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Giro-2 Deluxe and Tech2000 Driver



In thinking through what I wanted in a mount, I came up with 3 criteria which are the most important to me. These criteria are;

  1. Tracking: polar alignment is difficult, if not impossible, at the small window of my home, so equatorial mount is out of question. Common GOTO alt-az scope
    relys on two stars alignment, but its accuracy will suffer for two near-by stars which is only possible for a small window. The philosophy of Tech2000 Dob Drive sounds a reasonable solution: you track yourself manually at first and the drive takes over after a small period of time.
  2. Light weight, high capacity: GEM with reasonable load will be heavy; common alt-az mount is not good enough. The Germany Tele-optics Giro 2 Deluxe sounds a right candidate.
  3. More light but cheaper price: 8" SCT! What else?!

Giro-2 Deluxe (GR2-DX)

In searching for a suitable mount for my telescope@home project, somehow, I've to limit myself to alt-az mount for the movement of a GEM is always too complicated and require too many spaces. After some research, I take the plunge and order the GR2-DX alt-az mount from APM Germany (Markus Ludes).

Ordering the mount

The mount is available from a number of dealers on the internet. And among those dealers, Markus Ludes of APM gives the fastest and most useful response. Taking the exchange rate and also the shipping cost into consideration, ordering from APM Germany is the cheapest. I asked all the questions I wanted to ask and get them all solved within two days. I placed an order on 2002-2-28 and got the mount in less than one week on 2002-3-9. BUT...

Next time when you order anything if you're in Hong Kong, please try to ask if they can use DHL/Fedex/UPS or something alike instead of through the local postal services, since it will NOT deliver the parcel to your home and you will need to go to the central post office to fetch it. You paid a lot of shipping, but you will also need to travel and move the bulk yourself.

The services from Markus Ludes are quick and efficient. The packaging is average, cannot be classified as good, but it protects the stuff well enough. What is in the package;

Basically, the GR-2 DX mount does not come with anything except the mount head and a single arm. Not even a printed manual. I ordered the counter weight shaft (compatible with Vixen counter weight BUT NOT the counter weight shaft for the threads are different), a Vixen quick release dovetail clamp and also a dovetail rail of Vixen (adapted from Intes rail).

The head itself is a real bargain for its capacity. But be prepared to pay more for the adapters. In my case, the adapters, the counter weight shaft with shipping, approach to the price of the mount head itself. No manual is not a problem, for it is so trivial. But of course, you will want some instruction or written warranty or something printed, (or even a catalog!) when you buy a piece of equipment.

If I were asked to write the manual, I would just write a single word:- "Balance". That does not mean without exact balance that the mount would not work, but instead, it works even with a rather high degree of imbalance, you just need to lock the screw/knob tighter. What I mean is that, with proper balance, you will get a butter smooth mount. An ideal situation I mentioned below. I did not forget my Ranger, an Intes/Vixen dovetail plate is ordered for it.

First Impression

It's cloudy when I first receive it. I panned around in day light using up to 266x with my Tele Vue Ranger, it moves super smoothly and nicely! Much better feeling than my Bogen 410 head. I believe I can star-hop much better than before. The motion is familiar to me. It's nearly as smooth as the focuser of my Tele Vue Ranger!!! Hey, I told myself, this is my dream mount, and this is my dream mount in real life! I dare to try it on stars asap, I dare to try it on dark sky!!!

The feeling is simple: you have your telescope floating on the air, and you can move it freely as if an invisible hand is holding it for you! A new definition of ideal mount comes to my mind: the mount is something holding the telescope for you but NOT something restricting your freedom. The GR2-DX is such mount in action.

Tech2000 will send me an instruction manual of the GiroDrive, once I found it manageable to be installed by myself, I will get one. This super mount deserves a well designed motor drive. I just can't imagine how good it is when I saw this mount tracks!!!! I guess the mount head is around 5-6lb, a little bit heavy but considering its rated capacity, it is real light.

I ordered a Celestron C8 OTA immediately after testing this mount.

Meeting the C8 OTA

On Saturday I got the GR2-DX mount, on the same day, I ordered a C8 OTA immedately. I packed the mount, my old small tripod (Gitzo G106) and go to the local Celestron dealer on Sunday afternoon. The Gitzo is rated at 5-6 kg only. The GR2-DX mount head alone pushed it to the limit. So, I was prepared to be laughed.

I'm not sure whether my GR2-DX is the first one in Hong Kong, but I think so. The dealer was surprised to see this interesting mount, however, he found it a bit too expensive since at that price, we can get a CG5 already. Anyway...

