Servo replacement

danb1974 · 02-10-2012, 09:06 AM

Good news. Until the servo mechanics (SPM6836) will be available, the exact same mechanics is on the SPMSA2030L servo which is available and costs like 15$. Just replaced a damaged aileron servo this way.

Be warned though, replacing the servo requires soldering two tiny wires onto two tiny pads.

dbjn · 02-14-2012, 05:10 PM

My second MSRX is almost down for the count with aileron servo damage. Looks like a fix is needed for this.

I've take a mCX2 servo linkage and shortened it to 26.75 to 27mm (stock) with the eyelet centered on the treads to allow adjustments. The shortening was by bending a U shape to go through the top servo hole. When bending, take into account canopy clearance issues.
Cant the loop towards the front of the helicopter to clear the canopy.

Short term, no impact on fly-ability, the wire seems strong enough for abrupt aileron changes. Long term, this has to provide more protection from head on blade strikes. I suppose I find out on my third MSRX while waiting for servo mechanics to be released.

Vandal996 · 02-15-2012, 01:20 AM

I lost an aileron servo tonight after a particularly hard crash. I think the crash caused the damage but it happened pretty quick. The failure could have caused the crash in the first place. Luckily I had a board that had gon bad and was replaced by HH so I just removed the one off of the old board and replaced the bad one. I dont trust myself with a soldiering gun on the board with my $14 soldiering iron so I just cut the wires coming from the board at the motor and did the opposite on the good motor and then just soldiered the wires together. I was back in the air in less than an hour.

I guess I need to get a micro soldiering iron but dont really want to spend 130 bucks on the Weller. Any recommendations on a cheaper micro?

danb1974 · 02-15-2012, 02:16 AM

Anything with thermal control and fine tip. And very important some kind of no-clean solder flux.

dbjn · 02-15-2012, 09:20 AM

The damage to my aileron servo's has required repeated repairs, and always to the mechanical side of it. It's not always severe grounding type damage. Slowly loosening threads, widening of the hole for the servo wire, loosening of the cap screw, etc. All contributing to sloppy control.

I've taken parts off of other servo's to keep flying, but now I don't have anything else left for repairs.

As for a soldering iron, I could use a recommendation also. I've done some soldering with a standard 30W, but I've also messed up one board doing that by overheating a nearby component.

danb1974 · 02-15-2012, 10:35 AM

Use flux, move quickly. No flux -> heat does not properly transfer to soldering and solder does not stay where it's supposed to. Practice on a dead board.

I use solder paste (nc-559 from amtech), put a small amount onto the soldering than touch it with the (clean tip of the) iron, solder should melt instantly. To clean the tip of the iron use a _wet_ rag (there are special spongers for this but anything goes, even a non-synthetic sock) and move fast.

And really, the only way to get it right is to practice.

Dont155 · 02-15-2012, 03:52 PM

If you want to practice soldering, you can get little inexpensive kits like this to put together.

http://www.radioshack.com/product/in...uctId=11007963

They're cheap, fun to build, and the soldering skill you develop will be priceless in any hobby that uses electronics...

02-10-2012, 09:06 AM	#1
danb1974 Registered Users Join Date: Jan 2012 Location: Romania, Timisoara	Servo replacement Good news. Until the servo mechanics (SPM6836) will be available, the exact same mechanics is on the SPMSA2030L servo which is available and costs like 15$. Just replaced a damaged aileron servo this way. Be warned though, replacing the servo requires soldering two tiny wires onto two tiny pads.

02-14-2012, 05:10 PM	#2
dbjn Registered Users Join Date: Jul 2011 Location: Ohio, USA	My second MSRX is almost down for the count with aileron servo damage. Looks like a fix is needed for this. I've take a mCX2 servo linkage and shortened it to 26.75 to 27mm (stock) with the eyelet centered on the treads to allow adjustments. The shortening was by bending a U shape to go through the top servo hole. When bending, take into account canopy clearance issues. Cant the loop towards the front of the helicopter to clear the canopy. Short term, no impact on fly-ability, the wire seems strong enough for abrupt aileron changes. Long term, this has to provide more protection from head on blade strikes. I suppose I find out on my third MSRX while waiting for servo mechanics to be released. Attached Thumbnails

02-15-2012, 03:52 PM	#7
Dont155 Registered Users My HF Map location Join Date: Aug 2011 Location: Phoenix, Az	If you want to practice soldering, you can get little inexpensive kits like this to put together. http://www.radioshack.com/product/in...uctId=11007963 They're cheap, fun to build, and the soldering skill you develop will be priceless in any hobby that uses electronics... __________________ -Don T Spektrum: DX6i, Blade: mSR (Sold), mSRX, mCPX, 130X On the horizon: 450X or maybe a Kit... $$$ + Heli Hobby = To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

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02-15-2012, 01:20 AM	#3
Vandal996 Registered Users Join Date: Jan 2012 Location: Columbus OH	I lost an aileron servo tonight after a particularly hard crash. I think the crash caused the damage but it happened pretty quick. The failure could have caused the crash in the first place. Luckily I had a board that had gon bad and was replaced by HH so I just removed the one off of the old board and replaced the bad one. I dont trust myself with a soldiering gun on the board with my $14 soldiering iron so I just cut the wires coming from the board at the motor and did the opposite on the good motor and then just soldiered the wires together. I was back in the air in less than an hour. I guess I need to get a micro soldiering iron but dont really want to spend 130 bucks on the Weller. Any recommendations on a cheaper micro?

02-15-2012, 02:16 AM	#4
danb1974 Registered Users Thread Starter Join Date: Jan 2012 Location: Romania, Timisoara	Anything with thermal control and fine tip. And very important some kind of no-clean solder flux.

02-15-2012, 09:20 AM	#5
dbjn Registered Users Join Date: Jul 2011 Location: Ohio, USA	The damage to my aileron servo's has required repeated repairs, and always to the mechanical side of it. It's not always severe grounding type damage. Slowly loosening threads, widening of the hole for the servo wire, loosening of the cap screw, etc. All contributing to sloppy control. I've taken parts off of other servo's to keep flying, but now I don't have anything else left for repairs. As for a soldering iron, I could use a recommendation also. I've done some soldering with a standard 30W, but I've also messed up one board doing that by overheating a nearby component.

02-15-2012, 10:35 AM	#6
danb1974 Registered Users Thread Starter Join Date: Jan 2012 Location: Romania, Timisoara	Use flux, move quickly. No flux -> heat does not properly transfer to soldering and solder does not stay where it's supposed to. Practice on a dead board. I use solder paste (nc-559 from amtech), put a small amount onto the soldering than touch it with the (clean tip of the) iron, solder should melt instantly. To clean the tip of the iron use a _wet_ rag (there are special spongers for this but anything goes, even a non-synthetic sock) and move fast. And really, the only way to get it right is to practice.