Futaba BLS451 vs JR8915/8717

[t-rex pedro]

Which are the best cyclic servos out of these two?

[moonmanflyer]

Which are the best cyclic servos out of these two?

I have heard the jr's need to run higher voltages to be real good, but the bls451's will be happy on 4.8v.
I have just fitted 3 to my synergy i am putting together.

[raptorheli2]

this subject came up here last week.

quote from futaba USA-

The BLS451 is designed by Futaba for use in Nitro or Electric cars, they are not precise enough for the demands of heli flight.

The only brushless servo we offer at the moment for heli use is the BLS251.


Sincerely,
Krysta
Product Development & Support Specialist
Futaba Service Center USA

if it were me i would give these a wide berth since your buying new. if i had 451's then i would use them but i would certainly not buy them. futaba used to say use them in helis then when the glitching issues were reported they said the above and subsequently they removed helis as a suitable application from their website.

i run my 8915's at 6v and they are fine fyi.

cheers

[Ade_Law]

The BLS451 is designed by Futaba for use in Nitro or Electric cars, they are not precise enough for the demands of heli flight.

thats bollocks.... if they are anything like the BLS351 they are the most accurate servos ever.

theres something else going on here and futaba arent admitting to it.

Ade

[raptorheli2]

ade, thats futabas official response disagree or not. thats the word on them and i say again.....why do they say not to use them when they just limited their market? remember they DID say use them then changed their minds. something is very amiss there. there is a reason why they shouldn't be used and i would like to know what it is but the above is the best we are getting.

i also asked what happens if insurance needs to be claimed in another thread should we ignore their recommendation and have an accident with these servos, no one has replied to it so i'm not sure.

doesn't change a thing for me, wouldn't buy them.

cheers

[xygax]

Maybe due to the high peak current they consume they put so much load on the DC bus that its causing RX glitches cause they arent supressed properly... It may be a good idea to put a ferrite ring on the cyclic servo tails particulaly if you are on 35 Mhz and a low impedance capacitor at the rx to deliver the peak current instead of relying on the battery through its wiring..

Just a thaught...
Steve

[robgt]

I'm using them on my 600n at the moment... all seems prefectly fine to me so far.
They were purchased at the time when it was said they were fine for use on heli's.

Running a 6 volt regulated setup.

Any ideas what I should be looking out for in terms of signs of trouble etc (outside of the usual)?
Cheers,
Rob

[raptorheli2]

rob, people report glitches with the servos. i wouldn't overly worry about it myself if i already had them.

cheers

[robgt]

I'll keep an eye on them... not very comforting to know eh!
So far they've been great (really great!) and no glitching.

Spektrum DX7 setup...

Cheers,
Rob

[t-rex pedro]

theres something else going on here and futaba arent admitting to it.

Like what Ade?

Also, I just found the thread from last week about the BLS servos. Very interesting.

What would most people buy from new taking all of the above into account?

I'm leaning towards the JR's but have been using Futaba stuff all along hence the question.

[richieclarkie]

Personally I would be buying 8717s if money wasn't an option.

As it is I find 9252s are fine.

[jiberjaber]

BLS here since January - no probs running with an align 4in1 and AR7000 was originally in the titan, now in the knight.

[t-rex pedro]

Personally I would be buying 8717s if money wasn't an option.

As it is I find 9252s are fine.

Cheers Richie

I know I'm no 3D expert but I have been learning/trying new things and really want to crack this 3D thing!!!!!As I'm upgrading I dont mind spending a bit more to buy servos that will see me good for a long time.

Although Fast lad are doing 3 x 9252's for £150. Tempting!

Just to throw another ingredient into the mix - 9452's look really good and on flea bay for £38.99.

Decisions decisions!!!!!!

[Ade_Law]

mine are running sweet. however they do have the ability to pull 7.5amps stalled and have logged 5.5amps for a very short time in the air so if your reg isnt up to scratch it could cause issues with lockouts or glitches.

i run a loom which is basically 3 extention leads with the reg soldered into them. the servos plug in one end and the other end plugs into the RX this means the current for the 3 CCPM servos doesnt go through the RX. with the servos stalled on the bench i was seeing 0.5v drop at the RX without the loom now i see 0.1v drop.

Ade

[richieclarkie]

9451s at £38 is a REALLY good deal and I would seriously look at them. Don't spend £50 on 9252s.... thats well overpriced! You can get them from HK for much cheaper.

The issue here is that ALL of the top end servos work really well. One thing to bear in mind is that the better servos draw more current normally and therefore you'll get less flights per charge in theory too - particularly if they stall

As Ade says the BLS451s (he runs BLS351s) are fine and the likelyhood of them causing you problems is very low.

Why do many of the top pilots fly 8717s? Because they can run them at 8v direct off their lipos which improves feel and speed of the heli and of course makes "crack" manouvres easier too.

You pays your money.....

Cheers Richie

I know I'm no 3D expert but I have been learning/trying new things and really want to crack this 3D thing!!!!!As I'm upgrading I dont mind spending a bit more to buy servos that will see me good for a long time.

Although Fast lad are doing 3 x 9252's for £150. Tempting!

Just to throw another ingredient into the mix - 9452's look really good and on flea bay for £38.99.

Decisions decisions!!!!!!