The counter weight shaft is compatible with the counter weight from Vixen GP and thus that of the CG5. I borrowed one from a CG5 to the mount and attached it to the GR2-DX. A very good fit. I supposed the weight is around 10 lb. Now the tripod is operating at twice its rated capacity.

I soon realized that the counter weight is NOT required for proper operation of the mount. The counter weight is just to prevent the tripod from tipping over. Mounting the C8 OTA to the tripod, then the tripod is operating at over 3 times its rated capacity. It seems alright.

The dealer was impressed by how smooth the mount was. We balanced the OTA roughly, and a moderate push on the OTA caused it to rotate along the alt axis nearly three complete rotation! We were both impressed. Very smooth motion.

Anyway, I wanted to test the optics. I bought two accessories with me, the Tele Vue 8-24mm zoom and also the Tele Vue 5x Powermate. Am I crazy?! At 24mm, the OTA was operating at 83x. The view was sharp and clear, despite the sun was set and the transparency was low. Hey, that's aperture. To my surprise, the view was very stable despite the tripod was seriously overloaded.

I set the zoom to 8mm, the OTA was now at 250x. The view was again as sharp and as clear. 250x was not pushing the OTA with 8" aperture. However, the tripod was the weakest link here, and I had to wait for 5s+ for the view to settle down from vibration. Yes, I surely need a bigger tripod, but for larger DSOs, the poor little tripod can do the job. Even at 250x, the mount served me nicely and I could move around easily and freely. What a good mount!

BTW, the color of the C8 OTA has been changed from black to dark gray. On testing it under star (when I back home) shown that it's well collimated, and also, no image shift at all. I shall test more later.

Star Testing the C8 with Giro Mount

First target was M42, the trapezium stars were shown very nicely. I didn't find SCT to be inferior than a refractor here. It resolves very very nicely, very sharp and high contrast. The shape of the nebula was shown nicely despite the serious light pollution.

Second target was Saturn, even at 62x, the image was shaky and also the seeing was extremely bad. Plugging in the ToUCam revealed a very ugly ill formed image. Really need to upgrade tripod before anything else.

Finally, tried to push to high power on the Sirius to test collimation and also image shift. A 18mm Ortho with 5x Powermate were used. It yield 556x. Perfect collimation and no image shift.

C8 on the Giro/Manfrotto 074

The tripod was borrowed from a local amateur, and we exchanged our tripod to play for sometime. The tripod weights 3.7kg and rated for 8kg. The tripod was set with one leg on the bed with a large wooden board, and two other legs on the floor, extended to compensate the height difference.

Defocused image showed that the aperture was blocked due to the size of the window and the position of the Jupiter, around 70-80% aperture was used only. However, jupiter showed very nice detail despite the foggy weather and blocked aperture. At around 250x, the shadow of a satellite (later confirmed to be IO) was clearly seen.

The Manfrotto 074 was stable enough for a C8, shaking due to focusing could be damp out within two seconds. Not bad. Mount was the GR2-DX, very steady and easy to use, if the balance was better, it could even be better. I had no counter weight yet. Easier to use than the Manfrotto 410 geared head. At 250x, it was still very smooth. I wanted to buy a second arm for it right now, since I would want to use my Ranger there instead of a dead counter weight.

What was so nice about this setup was that, it can be setup within 3 minutes. And it weights only ~25 lb... Of course, much heavier than my Ranger setup at around 9lb only... But considering the weight and aperture, it was still nice! Even comparable with a 8" truss tube dobsonian.

Searching for a tripod

Candidates:

  • Manfrotto 074: 3.7kg, rated for 8kg ~$1100 (HKD)
  • Manfrotto 075: 4.3kg, rated for 12kg ~$1400 (HKD)
  • Gitzo 1345: 2.7kg, rated for 10kg, ~$1950 (HKD)
  • Gitzo 1415: 3.1kg, rated for 12kg, ~$??? (HKD)

Criteria:

  • Light weight
  • Heavy weight, enough not to tip over without a counter weight
  • Strong enough
  • Not shorter than 110cm when extended without center column
  • Shorter than 70mm when retracted

Tech2000 GiroDrive for the Giro Mount 2002-03-28

I placed an order of the GiroDrive from Tech2000 on 22 March 2002 and it was delivered to Hong Kong on 27 March 2002. I got it from the Post Office on 28 March 2002. The Post Office for insured parcel is open from 8:00a to 6:00p and so I could get it even I have to work. Using UPS will double the shipping cost without significant speedup, just one more tracking number and delivery to home.

