Pan and Tilt Mechanism

[JavaRN]

I am thinking of another addition to my Robot (after the SP03) and it is a pan and tilt mechanism for my camera. I found this:

http://www.active-robots.com/products/motorsandwheels/lynx-pantilt.shtml

I am a little worried as to whether the HS-422 servo (the lower motor) would fit inside the RN.

Has anyone ever tried the hs-422 before with the RN? What are your opinion about it?

Note: I've chosen this set because of its price. If you know of another pan and tilt which is better than this with a reasonable price please let me know

Charles

[MadDogJoe]

I used something along those lines, but used micro servos, I don't think a standard size servo would fit in the body, you can use the pan and tilt and change out the lower servo for a micro and it should work fine.

MadDog Joe

[JavaRN]

Thanks for your feedback, but is the hs-422 bigger in size than HSR-8498HB? because I managed to fit an HSR-8498HB in RN's chest for basic head rotation, but I wanted to add other movements to the head that's why I opted for this pan and tilt mechanism.

Charles

[MadDogJoe]

Not bigger, just a different mounting technique. They have the standard RC servo "ears" at a right angle to the body of the servo that tend to make mounting in a standard bot more difficult if it wasn't set up for them.

[davidalecmcinnes]

Hi there, I have actually shoehorned a Lynx pan and tilt into my Robonova, see pic. There are a few issue though; the servo in the chest cavity will need trimming to fit in there. The HS-422 is a 6V servo so a 1A diode is required to reduce the servo voltage. The pan and tilt also fouls the interface cable socket but the standard 2.5mm 3 pole jack socket can be replaced by a cable version. It works a treat though.

http://www.btinternet.com/~superluminal/images/DSC01576.JPG

[JavaRN]

Thanks for your feedback, but unfortunately I am no good in elecronics and so I would like to ask you if I don't put the diode you mentioned will the servo be damaged? does it make a difference if I connect it to the PWM ports where power is more controlled?


Charles

[davidalecmcinnes]

If you don't fit a diode, the servo could be exposed to voltages in excess of their rated limit which could cause damage or at least shorten its life.

Use a standard 1A diode like a 1N4002. Fit it to the servo dc+ wire by cutting the red wire close to the connector. Connect the diode between the severed wire, with the anode to the wire from the connector and the cathode to the wire going to the servo.

You can 't fit it to the PWM line as that will only reduce the voltage of the PWM signal. The PWM signal is at 5V TTL and is used as a switching signal to move the servo, it doesn't actually carry any power and hence wont have any effect on the voltage supplied to the servo.

Hope that helps

[JavaRN]

Thanks for the precise description how to connect the diode. I go and buy one today and try it out.

Charles

[JavaRN]

I went to the Electronics shop and found the 1N4007 1A instead of the 1N4002. Is that ok?

Thanks

[davidalecmcinnes]

Yes that's fine, it's a 1000V diode instead of 100V but it will do the job just as well

[CaptKill4Fun]

I am thinking of another addition to my Robot (after the SP03) and it is a pan and tilt mechanism for my camera. I found this:

http://www.active-robots.com/products/motorsandwheels/lynx-pantilt.shtml

I am a little worried as to whether the HS-422 servo (the lower motor) would fit inside the RN.

Has anyone ever tried the hs-422 before with the RN? What are your opinion about it?

Note: I've chosen this set because of its price. If you know of another pan and tilt which is better than this with a reasonable price please let me know

Charles

Hi,

Why not use the Hitec servo inside the RN1's body and using a Hitec "U" bracket pointing UP to almost any servo atop to connect servo horn to servo horn of the interrior and exterior servos and stick the camera to the plastic casing atop the external servo?

You can make the "backside servo arm" for the HS422 from almost anything (it's just a pin axis) and just glue it to the bottom of the HS422.

The internal Hitec servo is the "Pan", the external servo HS422 is the "Tilt" servo that tilts itself.

Almost any glue like rubber cement, Elmer's, 5-minute Epoxy or hot-glue will secure the camera to the "tilt" servo body and you'd still be able peel the camera off later should you decide to make further changes.

I've found that Elmer's Glue and 5-minute Epoxy are great adhesives that when you're done with the project you can peel it off things like smooth plastic and even wood without damage.

[JavaRN]

Yes I agree with your point but I wanted to use the other servo (the HS 8498B) for making a 5 DOF arm (my next project) that's why I've opted for the HS-422 servos and also, in the meantime I managed to install the whole pan and tilt mechanism including the diodes all the screws and a custom bracket I had to make to "fix" the hs-422 inside RN's Chest. When I manage to close the cover back again and somehow put on a 5 DOF arms I will post some photos.

Charles