Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

Recommended Posts

I am just in the process of buying my first telescope. There’s so much information it’s making it very difficult what to choose! I have decided to buy a GoTo telescope but I can’t find any information which answers my query. Basically, can you use a GoTo telescope without using the computer part and use it as you would manual one? Any advice would be gratefully received!

Share this post


Link to post
Share on other sites

Yes. GoTo is not required to operate a mechanically driven telescope. You can operate it in a manual mode simply by disengaging the clutch locks and moving it to whatever area you want to view.

  • Like 1

Share this post


Link to post
Share on other sites

Yes, as Buzzard75 says, that is the beauty of a Go-To scope, you can use it manually to look at brighter objects, and use the onboard computer to find those faint and invisible targets for you.

I use mine in both modes during most of my viewing sessions.

Share this post


Link to post
Share on other sites

I've got the AZGTI with a 127 mak . Yes it can be moved manually but trying to track a target even at medium magnification is almost impossible without power to the mount.

Share this post


Link to post
Share on other sites

Not all goto mounts can be moved manually as many actually require power to then instruct the mount to move.

Edited by happy-kat
A t missing
  • Like 1

Share this post


Link to post
Share on other sites
6 hours ago, Buzzard75 said:

Yes. GoTo is not required to operate a mechanically driven telescope. You can operate it in a manual mode simply by disengaging the clutch locks and moving it to whatever area you want to view.

This is not universally true. You need to read the small print.  Some designs do not include clutches. As a guide, German equatorial mounts are likely to include a clutch.  "Freedom Find" mounts can be declutched and moved without losing the GoTo setting.   Other mounts, including the Celestron SLT and SE mounts cannot be moved at all except under power and there is little point in trying to use them without the GoTo alignment.

  • Like 3

Share this post


Link to post
Share on other sites

I'd agree, the synscan upgrade fitted to my EQ5 doesn't have clutches, so while you can release the axles and swing the scope around to be generally pointing where you want, fine motion adjust would have to be via the hand controller to drive the motors. Then you've lost alignment and the scope park/home position, GoTo wouldn't be useful again until you redo the star alignment. No idea if it'll R/A track if you use it that way, not tried it myself.

Share this post


Link to post
Share on other sites
17 hours ago, Cosmic Geoff said:

This is not universally true. You need to read the small print.  Some designs do not include clutches. As a guide, German equatorial mounts are likely to include a clutch.  "Freedom Find" mounts can be declutched and moved without losing the GoTo setting.   Other mounts, including the Celestron SLT and SE mounts cannot be moved at all except under power and there is little point in trying to use them without the GoTo alignment.

Point. I don't have experience with SLT or SE mounts. Wasn't aware they couldn't be moved manually and required power. I would then wonder if that's true of the majority of these types of mounts that just have the one connection on the side of the scope rather than using a dual fork such as the Meade ETX's. I am particularly familiar with EQ's, dobs and fork style mounts and have never seen one of those that couldn't be declutched and moved.

Share this post


Link to post
Share on other sites

It is worth pointing out to novices that even if the GoTo mount incorporates clutches, that does not mean that the mount is going to be very usable as an unpowered mount.  Generally no mechanical slow-motion is provided. The fork mount of the CPC800 for instance incorporates horizontal and vertical clutches, but the horizontal clutch has little practical use and the vertical clutch is useful for placing the OTA vertically for stowage at the end of a session. The OTA is not balanced. 

Share this post


Link to post
Share on other sites

Do your research on any mount before you buy. Try to get hands on experience or comments from someone who uses the mount.

Although things have improved, goto used to be 'go somewhere in the general direction of' unless you spent big money.

The sales literature often gives the impression of 1/ plant on ground 2/point and go 3/ enjoy the view. All done in seconds.

The reality can be:

1/  Plant on ground. Feet sink. Struggle to level. Try to point north.

2/  Power on. Set real time clock. Confuse US/UK date format. May need to enter latitude/long.

3/ Start mount align procedure using up to 3 stars. Some of which are not visible due to trees, walls, etc. Try different stars.

4/  Select an object to view. Scope slews. Nudge to centre and hopefully view.

If you spend more you can get a mount with GPS added. This enters time/date/location for you.
Or you buy a mount/handset that has a battery backed clock included.
If you have a permanent pier, levelling is done once when you build.

Please don't be put off goto. It can be very good. Just don't always believe the sales literature.

Hope this helps, David.