Scanning through the package, I found the items were packed nicely. a little bit better than the Giro mount from APM Germany. Unluckily, the cable for the Roboscope PC option was missing. I emailed them and I am now waiting for their reply.

The drive unit looks very nice, also the hand controller (pendant). The PC link slot and the CCD link slot will only be available if you ordered the respective options.

I have finished all the installation and testing within 30 minutes as the manual suggested. I am a handicraft and mechanical idiot and so the installation is really really easy to an average person.

My transformer originally purchased for testing the Nexstar 5 work perfectly with the GiroDrive. It is voltage regulated. The GiroDrive is internally protected for reversed polarity.

At first, only azimuth drive moves but the altitude drive does not move at all. Both drives do move, but just the altitude one failes to move the belt and the mount head. I checked the alignment of the pully and the motor drive. Seems alright. What's wrong then?

Hey, I remembered that there're still a small plastic part which I still didn't touch. Since I read the installation instruction before I ordered the drive, and the instruction did mention this part. So, I didn't realize its importance. A printed appendix on an A4 paper is found inside the plastic bag, I read it carefully. The appendix solves my problem nicely. It gives extra thickness to the belt guide on the altitude belt. After the installation of this little part, the drive work perfectly.

I tried the new drive on some distance terrestial object. The pendant gives immediate response on all button pressed. The problem of backlash seems much less than that in the Nexstar 5 which I had evaluated earlier. I also love the feeling of the key press on the GiroDrive pendant more than the Nexstar hand controller.

The panning speed of the drive is not fast, but it is not too slow either. Anyway, I can always disengage the clutch and move the scope manually at super fast speed given the smoothness of the Giro mount.

Too little time between gaps of clouds to try out its tracking ability. I shall take some more time to set backlash values so as to make it perfect.

One draw back I realized is that, after the installation of the GiroDrive, the altitude motions become less smooth than before even with the altitude clutch is disengaged. I guess I've to remove the altitude belt guide in order to restore the smoothness. The azimuth motion remains super smooth. But still, after attaching the Ranger to the mount, I can make it rotate twice on the axis with a push. Not bad, just not perfect. (I was wrong, later I tried it under stars, it is at last as smooth as before!)

Tunning the GiroDrive 2002-03-31

To optimize the performance of the GiroDrive, I spent sometime in day light to tune the backlash and max speed of the GiroDrive. The max speed setting is simple, it determines what is the highest speed that the drive can go without erratic behaviour. The drive moves smoothly from low speed, and when it approaches its limit, it will move strangely and if we go further, it will eventually stop. We can set the limit for the drives before it goes erractic, and the instruction manual of the GiroDrive has perfect description on that.

To tune the blacklash, we need more complex steps. First, we need some stationary distant objects. The manual say we need stars near the Polaris, but personally, I found distant terrestial objects suffice. You need high power to detect the first moment. You don't have to worry about your reaction time, since the pandent will take care of it. Just try as many time as you can, and get the best value. After several training at day light, my drive can track the Sirius nicely at 300x for many minutes during the first test between clouds.

Tracking and panning motion is smooth for the alt-axis, but it is still not so smooth for the azi-axis, I shall spend some more time to tune the backlash for this axis. It is good already, but I think it could be even better.

It will show the alt-az values when it tracks. I tried to track Jupiter, and as my experience during manual tracking told me, only one axis is enough for a particular time outside my room window. Yes, the values do show 0.0 for a particular axis, haha. Hey, I suppose it is not absolute zero, but must be some small value. What an interesting mount!

First Night trying to do imaging 2002-04-01

Why I bought the light bucket setup?

  • I have chance to look through bigger scopes (5", 14")!
  • I suspect the number of DSOs which can be found with my 70mm is near the limit in the light polluted sky here; or at least I need something which can make those dim fuzzy easier for me.
  • I want to get better images of the planets with my webcam at home, that means, I need: a BIGGER scope, a TRACKING mount.

For the last reason, I tried to find the planets from my home window and see if I can do some imaging here like what I've done with my 70mm on a camera tripod without tracking. Finding target is much easier to do with the clutch disengaged and move the OTA manually. Sweeping the sky using the GR2-DX is a pleasant experience. It is as smooth as before the installation of the GiroDrive.

After finding the target, engaging the clutch will move the target quite a bit. It would be nice to keep looking at the eyepiece when engaging the drive so that you know which direction to pan to get back to the target.

Panning using the GiroDrive is as smooth as by manual tracking. Tapping the directional button provide motion precise enough for locating objects in a wider field eyepiece. When using high power (200x+), pan mode is simply a bit too coarse.

