Tripod and mount for 250 f/4.8, 10kg OTA

[pete_81]

Hi all,
My old telescope still gives me what I'd describe as great fun observations (I'm mainly visual at this point) of the heavens, but I've always had trouble (well, concern) with the tripod and mount.
The scope is an Orion Optics Europa 250 (1200mm focal length, f/4.8), and the GEM1 Equatorial mount (Gazer Equatorial Mount, pops up on Google ok).
I've added a few upgrades to the setup, mainly drive motors (both RA & Dec), cooling fans to the OTA, and a Crayford 10:1 focuser to better the rack and pinion supplied with the scope. The latest upgrades are Explore Scientific EPs from the plossls originally supplied.
So, when observing, the RA does track reasonably well for short (say 10min) obs, but there are times I feel it struggles on occasion, or just loses tracking after pointing at one object for extended time. The mount generally sits well under the weight of the counterweights (coming in at 7+4kg) but there is a definite shake if the OTA or tripod is knocked.
The GEM1 aluminium tripod (with accessory tray) weighs just over 4kg, with the EQ, RA drive, dovetail, tube rings and counterweight bar coming in at just under 5.3kg. With these stats, and lots of Google time, I conclude it's spec is somewhere between the EQ3 and EQ5 (eg https://stargazerslounge.com/topic/47747-orion-optics-europa-10-telescope-and-eq4-mount-worth-£250/).
With the Crayford and fans, (no objectives/camera,etc), the OTA weighs in at 9.3kg, so here comes the question and debate... Is the issue I have that the mount is just not substantial enough for the scope? Do I upgrade mount, and if so, what is the ideal?

Skywatcher seem to have the ideal selection/choice /distribution of mountings so I've been looking at the specs for each of these. Mainly payload capacity...
I'm making some assumptions that I've a scope plus potential DSLR that'll take the load to 10kg, so I'm going to need at least that, and giving a bit extra, I'd be expecting to need capacity of say 15kg and that would give me an extra capacity that would allow other attachments (guide scope, etc) as higher quality tracking may be required...
With that in mind, the EQ3 isn't even close. The EQ5 spec of 9.1kg payload doesn't really have enough, which pushes it to the Heq5 and above... The 13.7kg possible payload is into what I'd guess is ok, but should I be pushing towards the 15kg payload of the AZ EQ5...
That brings me to the next point about the ALT-AZ... Am I right in thinking that in this mode visual astronomy is possibly easier, mainly that the OTA doesn't need rotating in the tube rings!does a counterweight need using in alt-az mode if the 2nd mount isn't used?
The az-eq sounds like a very attractive option, bar the (almost) £1k, but as it is a single investment that will serve as the only tripod that would be ever needed for my uses.
Or the next payload capacity is into the "6" series like the NEQ6 and beyond. Handling (weight) and cost are sorta off putters here, but if its the only way to go, then ok... 

TL;DR, which tripod mounting is sufficient to use with a 250mm,f/4.8 1200mm Newtonian that weighs 10kg OTA, and have some spare allowance?
Lots to take in here, would appreciate advice!

[fifeskies]

I have an Orion Optics 10inch Newtonian (CT10L) , I use it on an NEQ6 pro and it is very suitable with minimal settling time after slewing. Its now on an observatory pier but I previously used it out on the tripod in the garden before I built my ROR observatory.

I also have the EQ5 but would not consider trying to use such a big scope on that mount.

If you try to find an NEQ6 in good condition second hand it is within your budget (under £1k), buy from a reputable source such as on here or a similar forum. The alt -az versions are also good 2nd hand but don't appear as often as the NEQ6.

[rl]

If you have any serious pretensions to doing astrophotography, just about the worst mistake you can make is to under-mount the scope. For a 10" OTA plus accessories you really need something in the EQ6 class. It's not just the weight...that sort of an OTA can be a bit of a sail and a small mount only makes shaking in the breeze worse. It's bending moments as well...the bigger diameter the OTA, the further the weight is from the axis, so you need more counterweights at the same distance, or a longer counterweight bar. 

My carbon fibre 8"  f/4.5 OTA weighs 7kg. Add a coma corrector, camera, decent 80mm finder, tube rings...filter wheel..it soon all adds up to about 13kg. I'm running an AZ-EQ6 which copes perfectly even in a moderate breeze but I need a third counterweight to avoid using the extension bar. The tripod is really good. 

[fifeskies]

Yes , you will need extra counterweights, I got mine second hand , but they are not a major expense even new compared to the mount cost.

With my CT10L , guidescope and camera , I need 3 with the extension bar fitted , or 4 with the bar kept shorter without the addition extension piece.

(My CT10L has a carbon fibre OTA but the weight soon mounts up)

[nfotis]

Judging from specs only, the HEQ5 seems to be the minimum required.

The NEQ6 seems to be an upgraded HEQ5, with belt driving (like the Rowan belt mod) and a more substantial tripod (using a pier later should raise the capacity and stability even more). The total weight is quite higher than the HEQ5, though.

