Does the WD20 will properly lock in a position such as home when deliberately powered down, or is it all dependant on the AEB ?
In fact does the WD20 have any safe or resting position such as vertical with the weight at the bottom ?
If not then the weight producing 45 nm of torque becomes the maximum that can be used with the mount in a remote situation (where power to the mount is not guaranteed). Please confirm …
Another question
How does the AEB work, if more than 45 nm of torque, will it slowly allow the payload to come to rest in a balanced position or will it simply fail and free-wheel with catastrophic results ?
And if the payload produces under 45nm of torque, then with the power off, how long will it hold in a position, days, weeks ?
Or will the scope slowly start to move ?
I park mine with the tube horizontal, so it doesn’t collide with my ROR. It’s on a pier and I have counterweights which are estimated to offset the 25 kg of gear. The brake holds the position when power is removed. This only applies to RA. I have my scopes in approximate fore-aft balance as the DEC axis does not have a brake. There is no benefit that I can see from deliberately having an unbalanced DEC axis.
When it powers up, it’s wise to sync time, unpark, track for a few seconds and then home the mount.
Thanks Buzz, so do you park it and drop the power or do you maintain the power after parking ?
Also is your weight delivering only 45nm of torque or is it delivering higher, I would need only 19 kg of payload and 5 kg of counterweight to deliver 45 nm (the safe power off braking limit) and would have no way of ever getting to my preferred 25 kg weight …
I park and then shut off power.
The pier is slim, the flange is 220 mm. I got it from Rotherham Valley Optiics in UK.
I have not needed an extension as the filterwheel tends to extend below the flange. With a very short refractor, I would possibly use a filter drawer to reduce the loading on the small focuser mechanism.
Thanks Buzz, I also have a 215mm top plate on a 180mm diameter pier, but I have a large 400mm wide RC and a focuser, EFW and Rotator almost as wide …
Another big concern I have is that they would hit the pier, especially slewing to zenith for sky flats which I do use.
Could I please ask if you were to put a dovetail bar extending all the way back to your camera, would it hit the pier’s top plate in Equatorial mode so needing the top plate to be a bit narrower to avoid a collision ? Sadly an pier extension would not work for me.