Tracking using the GiroDrive is a nice experience as well. Despite the manual said (and also by common sense), centering of the object should not be done in tracking mode or else, it will upset the vector learned by the drive. However, I found it not a major problem in long run. In some sense, tracking is to keep the object at the center, that is, a centering operation. Initial brief centering will have its effect diluted after some minutes.

Tracking for visual use is easy. Only after one minute or so, you will have the object remained at the center area for over ten minutes, which is good enough for sharing quick views with buddies.

Tracking for imaging use is not easy. Centering is difficult as well. When an object is in reasonable center of the FOV at 200x, plugging in the webcam is likely to have it at the edge of the CCD chip. I have a self-made double cross hair eyepiece (made from binocular eyepiece) and it did help here. Since the size of the CCD chip is small, I've to fine tune the tracking vector a lot to keep the target in the field of the CCD chip for 2 minutes or so. I have to keep my hand on the pandent like before, but now, it won't shake the whole setup, i.e. all the frames captured during adjustment, can be used for stacking.

I didn't try the guide mode, I suppose it helps here as well. The clear time these days are too little, not much time to clearly test everything.

Fine tunning the tracking information using a webcam is interesting. You look at the image floating on your computer screen and you make adjustment to counter the drift over time. It would be nice to reset your idea of "up" "down" "left" "right" about the buttons, with different type of telescope, refractors, SCT, and different diagonal, you better re-learn which is which orientations.

Inserting a 2x barlow make the whole thing even more difficult. But all we need are patience which is need anyway for good photos. At 1/25s, field rotation is negligible. Also, if I use only exposures within one single minutes for stacking, field rotation is negligible as well.

Since I'm now working with f/10 or f/20 instead of f/33+ like I used the Ranger before, the noise level is greatly reduced. The Cassini division, the shading change along the globe of the Saturn is very easy on the computer monitor, they're very subtle before even after stacking. More than three belts on the Jupiter can be seen on the computer screen during moments of better seeing are EASY. It is APERTURE.

Preliminary result is frustrating after some processing. The seeing has not been good, also the focusing is not as accurate as it should have been. My 70mm refractor shots on a fixed camera tripod exceed the performance of this new setup. I think I need some more time to train myself, just like what I did with my small fixed gears.

I need a stronger tripod to do focusing better. It simply shakes more than desired when focusing, making it not as accurate as it could be. Clear time is also a limiting factor here. Anyway, I could have done better, since it's already much better than my hand tracked setup before. I begin to think about electronic focusing... bad... I shall try more before pouring money again.

Last time I mentioned that the image formed by the C8 on my feather light Gitzo G106 tripod was ugly, this time, I see the same problem with the much larger Manfrotto 074. Later, I found that the ugly image was due to focusing accuracy. Previously I concluded that the bad image was a result of high frequency shaking of the tripod. However, now I know that it was a result of the out focus image of an SCT, it is quite different from the one with a refractor. I fined tuned the focus position a bit and the problem goes away immediately, I got a clear sharp photo. Cassini division is super easy after a slightly better focusing action.

Saturn was hidden by cloud so that I couldn't image it before the tracking is done. i took some Jupiter, but as said, they were no good, at least not as good as my best 70mm refractor shots. Anyway, seems like a promising setup.

Some notes from Tech2000

I've continuously communicate with Tech2000 to get the best out of the GiroDrive. The people there provides absolutely best services by answering all the questions and giving very useful advices, here are some of them:

You mentioned tracking Jupiter with one axis reading 0. Yes, the alt axis will show 0 if the planet is on the meridian or close to it. Yes also, the driver can show zero but still be moving very very slowly - too small a number to bother resolving on the display. All 480 trillion speeds are not displayed - only to the nearest .1 steps/Second.

My concern is that you may have the Pendant configured for Eq mountings. In that case the Dec axis is always zero unless you press buttons to guide or adjust the Dec position (or autoguider). While hopping around in experiments with modes, new users sometimes jump into Config mode on the Pendant and errantly press the Sel (up) button. This configures the mount for Equatorial! If this happened to you, the display will illuminate Eq and Dec led indicators on the left instead of Alt and Az indicators on the right. You will need to go into Config mode to change back to altaz. This can also explain some non-perfect behaviors in the backlash or panning/tracking smoothness since the software handles Eq mounts differently for very good technical reasons. It should start moves smooth and slow like hot butter! Especially in Guide mode which is very good at high powers.