If you are thinking to do imaging, equatorial mounts are a prerequisite as far as I know.

N.F.

[MarkAR]

I've put my 250P-DS on my AZ-EQ6 a couple of times in EQ mode for doing a little visual. I would say that would be the bare minimum, getting any sort of good balance was tricky.

[pete_81]

Thanks folks for these replies.

Did suspect the jump to EQ6 range would be necessary and whilst they're not out of budget, I don't want to end up with an EQ6 type for a pair of binos (too good a mount for my scope). I do like the idea of the AZ EQ6, and wondering what people think of these.

From reviews on FLO, YouTube, etc, they're at the top of the game, and they also appear to be lighter than the NEQ6 whilst having similar capacity and better functionality.

Next debate to have is the other makes, is there anything comparable from ioptron or others at same spec and price point? Not really seem much and expecting to hear only skywatcher but why not ask?! 

[fifeskies]

I previously had my CT10L on a dob mount , (which is alt/az) . 

For purely visual alt az is more convenient as it keeps the eyepiece orientation the same at all targets. With an EQ mount the eyepiece will end up under the tube  and at other inconvenient places depending on target.

 (which  you can resolve by rotating the OTA in the rings to bring the eyepiece back to a more convenient position.)

 

Large OTA are a bit of a sail for catching wind , now I have a ROR observatory , the high side walls prevent any issues of that kind, but my NEQ6 was fine out in the garden on calm nights before the build.

(a beach type windbreak can be useful to reduce wind issues as well)

 

 

 

Edited July 5, 2020 by fifeskies

[pete_81]

@fifeskies, seeing the ct10 there, I've also been wondering about dovetail with the skywatcher - rather than getting new tube rings, I'd assume using the original tube rings on the SW dovetail works? 

[fifeskies]

I have a Losmandy 380mm (15 inch) plate on the Orion Optics CNC tube rings for mounting to the NEQ6.

A vixen style dovetail would introduce too much flex for astrophotography though you might be fine for visual use.

For a more secure connection, it needs the 3in wide Losmandy style.

Edited July 6, 2020 by fifeskies

[pete_81]

Well, I've taken the plunge into this and purchased the SW AZ-EQ6 mount. Delivery took a little longer than hoped, and cloudy skies also proved an issue until Sunday night when I at last got the kit out.
For the very first time, I have really REALLY appreciated my scope - Saturn and Jupiter no longer jump around in the eyepiece (even being a bit daft at 350x just for fun!) with the even just approaching the eyepiece, which was my experience previously. As mentioned at the start of this post, I think the original mount was equivalent to the EQ3, but clearly not cabable of the scope it had been sold with!
So yes, expensive setup but SO PLEASED I took the plunge (although it's birthday, Christmas and any other occasions for the next few years all rolled into one!!!!!).

Coming back to the Losmandy plate though @fifeskies, I was very surprised with the mounting puck, (got the full setup of mount, power supply & ADM Losmandy), which seems to be on the limit of adjustment for the 2 star-headed bolts (I reckon there's around 5mm of thread holding the mount in place when fully tightened and to remove the plate (leaving tube rings + ADM on scope), the screws are popping out of the threaded section of the puck - an easy fix to replace the M8x45 screws that are present, but wondering if you (or any other readers!) have found this issue with the SW pucks?

Thanks to all with the advice offered previously, and to anyone else reading such posts, it again confirms that whilst Astronomy is expensive to start, buy big and buy once (until aperture fever kicks in!)!!!!

[fifeskies]

If I need to remove the Losmandy and Rings (to put my ED80 on instead for example) , I actually remove the anti slide out safety bolt at top or bottom of my Losmandy and just slide the Losmandy out, having already demounted the OTA.

That way you only need to loosen the clamp by a small amount, not fully unwind the star knobs, reduces puck thread wear.

[pete_81]

Thanks @fifeskies,
Unfortunately, I've tried the sliding idea (without removing the scope though) but with the few mm of 'engaged' thread, the adjustable side of the puck twists over once slightly loosened so that sliding the ADM out is quite tricky, any twist to the scope makes it virtually impossible, and it's been easier to just unscrew the star screws, and as they've come out (pretty sure no more than 5mm), the springs drop out and I accept I'll pick them up once getting the scope safely inside.

How much thread though do you think you have 'engaged' once tight - that is more my concern that there really isn't a lot of thread holding the full weight of the scope, and possibly more an issue when in AltAz mode which is how I'll likely be using the scope for the immediate future.

I just felt it odd that the Losmandy plates seem to be a standard size, as one would expect, with big names such as William Optics, ADM, Primaluce, but the SW puck needs opened to what feels the thread limit - did SW not think that the 'wings'(?) on Losmandy's are all the same (~74mm with taper to ~69mm) so make a puck that won't need to be opened too much??
I guess my concern is that there is so much force on the few mm at the end of travel of the puck - the screws really are on their limits of thread, even when engaged with the ADM which surprised me the first time the scope went onto the mount! Do you feel this is the case?