DS821 Servo Arm Rubbing On Canopy

Foshnuts · 08-29-2007, 05:45 PM

Hello,

I am building a Terx 600 and have installed the DS821 Servos that come with the DX7.

The servos are very deep and I have fitted them with the aid of spacers.

Here is the problem: I have put some heavy duty JR servo horns on the DS821's but with now I am getting some pretty serious rubbing on the canopy with the ball on the servo horn.

Mounting the balls on the underside of the horn is not an option because it will cause binding elsewhere.

I tried the smaller horns that came with the DX7 but they almost split open when the ball was inserted.

Regardless I want to keep the heavy duty horns on.

How can I adjust the canopy to stop this happening? I thought about extra washers on the canopy pins but I don't think it will be enough.

Thanks in advance for any help.

Pistol Pete · 08-29-2007, 07:37 PM

You have to mount the balls on the backside of the arm and shim the servo out enough so the links won't hit the aileron arms. Mine almost touch, there's only about a half a mm between them and even after doing that it still rubs on the canopy but not as bad as if the balls were on the outside of the arm. You can also shim out the canopy mounts but I really wish they just made a wider canopy.

BarracudaHockey · 08-29-2007, 07:39 PM

Better be careful with those servos if you start beating on that thing.

Sonny · 08-29-2007, 07:53 PM

On my 9351s I mounted on the inside of the horn as well. Just had to trim off the remaining length of the horn.

Skiddz · 08-29-2007, 08:17 PM

Measure the distance between the canopy mount posts on the heli. Pack the canopy full of foam, towels, rags, dirt, whatever to spread the canopy apart where it's rubbing. Tape the "ears" of the canopy back to the width you measured then take your heat gun (hair dryer will work if it's got enough wattage) and warm up the canopy. The fiberglass will relax a bit and allow the canopy to expand and gain some clearance.

I had to do this to mine. Now I've got a good 3/16 - 1/4" between my servo horns and the lid.

Raven_darkcloud · 08-30-2007, 12:07 AM

So far the slight rubbing on mine has had no bad effect on the can or servos.

08-29-2007, 05:45 PM	#1
Foshnuts Registered Users Join Date: Feb 2007 Location: Australia	DS821 Servo Arm Rubbing On Canopy Hello, I am building a Terx 600 and have installed the DS821 Servos that come with the DX7. The servos are very deep and I have fitted them with the aid of spacers. Here is the problem: I have put some heavy duty JR servo horns on the DS821's but with now I am getting some pretty serious rubbing on the canopy with the ball on the servo horn. Mounting the balls on the underside of the horn is not an option because it will cause binding elsewhere. I tried the smaller horns that came with the DX7 but they almost split open when the ball was inserted. Regardless I want to keep the heavy duty horns on. How can I adjust the canopy to stop this happening? I thought about extra washers on the canopy pins but I don't think it will be enough. Thanks in advance for any help.

08-29-2007, 07:39 PM	#3
BarracudaHockey Registered Users My HF Map location Join Date: Jan 2005 Location: Jacksonville FL	Better be careful with those servos if you start beating on that thing. __________________ Andy AMA 77227 Jacksonville FL To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-29-2007, 07:53 PM	#4
Sonny Registered Users Join Date: Mar 2007 Location: Easton, Pa., USA	On my 9351s I mounted on the inside of the horn as well. Just had to trim off the remaining length of the horn. __________________ Sonny To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-29-2007, 08:17 PM	#5
Skiddz HF Support My HF Map location Join Date: May 2006 Location: Carlsbad, CA (USA)	Measure the distance between the canopy mount posts on the heli. Pack the canopy full of foam, towels, rags, dirt, whatever to spread the canopy apart where it's rubbing. Tape the "ears" of the canopy back to the width you measured then take your heat gun (hair dryer will work if it's got enough wattage) and warm up the canopy. The fiberglass will relax a bit and allow the canopy to expand and gain some clearance. I had to do this to mine. Now I've got a good 3/16 - 1/4" between my servo horns and the lid. __________________ -Kevin No helicopters were harmed in the creation of this post. AMA CD # 7309, Turbine Waiver# RW 890 To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-30-2007, 12:07 AM	#6
Raven_darkcloud Registered Users My HF Map location Join Date: Mar 2006 Location: Portland, OR	So far the slight rubbing on mine has had no bad effect on the can or servos. __________________ Team Outrage OPM - Fly it like it aint yours! To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. JR X9303 2.4 Baby. I have felt the difference and I like it! Don"t make me list 'm all !

08-29-2007, 07:37 PM	#2
Pistol Pete Registered Users Join Date: Apr 2007 Location: Minnesota	You have to mount the balls on the backside of the arm and shim the servo out enough so the links won't hit the aileron arms. Mine almost touch, there's only about a half a mm between them and even after doing that it still rubs on the canopy but not as bad as if the balls were on the outside of the arm. You can also shim out the canopy mounts but I really wish they just made a wider canopy.

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