Losmandy GM-8

Ratings:Top:Astronomy:Equipment Reviews:Mounts:Losmandy GM-8

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Brand and Model:Losmandy GM-8
Price ($USD):$1495.00
Type:Equatorial
Attributes:checkedMotorized checkedPEC un-checkedGoto
Electric Power:12V
Weight (lbs.):21+15
Description:30lbs Weight Capacity.

21lbs Equatorial Head.
15lbs Tripod
7lbs counterweight

Losmandy's GM-8 Page
Cloudy Nights' Review 1
Cloudy Nights' Review 2

Vote Highlights Vote
Losmandy GM-8
I bought my GM8 earlier this year, in as-new condition. It is
easily set-up in about 5 minutes. It is rated to carry 30lb and this is probably a realistic limit for visual use.

I have used it with a lightweight 12" Newt (see Orion Optics DX300 review) which weighs in at about 25lb when using 2" Naglers. This arrangement is fine even at high powers as long as it's not very windy. I think it's steadier like this (legs retracted) than it is with the legs extended and carrying a Tak FS128 (OTA about 3kg lighter).

I like the clutch arrangement on this mount, being able to over-ride the drives by simply pushing the 'scope to the desired location. (Personally I don't like the 'locking' nut used on e.g. Vixen mounts.) The motors track well at high powers (400x) and I haven't found that I've needed the PEC. The anti-backlash works well. The control box is attached neatly to the mount, which saves treading on the thing in the dark. The cables connecting the motors to the control box are like those on a telephone and the arrangement works well. The only negative here is the cable connecting the hand-set to the control box, which is a cheap bit of non-extending flex (why didn't Losmandy use the same cable as used for the motors?).

The illuminated polar alignment 'scope is easy to use but is an expensive optional extra (140 GBP).

The mount is very well-finished and black-anodised. There is a
definite 'pride-of-ownership' thing. I might upgrade to a G11 to try my hand at some more serious photography but I don't think I'll sell my GM8. In terms of value for money and ease-of-use I think it's a definite step up from a GP-DX and is worth the extra cost (Losmandy products are comparatively more expensive in the UK compared to the US, Vixen seem not to be).

Overall Rating: 10
Performance:10 Ease of Use:10 Value:10
Weight: 10 (Trustworthy Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=135706

Losmandy GM-8
Best value for the money.
Upgradeble with many features.

Lamont

Overall Rating: 10
Performance:9 Ease of Use:10 Value:10
Weight: 5 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=327735

Losmandy GM-8
For visual use with 4" apo's and 8-9.25" SCT's, the GM-8 is excellent. Its excellent build quality and no searching for clutches in the dark are plusses. This is my second GM-8 and I recommend it without reservation.

Overall Rating: 10
Performance:10 Ease of Use:10 Value:10
Weight: 5 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=318675

Losmandy GM-8
My review won't comment much on the mount as equipment, other than to confirm that this is one well-machined and solid mount, at a high price (happily, someone else had paid for the options for mine). Instead, I want to focus on the viewing experience.

I bought my GM-8 used. It was an upgrade for my Celestron 8" SCT which had been previous mounted on its Celestron CG-5 mount, which I had upgraded to passable performance by building oak legs for it. The GM-8 appealed to me because other reviews described it as a mount which aids observing rather than getting in its way by virtue of its 'support' function.

My experience with the GM-8 is limited to visual observing, as I have yet to try any astrophotography. But, as an aid to visual observing, I am convinced this is a terrific choice. Why? As the reviews I read said, this mount aids in observing, not impinging on observing.

