HEQ5 Rowan mod vs EQ6R-Pro

[SupernovaF1]

Hello all

I am going to upgrade from the SW StarAdventurer to a proper GoTo mount.

Currently I have the SW 72ED but I will buy soon a 200p meant for both visual and imaging, though mostly visual. I would like to avoid guiding for the time being though I am sure its a matter of time until I start doing it. I dont think of going to need heavier scopes than that in the next two years.

I would target 3 to 5min exposures and the telescope will be used 95% of the times in my garden. Perhaps 5 to 10 gatherings a year outside. 

Portability is not big issue thanks to the handle of the EQ6R, but given that both have belt transmissions, the difference in RMS error tracking might be neglible for my needs?  

The price difference is relatively small in the big scheme of things but essentially it would almost pay the 200p DS so its obviously welcome.

Would you recommend the HEQ5 with the Rowan belt mod or should I to go for the the EQ6R.

Edited June 6, 2020 by rideway

[david_taurus83]

200p needs an EQ6 class mount for imaging imo. And even then it will need good guiding for 1000mm focal length.  HEQ5 prob fine for visual.

[TerryMcK]

I know you said that you are looking at just doing visual first of all however when you do decide to go AP the following will apply:

The 200P will blow around like a sail in the wind with the HEQ5, belt mod or not, even though it is 8.8kg. When you add on the tube rings, vixen, a camera, a guider and filter wheel you start to get very close to, if not exceed, the limit of the HEQ5 (for imaging).  The 6 class mount is far better for that size of scope.

For visual bear in mind that the eyepiece gets at all sorts of odd angles with a Newtonian on a equatorial mount. Sometimes you need a step ladder or become a contortionist. However you can rotate the OTA in the tube rings and you can always add something like a Wilcox Rotating Ring, which is cheap enough to make, to prevent the OTA slipping when you loosen off the clamp bolts.

The article is here http://www.andysshotglass.com/wilcox_rotating_rings.html

If using the SW200 for astrophotography make sure you get the 200P-DS version as the focuser and secondary mirror are positioned slightly differently to the P version and allows you to bring a camera into focus. The focuser is also a dual speed 10:1. You can also use it for visual too.

[CloudMagnet]

This is a question I have been asking myself recently. I also use the 200p right now just on its standard EQ5 so have been looking for an upgrade. I feel for the relative prices it is worth making the leap to the EQ6 and being comfortable within the load limits.

[SupernovaF1]

Thanks all. I agree with your messages. Think it will have to be the EQ6R. Cheers

[malc-c]

Just some comments based on my own experience.

Explorer 200P is fine for visual on an EQ5 or HEQ5 mount.  The belt vs gear drive won't make any real difference for naked eye observing.  However if you are also looking at an explorer 200 for imaging, then get the PDS version.  A few years back there was a long thread that spanned 16 months of trying to resolve an issue I had with a 5th and sometimes 6th spikes of the image with any bright stars.  The issue was resolved by swapping out the standard 200P secondary mirror for one the size of the PDS secondary.  

I also found that the EQ5 was at its limit for visual observing, and upgraded to an HEQ5.  My setup was housed in a purpose built observatory so it is protected against the breeze so that may have had some bearing on the mounts stability.  The Rowan belt mod originated from this forum.  A few guys had done their own DIY modification to convert their EQ6's, and at the time (around late 2011 if memory serves me correctly) I started messing about with pulleys and a belt to convert my own HEQ5. 

https://stargazerslounge.com/topic/121114-heq5-experiments-with-belt-drive/?tab=comments#comment-1198047

https://youtu.be/dh3F1xkdj98

As I used EQMod to control the scope I could use a 4:1 ratio, and even though I made up and sold a few kits for others, it was another guy with his own CNC engineering business that took both the belt drive for EQ6 and HEQ5 to the commercial level as he could machine the small pulley to maintain the default ratio so the mount could be used with the standard handset.  For imaging the belt driven mount is far better than the geared version, not only making the mount quieter, but it removes one area of backlash in the gear train and thus makes guiding less of a challenge.  In my case having a even ratio of 4:1 helps with PE as the error is very regular.

Some form of guiding is essential when imaging, and yes an ST80, small dovetail and rings, plus the camera and cables is soon going to put the total weight to the max for the HEQ5, and unless you have a sheltered spot it might be an issue.  For me I went around seven years with an ST80 / QHY5 arrangement 

However, recently I've tried to reduce the mass that the mount has to swing about, so I sold the ST80, small dovetail and rings, and converted the 9x50 finder to a Guidescope using a £30 adapter ring to mount the QHY5 camera to it, and whilst a scope with a longer focal length helps with tighter guiding, the recent results in testing and calibrating the set up are very encouraging.   The stars are small and round which is the main thing. 

So to summarise, opt for the PDS version of the 200P, if you can stretch to it, opt for the EQ6 with a belt drive, or if you observe from a sheltered area, a belt driven HEQ5.  The EQ6 has a better load rating, and would handle a 200P with a ST80 (or larger) guidescope, and should be more stable in a light breeze.  But no mount would hold a 200P steady enough in windy conditions.

