Post by RobbW on Jun 23, 2010 14:41:44 GMT -6
If my scope on a motorized EQ mount doesn't seem to be tracking properly, how do I go about determining if I simply don't have it polar-aligned properly, or if there is something more sinister to blame, such as faulty gears?
I'm borrowing my mom's 4" Galileo reflector telescope, which is on a relatively hefty looking EQ mount with tracking motors.I set up the tripod and made sure it was level using the bubble level on the tripod top. I pointed the DEC axis north and used my laser pointer to align it to Polaris.
Everything seemed to be operating properly. However, the scope seems to be off a little when it comes to tracking a celestial object. Last night, I was taking a look in the region of Deneb and Sadr. Several times, I put Sadr in the middle of the EP and left the tracking mount to do its thing. While looking in the EP, Sadr appeared to stay within the middle for a minute or so. But if I would leave and come back several minutes later, it would be well outside the FOV of the EP. I kept having to realign Sadr within the middle of the EP every few minutes or so. Actually, it was kind of variable. Sometimes it seemed as though the scope kept the star in the EP center for several minutes. Sometimes it would drift out of FOV within only a minute or two. I'm not exactly sure how long because the drifting always seemed to happen when I left the scope for a bit.
How far off-alignment would I have to be for the tracking to be that bad? I had my laser light pointing right at Polaris. I can't imagine it would be off that bad. The only other option is that the tracking motor isn't working properly for some reason. Maybe there's something wrong with the gears, or maybe the sidereal rate is off. I'm running the motor mount using a 12V battery jumpstarter. I'm assuming that's the correct voltage for the motor as it can also run off of 8 AA batteries, which is 12V.
I'm borrowing my mom's 4" Galileo reflector telescope, which is on a relatively hefty looking EQ mount with tracking motors.I set up the tripod and made sure it was level using the bubble level on the tripod top. I pointed the DEC axis north and used my laser pointer to align it to Polaris.
Everything seemed to be operating properly. However, the scope seems to be off a little when it comes to tracking a celestial object. Last night, I was taking a look in the region of Deneb and Sadr. Several times, I put Sadr in the middle of the EP and left the tracking mount to do its thing. While looking in the EP, Sadr appeared to stay within the middle for a minute or so. But if I would leave and come back several minutes later, it would be well outside the FOV of the EP. I kept having to realign Sadr within the middle of the EP every few minutes or so. Actually, it was kind of variable. Sometimes it seemed as though the scope kept the star in the EP center for several minutes. Sometimes it would drift out of FOV within only a minute or two. I'm not exactly sure how long because the drifting always seemed to happen when I left the scope for a bit.
How far off-alignment would I have to be for the tracking to be that bad? I had my laser light pointing right at Polaris. I can't imagine it would be off that bad. The only other option is that the tracking motor isn't working properly for some reason. Maybe there's something wrong with the gears, or maybe the sidereal rate is off. I'm running the motor mount using a 12V battery jumpstarter. I'm assuming that's the correct voltage for the motor as it can also run off of 8 AA batteries, which is 12V.