Skywatcher's equivalent to Celestron CPWI

evltoy (Wayne) · #1 01-12-2020, 04:44 PM

Hey All,

With 12 months in, I'm very new to this hobby. So far I have been through a Celestron nexstar4se and now using an evolution 8 and skywatcher Heritage 130P.

I'm now looking at doing astrophotography with exposures beyond the 1min mark with my DSLR. One thing I have notice in my research for an Equatorial Mount is that 85% (my opinion) of the people out there are using skywatcher EQ mounts.

Are the skywatcher mounts that much better than the celestron brand??

Initially I was 100% set on the Celestron AVX mount, mainly due to having very good success with the PC software - CPWI to align and control my mounts. Also I have not had any issues with firmware updates and in general the Celestron brand.... it just works very well for me.

The issue I have is I'm now questioning if I should go down the path of using an AVX mount when I see most users using skywatcher HEQ's

Can the Skywatcher mounts (HEQ5 Pro) work with the Celestron CPWI software? If not, what is skywatchers equivalent?

Thank you in advance & keep safe
Wayne

The_bluester (Paul) · #2 01-12-2020, 06:07 PM

I don't know if there is a direct Skywatcher equivalent now but the common method for the Skywatcher mounts and the variants sold under other brands is to install the ASCOM platform and the EQMOD software to control the mount via ASCOM, along with the appropriate cable for your particular mount.

Startrek (Martin) · #3 01-12-2020, 08:00 PM

New software to control Skywatcher mounts which is becoming popular is Green Swamp Server GSS although I don’t think it has all the capabilities and functionality of EQMOD ( I suspect they will develop more features with subsequent upgrades )
I had a look at some Vimeo video with GSS in operation and it looks too busy and complicated for me
EQMOD’s design will outlast the test of time, simple in design , user friendly, easily integrated and totally reliable
I can’t see myself using anything else other than EQMOD now and in the future on all my Skywatcher mounts

Harpage (Danh) · #4 01-12-2020, 08:11 PM

As others have mentioned, there are various other methods of controlling a Skywatcher mount with a computer - after all, if most people are using them, then there's surely a way. I'd personally recommend going for the HEQ5 though - I have one and it's great. Quite a few people have gotten dodgy copies of the AVX, and the AVX is mechanically inferior anyways in that it uses gearbox motors (apparently the gears are actually plastic) as opposed to proper stepper motors, and bushings, as opposed to proper bearings. Plus, the HEQ5 is cheaper anyways.

evltoy (Wayne) · #5 01-12-2020, 08:34 PM

Thanks Paul. I should have put more effort into my search on here as I found a few posts that talks about connecting the skywatcher mount to a PC. It seems there is no out-of-the-box software that come with the skywatcher mounts

https://www.iceinspace.com.au/forum/...d.php?t=185830

https://www.iceinspace.com.au/forum/...d.php?t=187035

https://www.iceinspace.com.au/forum/...d.php?t=187073

I have to say it looks to be very cumbersomer. One big plus for me with Celestron is you plug in a simple USB cable and install cpwi and you are off, no drivers, no special cable etc.

From a Mechanical/performance point of view are the Skywatcher mounts that much better that users see the cumbersome PC connectivity not an issue?

So there are dodgy copies of the AVX floating around! WOW, how can some copy that and badge it and pull it off as the authentic thing!

The_bluester (Paul) · #6 01-12-2020, 08:48 PM

It is really not all that difficult to connect them to a PC (No idea on a Mac though, I have never looked if EQMOD is cross platform)

All you really need is an EQDirect cable, install the ASCOM platform (Which requires .net 3.5 which is dead easy to install on Win 10 and not very hard on W7) and then to install EQMOD. It is generally fairly smooth sailing.

One point to note if you are likely to dive in to astrophotography, a lot of people start out with an EQ5 size mount and fairly quickly end up upgrading to an EQ6, and if you get an EQ6 you really want one with a belt drive (EQ6-R) as the belt reduction drive between the stepper motors and worm gear can be a lot easier to deal with if you are guiding than the reduction gearbox in the lower cost versions.

jahnpahwa (JP) · #7 01-12-2020, 08:59 PM

Quote:

Originally Posted by evltoy

From a Mechanical/performance point of view are the Skywatcher mounts that much better that users see the cumbersome PC connectivity not an issue?

Don't think about it as a trade off at all. You'll install the software that Paul mentioned, maybe mess around for a week with something not working, then you'll have 10+ years of being up and running in under a minute.

Startrek (Martin) · #8 01-12-2020, 09:14 PM

If you want to choose a Skywatcher mount , control it with EQMOD, I recently wrote 3 versions of procedures to use the latest version of Stellarium as your preferred Planetarium to navigate across the night sky
Of course there are many other ways to goto , navigate , plate solve etc .. but if your interested in using the popular Stellarium, I can post the 3 options which covers both older mounts and new mounts with the USB2B port

Happy to help if your interested

Cheers
Martin

Harpage (Danh) · #9 01-12-2020, 10:03 PM

The newer models of the Skywatcher mounts have a USB port anyways, so it's ready to be computer controlled out of the box. Plug it in, install ASCOM and EQMOD (or GSS), set it up (not that difficult IMO), and you're done!

evltoy (Wayne) · #10 03-12-2020, 04:25 PM

Thank you all for your comments. The advice has been valuable.

