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curious1
04-14-2007, 02:47 AM
How can I verify·if this is or is not·compatible with the BS2 ?

RC



TowerPro MG995 Servo·

http://forums.parallax.com/attachment.php?attachmentid=74054

Mike Green
04-14-2007, 03:11 AM
None of this tells you anything that has to do with compatibility with a BS2. The BS2 can control any standard R/C servo.
That means that the device accepts a control signal at TTL levels (0-1V is a logic low level, 2-5V is a logic high level, 1-2V is indeterminant).
A servo expects a logic high pulse roughly every 20ms and typically shuts down in the absence of pulses at that rate.
The width of the pulse indicates the position (or speed and direction for continuous rotation servos) with 0.5ms to 1ms at one end
of the range and 2ms to 2.5ms at the other end of the range. Minimum range is usally 1ms to 2ms.

The fact that this is marketed as a servo suggests that it should be compatible with a BS2.

curious1
04-14-2007, 05:31 AM
Just wanted to be sure before ordering.
These have considerable more torque than the Parallax's 3.4 kg/cm.
Thanks Mike,
RC

Bruce Bates
04-14-2007, 03:00 PM
RC -

Just be aware, if you're going to use them for locomotion (as drive motors) you will need to modify them for continuous rotation.

Regards,

Bruce Bates

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curious1
04-14-2007, 10:42 PM
Thanks for that tid-bit Bruce.
Is there a standard procedure to change from limited to continuous rotation ?
I would like to try to change the Parallax standard servo that came with the BOE kit to cont. rot. if possible.
I looked inside, I see the physical stops at the gears. What about the encoder, (or whatever it is) ? It seems to have a physical stop internally as well·and is coupled to the gear train.

Also, I assume that the larger servos would eat up batteries more quickly, will deal with that later.
Thanks,
RC

Mike Green
04-14-2007, 10:57 PM
Search the web for directions on converting a servo from standard to continuous rotation.

curious1
04-14-2007, 11:25 PM
http://www.princeton.edu/~mae412/TEXT/NTRAK2002/292-302.pdf
GOT IT !
Everything is here if anyone else is interested.
RC