Attaching Servo to Door?

Hi, I am working on an automatic door opener, using an arduino to control a servo motor which pulls some string to torn a door knob (that bit works by the way), however, I am having problems attaching the servo to the door. I don't want to use screws if I can avoid it because I don't want marks if I ever decide to remove the motor from the door.

I have tried:-

  • Blu-tac (and lots of it)
  • String attached to secure points on the door and the wall (no screws were used).

Basically, what I am asking is; does anyone know any method by which I could attach a servo motor securely to a door without using screws (nails or anything that penetrates the door) or any of the listed items above?

Thanks in advance, Aaron

I can't visualize what you're doing, but if you have clearance between the door and door-frame you might be able to make a "clamp" out of some sheet metal or from a strip of metal. (And, maybe some of that blu-tack or other removable adhesive if necessary to hold the clamp in place.)

Usually, you can patch & paint holes in a wall or door... But, if you are a renter or if it's your parent's house, that might not be an option.

Firstly, are you sure that a servo motor will be powerful enough to open/close the door?

... but you can't determine that until you can attach the motor to the door.

You have a catch 22 situation here.

2 part epoxy? JB Weld? Monster Glue? Duct tape?
Mount the servo to flat piece of something to provide a bigger "frame" to secure with one of the above?

Thanks for the quick replies :smiley:

DVDdoug:
I can't visualize what you're doing, but if you have clearance between the door and door-frame you might be able to make a "clamp" out of some sheet metal or from a strip of metal. (And, maybe some of that blu-tack or other removable adhesive if necessary to hold the clamp in place.)

Usually, you can patch & paint holes in a wall or door... But, if you are a renter or if it's your parent's house, that might not be an option.

I've attached a photo of the door, the string with a battery attached to the handle is for the servo to pull (the battery adds mass to the rope, as the servo is pulling down, to reduce strain on the motor). Also, yes, it is my parents' house (and I'm 16 so it'll be like that for a while) and I don't want to destroy their door, so screws aren't really an option.

What exactly do you mean by a clamp, I'm quite new to DIY stuff so I'm not too sure on how that would work.

JohnLincoln:
Firstly, are you sure that a servo motor will be powerful enough to open/close the door?

I have tested the servo by holding it firmly on the door, and it is powerful to open the door. I have also done some things to reduce strain (see attached image). If you are interested, the servo I am using is here: http://www.amazon.co.uk/gp/product/B0098MAKYC?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00

CrossRoads:
2 part epoxy? JB Weld? Monster Glue? Duct tape?
Mount the servo to flat piece of something to provide a bigger "frame" to secure with one of the above?

That's a good idea too, do you think it would work with my door, I've attached an image. I don't want to buy things without first knowing if they're going to work :slight_smile:

PS: Don't ask about the screws on the right bottom of the door, I have no idea why they're there and I didn't put them there...

There's something interesting about hot melt glue.

While it does a good job of holding in general (unless of course, it gets hot), it is weakened by alcohol, so soaking alcohol under it generally allows it to be peeled off slowly.

Of course, alcohol also dissolves acrylic paint, so if the door is painted with acrylic, this is a non-starter.

That door has already had problems, possibly someone opened it against an object sitting behind or closed it with something in the jamb and it started to de-laminate along that border and has had to be screwed back together.