Edited by Carbon Brush
  • Like 2

Share this post


Link to post
Share on other sites

Have a look on you tube at the Astronomy and Nature demo of the Skywatcher Az GTI Mount as that type can be moved manually without losing position.

Share this post


Link to post
Share on other sites

Joined the forum then was away for some weeks. 2nd post now I think, taken me long enough:

Really seems a little pointless getting a goto and then using it manually. They were not designed for such usage. They can or some can be used manually, however it seems like making life a little difficult for oneself. Even in Manual the interpretation of Manual is you use the motors and bits to slew to a target. Scanning around the sky with one, as people will do with binoculars for example, is not really a feasible idea or action. And if you decide that you want to view say Jupiter, then M51, Globular in Hercules, just make life easy and use the goto.

Where about are you, locating a club and collecting information and just seeing the equipment in action is usually a worthwhile idea.

Was there also any particular goto that you were thinking of?

I use a Skywatcher Az GTi and a 72mm ED on it. With Skysafari and with the Wifi it functions as a nice easy to use set of equipment. An aspect of observing often forgotten. The 2 saying are "Aperture is king" and also "Your best scope is the one you use the most".

The AZ GTi and 72ED fall into the last catagory for myself. Little option really as they are my only ones.

Share this post


Link to post
Share on other sites
1 hour ago, PEMS said:

Really seems a little pointless getting a goto and then using it manually. They were not designed for such usage. They can or some can be used manually, however it seems like making life a little difficult for oneself. Even in Manual the interpretation of Manual is you use the motors and bits to slew to a target. Scanning around the sky with one, as people will do with binoculars for example, is not really a feasible idea or action. And if you decide that you want to view say Jupiter, then M51, Globular in Hercules, just make life easy and use the goto.

Benefit of having a GoTo that you can move manually is that if you don't have power or you run out of power, you can still do some observing and you're not reliant on GoTo. Having one that you can't move manually means you're basically done for the night if you're out of power.

Edited by Buzzard75

Share this post


Link to post
Share on other sites

As mentioned in previous posts, you are looking for freedom find feature in a GoTo telescope. I have a 10 inch Dob GoTo, and it has the freedom find, you can manually move it and still it would track and slew to objects.

 

This page explains the freedom find feature:

http://skywatcheraustralia.com.au/knowledge-base/

 

Note that GoTo alignment is not straightforward and will require some time for reading the manuals to understand how to align it and make it work.

Share this post


Link to post
Share on other sites
10 hours ago, PlanetGazer said:

Note that GoTo alignment is not straightforward and will require some time for reading the manuals to understand how to align it and make it work.

GoTo alignment can be very simple once you have got used to how it works.  For instance, with a GPS-equipped mount:

Turn it on.

Wait a bit.

Aim telescope at named alignment star 1.

Align with star. (coarse and fine adjustment)

Let mount traverse to vicinity of alignment star 2

Align with star 2.

Job done!

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By Spider-Man
      Hi everyone,
      I'm looking to get a reasonably portable astrophotography set-up, using a 60-100mm refractor, with a suitable goto mount.  I spotted the Explore Scientifice exos2-gt with pmc-eight goto system, which looks like quite an elegant solution, and wondered if anybody in the forum owns this mount, and what they think of it's performance & usability?
    • By Andy_ZH
      Hello all,
       
      this is my first post at SGL, and it will be quite long. I am not native a English speaker, so please excuse any mistake.
       
      I have quite some plan with my telescope mount and its goto control, and I am looking for some feedback and comments. If somebody else did a similar project, please let me know. And please feel free and encouraged to make suggestions, ideas, critics, etc.
      The story in a few buzzwords: Raspberry Pi Zero → direct control of TMC2209 stepper drivers via the Pi's Uart serial interface to drive my telescope mount. I am writing a software (optionally: open source?) to control the mount. The language will NOT be C, as typically used for Microcontrollers (I know for instance OneStep)
      I am using Kotlin, which is a more advanced JVM language.
       
      I think this should be enough information to filter the readers who are interested in reading the rest of my post.
       
