Advice on EQ5/HEQ5 or similar mounts

[The_bluester]

OK, my recent child induced mount issues have set me thinking.

I am beginning to find the Celestron CPC mount limiting, I think it is a brilliant mount for visual observing and particularly for showing the night sky to very inexperienced people. The fact that it tracks reliably and the EP stays in pretty accessible places makes it hard to beat for that function.

The obvious drawbacks are that it is more or less useless for AP due to field rotation (I knew that when I bought it) and I am beginning to find the goto mount limiting. I have a few favourite objects and predictably enough they are often well separated in the sky. When I decide to change from one to another the "Set it slewing and go for a cuppa" routine can wear a bit thin. But the goto is still handy at my experience level to get it to point to objects I am not familair with.

My question on the EQ/HEQ is related to this. The CPC Alt/Az is useless until it is aligned (Not utterly, even with the dead controller we had a look at the moon and 47 TUC for the folks who were visiting and bumped the scope around manually Dob style, it is not an easy mount to do that with, but a low powers it was possible) The CPC mount sits there dead as a dodo until it is aligned then the drives spring into life.

With an EQ5/HEQ5 pro and SynScan, can the hand control be set up to run the RA motor at siderial rate as a simple clock drive if the controller has not had any star alignment? That would allow me to decide to change objects, release the clutches, slew the scope manually and lock it up again to centre with the hand controller and let the RA drive take over the work, making the assumption that I have done an OK polar alignment. If I want goto I can then do a star alignment as required. Obviously it also makes the mount useable as an AP setup with longer exposures, in the amateur end of the market I have trouble seeing a derotator as a great alternative.


I hope my wife does not read this! It sounds like I am looking to buy a new mount, then a new OTA to go on it even though I have got mine going again, that would get me in trouble!

[Merlin66]

Paul,
If the HEQ5pro has power, it will allow non GOTO functionality. You can certainly just rough polar align and start observing...
I changed over from a Meade 12" Lx200 to Celestron. Initially the C9.25 which I found fitted well with the HEQ5pro mount.
More recently I've gone for a C11 on a NEQ6pro mount for spectroscopy.
Just de-fork the C9.25 OTA, fit a dovetail and put it on a HEQ5pro mount - a marriage made in heaven.

[The_bluester]

Lol, this will really get me in trouble with my wife!

I already have a dovetail bar on it, I fitted it ages ago to allow me to add a counterweight as the weight of my wifes DSLR was enough to cause tracking issues. The bar is the narrow Losmandy one, I was looking at it last night and evaluating it for supporting the OTA!

[Merlin66]

Paul,
We have family in Kilmore and visit regularly.....
I started with the narrow (Vixen) dovetail and quickly changed both the C9.25 and C11 to the wider Losmandy type - IMHO better stability.

[The_bluester]

All a bit of a moot point at the moment in any case, it is a bit hard to justify while the fork mount is working. If I could not get it going I might have been able to go out and buy one today. Silly me being an ex techo fixed it!

How do you reckon the C9 would do stability wise for AP if I put it on the HEQ5? I would not be too fussed about having to fit a wider dovetail to it. I did look at it and think it would probably be OK for visual work but would allow too much rotation around the dovetail bar for AP with a guidescope hanging off it. If I go down that route I suppose I could relocate the narrow dovetail to the top of the OTA to fit a guide scope and use a wide dovetail underneath to mount the whole assembly.

[Merlin66]

For me the wider Losmandy dovetail works very well!
All my electronic finders/ guide etc etc are mounted on top of the tube using the ADM minirail system.
The combo should be good for AP. I have to guide and hold a star image on a 25micron slit indefinately!!!

[The_bluester]

Just found out a mate is about to sell an EQ5, not sure if it is an EQ or HEQ5 though, have to wait and see. If it is a HEQ it might be worth my snapping up.

[The_bluester]

OK, his mount is an EQ5 not a HEQ. Not sure it would be heavy and rigid enough if I end up looking at AP in future.

[The_bluester]

Ok, I am looking like I might actually get finance minister approval for a remount (and a pier, which is easier for a gem like the eq series in some ways)

I am really trying to decide on suitability of various mounts. If I tried at ap, the c925 ota looks to with in at 10kg, hang a camera on it and any sort of guide scope and it would hit the 13 mark pretty quick. Is it like anything else, 13kg payload means that it really works better at 80%?

Am I likely to be better off with the neq6 in other words. I have trouble seeing the CPC mount performing even on a wedge, which is half the cost of a new mount anyway.

The big benefit to the CPC mount is that I can be up and observing in five minutes, once I am competent at a gem, how long should I be looking at setup wise, at least for visual use?

[Davros]

Personally i would go for a second hand EQ6. Since the EQ8 is coming out there should be a few on the market soon. I own an HEQ5 and i would have rather the 6 in hindsight for its extra carrying capacity.

[Shiraz]

ditto. my HEQ5 runs out of steam for AP at around 11kg - it works, but is thrown off a few arcsec by the slightest puff of wind. the EQ6 is way more stable at this sort of load.

[Barrykgerdes]

Hi Paul

I think you should be talking to the chancellor of the exchequer about a PMX or a G11 or equally exotic mount. She will of course be fuming and won't talk to you for weeks. When she cools off suggest a compromise of an EQ6. With a bit of luck she might think that if she settles for that it will be the cheapest way out.

Barry

[The_bluester]

Lol, I must have an understanding treasurer. I was talking to her about it last night, explaining that I was not really sure which way to jump, that the HEQ5 would be plenty for visual, but then the CPC mount is really good for that too, despite the limitations that it imposes in order not to destroy the goto alignment. Then I said that I reckoned that the HEQ5 would be right at the limit for any decent sort of AP and she said that if I bought the 5 I would just end up wanting to upgrade it later so buy the right one first time out!

