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Almost 10 years with Avalon M-Uno


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Soon approaching 10 years with the Avalon M-Uno, I thought it could be of interest to share my experience for astrophotography with this mount. Before the M-Uno acquired soon 10 years ago, I had 3 years struggling with 2 different AVX mount (one still in use but I won´t compare with it).

Before starting reporting my experience, below my typical set up and situations:


I am typically imaging with

  • SCT C8 (with an a Star Arizona FR, so down to 1460 mm), with a large dew cover making it twice longer or
  • WO GT81 (with FR so to 380 mm) or
  • FMA 180 at 180 mm or
  • Sigma Art 50 mm (only with my canon)

So I can cover a wide range of FL . Lately, I am now typically setting up  in “dual rig”  by attaching the DSLR (with the  FMA or with the 50 mm) on the under side of the arm as “counter weight” with a ball head/canon), while the C8 or the WOGT81 is on the main saddle (see pictures). I never tried to combine the C8 and the WO GT81 in any ways so far. 

Imaging Camera:

  • Main imaging set up is typically with a SX694 mono with miniFW, OAG integrated, Lodestar on the C8 or the WOGT81 or the FMA
  • Canon 80D astro modified mostly used with the FMA or the Sigma art


  • Lodestar with the OAG of the MiniFW starlight Xpress most of the time (with either scopes, so different guiding scales)
  • an ASI224MC and mini guidescope (ZWO miniguide scope) if I am imaging with the canon and FMA or the Sigma Art 50 mm (a matter to avoid setting up/using the WO or the C8 as “guide scope” with the SX694/min FW). So a “light” set up when working at 50-180 mm.

Pay load: considering the different set up I am combining, the total payload varies anywhere from about 4 kg up to 15 kgs.  

Mount set up and usage:

  • My M-Uno is among the first years it was produced and must be >10 years old model (white cover arms and chrome painted saddle/DEC and RA clutches). It is permanently set for 7 years on a brick pier.  Very robust as I never had to re-do any polar alignment for many years. I am running it with a DC adapter (adjustable 12V or 15V), not battery. No issue on powering the mount ever and stable.
  • The mount is staying 7/7, 365 days outside for 7 years, under a Telegizmo cover (also soon 10 years old, very good! and an additional cheap light grey BBQ cover, and with a blanket and a regenerative 500 gr dessicant inside, both absorbing moisture build up under the cover, and I monitor temp + moisture under it -and when moisture >85%, I typically dry the desiccant and let the mount “breath” before covering it up again (If not used, I uncover and dry the blanket/dessicant at least onceevery 4 weeks or find a time to get it dry after some high humidity nights in operations).
  • Total operating hours: Difficult to say as I never really looked at counting, but it must have some 2000-2500 hrs of usage over past 10 years. It could be more if the weather was better and I would not have to travel for work (and unfortunately, I miss many good nights)
  • The arm is set up so I don´t need to change its position when changing set up to cover all above gear set up (unfortunately I cannot remember since I set it up in the very 1st days to accommodate the C8 and the WO). I only need to add the extension for the WO GT81 or the “light” set up as compared to the SCT C8 (no extension) and final touch with eventual small counterweights on either sides depending the set up. So a quick and simple turn around when needed between the different set up. 
  • DSC_0589.thumb.JPG.1e0a4739290befcc0d498669f31ebc74.JPGDSC_0769.thumb.JPG.c4284f85cf49280bf9d90a5343785555.JPG

Conditions South Sweden:

  • Backyard in a Bortle 7 sky city. Seeing varies quite a bit as also often jetstream passing by as well. 
    • Temp: from -25C to +30C (under the cover reaching +40C), so quite tough environment year long. Most typical winter is -10 to +5 and summer +15 to 25C. In operation, I have been imagining down to -15C, but most typically -10C to +5C in winter.
    • Humidity: vary quite a lot along the year, can be quite dry in winter, and high humidity in fall. But basically 70 to 90% RH would be typical range, so a dew heater strap is required most of time as soon as >75-85% humidity level
    • Wind : the wind is typically in 2 to 6 m/s range (gust 8-12m/s), rarely above when nights are clear.


So that was all for the background, now what people are most interested to know about:

