Review: The AM3 Harmonic Drive Mount and TC40 Tripod from ZWO - Part 2 of 2
Once you use a harmonic drive mount, such as The AM3: It would be very difficult to go back to any kind of normal (non-strain wave) mount!
The AM3 Harmonic Drive Mount from ZWO
The AM3 was just a pleasure to use; it’s the sort of situation where the equipment is almost “out of the way”. It’s not a burden (like many other conventional mounts can be). It allows you to focus on other aspects of your astrophotography.
- Insure that the mount shows up in your list of Available Networks / Select it on your smartphone/or tablet (this also helps make faster connections in the future).
- Bring your mount/rig outside - Mine is always ready-to-go, with The AT80EDT refractor on it. I’m sure this is common practice (with small-medium sized refractors).
- Set-up rig: pointed North (polar alignment). Supply power/plug-in, power on.
- At this point, you should be able to launch The ZWO Mount software, and select an object to slew to.
While we’re on the subject of polar alignment… Polar alignment with The AM3 harmonic drive mount is different than what you’re used to…
So, I might go as far as to say that: In the beginning, you might miss the original way of polar aligning (I did!).
When you’ve done something the same way for many, many years – it’s not easy to learn/get used to a new way of doing it.
With The AM3 Mount:
- You make sure that your rig (mount & scope) are in the Home position - Not Park. *For those who aren’t aware, there’s a difference!
- Then, you point your scope to your respective polar alignment position. For those of us in The Northern hemisphere, that is the NCP / near Polaris (“the North Star).
*Home Position, is the position in which you would point/align your telescope to the North celestial pole (for those of us living in the northern hemisphere). The South celestial “pole” / area for those in the southern hemisphere, to put it in simple terms.
The “Park” position, was/is designed for use in an observatory. Those operating inside any type of observatory, would utilize the Park position, to keep the telescope out of the way, when opening/closing the dome.
I know, pretty neat, right?
Everything is, of course well-covered, and illustrated in the (freely downloadable) user manual.
However, I will mention page 16 of the user manual; and draw your attention for a moment, to figure 3.4.1 entitled ‘How to adjust the latitude?’
Why this particular figure? Because the number 341 is some kind of lucky number for me, so there you go – maybe it’ll bring me some luck if I mention it in this review?
Some additional (selected) Specs:
- Uses Strain wave gear + Synchronous belt technology; with a reduction ratio of 300:1
- Typical periodic error of only +/- 15"
- Latitude adjustment range: 0 to 90°
- Maximum slew speed of 6° per second (pretty fast in use).
- Mount can operate down to -40° Celsius
There are two gears, to adjust the latitude on The AM3 Mount. This is done using the included M6 Allen key – by loosening two hex screws (counter-clockwise).
Gear 1: goes from 0° to 60°.
Gear 2 goes from 30° to 90°. Again, it is all well covered, and illustrated in the (downloadable) user manual.
Switching The AM3 Mount from Equatorial mode to Alt–Azimuth mode, is done via the hand controller. You press and hold the ‘C’ (cancel) button, while turning on The AM3 Mount’s power button. When you release the ‘C’ / cancel button, the status indicator light turns to green, from red.
...Currently “migrated” to DSLR-based AP
Upon deployment, on subsequent nights, you’ll most likely just need to make a mild adjustment (to get accurate polar alignment).
Luckily, the overall accuracy of the mount helps matters.
Pros:
- Lightweight, easy to move around/re-position.
- Able to hold large telescopes, without much concern about balance/balancing, etc.
- Robust, accurate, and fairly quiet.
- Ability to function in equatorial, as well as Alt/Azimuth mode!
- Boasts many features, including: WiFi, Bluetooth, and (wired) hand controller.
- Operates seamlessly with just about all astrophotography software out there.
Cons:
- Relatively expensive, compared to several (conventional) mounts out there.
- The TC40 Tripod (which suits it best) may be considered a little expensive (although it can be found for as low as $349 at Astronomics).
- Polar aligning will take some getting used to…
- The conventional way: Using more than one model of refractor telescope for astrophotography (as seen in photos above).
- Using both dedicated Astro camera (CMOS) and DSLRs.
- With just a DSLR and telephoto lens.
- As an Alt/Azimuth Mode mount: For both telescope, and binocular visual observing!
Just to give you an idea.
These are very low cost Barska brand binoculars (15x70)
I hope to get a chance, to try a nice sized binocular telescope on this mount – personally, I think it would be a lot of fun!
I also enjoyed attaching my Canon DSLR and lens directly to this AM3 Mount, with great results (still post processing)…
The AM3 is obviously a versatile tracking mount, for more than just astrophotography - Although admittedly, I’m probably one of the few people who’ve actually used it for visual observing! Yes, it may seem a bit odd…but it is nice to know it can do it.
Aside from doing your polar alignment in a new, different way…The only obvious, and real “obstacle” I can see, is the slightly higher cost.
There are many astrophotographers, trying to accomplish some good astrophotography, while staying within a reasonable budget. For folks like us, the expense poses a bit of an obstacle.
However, I could not see anyone spending the same amount of money on a non-strain wave mount.
As for a few specific examples, take the top end mounts from Sky-Watcher…
Equatorial, GoTo mounts, such as:
The HEQ5
The EQ6-R Pro
The AZ-EQ6 Pro
The bottom line, is that The ZWO AM3 Harmonic drive equatorial mount can be found for as low as $1499 US dollars at Astronomics.
So - this would be my recommendation (which, for many, will seem like a “no-brainer”) - if the Go To mount which you are considering, costs as much as (or more than) The ZWO AM3, I would advise you to go for The AM3.
However, let’s not forget the tripod. If you don’t have a suitable/sturdy enough tripod - you’re obviously going to need one.
You may find yourself leaning towards getting the TC40 Tripod from ZWO – because, of course, it fits the AM3 mount like a glove. They were basically made for each other. So you must take into account the expense of ZWO TC40 tripod, when considering the total cost of your mount.
In the spirit of not overlooking anything or leaving anything out: I’d like to mention, that for those who don’t mind spending a bit of money on an extra gadget - which will make your life easier - I would like mention The PoleMaster made by QHY. You can read about it, and see about ordering one, by visiting Explore Scientific (for starters).
The PoleMaster is a fascinating little gadget, which mounts onto the front of your telescope mount, and allows you to accurately (and easily) polar align. I have not used one myself, but it seems to be an ideal addition to an AM3 Mount.
I will add any additional items of interest to this review, as needed.
A huge thank you, to ZWO for the loan of the equipment for this review!
Next up, will be a review of The Astrophotography Manual A Practical and Scientific Approach to Deep Sky Imaging by Chris Woodhouse. This is the very latest, second edition. I can tell you right now, if you enjoy using dedicated Astro cams (CMOS) for your Astrophotography – then you simply must get this book ASAP!
Until next time,
Clear skies!