The best example is last week. Although it was bitterly cold out (about -18 Celsius), the sky was clear and the moon was relatively new. I headed out into the country to do something I had yet to do: work my way through the Virgo cluster of galaxies, in preparation for our club's Messier Marathon. One thing I had changed in my mount was to add the ultra-high molecular weight (UHMW) clutch pads to the mount (some disassembly and reassembly required, but nothing onerous), which I had ordered from Losmandy for just a few bucks. The net result astounded me, when I thawed out and looked back on having hit 15 new galaxies in just a few hours: I realized that I had hardly even grabbed the electronic hand control unit to guide the scope! Using an 8x50mm finder and a 32mm Erfle (63 power, 70 degree apparent field, yielding a 1 degree actual field on my SCT), I had slewed my way through the entire Virgo cluster just grabbing the scope and moving it by hand from one reference point to another. It was like using a smooth dob, but with automatic tracking the minute one lets go. This just confirmed some earlier reviews (albeit on another site) about how this mount makes observing a joy.

The key, of course, for readers not familar with the Losmandy line, is the clutches: you balance the scope and set the clutch tension and then you can just slew the scope around by hand until you are where you want to be, and then you let go and the motors continue tracking. There is none of the searching for the clutch levers and releasing them, then slewing, and then tighting them of the Vixen (and its Chinese-made clones) mount lines. The key to some of this performance is the new clutch pads. Prior to adding the UHMW clutch pads (i.e. with the old nylon pads), I was able to get close in the finder but then had to use the paddle controls (that is the stepper motors) to zero in on what I was atfter. Last week, I just continued to slew by hand, even at 63 power through the eyepiece.

Bottom line: the mount is terrific. And, an added observation: if you already have a Losmandy mounts and slew by hand, get the UHMW pads. They are a terrific investment.

Overall Rating: 9
Performance:9 Ease of Use:10 Value:8
Weight: 5 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=205555

Losmandy GM-8
A very good mount. It moves smoothly, tracks well, and is generally easy to use. It is a pleasure to operate and own. In addition, it is extremely well made...mostly. Black adonised metal, bearings on the axes, and excellent fit and finish. On the other hand, the plastic and controllers appear cheap and fragile, and the metal motor covers that are available as an option should be standard items instead of those flimsy plasic boots. Also, the tripod is a little light...in order to take advantage of the mount's 30+ lbs. rating it is necessary to upgrade the tripod to damp down vibrations. In light of these faults, the GM-8 is still an outstanding mount and the best choice in its weight and price range. I recommend it.

Overall Rating: 9
Performance:9 Ease of Use:10 Value:10
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=345296

Losmandy GM-8
This is a great mount for it's price! I have owned this mount since 1996 and it has be my portable work horse. I have a bigger AP900GTO mount and I still use my GM8. Quality is good but I would recommend you get the metal motor covers and the clutch upgrade. Makes the mount easier to use and the motors well protected.

This mount also need a little maintenance. I find that I need to break it apart for relubing at least once a year unless you use Lithium grease then you only have to relube it once.

I have only one complain with this mount and that is the PEC. You have to RETRAIN it everytime! This is really a pain but the of this mount is respectable.

Overall it's a great portable mount and very easy to assemble.

Overall Rating: 9
Performance:8 Ease of Use:9 Value:10
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=321840

