Ultra Light 3 Gram!!! Servos. You can do it! - Page 3 - RC Groups
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Sep 14, 2003, 03:22 PM
De-Brushed user
If you need a small/light receiver, the MPI micro RX is light. Mine weighs 4 grams w/ the long Azarr antennae and regualar connecting pins, im sure removing the pins and their plastic bases would shave off a gram. Im not brave enough to do that, and none of my stuff would notice a gram.
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Sep 25, 2003, 03:20 AM
Registered User

What do you people think of the new Saturn s49 servo that has ben released. Its specs are:
Weight: 4.9g
Torque@4.8v: 1.2kg/cm
Torque @6v: 1.5kg/cm
Speed@4.8v: 0.12
Speed@6v: 0.10
Size: 20 x 8 x 16.2
And it only costs 17.20pounds sterling.

What you think?

Ian Mc Donald
Sep 25, 2003, 03:44 AM
Registered User
I'm using the saturn 4.9 in my ventus and soon to appear rc whoopee (quintuplane!!!)

I'll let ya'll know how they fair.
Sep 26, 2003, 06:47 PM
Registered User
I reckon they could (like the saturn 54) as they have a push fit gear set so you could remove the top of the case.

Ian Mc Donald
Sep 29, 2003, 04:31 AM
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Mario's Avatar
Hi everyone,

It's been a while since I posted and just wanted you all to know that I got word from a cool company that has taken my suggestion and desire for a lightweight and affordable ultra micro servo, that we could use both in "palm size" fixed as well as rotary wing miniature models, for total RC control.

I am happy to know this is in the works and that it will be around 1.5 grams, as an "off the shelf" affordable item, something I have been craving desperately, for a while now, so that I can make available my "Palm Size" heli kits.

Stay in tune either through this post or through my web site which I will update as soon as I can disclose more.

Mario I. Arguello
www.micro-flight.com (revamped with new stuff)
Last edited by Mario; Sep 29, 2003 at 04:45 AM.
Sep 29, 2003, 10:49 AM
Crashmaster Extraordinair
is there anything wrong with re-gearing a servo to increase its torque and decrease its speed, or vice versa?
Sep 29, 2003, 11:02 AM
Hmm, kerosene... :)
NightSwan's Avatar
Sparr, I wouldn't be concerned with increasing torque (e.g. higher gear-ratio)

Increasing speed will probably also increase the current the motor needs (to start up) . This may lead to smoking motors and/or control circuits.

Other than that, good luck and let us know how it works out

Sep 29, 2003, 11:40 AM
Crashmaster Extraordinair
Actually I was less interested in the speed/torque results than in the weight savings from eliminating gears (and gear shafts). I have some stripped gears from a HS55 here, just counted all the teeth. Ratios look like 20:8, 48:10, 48:12, 32:8, and 31:10, for a total of approx 600:1 with 6 gears (including the 8 tooth metal pinion). Replacing the first drive gear with a clone of the second drive gear and then removing the 4th drive gear would give you a ratio around 372:1. This would give you about 80% more speed, 40% less torque, and save you the weight of one of the two heaviest gears at the cost of the weight of half of one of the middle gears. If you could replace the pinion with a 6-tooth plastic pinion then you would save even more weight and get back closer to the original performance.
Sep 29, 2003, 11:56 AM
Crashmaster Extraordinair
also, it seems that the wires from the PCB to the POT could be eliminated completely. the pins on the POT line up almost perfectly with the contacts on the PCB. the PCB would be mounted kinda crooked inside the case, but thats a nonissue. I am going to be trying both this idea and the previous one shortly.
Sep 29, 2003, 12:27 PM
Crashmaster Extraordinair
unfortunately the small half of the second drive gear doesnt quite fit in place of the first drive gear, and I am not up to the task of building a new gearbox. maybe the wire removal idea will work out better
Oct 01, 2003, 06:18 PM
Registered User
I along with many others have been "Speed hacking" servo's for quite a while now. The best servos we have found so far are the supertec pico, the multiplex ms-x1 and the supertec s136l/2bb (this one is 33g so is not suitable for micro flight)

The pico and ms-x1 both weigh 6g(ish) and have a 5gear gear box.

Here is a link on how to speed hack them.

I am not sure if it is possible to remove the 2 gears which are no longer used i will check in the morning.

I hope this helps

Ian Mc Donald

(p.s. the guide says "this guide assumes the servo is already modified for 360deg controlled movement". This is what we do in robotics to make the servo's go continiously around by disabeling the pot. Leave the pot as it is and you will be fine)
Oct 01, 2003, 10:51 PM
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Mario's Avatar

How much lighter does the servo weight after the speed hacking?

Oct 01, 2003, 10:58 PM
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EricCartman's Avatar
is the 1.5 the 1.7 falcon servo or the 1.4/1.9 didle servo?
my palm heli is only 3 in.
Oct 02, 2003, 01:40 PM
Registered User
Mario to be quite honest i dont know but i should be back on later at about 11-12o'clock gmt and will put up the weight of the full gear set and the weight of the gear set less the gear accurate to 0.1g

Ian Mc Donald
Oct 02, 2003, 01:45 PM
Registered User
jnowell's Avatar
Here's an old, ugly pic of my first GWS Rx lightening project. I took off the Pos and Neg pins, and most of the pin block. Replaced everything with Magnet wire, and even mounted the ESC on the side and connected it up with magnet wire as well.

It was my first sub 1 ounce model, before I found RFFS and actuators.


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