  • Maintenance: after 10 years, it is all in its original piece and one could say maintenance “free”:
    • The only “maintenance” I needed to do was a few months ago, when I noticed more difficulties to get low RMS in great conditions (I was up on 0.5-0.8” total RMS range for a while and with some spikes going up to 2-2,5” while historically I could manage lower RMS and lower spikes than that in great conditions). After checking with Avalon (always very fast supportive customer support), they recommended to check the belt tensions: the belts felt a bit under tension which I could imagine normal loosing a bit after 10 years exposed to huge condition variations constantly beside operating. I simply did about a 1/5th of a turn on the tension mechanism and it is now fully back on great  performance (see phd2 logs) from “good/ok-ish” performance. I could visually check the belts by opening the covers, and they looked problem free (like any other parts). No re-grease of any kind ever needed.
    • Durability: considering the conditions it stands (yearly outside under cover for about 7 years), I am amazed:
      • not a rust point, apart on the chromes of the original DEC/RA clutches and the original vixen type saddle (this is some years already that Avalon is not supplying with chrome on those parts, I see on commercial pictures those parts with some dark paint now, so an issue Avalon has addressed for quite sometime already).  Anyhow, this is only a cosmetic visual issue as the saddle like clutches do work as expected (and the rust seems stable for several years, it has come up within 2-4 years it was standing out). All bolts and any other parts are rust free, like brand new. Despite a number of shocks with dovetail, no scratches anywhere, very good paint job.
      • Electronics: no issues to report. Never had any issue with the Stargo hardware part (in the early days, software/firmware could have some glitches but it is now many years with stable running and keeping windows 10, ascom and other running software (Nina, phd2) up to date (and currently running last stargo firmaware/software).  
  • Operating performance:
    • Apart the early days of some firmware/software glitches, I would say the operating performance has always been a wonder: I don´t think I ever lost a single sub (imaging typically 10 min subs) due to a mount failure or related issue. The no-meridian flip is the main reason I chose this mount and it is just wonderful (although I guess today´s softwares and reliability makes the automatic meridian flip possibly easier and more reliable than >10 years ago). I set up the scope, plug everything on a laptop (10-15 min to set up every thing, what takes longest is manual focusing- and then launch the sequence, then I can go for a deep sleep without any concerns at all): no need to think where it is pointing and thinking how/when it will handle a meridian flip and to get this into account. Basically: no “baby sitting” required ever which is I think the best out of this mount. If something has gone wrong past 10 years has been on other things than the mount 
    • Very easy start up to operate. Start, Sync home position, then go to 1 star, do a plate solving and one is pretty much spot one in a given area of the sky just after 1 plate solving. 
    • I have not had to do the polar alignment for very long, but for what I remember, the clutches and adjustment were easy to get it precisely done (and very sturdy since I have not had to touch this again for years).  
    • I never run it with the hand control, so I cannot comment on that
    • Software and communication: no issue to report, I never had any problems for many years (again part the early days which needed some update firmware) to have it controlled via Stellarium like to talk with any other software via ascom (ATP, Nina, ASTAP, phd2, astrotortilla). It connects and I never had a connection lost from the mount to the computer and softwares. The Stargo software is easy to use once customized to it, although the plate solving and database not that great, better to use dedicated connected planetarium or other plate solvers on my point of view.  


  • ergonomy: I think it is very well thought mount on its ergonomy despite its unique design. It comes also with a detachable hand holder if one need to transport it. It has also a very usefull cable management "pass trough" the RA axis as well. I have a pegasus advanced set up placed under the arm and some cable guide stickers  around, I think there are many ways to get a good cable management whatsoever your set up can be.  


