What's a good mount to replace a Tak NJP?

[gregbradley]

I have been using a Tak NJP mount for several years now. It is a great mount. But my TEC180fl is pushing its weight limits to the max.

So I am looking to upgrade it. Not straight away but in the not too distant future.

What is a high end mount that could handle a TEC180 (the NJP can but its a bit undermounted for that scope)?

The obvious brands are AP (AP1200), Bisque (they are bringing out a mini ME).

I wonder how the ASA and other unique mounts are coming along.

Greg.

[renormalised]

Mini ME...sound like Austin Powers:):P

Anyway...have you had a look at the Chronos (http://www.chronosmount.com/) mounts. They're not cheap, but they'd be an excellent choice, I think.

Or have you looked at these Parallax GEMS (http://www.parallaxinstruments.com/mount.htm)

[Zaps]

How about the EM-400 or EM-500? :)

[gregbradley]

I like Tak mounts but an EM400 is really only a slightly beefed up NJP.
EM500 are quite expensive.

Also I want to use PEC and Tak mounts don't allow that so whatever PE they have thats what you get. Their native PE is quite low though. The beauty of them of course is ease of use.

I don't know that Tak has a mount in the same class as Paramount or AP1200.

Greg.

[RB]

Agreed Greg.

The EM400 is a wonderful mount, straightforward to use, excellent performance but for your payloads it just not enough.
I was tempted by the EM500 but it's a bit too big for my needs.

The AP1200 would be wonderful.

[gregbradley]

The Chronos sounds good but US$25,000 plus shipping plus GST is around 2 or 3 2nd hand Paramount MEs or more.

Greg.

[gregbradley]

The TEC180 with cameras, lets see, the OTA is about 30lbs and the camera 10 and the filter wheel, autoguider and guide scope is another 8 pounds, the rings about 12lbs and the dovetails about another 6lbs. So what's that - about 41kgs? I think the NJP was rated to about 25kgs and it obviously can handle greater than its conservative rating. But I want super round stars everytime without having to have everything exactly perfect to get there. Perhaps unrealistic. I'll see how the PME goes in the next few days.

Greg.

[Zaps]

Those Takahashi mounts are superb, but I guess they're not for everyone. That craftsmanship with its simplicity of quality always appeals to me.

The other extreme is the ASA DDM mounts. Also superb, apparently, but they take it to another level. The learning curve seems to be steep, and in fact they are possibly more suited to (semi-)professional astronomers.

[renormalised]

Tak does have a mount that is actually considerably larger than either a PME or AP1200, the EM3500, but it's very expensive and is designed to carry 1000lb.

They use it for their monster APO's and other scopes.

[bert]

Greg,

If you want perfect stars everytime, Personally I would be looking into adaptive optics, you are half way there with your purchase of the sx lodestar to go with the starlight ao system. Cheaper than a new mount too.

Brett

[gregbradley]

Yes that would work with the Microline 8300 but not the Proline 16803 which requires a larger opening. I believe the SX AO has a smaller opening like 2 inches which is too small for these large chips. Or at least so I am told.

Greg.

[multiweb]

The SXV-AO Large format is 80mm ID. That should fit your sensor.

[gregbradley]

Ooh I didn't know they did a large format. That's good to know.
I'll check it out.

Cheers,

Greg.

[ericwbenson]

No, the SXV-AO-LF has a 60mm optic. The actual clear aperture is even less (~2-3mm?) due to the mounting ring. The SBIG AOL is a little bigger at ~65mm aperture. Looking at the attached CAD diagram both are marginal with 16803/9000 chips. The yellow circle inside the 52.1mm chip diagonal is the projected 57mm aperture, 75 mm from the chip with a f/6.8 light cone. If you plan to crop (or deal with severe vignetting) it might be OK, but only a quarter of the guide chip will be fully illuminated.

EB

[multiweb]

:doh: You're right. 60mm and you'd get the shadow of the pickup prism.

[gregbradley]

That's what I thought - its too small for large chipped cameras.

But its good they have made one. They are bound to make a larger version once the demand for this one is satisfied and its a winner for them.

Greg.

[Paul Haese]

Well I have been really happy with my EM400. Not sure of the payload I have on it at present but it can and does produce lovely stars.

That said, it does have some down sides and I am looking for a much larger mount which has a home position. It may yet take several years to find what I want, but for now the EM400 is doing great.

[wysiwyg]

Greg,

PME! No questions asked! :thumbsup:

Planewave also make a nice mount, roughly the same price as a new PME but can handle bigger payloads 125kg almost double of the PME. The High Res encoder version is about $18.5K.:eyepop:

Cheers
Mark

[gregbradley]

EM400 seems good. I think it is much the same as the NJP only a bit beefier but perhaps Tak also upgraded other aspects of it.

Tak mounts are definitely good and user friendly. I keep hearing the PME is in a whole different league. I will find out in the next few days. Its certainly a much larger and beefier looking unit.

[Paul Haese]

Greg you are right the PME is another ball game altogether. You can buy good second hand ones on astromart but getting it here can be a hassle. The PME has many superior functions over the Tak or other mounts, but it depends on your budget and what you are looking to acheive.

