By the way, there should never be a 1x (or greater) sidereal guiding rate, since that can potentially allow backlash to happen. With anything slower than 1x sidereal rate, the RA axis will never have backlash, since the stars are moving at 1x sidereal rate.
For example, if you choose 0.4x sidereal rate guiding, your RA axis will move at most between 1.0-0.4 and 1.0+0.4 sidereal rate. Both are positive numbers, so the RA motor never reverse direction. It either speeds up a little, or slows down a little, but always rotating in the same direction, averaging at 1x sidereal, the rate which the sky is moving at (360 degrees every 23 hours 56 minutes).
I.e., ignore all the ads you read about mounts with "no RA backlash." They are to fool the ignorant buyer with meaningless jargon, since there is no such thing as RA backlash in practice. Snake oil.
Chen
