Servo saver mod

[gabeoravitz]

Edit: This can apply to any micro that uses rotary servos, really. I've personally done it on several Walkeras as well as my 150.

Back when I first started flying, I was flying Walkera micros. They've been using rotary servos for a while, and I was constantly stripping servo gears. Once I found the servo saver mod, I never stripped another servo. I've since done the same mod on my 150 and as expected, have not stripped a servo since. Instead, the servo arm jumps, and you just have to put it back before you fly again.

Follow these instructions: http://benmlee.com/Genius_Servo_Saver.htm

Make sure you read every step. If the arm is too loose, put some kind of rubber ring around it to make it tight. Pic attached below of what I've done.

[jmiceli11]

Is the rubber around the servo arm fuel tubing?

Thanks,
John

[gabeoravitz]

No but that stuff works too. I don't even remember what these little rubber things were for. I had them in my box of random stuff. I think they might have been rubber skid grips things for my 450 or something. Or maybe 250 dampers of some kind? I sliced them in half to make them thinner.

[mba83]

That's a pretty neat idea. I wonder if it makes sense to do something like this on larger helis (250/450) as well?

[Nelsonisms]

I may have to give this a shot.

Worst case if it didn't work is I'd need a servo gear set that includes a new horn anyways, so it's definitely worth a try if it can save the gears.

I'll have a look at the hardware store to see if they have some small rubber o-rings that will work.

Thanks for the idea.

[gabeoravitz]

Originally Posted by mba83

That's a pretty neat idea. I wonder if it makes sense to do something like this on larger helis (250/450) as well?

I probably wouldn't do this on something larger because of the larger forces on bigger helis that could cause unwanted slippage.

[gabeoravitz]

Originally Posted by Nelsonisms

I may have to give this a shot.

Worst case if it didn't work is I'd need a servo gear set that includes a new horn anyways, so it's definitely worth a try if it can save the gears.

I'll have a look at the hardware store to see if they have some small rubber o-rings that will work.

Thanks for the idea.

Funny you mention the horn coming with the gear set. I ordered a pair of gear sets and the picture on rcdepothobbies.com showed the horn. However, the package I got had no horns. I'm not sure what that's about.

[NerpGuyLTD]

Great stuff I just stripped a servo on my first flight after adding in the metal swash, this mod should do the trick

Sent from my Nexus 10 using Tapatalk 4

[vronny]

Originally Posted by gabeoravitz

Funny you mention the horn coming with the gear set. I ordered a pair of gear sets and the picture on rcdepothobbies.com showed the horn. However, the package I got had no horns. I'm not sure what that's about.

I also received some servo gears with no screw or servo arms HSP15001T instead of these HSP15001 which shows a arm.

[Nelsonisms]

Originally Posted by gabeoravitz

Funny you mention the horn coming with the gear set. I ordered a pair of gear sets and the picture on rcdepothobbies.com showed the horn. However, the package I got had no horns. I'm not sure what that's about.

Originally Posted by vronny

I also received some servo gears with no screw or servo arms HSP15001T instead of these HSP15001 which shows a arm.

Hmmmm. Good to know. Thanks for the heads up.

[Nelsonisms]

Does anyone have some digital calipers to measure the outer diameter of the round portion of the servo horns that fit over the servo splines? I'm trying to figure out which o-rings will fit snugly around them, but I don't have the heli yet. (should come today). If I get it sorted out I'll post back which size o-rings worked the best.

[DPW]

Originally Posted by Nelsonisms

Does anyone have some digital calipers to measure the outer diameter of the round portion of the servo horns that fit over the servo splines? I'm trying to figure out which o-rings will fit snugly around them, but I don't have the heli yet. (should come today). If I get it sorted out I'll post back which size o-rings worked the best.

PP Vernier Caliper set 80mm & 150mm $1.29
Measures down to 0.001 mm.
Just use plaster or a soft hot melt glue to get a profile of the location.

[Nelsonisms]

Originally Posted by Dipweed

PP Vernier Caliper set 80mm & 150mm $1.29
Measures down to 0.001 mm.
Just use plaster or a soft hot melt glue to get a profile of the location.

OK I see how my question could have been misinterpreted that way. I know how to use calipers and I already own a set. What I don't have is the heli.

I was hoping someone with a set of calipers and the heli handy could measure the diameter of the horns. You wouldn't need to make a mold or anything, just clamp the calipers around the outside servo horn and get a rough reading...it doesn't have to be too exact. If not I will do it when the heli arrives, I was just hoping to swing by and pick up some o-rings beforehand. Thanks.

[mdecker79]

Originally Posted by gabeoravitz

We need a T-rex 150 dedicated section on HF. If we did, this should be stickied there, because it's saved me a TON of time and money.

Back when I first started flying, I was flying Walkera micros. They've been using rotary servos for a while, and I was constantly stripping servo gears. Once I found the servo saver mod, I never stripped another servo. I've since done the same mod on my 150 and as expected, have not stripped a servo since. Instead, the servo arm jumps, and you just have to put it back before you fly again.

Follow these instructions: http://benmlee.com/Genius_Servo_Saver.htm

Make sure you read every step. If the arm is too loose, put some kind of rubber ring around it to make it tight. Pic attached below of what I've done.

What plugs are you using for your servos? Did they fall apart and you put on new connectors? The wires are different colors then the stock plugs.

[Miracle Boy]

Originally Posted by Nelsonisms

OK I see how my question could have been misinterpreted that way. I know how to use calipers and I already own a set. What I don't have is the heli.

I was hoping someone with a set of calipers and the heli handy could measure the diameter of the horns. You wouldn't need to make a mold or anything, just clamp the calipers around the outside servo horn and get a rough reading...it doesn't have to be too exact. If not I will do it when the heli arrives, I was just hoping to swing by and pick up some o-rings beforehand. Thanks.

I've just measured the diameter of the servo horn collar on mine and it's appox 5.75mm

[Nelsonisms]

Cool, thank you MB. So I didn't find any that small at Home Depot (at least not online). The smallest I found was 6.35mm (1/4 inch). So I'll probably swing by the LHS tonight and see what they have. Worst case I'll get some fuel tubing and try that.

[Miracle Boy]

O.K. Cool, Let us know how you get on!!

Cheers!

[DPW]

Originally Posted by Nelsonisms

I was hoping someone with a set of calipers and the heli handy could measure the diameter of the horns. Thanks.

I got 5.1mm OD plastic is just not that dimensionaly stable. It maybe by design 5mm+ 0.5 mm?
Using plastic caliper 3 measures. Mic may give a better reading (don't have).

[Nelsonisms]

Originally Posted by Dipweed

I got 5.1mm OD plastic is just not that dimensionaly stable. It maybe by design 5mm+ 0.5 mm?
Using plastic caliper 3 measures.

Excellent. That's about what I was thinking. So we'll need to source some fairly pliable o-rings that have somewhere around 4mm inner diameter.

[Hydros27]

NAPA 407004 have a 4.5mm ID.