  • Guiding and image results: likely one of the most frequented question on mount performance, and in particular those type of mount as guiding is required. Nevertheless, it can be noticed I have been using it without guiding with the FMA 180 mm as well as my 50 mm lens and I could take up to 4 min long images without issues (longer may be possible I guess). Anyhow I am typically using it at lower imaging scale so guiding is needed. The guiding performance is depending of many factors, so I try to summarize here in simple conditions factors. As important as seeing conditions (incl. where you point, zenith vs horizon), the wind has definitively its importance with the Avalon (this is well commented eleswhere, and even if the guide graph may not look great, the image can still be great). Yet, as compared to general rule of reaching a guiding RMS to be half of the image scale for good results, it  does not seem to apply with the Avalon: When imaging with the C8/FR, my image scale is 0.64 “/pixel, yet I still get really good result even with 0.6-0.7” total RMS (I guess the stars may be a bit bloated or not perfectly round, but that´s looking on pixels level or measuring excentricity in PI one can effectively see). Also the RMS results I report is included the few spikes/peaks which can extend to +/- 1,5 to 2,5" but those are typically very short duration and very few (may be 1 to 5 spikes in my typical average conditions for 10 min, meaning only a few seconds in total per sub of "wild" guiding, overall you will be within short range and those few sec will not show up strongly on the images). Those spikes can be typically wind gusts related for most, possibly also some dust accumulated over the years in the mechanisms. Anyhow as a summary and data for a  full night session (and not just picking up some few 100 or 200 scales of phd2 live window), and for a typical declination in the range 30 to 70 degrees which is where I typically image:
    • Good seeing conditions and wind less than 4-5m/s (gust to max 6-10 m/s), whatsoever set up, guiding scale and pay load in the range I use as explained above: 0.3X“ to 0.4X“ total RMS.
    • Medium seeing and wind of 4m/s to 6m/s (gust to 8-12 m/s): 0.4X“ to 0.5X“ total RMS: when using the C8 with its long dew cover fully extended, it is definitively more sensitive to the wind with more "spikes" and it will give results on the high side of this scale at 6m/s. In such case imaging at 1460 mm (image scale of 0.64), I can get the stars not being “ideally” round, yet this is fully acceptable and those defects can be easily addressed in post processing (deconvolution methods, or simply multiscale softening on star selection, and some other methods to make them look perfectly round while pixel peeping).
    • Poor seeing (or near horizon), and wind >6m/s up to 8m/s (gust to 16m/s): I never tried in worst wind conditions than 8 m/s with the C8 I think and but in this range in such case, I avoid the C8, as it will start to clear show some star elongation or quite bloated , yet this is still fully acceptable to my taste, but it handles well the WOGt81 in such conditionsl with RMS below my image scale and I can be in such worst conditions (rare anyway) up to 0.6-1.2” range, so no issue with the WOGT81. In those windy conditions, I think the main issue is the frequencies of strong gusts and not the average itself, a very steady wind of 6-7m/s can still give very decent rms, but variable and strong frequent gusts of >15m/s may be the problematic case).  
    • The DEC is typically a bit better than the RA by maybe 0.05 to 0.1”
    • I don´t need to play around with the settings to get to above results: I simply use the recommended setting by Avalon for phd2 as per their website (lowpass2, aggressiveness to 100 , min mov of “0” and exposure time of 1s or 1.5 s depending the seeing conditions and if very windy I increase to 2 sec exposure, as too short would likely just go all around the places). Guiding rate in stargo is set according to Avalon´s recommandation depending the guiding scale use and seems to work in about all situations. For RA, I tickle the “Auto tracking Adj” and it seems to actually help. So I get from 0.3X” to 1.2” depending the set up and seeing/weather conditions as described above (all above case using the OAG with my WOGT81 or C8 so in the 380mm to 1460 mm range, so well enough to get good images). With the miniguide scope 120 mm and ASI224MC as guiding set up, I typically don´t get those low RMS, always a bit more, but I don´t really care as it is still way below image scale in such cases (imaging with the FMA 180 or wide angle FL lenses for 5-10 min subs). 
    • I can imagine if I would used the mount with the exact same set up all the time, there is likely room for further improvement of the guiding (in phd2 parameters, like possibly optimizing the balance, payload distribution of a given system), but I never had to bother.


My learning regarding getting the best guiding performance and some tips in case of windy conditions:

    • Balance well the set up. It is quite easy to find the balance (as compared to my AVX´s), as it is very free when unclutched. As I can tell, a "perfect balance" is not always required, and some light unbalance may results in better guiding (but that´s not statistical proof, maybe a a little gain of some 0.2,0.5 RMS)
    • Cable management: I could notice it quite sensitive to hanging cables (especially with some wind) as well as cable drag. So make sure cables are well attached, not hanging around and no drag (I use cable clips sticked onto the mount and Velcro straps)
    • In case of windy conditions kind >5-6 m/s (gust >10-12 m/s): avoid the C8 or if no dew is expected, do not use the dew shield cover with the C8 (and/or avoid shooting too much towards the zenith or put the dew shield to minimum and not fully “extended”). In windy conditios and dew shield fully extended, the RMS can start getting into the imaging scale and start to get some subs with slightly elongated star (if one goes into pixel peeping). With the WOGT81 I could image without any issue with wind up to 8-10 m/s (gusts 16-18), but above that kind of wind, I have not been out. 


  • Soon 10 years and it has been just a wonderful experience. Robust and very consistant in many different set up with varying payload and situation, and durable in tough environment for many years and trully maintenance free. Great design to skip the meridian flip hurdles, no backlash (some very little can be measured by phd2, but i never used such correction) and baby sitting free. Guiding performance is great for my need, and very consistant whatsoever the set up, pay load, guiding scale.
  • The design is not without limitation (to be careful if it can handle long refractors), yet, it covers my needs with minimum adjustments between variety of set up and scopes I use
  • I don´t feel the need to find a replacement and still enjoy it every night… Would I buy a new one? Likely… but ... basically it looks like I don´t need before many more years hopefully. It is pricey as compared to many other mount, but it is definitively worth considering its longevity so far
  • It may not be best if you have long refractors or very large SCT, RC and using large dew shields if you are in a regular windy area (average winds >5-6 m/s). In such a case, I believe a dome would be more than welcome.
I may update this in 5 years or 10 years.... Note I saw in some forum some people asking why not much is reported in forums regarding the avalon´s: yes they are not "mainstream" and premium, so there are not that many users who can report, yet I believe a simple reason is also those mounts are simply so little trouble, easy to use, that such users simply do not visit much the mount section forums looking for help or reporting problems. At least this is the case for me, since I have the avalon my presence on forums and dedicated sections about mount is very little. 

PHD2_GuideLog_2023-09-09_184041.txt PHD2_GuideLog_2023-09-01_185832.txt

Edited by Erquy
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