Another tip. The tighter feeling you experience for manual altitude movement, after mounting the GiroDrive, is from the pulley grove. We specify it tight (zero belt slop) for firm grip on very long refractors (which are always easy to move by hand with such a long lever arm). This will seat itself in over some months of initial use and you will notice a smoother and softer behavior for your short tube, again like Giro2 without the drive. Leave the altitude arm clamp just a little bit looser on top of the Giro head to compensate during belt break-in period.

*** If Pan mode too coarse at high powers - use Track mode for more gentle centering (center then exit Track then enter Track again). Otherwise you may set the Pan maxspeed lower to produce lower coarse movement at high power.

*** Engaging clutch shifts target - use hand control only, after target is first aquired.

*** You have used Track mode for imaging. Track mode cannot be used for imaging! Use the Guide mode, but only after Track mode has the close tracking data. In astrophotography everyone should know - when the object has good tracking... touch nothing to change the instrument, only do the guiding!

Short observation with my friends at home

I've some observing buddies who usually go backpacking and camping with me BEFORE my baby was born. Last time they go camping without me, they didn't even take the binoculars. They enjoy the sky like me but they don't have anything other than binoculars.

When they heard that I bought a larger telescope, they're surely interested. They came to my home one night, there were some cloud that night. We could only observe from my little room window.

We waited for the Saturn and Jupiter to come across my window at better angle. Hey, it's not easy to track with the GiroDrive when cloud moved in occassionally before the drive learns a good trajectory. But it was good enough to share the views with my friends over 200x which was a pain with the hand tracking system before.

The Manfrotto 074 was not up to the job. It was stable enough if we didn't touch the telescope at all. But if I need better focusing, it would be just easier than impossible.

The tripod was the first suspect for the serious shake, but maybe there were some other reasons like imbalance in azimuth axis (I'm still waiting for the custom made counter weight). For the tripod, I will go for a Gitzo rated for 12kg rather than this Manfrotto rated for 8kg only. The owner of the Manfrotto 074 continuously told me the little Gitzo G106 was very strong.

More notes: the backlash parameters seemed a little bit sensitive to the change of telescope. For my case, those parameters were trained using the Ranger but when it was used with the C8, backlash was more serious than it would be. Natural, but it seems that if the GiroDrive can provide several sets of backlash values, it would be nicer. Also, I found if more buttons are available, it would be easier to use. I found when switching between modes, I would sometime missed the SEL confirmation, let myself left in the "modeless" mode. The buttons were "overloaded" (OO programming term) a bit more than desired.

First Night trying to do imaging 2002-04-01

Why I bought the light bucket setup?

  1. I have chance to look through bigger scopes (5", 14")!
  2. I suspect the number of DSOs which can be found with my 70mm is near the limit in the light polluted sky here; or at least I need something which can make
    those dim fuzzy easier for me.
  3. I want to get better images of the planets with my webcam at home, that means, I need: a BIGGER scope, a TRACKING mount.

For the last reason, I tried to find the planets from my home window and see if I can do some imaging here like what I've done with my 70mm on a camera tripod without tracking.

Finding target is much easier to do with the clutch disengaged and move the OTA manually. Sweeping the sky using the GR2-DX is a pleasant experience. It is as smooth as before the installation of the GiroDrive.

After finding the target, engaging the clutch will move the target quite a bit. It would be nice to keep looking at the eyepiece when engaging the drive so that you know which direction to pan to get back to the target.

Panning using the GiroDrive is as smooth as by manual tracking. Tapping the directional button provide motion precise enough for locating objects in a wider field eyepiece. When using high power (200x+), pan mode is simply a bit too coarse.

Tracking using the GiroDrive is a nice experience as well. Despite the manual said (and also by common sense), centering of the object should not be done in tracking mode or else, it will upset the vector learned by the drive. However, I found it not a major problem in long run. In some sense, tracking *is* to keep the object at the center, that is, a centering operation. Initial brief centering will have its effect diluted after some minutes.

Tracking for visual use is easy. Only after one minute or so, you will have the object remained at the center area for over ten minutes, which is good enough for sharing quick views with buddies.

Tracking for imaging use is not easy. Centering is difficult as well. When an object is in reasonable center of the FOV at 200x, plugging in the webcam is likely to have it at the edge of the CCD chip. I have a self-made double cross hair eyepiece (made from binocular eyepiece) and it did help here. Since the size of the CCD chip is small, I've to fine tune the tracking vector a lot to keep the target in the field of the CCD chip for 2 minutes or so. I have to keep my hand on the pandent like before, but now, it won't shake the whole setup, i.e. all the frames captured during adjustment, can be used for stacking.

