refresh rate) does not affect the speed of the digital servos. It only results in the servo developing its full holding power faster. This has a benefit with high performance Helis, on a planker, not so much.
I have the R6008HS that came with my 8FG in a 30cc size Yak 54. Since I have digital servos, I've tried both normal and HS mode. No detectable difference at all, of course you do have to take into account my flying skills[:-]
Pete

bachynski

My Feedback: (1)

Many thanks to Landeck, aghost, and pilotpete2 for all the good info. I guess what was really confusing me was that I didn't know that the R617FS Rx didn't operate in HS mode. Now everything makes sense! Sure is nice to have a forum like this to clear up these matters. BTW it doesn't sound for now that I would need or appreciate a digital servo for now. After 15 years I'm happy if my plane lands and looks like I'm light years away for 3D flying. Thanks a lot guys. Much appreciated.

rmh

My collection of servo,s JR/ Futaba/ Hitec/ Spektrum etc., plus a number of ? brands show that 2.4 systems really change performance -compared to older PCM (512/1024/2048) or analogue
They all smooth out and are faster - all of em
Some favorites are analog, 3 pole, excellent circuitry!
Digitals - don't see any real improvement in many cases -
spending a LOT of money on servos really doesn't show any real gain - some will disagree on this.
When I got my first DX7 and 7000rx, The aerobatic plane I put it in, needed more expo to reduce the quicker movement around center .
Many fliers noted the same thing

bachynski

My Feedback: (1)

Thanks rmh,

Currently my servo stable consists futaba s148, some Hitecs from the same era, and Royal servos. Remember Royal ! My RC workshop is like a trip back in time. Thanks for you good advise and info. I'll need it to start upgrading.

rmh

Remember that the output of these older designs was typically not over 40 inch ounces and saw 4.8 packs in 500- 750 ma sizes

My good, older 148's work very well on 6 volts- so you may want to check the others too -on higher voltages
2.4 is prticular about having power which never droops into the 3 volt range -
check yer batts under the loads they will be seeing.- not just using a load checker .
Most old batts just are not up to the current (pun) requirements of computer type rx - any of em

karolh

Bachynski,

I remember those Royal units quite well, as my Royal tach of '83' vintage still works quite well.


Rmh,

Those S148 servos have been my workhorses over the years, and I have never had one fail me in flight. Back then they all started life running on 4.8 volt Nicads and now are run on 6.6 volts from A123 battery packs.

Karol

DougV

You can run analog servos with all Futaba receivers, HS receivers or not. With HS receivers, just run the analog servos in regular mode not HS mode. (you set the mode on the receiver)

Doug.

Adrian14mz

Looking for an answer ??.

Hi all.
I sold 4 x S3152 servos to a friend of mine but they wont work on his FF6 PCM/PPM TX/RX.

Any views on this.

Adrian.

johonmirae

I don't think the 617FS has a high speed mode. Running analog servos on this RX is not a problem.

pilotpete2

Methinks you are quite correct
Pete

pilotpete2

Do any other servos work with this setup?
Something other than the servos is more likely the problem.
Pete

Bax

My Feedback: (11)

The servos do not require a "high-speed" mode for operation. If they won't work with your receiver, something else is going on.