      Now the long and detailed story:
      My professional background: I am a physicist, and did a PhD in EE (Power Electronics). Later, I became software engineer. Besides being fascinated by Astronomy, I am a tinkerer (Reprap 3D printer, electronics, …). I did grind my first mirror (a 6'' Schiefspiegler) when I was 15 years old, and I built the cookbook CCD cameras in the 90's.
      After many years without a telescope (study time, relationship, ... ), I settled down with my family, and I started to get back to Astronomy.
      Recently, I did by a quite a massive second hand mount: the “Vixen New Atlux” from another other stargazer in Switzerland. My opinion is that the New Atlux' mechanical design is superb. It has (had...) internal wiring, the counterweight bar can be hidden in the mount for transport, good polar alignment screws, it has an excellent polar finder with a dimmable LED.
      But on the other hand the electronics: two weak servo motors in combination with the incredible Starbook 5.... Seigh... the starbook...(!) it is, well... the mount is just superb, and no more comments about the starbook game boy, which shall rest in peace at the garbage dump.
      I removed the servos and all electronics, and I put 2 stepper motors into the mount, which are coupled to the gear with a timed belt. My original plan was to put an Arduino into the mount in order to control the steppers. I have an old goto Celestron cg-5 with Starsense, and it would have been quite easy to mimic - with the Arduino as interface – the servos of the old cg-5 and translate the Starsense control signals to my New Atlux. I can write C, and there is even an open source project called OneStep, which uses a Microcontroller in a similar way as I do.
      But I don't like to write C code anymore. In the 3D printer community, people need to use real time electronics to control the printer steppers. Due to the real time requirement, C with a real time microcontroler (Arduino & similar) are the only option for 3D printers.
      Do we need real time for our telescope? No. We don't need to control a lot of Motor accelerations and high speed control. For the telescope, we need to set the Motors speed precisely, and we need to drive to any position in an accurate and controllable and slow way.
      Then, there are new stepper motor drivers available with as much as 256 microsteps. The TMC2209 stepper driver , which is very well know in the 3D printer community, is not vibrating at all. It runs just smoothly, also at very low speeds. I do drive my motor with 0.25 rpm (sideral speed). In case of a slew, I can accelerate to 1500x sideral speed, which also would allow me easily to track the ISS. Wonderful.
       
      The current status of my project is:
      The mount is equipped with the two new motors The TMC2209 drivers are connected to the Raspberry pi GPIO Interface, and I can control them via Software. Theoretically, I could attach up to 4 motors with a single Uart interface (1 wire protocol). For instance, a focuser or a filter wheel could be attached. I selected Kotlin as language. Java also would have been possible, but I think for a new project, Kotlin will lead to a much more readable code. The TMC drivers can be driven via a chip-internal clock signal. Different to what the 3D printer community is doing (they use the step / dir pins, and create every single microstep with the microcontoller), I can send a “speed” signal from the Raspi via UART to the 2209 chip, and it will execute this speed for me without any further action. The only time critical issue was that I need to precisely count the steps that the 2209 stepper drivers executed. This is done via a GPIO pin, receiving its index signal (a pulse for every 2209 fullstep). Here comes the pain with Linux (non real-time) and the Pi: For user programs, it is impossible to guarantee that every pulse from the stepper drivers will be registered. But I cannot afford to have a step count drift over time. The solution was that I wrote a Linux kernel module in C. I wrote that I don't want to write any C code. Well, a few lines for the kernel module were indeed necessary. I can live with that, having in mind that the rest will be written in Kotlin. The only task of the Kernel module is to count every registered step at the Pi's GPIO input pins. This kernel module output is then mapped to a character device file in /dev/ for every stepper. In Kernel space, it is possible to register and count interrupts without missing even any one of them. From a hardware point of view, this is indeed everything we I need. The project cost so far: 2x10€ for the stepper drivers, 2x10€ for the motors, 2x20€ for the tooth belts and pulley, 10€ Pi Zero plus some peripheral expenses: Micro SD card, USB charger, and 1200 € for the used Vixen new Atlux mount. And a lot of time.
      I have so many ideas on how to extend the ecosystem of my software, but these ideas are for the longer term (maybe years from now on):
      Multi-star alignment. The alignment should be able to be updated continuously during an observation night. With a set of stars, it should be possible to calculate the quality of the aligment points, and e.g. drop them if they are errorneous. PEC correction (should be easy on the Pi) End-Stop support The polar alignment routines of today's goto scopes are quite good. But what I would like to have is some audio-feedback when I move the alignment screws into the right direction. Possibility to pre-plan an observation night (e.g. the mount could tell you that the Jupiter moon shadow will be on Jupiter in a few minutes). Record the telescope movements during the night in order to be able to tag any picture. The TMC drivers have much more capability than what I am using currently. For instance, they could be current controlled for slews in order to set the stepper current exactly to the value that it needs without stalling. This saves a lot of energy. The TMC drivers have a feature called “Stall Guard”. This could be used instead of endstop switches (for 3D-printers, this is done frequently). Advanced options for tracking: siderial, solar, moon speed, ISS speed. Tracking in both axis (e.g. to compensate polar misalignments of atmospheric refraction) or just in right ascension. Commercial mounts do not allow much customization here. With slow slew speeds, 5V input via a USB-C cable is sufficient for the Pi + Motors. Usb-C and newer usb battery packs allow to output a higher voltage via USB. With an “USB-trigger”, the input voltage can be selected to my needs. Higher voltage allows higher slew speeds, but consumes more power. Autoguider support, or even better: simply connect a webcam via the Pi's USB connector and do the guiding on the Pi The Raspberry Pi touch screen could be used for telescope controlls Advanced German mount limits and meridian flip control (e.g. a warning about a necessary flip when driving to a specific goto target). An Android App, connected via WiFi to the Pi could be used as display alternative Language control (have a look at Mycroft, an open-source artificial intelligence). "Hey mount, please slew to the whirlpool galaxy!" Control the mount via SkySafari and Stellarium The Pi has a built in camera interface. How about an open source auto align? The Pi could look at the stars to align itself, which makes a lot of sense. I did already order a long focal length lens and monochrome camera from Arducam in order to do some experiments (the standard Pi camera has 3.5 mm focal length and is not really usable, although star imagining is possible). My first observation site is my balcony. And there, the real Starsense does not work at all. It always spin-loops on 2 alignment positions where the sky is covered by the roof – how silly is that?. This can be done better. Further, Starsense is doing only a initial alignment. It should update its position and accuracy over the time! I think I could do this better.  
      Besides all my ideas, the first and most important focus of the software will be:
      Readability (therefore my choice of Kotlin), extensibility and open source. I like to have the Maths of the internal mount model clearly visible and understandable in the software. The calculations that are done within all our goto mounts are no rocket science. I admit, I am the nerd guy who wants to go the hard way and implement this from scratch.
      I am looking for a good project name, do you have any suggestions? How about QuickStep? this is possibly too close to OneStep and would offend the creators of OneStep?
      Does anyone of you have interest in joining my plan? Doing such a project in a small group would be more encouraging then just doing it for myself. And of course later on, I would appreciate if other stargazers would update their old mounts with my software.
       
