Quote:
Originally Posted by alistairsam
Thanks Cathy.
What is the expectation of how low the backlash would be?
My main issues are with goto's not being precise when you re-slew to the same target even if on the same side of the pier and of course the periodic error.
With the belts, I imagine the backlash would be very low so apart from removing PE, would one expect to see an improvement in goto's as well?
anyone tested this?
Cheers
Alistair
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Hi Alistair,
What pointing error are you getting with your gotos when slewing back to the same target?
The main source of backlash which will give you gross pointing errors is from the worm-wheel mesh.
The secondary source of backlash is from the clearance between the motor gear teeth to the transfer gear and then on to the worm drive gear.
Gear clearances may amount to 10 to 20 arc sec of backlash which cause a lot of grief when guiding.
And third, the worm wheel PE and combined eccentricities in the drive gearing.
The gear clearance is eliminated with a belt mod and as such the mount response to guide corrections is much improved.
Next time I'm set up testing I'll do a backlash test on my NEQ6.
Thanks,
Dave.
ps Purposely setting a slight imbalance in RA and dec causes the worm wheel contact to be on one side and can help a lot with that backlash problem.