And on to the real question, AP of any serious variety is a fair way down the road for me but if I spend money on a mount I would like to keep the option open which is why I am looking at a GEM at all and why I am considering a top end (Relatively) item. However visual is and will remain far more common an activity and with the CPC mount I can be observing (Ignoring cool down time) within a couple of minutes of carrying the OTA and fork assembly out to the tripod.

If I install a pier I can hopefully expect a polar alignment to remain good enough between sittings to be straight underway for visual observation with good enough accuracy of polar alignment to be useful, but for a reasonably competent person if I am going to a remote site (I do understand exactly what we are trying to achieve with a polar alignment and don't expect to take too long to come to a reasonable level of competence) how long should it take to align the likes of an EQ5/6 variant and be ready to observe? At home if I do a pier (Or even if not) I can easily do a solar noon measurement to find true south and mark it up somewhere to give an aiming point to get close to the pole, and I can drive a spirit level as well as anyone else, but at a remote site unless I am really early, solar noon will be more of a problem and less accurate devices are likely to take over that measurement.

I am ignoring star alignments in that question, one of my bugbears as mentioned previously is that I am getting tot he stage of wanting to star hop manually and I can not do that with the CPC, as soon as the clutches are released the alignment is gone and object tracking with it. At least when using the HEQ/NEQ as a basic clock drive, I can just declutch, point manually, lock up and then fine tune pointing with the hand controls. If I really want goto I can do a star alignment.

[ZeroID]

Paul, you seem to have all the ducks lined up to go there.
Finance Minister approved, EQ6 does the job with some spare and a pier on the plans.
Why are you prevaricating ? Lay your money down and strike while the iron is hot. Its exactly the path I was given when I got serious and it has worked for me so far.

btw I use my Android tablet with an inclinometer for a Dec alignment starter. And the compass function gets you pretty close as well. Don't you just love modern technology !?

[The_bluester]

I was actually thinking of that, with the Iphone 4 it has a nice flat long edge for a spirit level app. Should be enough to get close to the dec setting.

[The_bluester]

Still thinking about a remount, however I have thought of a reason to take the heat off the idea (Silly me)

I have to do a bit of experimenting to see if the mount will run the RA motor in EQ mode (Azimuth motor when not mounted on a wedge) without a star alignment then I could use that function to do the tracking when wedge mounted, allowing me to release clutches, maually point and lock up again while ignoring any star alignment (As it becomes irrelevant) and using the mount only as a clock drive.

If the mount will not run the RA drive in EQ mode without a star alignment then I could wedge mount it, do a simple one star alignment to get the RA motor running and then ignore the mount, if I want the Goto function to work I could simply switch off, power up again and carry out a star alignment then off it goes as an automated scope.

The only issue is getting a wedge for it, Celestron products seem to have got very expensive in Australia since I bought this scope (With a CPC800 being slightly more costly now than I paid for the 925 and a new 925 being over a thousand more) and the cheapest I have seen the current Celestron wedge is about $650 here in AU. Expensive enough to be offputting but not expensive enough compared to the US to really be worth tracking one down and importing it myself.

[The_bluester]

A bit of a further update.

The scope is able to be cajoled into running the RA motor in polar mode without doing a proper star alignment. Assuming I do a decent polar alignment of the mount itself so it tracks nicely, I am able to start the alignment in "EQ South" mode for a one star alignment, let it suggest an alignment star then press enter and then align as if I have actually pointed to the assigned star and off it goes with the RA (Previously azimuth) drive running. Obviously goto's are no good as it is not pointed where it thinks it is but it allows me to get around my bugbear of having to wait for it to slew if I am not feeling lazy and letting it do the goto for me.

If I wan't goto to work I can always actually point it at the suggested star and align the electronics properly. It is just a pity the encoders are on the motors and not the axes as then it would be able to retain an alignment either in Alt/Az or polar mode with the clutches relased.

[2stroke]

Just grab a eq and be done with beating a dead horse unless ya tight for cash. At $650 and if you can sell your mount off it, you wont be that far off an eq5/eq6 in price anyhow.

[The_bluester]

There is that, only problem is I have no idea what the existing mount is going to be worth as a spare part for someone. Cash is tight enough to keep me from just running out and splashing it seeing I brought the original mount back from the dead.

Plus I would really like to get hold of one of these for my other expensive hobby. The cost is about the same as an NEQ6, I might sit back and see what pops up secondhand when the EQ8 starts to be delivered.

http://www.independentmotorsports.com.au/wp-content/uploads/2011/02/Racepak-Dash.jpg

[Poita]

Do you have a wedge for your CPC?

[The_bluester]

No, that is the point of discussion above, between adding around $600 to $700 for the proper wedge and the potential to sell the existing mount and tripod I would be halfway to the cost difference of putting it on an NEQ6.

The biggest wedge issue I can see is that by what I have read, the current "HD pro" wedge is really the only one worth having as the earlier ones are not stiff enough for scopes like the C9.25, naturally the HD Pro wedge is costly and even more so in Australia. They are about half of the cost in the US but by the time you buy one through a freight forwarding mob to get around the distributor agreements Celestron has in place and then pay the freight on something that is pretty sizeable and heavy, the cost and risk starts to look unattractive.

[Poita]

Make a wedge, it is easy and will cost you <$100. Way less.

[The_bluester]

I have been thinking about that. If I made a nice heavy one as part of a pier I could use that at home and just use the Alt/Az tripod when at star parties etc.