Drift Align and HEQ5PRO GoTo system

[Jeffkop]

Hi to the community again. I am having trouble digesting the following.

First let me explain how I think my GoTo system works. I believe that for it to point me to a selected object it first has to start from an orientation that basically is pointing to the SCP. So that is its known and understood position from power-up.

OK, so all I have digested from drift alignment material is that I try to first of all find a low star in the East or the West then after successfully tracking that I am to select a star overhead. Once I have tracked successfully here I can clearly understand how my mount will be polar aligned.

BUT ... set up the mount and scope to do the drift alignment I would have had to manually move the scope to the star positions. (It would take an eon to electrically slew the mount there)

SO ... given my opening statement then how do I restart the mount pointing to the SCP without upsetting the polar alignment just achieved.

So in other words my scope is polar aligned, but not able to be GoneTo anything.

I am assuming that these sytems do not have any positional feedback and so rely on a known start-up position. Unfortunately the GoTo manual is sadly lacking in specifications etc.

Thanks once again for anyones interest. I know I am missing something, I just cannot think of what it is.

Jeff

[Kokatha man]

Hi Jeff - check the "SynScan bug..." (and another) thread in this forum section on HEQ5's, but yes, you do need to polar align first. Then you choose a star alignment - the 3 star align is best - and the handpiece will offer you 3 stars to use: at the moment most likely Sirius, Achernar and Acrux in that order. When you press "enter" for the first star (eg Sirius) it will slew/move towards that star, but being the first slew and depending on how good your polar alignment is, you will have to manually slew it to get Sirius centred in your scope. If you're finding that it isn't slewing quick enough you press the "rate" key and punch in a number up to 9 (the fastest) and "enter" and then it will move at its' fastest slew rate.

The second and third stars will be slewed to much more accurately than the first (again depending on the polar alignment accuracy you initially achieved) and hope fully after you press enter for the third star it will say "alignment successfull."

Cheers, Darryl.

[Kokatha man]

Sorry I didn't really answer you Jeff - but when you use the drift align method and tinker with the alt and az fine adjusters to minimize drift for the first star you've attempted to drift align; you then do the same for another in the other position you indicated. Having done this you should be reasonably polar aligned. Then you can go do a 3 star align as I said in my prior post to enable GoTO.

My bit about changing the slew rate can be done at anytime after powering up, and before any other procedure, to slew to your first drift align target.

[glasseyes]

Jeff wrote ..
BUT ... set up the mount and scope to do the drift alignment I would have had to manually move the scope to the star positions. (It would take an eon to electrically slew the mount there)

Hi Jeff,
As Darryl has suggested the mount has speeds 0-9 for slewing. At the fastest speed 9, the mount can slew in RA from east to west in about 1 minute.

Jeff wrote ..
SO ... given my opening statement then how do I restart the mount pointing to the SCP without upsetting the polar alignment just achieved.

Remember that when you power on the mount, you should have the mount in the "home" position and when you power it down, select "Utility" and "Park Scope" to return it to the "home" position before you power it down. This lets the stepper motors know where the mount is pointing to start with.

John