I didn't try the guide mode, I suppose it helps here as well. The clear time these days are too little, not much time to clearly test everything.

Fine tunning the tracking information using a webcam is interesting. You look at the image floating on your computer screen and you make adjustment to counter the drift over time. It would be nice to reset your idea of "up" "down" "left" "right" about the buttons, with different type of telescope, refractors, SCT, and different diagonal, you better re-learn which is which orientations.

Inserting a 2x barlow make the whole thing even more difficult. But all we need are patience which is need anyway for good photos. At 1/25s, field rotation is negligible. Also, if I use only exposures within one single minutes for stacking, field rotation is negligible as well.

Since I'm now working with f/10 or f/20 instead of f/33+ like I used the Ranger before, the noise level is greatly reduced. The Cassini division, the shading change along the globe of the Saturn is very easy on the computer monitor, they're very subtle before even after stacking. More than three belts on the Jupiter can be seen on the computer screen during moments of better seeing are EASY. It is APERTURE.

Preliminary result is frustrating after some processing. The seeing has not been good, also the focusing is not as accurate as it should have been. My 70mm refractor shots on a fixed camera tripod exceed the performance of this new setup. I think I need some more time to train myself, just like what I did with my small fixed gears.

I need a stronger tripod to do focusing better. It simply shakes more than desired when focusing, making it not as accurate as it could be. Clear time is also a limiting factor here. Anyway, I could have done better, since it's already much better than my hand tracked setup before. I begin to think about electronic focusing... bad... I shall try more before pouring money again.

Last time I mentioned that the image formed by the C8 on my feather light Gitzo G106 tripod was ugly, this time, I see the same problem with the much larger Manfrotto 074. Later, I found that the ugly image was due to focusing accuracy. Previously I concluded that the bad image was a result of high frequency shaking of the tripod. However, now I know that it was a result of the out focus image of an SCT, it is quite different from the one with a refractor. I fined tuned the focus position a bit and the problem goes away immediately, I got a clear sharp photo. Cassini division is super easy after a slightly better focusing action.

Saturn was hidden by cloud so that I couldn't image it before the tracking is done. i took some Jupiter, but as said, they were no good, at least not as good as my best 70mm refractor shots. Anyway, seems like a promising setup.

Added on 2002-4-7: Some notes from Tech2000

  • I've continuously communicate with Tech2000 to get the best out of the GiroDrive. The people there provides absolutely best services by answering all the questions and giving very useful advices, here are some of them:
  • You mentioned tracking Jupiter with one axis reading 0. Yes, the alt axis will show 0 if the planet is on the meridian or close to it. Yes also, the driver can show zero but still be moving very very slowly - too small a number to bother resolving on the display. All 480 trillion speeds are not displayed - only to the nearest .1 steps/Second.
  • My concern is that you may have the Pendant configured for Eq mountings. In that case the Dec axis is always zero unless you press buttons to guide or adjust the Dec position (or autoguider). While hopping around in experiments with modes, new users sometimes jump into Config mode on the Pendant and errantly press the Sel (up) button. This configures the mount for Equatorial! If this happened to you, the display will illuminate Eq and Dec led indicators on the left instead of Alt and Az indicators on the right. You will need to go into Config mode to change back to altaz. This can also explain some non-perfect behaviors in the backlash or panning/tracking smoothness since the software handles Eq mounts differently for very good technical reasons. It should start moves smooth and slow like hot butter! Especially in Guide mode which is very good at high powers.
  • Another tip. The tighter feeling you experience for manual altitude movement, after mounting the GiroDrive, is from the pulley grove. We specify it tight (zero belt slop) for firm grip on very long refractors (which are always easy to move by hand with such a long lever arm). This will seat itself in over some months of initial use and you will notice a smoother and softer behavior for your short tube, again like Giro2 without the drive. Leave the altitude arm clamp just a little bit looser on top of the Giro head to compensate during belt break-in period.
  • *** If Pan mode too coarse at high powers - use Track mode for more gentle centering (center then exit Track then enter Track again). Otherwise you may set the Pan maxspeed lower to produce lower coarse movement at high power.
  • *** Engaging clutch shifts target - use hand control only, after target is first aquired.
  • *** You have used Track mode for imaging. Track mode cannot be used for imaging! Use the Guide mode, but only after Track mode has the close tracking data. In astrophotography everyone should know - when the object has good tracking... touch nothing to change the instrument, only do the guiding!

