Accurately setting the “Home” or “Park” position on a Skywatcher EQ5 Pro Mount
Update 18 Jun 2011:
Since I originally prepared this article I’ve found that the steps set out in the Starting from a known position section aren’t necessary. When the mount is powered on, regardless of whether you choose to start from parked position or not, and irrespective of what position the axes are in, the positions of AX1 and AX2 shown in UTILITY → SHOW POSITION will be the same. I’ve therefore removed the steps that are no longer required
It’s been quite a while since my last posting. In the intervening period I finally got round to acquiring a decent mount, the SkyWatcher EQ5 Pro. The only trouble is the weather’s not been too good andit’s way past 10pm before it gets dark enough for observing!
One element of setting up an equatorial mount is the establishment of the “Home” position. This is where the mount is “parked” at the end of a session. It is sometimes described as “weights down, scope up” and is often the position displayed in adverts. There’s an excellent video tutorial on YouTube accessible via http://www.astronomyshed.co.uk/ (“Complete Setup From A to Z Part 1”) which shows how to establish this position using an HEQ6 mount.
In essence, the procedure uses a spirit level to “level” an axis then rotate the axis by 90o so that it is then perpendicular. When both the RA and DEC axes have been set this way, the mount is in the correct Home position.
As owners of Skywatcher EQ5 mounts have long accepted, the setting circles leave a lot to be desired, and while it’s possible to use the technique in the tutorial on an EQ5, the inaccuracy of the setting circles means it’s a bit of a hit and miss affair.
The following procedure builds on the technique, using the Show Postition function of the SynScan controller to accurately determine when an axis has rotated through 90o. Though described for an EQ5 mount, this procedure can be used with any equatorial mount with SynScan, whether factory-fitted or upgraded.
On the EQ5 tripod, one leg is marked N. This is the leg which is pointed North. For the purpose of this procedure this will be regarded as the front of the mount.
It is assumed that the user is familiar with the operation of the SynScan controller and its menus. Navigation to a sub-menu will be described thus:
UTILITY → SHOW POSITION
( Starting from a known position section removed)
Setting the RA axis
- Stand behind the mount, release the RA clutch and rotate the RA axis until the weight bar is horizontal and to the left. Use a spirit level to check then lock the RA clutch.
- Switch ON
- Step through the setup procedure. Note: Setting date/time/location correctly is not required at this, or any other stage of the process, nor is 1,2 or 3-star alignment.
- Show the position of the axes. UTILITY → SHOW POSITION
- Use the scroll keys to change the display so that the axis positions are shown in degrees, minutes, seconds:
AX1=+090o 00′ 00”
AX2=+000o 00′ 00”
(AX1 is the DEC axis, AX2 is the RA axis)
- Set a fairly high slew rate (RATE 8 for example) then use the RA directional key to slew the mount until AX2 is close to reading 90o. Select a slower rate and carefully slew until the display reads
AX1=+090o 00′ 00”
AX2=+090o 00′ 00”
- Using a fine marker and straight edge, make a mark to enable you to manually return the RA axis to its parked position.
Setting the DEC Axis
- If you have one, fit a dovetail bar to the puck. This will provide a straight edge to rest the spirit level on.
- Release the DEC clutch and rotate the DEC axis until the dovetail is horizontal, using the spirit level to check.
- Again, start off with a high slew rate and rotate the DEC axis until the display indicates the AX1 axis is 90 degrees different to what it was. If your preference is to have the DEC motor to the left, then the display should read
AX1=+180o 00′ 00”
AX2=+090o 00′ 00”
If, however, you prefer to have the DEC motor on the right, the display will read
AX1=+000o 00′ 00”
AX2=+090o 00′ 00”
- Using the marker and straight edge make a mark so the DEC axis can be returned to this position manually
- Switch OFF
- Switch back on again and step through setup.
- Choose UTILITY → PARK SCOPE then switch off when prompted
The mount now has its axes accurately positioned and parked.
Paul's Blog 
Excellent Thread I never knew it was so easy.
Thanks Paul,
Using your method threw up a problem I had, namely using the wrong cog on the RA motor. Synscan showed the mount had moved 136 deg not the 180 it actually had moved. Correct cog now used and everything works.
Thanks again.
Arrrgh!
WRONG COG !!!
Days – weeks wasted!
Thank you, thank you, thank you!
I couldn’t understand why a 90 degree slew was showing as about 67 degrees in the Ax1/Ax2 display of Show Position.
