I added the "go-to" motors and electronic board upgrade to my older non-go-to Atlas mount. Now, RA and Dec work fine for slewing to objects at different speeds but then the RA does not kick in and track an object. It remains stationary. I suspect the clutch on the drive gear is not tight enough but why does it still work when I slew? And, how do I get inside this mount to fix it?
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
The main problems encountered with the mechanics of the telescope centre around
the mechanical swarf, grease compound, the liberal use of grease and the quality
of machining of the main DEC and RA gears.
1. Remove the motors from the telescope. Be careful when removing either
motor as there is a compression spring between the motor mounting frame and
the worm shaft assembly.
The RA motor is located under the telescope body, removing the 4 screws and
2 Allen bolts will allow the bottom cover to be removed, thereby allowing access
the the 2 Allen bolts holding the motor in place. Unplug the motor from the
main PCB before removal.
The DEC motor is in the the fork arm containing the clutch and fine DEC adjustment
control. (Never to be used with power applied to the scope). Remove the 3 small
Allen screws holding the plastic cover plate in place and the DEC clutch knob
to allow access to the motor. Remove the RJ45 connector located inside the telescope
fork arm. Then remove the motor by unscrewing the 2 Allen bolts holding the
motor in place.
2. Remove all grease from the motor worms, especially around the RA motor's
magnetic pulse detector and the permanent magnet built into the worm shaft.
3. Remove all grease from the main DEC and RA gears, making sure to clean into
the gear teeth.
4. Lightly re-grease with a Molybdenum Disulphide based grease (Castrol MS3
is great for this application if you can get it)
5. Assemble in reverse order. But before doing so, carry out the electrical
adjustment above then, (a) relocate the the RA and DEC control PCB's in the
vertical plane thereby gaining access to their respective backlash Allen screws.
Adjust for 20thou max clearance when in final position. Note:- the DEC adjustment
screw has to be replaced for a longer unit complete with a thin bolthead as
this adjustment has to be carried out with a spanner....there is no room for
an Allen key adjustment here.
6. A drop of Loctite must be applied after adjustment.
7. The final part of the process is to run in the gearing. Apply 12 volts to
the motor wires, either at their respective plugs or to the motor direct. Allow
to run for 2 to 3 hours in each direction by reversing the battery polarity
to bed the teeth engagement. Remember to release the clutches.
Equatorial mounts need to be polar aligned to work correctly. Once the scope is polar aligned (see manual or look online for polar alignment instructions), turn on the RA motor. Loosen your RA and DEC locks and find a object you want to view, The motor should keep the object in view for a while (depends on how good the motor tracks and how good your polar alignment is.) Spending 10 minutes polar alignment on my C8 keeps the object in view for about an hour without adjustment.
The older Lx200's go into tracking mode when turned on if they are not recieving a signal from the handbox. It does this on purpose so you can use the telescope without the handbox and still track sky objects. If it is still doing this with the handbox plugged in then you have a bad chip in the electronics and Meade is notorious for not having parts for their older telescopes. Don't send it in to them to repair. It will cost you a fortune to mail back and forth and they still can't repair most electronic problems with their older scopes(from my personal experience).
The problem is the addition of the 80mm telescope to the assembly. The telescope is now out of balance, and places extra weight off-center as the position chages. Too great an off-balance will cause the main gears to 'jump' the worm teeth. The solution is to restore balance by adding counter weights as needed. Loosten the axis locks (carefully) and see which direction it wants to move. To balance my LX, I used a small bag with lead buckshot to determine how much weight was needed and where to achieve balance. Then I added fixed weights to the mount. Once this is done, the scope should track correctly.scopestuff.com has balance kits at reasonable prices.