Short observation with my friends at home

I've some observing buddies who usually go backpacking and camping with me BEFORE my baby was born. Last time they go camping without me, they didn't even take the binoculars. They enjoy the sky like me but they don't have anything other than binoculars.

When they heard that I bought a larger telescope, they're surely interested. They came to my home one night, there were some cloud that night. We could only observe from my little room window.

We waited for the Saturn and Jupiter to come across my window at better angle. Hey, it's not easy to track with the GiroDrive when cloud moved in occassionally before the drive learns a good trajectory. But it was good enough to share the views with my friends over 200x which was a pain with the hand tracking system before.

The Manfrotto 074 was not up to the job. It was stable enough if we didn't touch the telescope at all. But if I need better focusing, it would be just easier than impossible.

The tripod was the first suspect for the serious shake, but maybe there were some other reasons like imbalance in azimuth axis (I'm still waiting for the custom made counter weight). For the tripod, I will go for a Gitzo rated for 12kg rather than this Manfrotto rated for 8kg only. The owner of the Manfrotto 074 continuously told me the little Gitzo G106 was very strong.

More notes: the backlash parameters seemed a little bit sensitive to the change of telescope. For my case, those parameters were trained using the Ranger but when it was used with the C8, backlash was more serious than it would be. Natural, but it seems that if the GiroDrive can provide several sets of backlash values, it would be nicer. Also, I found if more buttons are available, it would be easier to use. I found when switching between modes, I would sometime missed the SEL confirmation, let myself left in the "modeless" mode. The buttons were "overloaded" (OO programming term) a bit more than desired.

Summary on the final setup

After consulting the people in the local photography newsgroup, I finally managed to find a dealer who can order a Gitzo G1415 for me. The Gitzo G1345 is really lighter and taller, but it is rated for 10kg only and it is only marginally acceptable for my setup. Yes, I'm confident that Gitzo can do well even exceed its rated capacity, but I want something better. So, I stayed with the Gitzo G1415 which is rated for 12kg. It is not tall at 118cm only, but it is more compact for travelling and it is stronger.

Here is a summary on the setup:

Components Usage Type Weight
Ranger + 410 + G106 Extreme portability, for hiking and camping 9 lb
Ranger + GR2-DX + G106 Highly portable, for hiking and camping, DSO searching 12 lb
Ranger + GR2-DX + G106 + GiroDrive Field imaging with highest portability 15 lb
Ranger + GR2-DX + G1415 + GiroDrive + Counter Weight Home imaging for objects in bad angle 21 lb
C8 + GR2-DX + G1415 Most portable setup for DSO hunting 25 lb
C8 + GR2-DX + G1415 + GiroDrive + Counter Weight Home imaging for objects in better angle 35 lb

The Gitzo G1415 is rated for 12kg, its weight is 3.1kg only. The useless central column is absent, thus saving weight. It is less than 60cm when retracted, so it is really compact. I will have to wait until mid-May to have it. Since even the local distributor does not have it. I just hope that it worths the wait.

The Roboscope PC Link Cable

I received the cable finally today (2002-4-11), and this time, it took much longer than the last time. I attached the Pendant to the PC using this cable and I tried to use the Roboscope software.

Previously, I felt sick when I learned that it is a DOS based software written in BASIC! But when I first tried it inside my home, it was not that bad actually. BASIC was my first programming language as well. So, I'm familar with the environment.

Maybe I shall re-write it for Windows when I have time, but I think it would need a driver for Windows NT/2000/XP but for Windows 98/ME, access it through VxD is okay. Anyway...

It was cloudy when I first received the cable, so I've no way to test it accuracy.

The Roboscope PC GOTO

The Roboscope PC Link options does not contain any encoder, that means the software keeps track of the amount of movement with respect to the motion/slewing done. Sounds not very good at the beginning, but a real life test tells us what's going on.

Considering this option at only at $99 USD, it's a bargain. At the same time, it's just a jacket on the pandent, a cable and also a BASIC written software, it is not real cheap. But anyway, as a GOTO system, it's inexpensive, or maybe the cheapest one available.

Hey, I test it tonight (2002-2-12) from my town center home window. I do a two stars alignment using Canis Major alpha (Sirius) and also the Canis Minor alpha (Procyon) as the alignment stars. I cannot use farther away stars since the window is ultra-small. I prefer to use my Ranger here since it allows more movement.

What can be seen with just 70mm at the town center where five spot lights were sweeping across the sky?!