Hope that helps, 

Edited June 9, 2020 by malc-c

[SupernovaF1]

21 minutes ago, malc-c said:

Just some comments based on my own experience.

Explorer 200P is fine for visual on an EQ5 or HEQ5 mount.  The belt vs gear drive won't make any real difference for naked eye observing.  However if you are also looking at an explorer 200 for imaging, then get the PDS version.  A few years back there was a long thread that spanned 16 months of trying to resolve an issue I had with a 5th and sometimes 6th spikes of the image with any bright stars.  The issue was resolved by swapping out the standard 200P secondary mirror for one the size of the PDS secondary.  

I also found that the EQ5 was at its limit for visual observing, and upgraded to an HEQ5.  My setup was housed in a purpose built observatory so it is protected against the breeze so that may have had some bearing on the mounts stability.  The Rowan belt mod originated from this forum.  A few guys had done their own DIY modification to convert their EQ6's, and at the time (around late 2011 if memory serves me correctly) I started messing about with pulleys and a belt to convert my own HEQ5. 

https://stargazerslounge.com/topic/121114-heq5-experiments-with-belt-drive/?tab=comments#comment-1198047

https://youtu.be/dh3F1xkdj98

As I used EQMod to control the scope I could use a 4:1 ratio, and even though I made up and sold a few kits for others, it was another guy with his own CNC engineering business that took both the belt drive for EQ6 and HEQ5 to the commercial level as he could machine the small pulley to maintain the default ratio so the mount could be used with the standard handset.  For imaging the belt driven mount is far better than the geared version, not only making the mount quieter, but it removes one area of backlash in the gear train and thus makes guiding less of a challenge.  In my case having a even ratio of 4:1 helps with PE as the error is very regular.

Some form of guiding is essential when imaging, and yes an ST80, small dovetail and rings, plus the camera and cables is soon going to put the total weight to the max for the HEQ5, and unless you have a sheltered spot it might be an issue.  For me I went around seven years with an ST80 / QHY5 arrangement 

However, recently I've tried to reduce the mass that the mount has to swing about, so I sold the ST80, small dovetail and rings, and converted the 9x50 finder to a Guidescope using a £30 adapter ring to mount the QHY5 camera to it, and whilst a scope with a longer focal length helps with tighter guiding, the recent results in testing and calibrating the set up are very encouraging.   The stars are small and round which is the main thing. 

So to summarise, opt for the PDS version of the 200P, if you can stretch to it, opt for the EQ6 with a belt drive, or if you observe from a sheltered area, a belt driven HEQ5.  The EQ6 has a better load rating, and would handle a 200P with a ST80 (or larger) guidescope, and should be more stable in a light breeze.  But no mount would hold a 200P steady enough in windy conditions.

Hope that helps, 

Thanks for your answer, it is very reaffirming. I have ordered a EQ6R (4 to 5 weeks wait!) and soon after that I will buy the 200PDS indeed. One shock to the bank account at a time

I think I will skip for now the ST80 as I want to try first to piggy back my SW 72ED instead. Might be too much though weight-wise should be fine. Wish I had such an observatory as you!

Many thanks again and wishing you clear skies.

[malc-c]

The ED 72 would make a very nice guidescope

[Adam J]

1 minute ago, malc-c said:

The ED 72 would make a very nice guidescope

Probably overkill, a evoguide 50ed would do the job just fine. 

[SupernovaF1]

2 minutes ago, Adam J said:

Probably overkill, a evoguide 50ed would do the job just fine. 

I agree Adam but I already have one so would be cheaper. As long as it works, I am happy to keep it. 
Cheers

[Adam J]

19 minutes ago, rideway said:

I agree Adam but I already have one so would be cheaper. As long as it works, I am happy to keep it. 
Cheers

Suppose so, I just like to reduce weight whenever possible. 

[malc-c]

54 minutes ago, Adam J said:

Probably overkill, a evoguide 50ed would do the job just fine. 

It may well be, but at under 2kg would be well with in the load capability of an EQ6, and he already has the scope.

[malc-c]

The Evoguide is a nice scope, and benefits from a slightly longer focal length of a standard 9 x 50 finder, but the standard ST80 is £60 less, and almost double the focal length, which gives a better guide ratio with any given camera.  But is twice the weight of the ED50....

 

[Adam J]

18 hours ago, malc-c said:

The Evoguide is a nice scope, and benefits from a slightly longer focal length of a standard 9 x 50 finder, but the standard ST80 is £60 less, and almost double the focal length, which gives a better guide ratio with any given camera.  But is twice the weight of the ED50....

 

It's also got a terrible focuser that's prone to flexure. 

[malc-c]

1 hour ago, Adam J said:

It's also got a terrible focuser that's prone to flexure. 

Which scope are you referring to Adam, the ED50, evoguide or ST 80 ?

[Adam J]

The st80 having owned one I found that the 1.25 inch focuser with extention had flex that effected longer exposures it's plastic construction was most likely not helping either. Chucked it and used a 50mm finder ever since. 

Edited June 11, 2020 by Adam J