Months ago I did some re-adjustment to the Right Ascension work gear tension. When I put it back together I re-assembled incorrectly. Various reasons for not testing the scope directly after, meant I totally forgot about this. I was sure it had to be something simple, but not that goddam simple.
I love you!! 😉
Great tip. I will do this before my next viewing session.
very good – thanks for taking the time to share this useful tip
What settings would you usein the Southern hemisphere ?
Thanks
Hi John,
The procedure described is meant to set the axes of the mount in the traditional “Home” position where the weights point down and the scope is pointing upwards. This should apply equally regardless of which hemisphere you’re in as the technique doesn’t involve polar alignment.
I’ve found it useful to mark the positions of the RA and Dec axes once the procedure’s complete so that the mount can be quickly returned to the Home position after a scope has been mounted and balanced
I too was having problems with this. I’ve just spent a couple of hours trying to sort it because I couldn’t lock the clock in position to turn the RA 90 degrees. Then I came across this method and within ten minutes my home position was set, thanks for taking the time to explain it.
Paul
Stumbled on your site. Great post and super supplement to the Astronomyshed video.
Thanks again
Alec
Hi,
I’m a relative newbie (2yrs but only had the scope out maybe 10 times). Just came across your post. My EQ5 Pro synscan was working fine. Then all of a sudden when performing an alignment, the scope was way out first star, in this case Vega. The scope points approx 20 degrees too low and 15 degrees to the left. I tried the 1 star park procedure as recommended on SGL (first time using the option yes to ‘from home position’ and then again selecting ‘No’ to the home position. I tried this a few times but it made no difference. After this first happened I upgraded to the latest version (3.37?) but has made no difference. Can the firmware just die?
Many thanks
Hi Mark,
Apologies for not getting back to you sooner. It does seem odd that your GOTOs should be so far out. All I can suggest is to clear the PAE data on the handset and double-check your Lat/Long and date/time during setup.
When I set up I make sure the tripod is as closely aligned with North as I can get it, and it’s level. I then attach the mount and check my polar alignment. Only when I’m happy with that do I then switch on and go through the setup procedure. As I’m almost invariably using my laptop and EQASCOM I don’t go through star alignment on the handset, but use Stellarium to get to a target star and either use a gamepad to adjust and sync position, or use Astrotortilla to take a picture, plate solve it, work out how far “off” I am and automatically re-position the mount.
Regards,
Paul
I did the following which worked.
Do a 1 star alignment and wherever the mount slews to unlock the clutches and manually centre the eyepiece onto the star. Relock the clutches, press enter and then park (Custom Park option) the telescope. When the mount has slewed back to the parked position switch off, unlock the clutches again and manually set the mount back to the correct parked position. Relock the clutches and restart doing a normal star alignment.
Hi,
Thanks for all who have contributed here. I came across this post trying to figure out why my NEQ6 pro wouldn’t sync home position with EQmod. Independent of EQmod it would get back to it’s “HOME” ( looking at NCP). But as soon as I connect to EQmod it would start acting strangely. I recently had my NEQ6 “tuned” with the famoud belt drive mod. looking through this blog and comments I am wondering if the wrong set of cogs were replaced etc.
Anyway I am not knowledgeable in these matters and I just want it to work. I would be very grateful if someone could point me in the right direction to check if all is well with my mount ( a sort of self test .diagnostic) and that it’s capable of just managing just with SYNscan HC. I had upgraded to the latest Firmware some months ( 5-6) ago.
Thanks for any help or pointers in advance
Clear Skies..
July 2017 and still proving an extremely informative piece of information. Many, many thanks!
As a fresh owner of an EQ5, I was looking with interest for such a guide and I was very happy when I found it.
I have one question, please: after performing the procedure and parking the scope, when I turned it on again, I wanted to see which values are shown for AX1 and AX2 position.
So the displayed values were AX1 = +090 and AX2 = +000, despite that at the end of the procedure I had AX1 = 180 and AX2 = 090.
Is that normal, or I did something wrong?
Thanks in advance for your support.
Hi and thanks for stopping by.
It’s been a while since I used the handset on my EQ5 so I can’t remember what was displayed on mine. I doubt you’ve done anything wrong though. What I did with mine was draw a line across the fixed/movable part of each axis once I’d set the home position so that all I need to do to set the mount back to it is make sure the line line up. Hopefully the diagram at
will help.
Best regards, Paul
Thanks for your reply,Paul.
Yes, this kind of marking I also considered :-).