I just went to see the weight of my setup and I'm on 6kg and that is with no filter wheel or Guide cam for future setups. I did read a review of a user that has been using the AVX for many years says that its recommended the payload be no more then 5kg for accurate DSO guiding.

I'm now looking closer at the Skywatcher mounts (EQ6-R) and yes the new units come with USB and cable (bonus), but the price is $1k more than what I was looking at.... I guess you get what you pay for.

Thanks again.. keep safe
Wayne

Startrek (Martin) · #11 03-12-2020, 05:13 PM

Quote:

Originally Posted by evltoy

Thank you all for your comments. The advice has been valuable.

I just went to see the weight of my setup and I'm on 6kg and that is with no filter wheel or Guide cam for future setups. I did read a review of a user that has been using the AVX for many years says that its recommended the payload be no more then 5kg for accurate DSO guiding.

I'm now looking closer at the Skywatcher mounts (EQ6-R) and yes the new units come with USB and cable (bonus), but the price is $1k more than what I was looking at.... I guess you get what you pay for.

Thanks again.. keep safe
Wayne

Wayne
I have two Skywatcher EQ6-R mounts at two different locations , one is the original model that has the standard RJ45 handcontroller port and the other is the latest model which has the USB2B port
I control both ( giro and navigation) using EQMOD and Stellarium with my laptop on a little table 1.8m away
The older one I use the EQDirect cable ( USB2A to RJ45 ) 1.8m long with a 3m USB extension cable ( total 4.8m long cable )
The newer one I use a USB2B to USB2B cable 5m long
The recommended max payload on these mounts for Astrophotography is around 15kg
My newer USB EQ6-R mount carries a 6” f6 newtonian reflector, 50mm finderscope, 60mm guide scope with helical focuser , ZWOASI120MM-S guide camera , ZWOASI2600MC OSC imaging camera, JMI auto focuser, Kendrick Dew heater bands, mounting bars and many cables
Payload is around 9kg
My older EQ6-R mounts carries an 8” f5 newtonian reflector , 50mm finderscope, 60mm guide scope with helical focuser, ZWOASI120MM-S guide camera, ZWOASI2600MC OSC imaging camera , JMI auto focuser, Kendrick Dew Heater bands , mounting bars and many cables
Payload is around 15kg

Both mounts track and guide really well, whisper quiet
Both mounts run sub arc sec guiding ( PHD2 ) on nights of average to good seeing

Just some further information which may be of some help

Cheers
Martin

The_bluester (Paul) · #12 03-12-2020, 08:44 PM

Another advantage of the EQ6-R over the lower cost EQ6 and the EQ5 variants is the drive system. The stepper motors that drive the mounts run far too fast to drive the mount, so they have two stages of reduction drive. The cheaper EQ6 versions have a reduction gearbox which drives the worm gear, and the worm drives a ring gear which is what drives the axis. The EQ6-R and the AZEQ6 have a pulley and belt reduction drive between the stepper motors and the worm gear, the AZEQ5 may have a belt as well.

The advantage of the belt drive is that the reduction gearboxes tend to introduce much more complex periodic error into the RA drive which while it can be done, is harder to guide out. But they can also introduce backlash which is difficult to get rid of. That does not matter much in RA but in declination it can make guiding tricky and less effective.

Startrek (Martin) · #13 03-12-2020, 10:34 PM

Quote:

Originally Posted by The_bluester

Another advantage of the EQ6-R over the lower cost EQ6 and the EQ5 variants is the drive system. The stepper motors that drive the mounts run far too fast to drive the mount, so they have two stages of reduction drive. The cheaper EQ6 versions have a reduction gearbox which drives the worm gear, and the worm drives a ring gear which is what drives the axis. The EQ6-R and the AZEQ6 have a pulley and belt reduction drive between the stepper motors and the worm gear, the AZEQ5 may have a belt as well.

The advantage of the belt drive is that the reduction gearboxes tend to introduce much more complex periodic error into the RA drive which while it can be done, is harder to guide out. But they can also introduce backlash which is difficult to get rid of. That does not matter much in RA but in declination it can make guiding tricky and less effective.

Backlash although still evident in the EQ6-R can be reduced or “tuned” out by adjusting the belt tension on your RA and DEC axis pulley drives and adjusting your worm gear tension. I’ve done both adjustments in approx 20 minutes with Allen keys and a Philips head screw driver, a very simple procedure. The EQ6-R is designed so the “average Joe” can carry out these adjustments without stripping down the whole mount like some of the earlier gear driven models. The results show in your guiding , almost zero backlash on Dec most nights

The_bluester (Paul) · #14 04-12-2020, 10:44 AM

That is my meaning exactly, the EQ6-R belt drive is a big advantage over the gearbox driven versions. I would personally leave the reduction gearbox versions for visual use.

I know of someone who has spent a lot of time fiddling with worm gear mesh and end float, and also tweaking the reduction gears as best they can on an NEQ6, and PHD2 still suggests a backlash compensation in the region of 1200 milliseconds! It has no detectable Dec backlash at the puck, most of it is coming from the reduction gearbox and it makes guiding quite hit and miss.