How am I going to fix this? (Servo arm failure)

[dylanbeaudette]

Deep inside of a carefully assembled and painted DR1 a tiny servo arm broke. Thankfully I was able to bring the plane down without incident. Now, I scratch my head wondering how to replace the broken part without tearing the plane apart.

Tiny servo arm
Just beyond my pliers’ reach
She no longer flies.

Any suggestions? I was thinking about prying out the servo, replacing the arm and glueing.

 

[Burnhard]

Looking at the picture I can think of three options:

First, as the servo is glued to the foamboard, you can try to loosen the servo, take it out and attach a new arm. You will need some long surgical pliers for that (can be found on amazon). The problem will be to fiddle the servo back in and to glue it back to the foamboard. As there is so little room, that will be difficult.

Second, you can punch a small hole opposite the servo arm so that you can unscrew the broken arm and put in the new one. That will again require ling surgical pliers. However, even if you manage to get the new servoarm on the pushrod and on the servo, installing the servo screw will be a fidely task.

Last and probably easiest, I would be considering cutting a big enough service hatch which allows you direct access. I know its a pain to cut a painted aircraft but this should be by far the easiest option.

Good luck!

 

[Flying Monkey fab]

Second, you can punch a small hole opposite the servo arm so that you can unscrew the broken arm and put in the new one. That will again require ling surgical pliers. However, even if you manage to get the new servoarm on the pushrod and on the servo, installing the servo screw will be a fidely task.

Looks like you covered the bases, my vote is for #2

 

[Mr NCT]

On my DR1s the servo usually tears away from the foam

 

[Shurik-1960]

I like a children's joke about a Sharp-eyed Falcon (an Indian from American westerns) who, after a month in prison, saw that there was no fourth wall in the cell... So the topikstarter thought for a very long time, thought and realized that you can cut a normal hatch in the foam with a stationery knife and then paste it back. 40 years ago, when I was making planes out of balsa, I often had to cut through the fuselage for additional mounting. Stop scratching your head, cut boldly and you will be happy!!

 

[dylanbeaudette]

Thanks for all of the great ideas and reminder about the beautiful simplicity of cutting foamboard. I'll post back once the operation has been completed.

 

[dylanbeaudette]

Finally took a blade to this beauty, and safely extracted the servo with the broken arm. Would have been a simple repair if I hadn’t accidentally cut out the wrong servo! Both were easily glued back into place. No longer as clean a build but should be airworthy again!

 

[Shurik-1960]

Congratulations on the successful resuscitation operation of the model. Probably cut 2-3 mm every day ? In total, more than 2.5 months have already passed ...))))