My first target is M42, aiming to test the GOTO accuracy. I centered the alignment star using a 17mm (28x) self made cross hair. M42 is found at the dead center. No surprise. I slew to M41. I found that the transpareny tonight has to be very very very good. The view is excellent with just 70mm. I put in my zoom to find the optimal framing to the view. Call my wife in and I take care of the baby for a while. Tracking is really nice at low power (60x at maximum). We can share the view so easily, which is hard before. Good, she can do focusing for as long as she wish, finding the optimal focus point for herself. The mount is rock steady for this little 70mm scope, she can turn the focus knob without moving the scope a single bit.

I then slew the M47, again, very accurate. Let my wife see it, she said that she saw only a few stars. But after a short while when her eyes get more "dark" adapted, she cried out saying that the view was so good!

I then slew to M44, oh!!!! What an excellent view!!!! I missed that feeling for very very very very very long!!!! I immediately remembered that I am a visual observer. This is where my real interest lies in!!!! I called my wife in and she enjoyed the view tremendously as well!

I love this mount. I love GOTO in such a light polluted sky. Without it, I need to spend over 5 minutes just to find M41 which was super easy at darker sky!

I tried to do some afocal shots at M44 with my DC. The center was not perfect, the focus was bad. I slew to Sirius, it was not so convenient here as I need to find the RA/DEC from Skymap, Roboscope software does not support slewing to stars, just DSOs, not even planets. Anyway, the software is just primitive.

Why I slew to Sirius? It's because I need something brighter to focus. After focusing it to pinpoint at 8x zoom, I switch it back to 1x, and then slew back to M44 to take photo with 20s. Again no good.

I decided to take off the Ranger, and take shots with the DC alone. The result is encouraging at the town center. The cluster was clearly shown after some processing. Too good! Can't imagine I can take DSOs here at the town center, with a DC, with a alt-az mount...

The software is not attractive by itself, but the accuracy, which is the most important, is good. Slewing using the PC is faster than using the pandent, I don't know why. BTW, I didn't do any calibration for the Roboscope for my mount, I just use the default, but the result has been very good by then.

The main drawbacks of the software:

  1. No slewing to stars/planets support: only if you know they coordinates, you might read your sky atlas software for their values BUT
  2. It does not work quite well when switched to background, it's a DOS based application anyway
  3. It will CHANGE your PC clock without asking you, might even fool you the current time!!!!!!!
  4. Some printer driver will interfere its operation, mine does... X(
  5. Text based, need manual digging...

Frankly, it's just barely useable at best. The accuracy, on the other hand, is amazing.

Taking the thing outside

When the first time I bought my C8 outside, I still didn't get a battery pack and therefore, it makes no sense to bring the GiroDrive out. So, I removed it and I took only the C8 which was placed inside a backpack and then carry the 074 tripod of my friend (aka Delphi in HKAS) and the Giro mount head with hand. I've a friend to take the tripod for me. The whole thing are nearly 30lb.

The size of the C8 is like a vacuum cleaner but it is lighter. So, I told my friend to be prepared to take out a vacuum cleaner with me.

I've a 55l backpack which is originally used for wild camping. It can fit the C8 with some space left for eyepiece, some smaller atlas and also maybe some little stuff. But if I were to use it for camping with the C8, I would end up without a sleeping bag and mat. It was not a very good fit since it's a bit crowdy to risk breaking the cheapy finder bracket. Anyway, if you don't drop it on the floor, it should be very very safe.

Finally, the complete setup

The counter weight is ready, but I just don't have time to pick it up. Now, let's round up the full setup for my C8 just without the counter weight.

The Gitzo G1415 arrived finally, and it's lighter than I imagined and it's also stronger than I imagined. The joint are air-tight, it is ONE PIECE of tripod, instead of three legs. It does not have a center column, which is useless for astronomy use. It is very very very very stable, and tapping on the OTA at 250x, the vibration dies down without 1.5s at most. My dream of a motofocus gone away, maybe except the problem of image shift. But I am very sure that I won't want the motofocus too soon.

On the right, you can see my small sealed lead acid (SLA) battery, which is heavy despite it looks small. It should be able to provide the power for over 20 hours for the GiroDrive. I think I shall buy some more little electric devices to attach to it, e.g. a red LED light, a little hair-dryer or dew heater, etc. Or else, it does not quite justify the its weight. Hey, I used it as the counter weight as well. The friction is low enough not to hinder the balance or smoothness of the whole system.

Finally, I've removed the friction control knobs of the Giro mount, since it SHOULD NOT be used. Balance is the key to use the Giro mount and if you need to use the friction control knobs, you better rebalance your scope a bit.

When the 3kg brass counter weight come, the setup is finished.

Good luck to your quest of a suitable telescope for your own fun!



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