If I had the choice without cost considerations I know I would have a PME, however the Tak has been a great unit.

[wysiwyg]

Greg,

When going through the process myself the two major factors I was looking for was Precision and Setup time. The goal for me was to reduce what I called "stuffing around" time and increase imaging time, regardless whether it was a permanent setup or portable.

With the PME its really flicking one switch and off you go when in a permanent setup. In the field its slightly more than that but IMO still considerably less hassle than any mount I have seen or used.

The PME may look chunky but its actually very light considering its size.

I'm sure once you got yours up and running you will quickly realise its benefits.

Every mount has its flaws, there is no such thing as a perfect mount, but when looking from a precision and setup time perspective its second to none IMO.

Good Luck!

[Zaps]

Takahashi wners would disagree with you, I'm sure. The Tak mounts are natively very precise and some of the easiest and fastest of all to set up. In my opinion.

;)

[rally]

Zaps,

As a Takahashi mount owner - EM200 and NJP, I can say that compared to a P-ME and other higher end mounts they really are quite primitive when it comes to automation and computer control.

The Takahashi mounts are mechanically excellent if maintained, that is something that most Tak owners would agree with.

But . . . .
they have no home position and/or no absolute position positioning in their encoders, so its virtually impossible to setup an automated remote control system.
I once asked on the Tak Users Group if anyone had done so - years later my post still remains unanswered.

Even an EQ6 can be setup with Periodic Error Correction - you can't do this on a Tak with Temma ! (at this point).

The Temma only reports its position to a low resolution so using say TheSky6 at high mag - its jumpy - because the software does not know where the Mount actually is to a high degree of accuracy.

In all but the very, very latest Temmas with new Hand Controllers, if you are in the Southern Hemisphere you need to hold those two "magic" keys down on the hand controller at bootup in order for RA to rotate in the right direction ! - this is a disaster if you have any momentary power glitches and necessitates a human at the helm.
I cannot understand in this day and age how Tak thinks this particular process is acceptable.

Any Pointing model you create is hard to make permanent because of the lack of absolute encoding - which means you have to manually sync the mount at every session.

When you consider that an EM400 is only slightly less expensive that the the price of a P-ME you can see why people would buy a P-ME instead for astrophotography and observatory control.

You can set up a P-ME in the field with the right pier very rapidly - it can be done to an extremely high degree of accuracy and with a pointing model you can have a Polar Alignment accurate into the arc seconds range within 10 minutes of having the equipment assembled.

The degree of integration that comes with the available software is another reason that makes the P-ME so much better.
A long story could be written about this alone.

Like anything there are pros and cons and the cost is high, TheSky6 (supplied) must be used to control it no matter if you use ASCOM or not.

But back to the OP's thread "Replacing his NJP" - an EM400 is basically just the updated version of the NJP - same controller, slightly different mechanical arrangement - there is barely any net gain so I couldn't see any benefit.
Certainly a retrograde step considering Greg already has a P-ME
for his other OTA's.

Cheers

Rally

[netwolf]

If the Tak uses Servo motors would it be possibly I wonder to retrofit it to be controlled by the Sitech controller or any other Servo controller like SS2K etc.

Regards
Fahim

[wysiwyg]

Anything is possible, but the question remains at what cost and effort?
By the time you add the cost of these mods and assume you get it working, then why not get a PME. It would probably be way cheaper and you will be given an out of the box solution from the get go!

Mark

[gregbradley]

Thanks for the replies.

It seems the PME is the clear favourite still. I got my permanent pier bolted to its concrete pier today and packed it with cement under it so it was level.

The PME is surprisingly light. Its about 35kgs or so and not that much heavier than the NJP which surprised me. It is physically quite a bit bigger.

I intend still using my NJP for now and probably will later install it at my dark site observatory for when I go down there. Skies there are still superior to where I live.

If you use the Chick Faranda Temma driver you can park the Tak mounts and the next night it is still synched and ready to go at the flick of a switch.

But I agree no PEC is probably its biggest drawback and also the holding down the S1 key at bootup to set it to Southern Hemisphere smacks of those complicated Japanese clocks where you had to hold down lots of keys to access various functions. A bit of hangover from earlier Japanese manufacturing there.

Thanks for the inputs.

Greg.

[ausastronomer]

Hi Greg,

I am not an imager hence don't know a lot about these mounts from an end user point of view. However, I know a couple of guys in the USA who use larger refractors on the Mountain Instruments MI-500 mount and are very happy with its performance. I believe the larger Mountain Instruments Mounts are now made by Mathis Instruments. Just wondering if there is a reason why one of these mounts has not been mentioned by anyone, as they have the load capacity and cost a bit less than some of the other mounts in this load capacity range.

http://www.mathis-instruments.com/specs.html

Cheers,
John B

[wysiwyg]

If you want to use the mount remotely though you have to add $4400 to the price of the MI-500 + $250 power supply + Scope Adapter plate $800. The only upside is Weight Capacity, 50kg more than PME.
So now your looking at a mount worth over $17K US.

PME has all that for $14.5K US, its still a cheaper option.