Losmandy GM-8
The GM-8 with Gemini Go-to is a very high quality mount. Is it worth the $2.4K? I would say yes, if you can stomach spending that much on just a mount. My only complaint with Losmandy is that they kill you on options. The only extras I bought were the tripod knobs for mounting the eq. head, the eyepiece tray, and polar scope. The illuminator is too bright, otherwise the polar scope is good. The dovetail plates are not cheap items either. The motor covers are not needed as with the std. GM-8 as the gemini servo motors don't require them. The gemini like all computer software is only as good as the person inputing the data. The user has to set things up, otherwise the factory defaults are set, which will not be set to you locale. Once set up properly for location, UTC time, local time, and mount type operation, is rather simple. Using a 120x (5mm nagler type 6) in my TV85, and only a one star alignment (once polar aligned) a selected object will be in the field of view, centered if using a lower power ep. Tracking is absolutely quiet. If you observed the mount you could not even tell it was functioning. Slewing at go-to speed is not quiet, however the servo motors are not noisy, but provide a noticeable servo whine. The hand paddle and gemini menu appear at first daunting from reading the manual, however in use become rather simple and intuitive. Is this mount for you? Well if you have multiple scopes and want a go to function it is a good robust system, well made, nice to look at and operate, and likely to give you years of great service. If you just want a go-to scope spend the $2.4K on a Meade or Celestron and take a chance you might get a decent OTA, and no computer problems. One thing about the GM-8 with gemini, the mount can be used without the computer. Loosen the clutches and push the tube where you want, almost as smooth as a dob. You can also turn on the puter, ignore go-to, point the mount where you want and it will still track and keep the object in the center of view. If the puter has a problem it is readily removed by loosening two levers, and can be sent to the mfr., yet you still have use of the mount. I use the mount with a TV85 and MK67 mounted side by side and love the arrangement. It can look rather odd in some tube orientations, however the mount seems to have no problem with the load. With eyepieces and dovetail plates, plus the off center loading it probably is close to the 30# limit. For visual use the scope is recommended, but for serious astro photography I would recommend the GM-11. For the money Losmandy should provide a place to hold the hand paddle, but unfortunately they don't.

Overall Rating: 9
Performance:9 Ease of Use:8 Value:9
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=174054

Losmandy GM-8
This is going to sound somewhat contradictory. I now own my second GM8. I've also had a GP and GPDX. Both times the GM8 replaced the GP's. Both the 8's and my 11 have exhibited large periods at given spots on their gears. I've also seen more rework is need on the Losmandy's than the Vixens. Another issue is payload rating. In regards to overall stability, I've found the Vixen's to be conservatively rated while the Losmandy's seem to push the limit. A GPDX vs. a GM8 in regards to portability, even while comparable in weight, seems to be more manageable with the Japanese units.

OK, early on I said both Vixens were replaced with Losmandy's. The overriding issue with that in the GP replacement was indeed payload. After receiving it I found the slip clutches to be a visual obervers dream. That was a bonus. A few years later, I opted for a GPDX. Due to additional weight being added, I got my second. While the slip clutches are now a known factor, which made the decision easier, the payload rating this time around has been another story.

Since this in a visual only rig, I still find the clutch arrangement worth the tradeoff. IMHO to make a blanket statement that it is superior to the DX is a misnomer. My scope has now shed those pounds, and the DX even with the clutch issue, is now missed sometimes. It sure is easier to tote.

On a sidebar, the SS2K GOTO on the Vixen's is a sweet unit. I got the Genesis on my G11 and it has given me continual problems. That in itself would be a minor issue if an acceptable level of service could back it up. That has proven to be even more problematic than the unit itself.

Overall, a very nice rig, but not worthy of the 9.9 avg I see.

Overall Rating: 8
Performance:8 Ease of Use:8 Value:8
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=170781

Losmandy GM-8
Never sell it, noe equipped with LDSC, DSCH, AMC, DGC, GM-8DSP (with
second GM-8 SP), and a specia RA motor (eliminates the 1 sec full-step
image shaking at high magnifications).

Overall Rating: 10
Performance:10 Ease of Use:10 Value:10
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=141962

Losmandy GM-8
I HAVE A GM-8 AND HAVE BEEN USING IT FOR , FOUR YEARS.
IT IS WELL MADE LARGE, AND STURDY. THE DRIVES ARE VERY ACCURATE. I HAVE A 18LB OPTICAL TUBE MOUNTED ON IT
AND THE MOUNTINGS PERFORMANCE IS VERY GOOD. ONLY
COMPLAINT IS WITH THE PEC DRIVE, HAS NO MEMORY SO THE DRIVE MUST BE TRAINED FOR EACH USE. THIS MOUNT
CANNOT BE COMPAIRED TO ANY OTHER IN ITS CLASS IT IS THAT GOOD.

Overall Rating: 10
Performance:10 Ease of Use:10 Value:10
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=136660

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