      Any comments on my project plan are welcome!
       
      Clear Skies!
      Andy
       

    • By Davehux
      *NOW SOLD*
      I've just blown all my pocket money on a Rowan belted HEQ5 Pro, so it's time to move on my trusty EQ5 GOTO, before my wife spots 2 tripods in my shed 😉
      I'm sure everyone knows these mounts, but just to say that it's in full working order, with just the usual wear marks here and there, and a few marker pen lines for Home and counterweight positions.
      Comes with 12V power lead and car cigarette plug, and sync lead with USB adapter to let you upgrade the firmware on the Synscan handset. It's currently at 4.39.05, which was the latest version a couple of months ago. There are 2 x 5kg counterweights as well.
      I still have the boxes for my HEQ5, so I can courier it within mainland UK included in the price. If you live elsewhere, we can work out a price.
      Yours for a sensible £350 - a new one will cost you around £575 from most of the usual retailers. Paypal Gift or Bank Transfer most welcome
      Thanks for looking
       
       





    • By David Ettie
      Anyone out there replaced the Motherboard on an Orion GoTO truss tobe Dobsonian, our Societys 16" started giving error messages stating it could not connect to either axis, we ordered and replaced the Motherboard which promptly "burnt" out, we are seeking a repair (believe this is basically a re-branded Skywatcher) any advise or help greatly appreciated.
    • By Ceebee58
      Newbie , bought a skywatcher Capricorn ( around £100) but still unopened as I have some unexpected money and wonder what to do .
      options I see are ; 
      Use the Capricorn and get to know the sky and how to align the eq mount. Move on if I get the bug , maybe get a couple of better eyepieces.
      Return for refund and choose one of;
      Use my approx £350 budget to get a 90+ aperture scope .
      Blow the budget on an entry level GOTO scope , don’t bother learning stuff but just observe.
      What would you do ? To be honest I think the learning thing is part of the fun but GOTO scopes seem to be the ‘in’ thong
       
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.