Futaba 3001 / 3004

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Hamish - 29 Oct 2005 10:38 GMT

Can anybody explain the reason why a 3004 servo is less expensive than a
3001 servo (about £1).

My investigation has shown that the 3004 is identical to the 3001, other
than its weight is less, which I would have thought would have made it more
expensive.

Paul

http://www.futaba-rc.com/servos/servos.html

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John Privett - 29 Oct 2005 13:00 GMT

> Can anybody explain the reason why a 3004 servo is less expensive
> than a 3001 servo (about £1).
>
> My investigation has shown that the 3004 is identical to the 3001,
> other than its weight is less, which I would have thought would have
> made it more expensive.

I've been puzzled in the past by the similar comparison between the 148 and
the 3003. I'd not noticed the 3004 until now.

The 3004 seems to be an "economy" version of the 3001, in the same way that
the 3003 is an "economy" version of the 148. But apart from the different
mounting holes/slots I've not previously seen any significant difference
between those two either. :-(

But looking at the specs on Ripmax's site,

http://www.ripmax.com/item.asp?itemid=P-S3003
http://www.ripmax.com/item.asp?itemid=P-S148

http://www.ripmax.com/item.asp?itemid=P-S3004
http://www.ripmax.com/item.asp?itemid=P-S3001

they quote different speeds and torques.

3003
Torque 3.2 Kg/cm
Speed 0.23 sec/60°
Dimensions 40.4 x 19.8 x 36mm
Weight 37.2g

148
Torque 3.0 Kg/cm
Speed 0.22 sec/60°
Dimensions 40.4 x 19.8 x 36mm
Weight 44.4g

3004
Torque 3.2 Kg/cm
Speed 0.23 sec/60°
Dimensions 40.4 x 19.8 x 36mm
Weight 39g

3001
Torque 3.9 Kg/cm
Speed 0.22 sec/60°
Dimensions 40.4 x 19.8 x 36mm
Weight 48g

So they reckon the 3001 is slightly faster and significantly more powerful
than the 3004.
And the 148 is slightly faster but slightly less powerful than the 3003.

I'd go for the 3001.

Signature

John P. - who flies on Epsom Downs, UK.
http://www.flyrc.org.uk/
I'm sick of spam, so replace 'nojunkthanks' with 'john' if you want me
to read any e-mailed reply!

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A.T. - 29 Oct 2005 21:02 GMT

Someone is either not reading Futaba's own catalogues or making a number of
typing or editorial errors in their advertising. However, S3001 is
preferred given the ball bearing which reduces slop on output shaft.
See variance in published details for each Futaba servo at
http://www2.towerhobbies.com/cgi-bin/wti0002p.pgm?M=FUT
or short form spec list at http://www.futaba-rc.com/servos/servos.html

IMO a more accurate list of specs appears at
http://www.servocity.com/html/futaba_servos.html which lists S148, S3001,
S3003, S3004 as all the same torque etc, as they were originally published
by Futaba of Japan - the manufacturer.

S3003 was introduced as a replacement for the old S48 [which became the S148
with J in lieu of G plug.]
S3003 motor is mounted direct to board of servo and does not withstand a lot
of vibration = not for use in Heli. Accordingly, S148 was quickly
reintroduced for the cheaper Heli packages.

Only recently has a slight torque increase been published which does appear
noticeable in practice. possible change of motor?

Tower Specs appear different from Ripmax as quoted below by John =

S3003 Speed: 0.23sec/60 deg @ 4.8V or 0.16 sec/60 deg @ 6V.
Torque: 44 oz-in @ 4.8V or 56.8 oz-in @ 6V
(3.2kg/cm @ 4.8V or 4.1kg/cm @ 6V)
Size: 1.6"L x .8"W x 1.4"H (41x20x36mm) w/o output shaft
Weight: 1.3 oz (37.2g)

Ball bearing version = S3004
Speed: 0.23 sec/60 degrees at 4.8V
0.19 sec/60 degrees at 6.0V
Torque: 44 oz-in (3.2kg-cm) at 4.8V
57 oz-in (4.1kg-cm) at 6.0V
Length: 1.6" (41mm) Width: 0.8" (20mm)
Height: 1.4" (36mm)
Weight: 1.3 ounce (37.2 grams)

S148 - Older but higher quality and less prone failure from vibration and
may be used in light Heli. - no bearings

Control system: Pulse width control, 1.52ms neutral
Motor: 3-pole
Power requirement: 4.8 or 6.0 volts (from receiver)
Power consumption: 6.0V 8mA (at idle)
Torque: 41 oz/in @ 4.8V or 57 oz/in @ 6V
(3.2 kg/cm @ 4.8V or 4.1 kg/cm @ 6V
Transit Time: 0.23 seconds/60 degrees @ 4.8V or .19 sec/60deg @ 6V

S3001 is simply the ball raced version of S1489 - shows same power at 6V,
power quoted at 4.8v appears to be incorrect as specs are the same in
Futaba's own international catalogue except S3001 weighs .7gm more.
Torque: 44 oz-in at 4.8V 57 oz-in. at 6V
Transit: .23 sec./60° at 4.8V .19 sec./60° at 6V

regards
Alan T.
Alan's Hobby, Model & RC Web Links
http://homepages.ihug.co.nz/~atong/
.................................................................

> > Can anybody explain the reason why a 3004 servo is less expensive
> > than a 3001 servo (about £1).
[quoted text clipped - 50 lines]
>
> I'd go for the 3001.

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Model Forum / Radio Controlled / Air Models / October 2005

Futaba 3001 / 3004