Home position

[dawson]

When the mount is polar aligned, is the home position of the ota when Polaris is in the FoV?

Is it important to start the star alignment with the goto handset from the home position, or will it just get it's head around it all when you show it where the two or three stars are?

Thanks

James

[Daz Type-R]

All the home position does is tell the mount where it is when power is disconnected. If you finish your session and just pull the power, the mount won't remember where it was pointing when it was turned off, so you would need to star align etc all over again. If you set it to the home position then pull the power, as long as the mount has not moved, then you should be able to just start with no need for star align, as it will remember where it was pointing. The home position can be anything.

[+RonC]

Disagree I'm afraid, you must set and mark the home position (see Dion's vid on Astronomy Shed!) Always start from the home position and do a star align before anything else. When your done, press Utility, scroll down to Park scope and it will return the mount to it's home position. Pm me if you need, but I've used this system for 2 years now and it works but check out Dion's video.

 

Cheers

Ron

 

Also a vid on there about modding and reviewing a MAK 180 I noticed??

Edited May 15, 2013 by Ron Clarke

[Daz Type-R]

Ohhh. When I first set up the mother in laws 130P syncscan GOTO at the end of each session I just parked it, packed it all away and finished. The next night I just put everything back in the exact same place and carried on, no need to star align etc! I may of got park and home terminology confused in my original post, also, I never set a home position, it defaulted to zero degrees by zero degrees, i.e, pointing North and horizontal.

Edited May 15, 2013 by Daz Type-R

[+RonC]

OK Darren, but thats how I use my HEQ5 and EQ5 and always have.

 

Cheers

Ron

[philjay]

Park is different from home im afraid.

Park can be anywhere where you set it but home is a set position that the mount requires to basically have a datum to start from. The home position for an eq you will find is what i showed you the other week james. Dec axis pointing straight down and the scope pointing north.

With a low power ep in it you may get polaris in the fov but if you have a high mag set up you wont, its just that last week you had a low mag set up for alignment and i said can you see polaris in the ep, if so it would be ok. If you remember polaris wasnt central, it shouldnt be if your mount is correctly polar aligned and your scope and mount are aligned correctly.

[+Graham]

As per what Ron and Phil have said.

The home position is the datum point from which the scope always starts.

The Park position also has the function of auto storing all the star map data.

This means so long as the mount has been 'parked' from a previous session or you have manually saved the star map, if for any reason your mount throws a wobbly and looses its position you can send it back to 'park' and it will reload the star map and you can then carry on.

[dawson]

I think i might have some cone error. Its on my list of jobs to do. Just that the other night the goto was playing up. I think also my polar scope isn't very acuratelt aligned with the mount so thats on my list of jobs to do too (felix has found me some m3 grub screws i can adjust by hand as altering the polar scope with an allen key is tricky to say the least).

Why does it need to start from the home position? And at what point in the whole set up process does it need to be in the home position?

I'd have though if you show the computer where three stars are, and it assumes the mount is level and polar aligned and the latitude and longitude and time and date are all correct, it shouldn't make a jot of difference where it starts from.

Also, does it matter which way i mount the ota on the mount? With the dove tail clamp screws pointing at the zenith, should the eye piece end of my mak be on the left or right as you stand behind the mount? I ask this as the other night when i started three star alignment and told it the first star i wanted was arcturus it slewed to about he right declination, but looking north west rather than south east... If it does that shouldbi just correct it manually with the key pad or abandon that set up and start again from scratch by re powering up?

James

[+Graham]

James.

Think of it as you being at home.

When you leave your front door you know weather you need to go right or left to get to the shop. If I blindfolded you and dropped you off in the middle of nowhere and told you to go to that same shop you would not have a clue which way to go.

 

The 'home' position is for want of a better explanation the starting  point that the computer/handset always works from.

It is inbuilt into the goto that the 'home' position is at PA.

You need the mount to be in this position at set up so the computer / handset knows where the scope is pointing.

Once you have done your 3 star alignment it makes no difference where you slew to in the sky because the star alignment will tell the computer/handset where the scope is now pointing.

[Perkil8r]

The AZ EQ6 or whatever it is may well be different though due to the encoders.

 

@Graham we released the clutches and randomly slewed the scope to an un determined point in the sky. Asked it to slew to Jupiter and it found it straight away.

Edited May 15, 2013 by Perkil8r

[+Graham]

James.

Sorry didn't realise we were talking all singing all dancing mounts here.

As per what Mike has said.

As far as I know the encoders on your pukka mount are on the axis shafts not the motors.

There for I would also conclude that normal set up is not a requirement.

But I stand to be corrected.

[philjay]

The mount was in eq mode and had to be set in the home position mike remember. Yes maybe in altaz there is adifferent home, i suggest a look in the manual for that. However the dual encoders and declutching were after the calibration of the goto and the home still remains the same no matter what you do afterwards.

James, what does it tell you to do in the manual, i suggest thats a good starting point

[dawson]

The manuals (one for the mount, and one for the handset) don't give the specifics on this which I'm surprised about:

 

http://www.skywatcher.com/swtsupport/Instruction_Manuals/AZEQ6_instruction%20manual.pdf

 

www.skywatcher.com/swtsupport/Instruction_Manuals/SynScan_HandControl_web_280313V3.pdf

 

I'll do it the other way tonight and see if that makes any difference.

 

To be honest, I'm still not sure why it needs to start in the home position if it knows the point of three stars; knowing that would surely allow it to traigulate any other point in the sky. If you blind folded me and dropped me in the middle of somewhere, and pointed to where Lincoln was, where Newcastle was, and where Southampton was, I'd have a pretty good idea where Nottingham was. I can't get my head around what is special about the home position other than it roughly being Polaris and therefore a 4th star in the alignment process. Sorry for being thick!

 

James

[dawson]

I loaded the OTA the other way last night (I'm struggling to remember which way I did when now), but it slewed the correct way for Arcturus (though was a fair bit off, but I'm going to start another thread about why that was).

 

James