A short tale of three parallelograms

[BinocularSky]

Since the demise of UA (Larry Patriarca retired), there has justifiably been interest in the other "pretenders" for the parallelogram market. I recently acquired an Astro Devices model - full review in the next few weeks, but here's a bit of a taster and comparison.

In the image are three parallelogram (P-) mounts: L-R a Universal Astronomics T-mount, an Astro Devices Parallelogram Standard III PRO and a Vixen Skymount (which became the Orion Paragon Plus)

They are shown on & with respectively: Surveyor tripod, Miyauchi Bj 100 (5.6 kg); Manfrotto 075, Helios Stellar 20x80 (2.62 kg); Amazon Basics, Opticron Oregon (old version) 20x80 (2.05kg).

Specs and commentary are as follows:
 

T-Mount (included because (a) I have one, and (b) if you find a used one, get it! Mine is over 15 yrs old and still as good as ever.)

Arm length (between fulcrums): 30.5 cm
Arm material: Steel, 32 x 32 mm box section
Rated payload: 30 lbs
Vertical range of motion: 48 cm
Counterweights: 3x5 lb, included
Counterweight bar: 19 mm solid; screwed end for weights is 30 mm diam
Tripod mount: Proprietary post; was available in 5/8" (survey tripod), 3/8" and M10.
Binoc mount: Proprietary horizontal and L brackets with 1/4" screws.
Degrees of motion: 5
Centre of mass adjustment: Vertical and longitudinal
Price: (no longer available; was $449 + shipping)

 

Astro-Devices

Arm length (between fulcrums): 52 cm
Arm material: Steel, 19 x 33 mm, slotted (for weight reduction) U section
Rated payload: 15 lbs (I was dubious about this and put my Miyas (12.5 lb) on it. Long damping time, but otherwise stable/secure.)
Vertical range of motion: 84 cm (Accommodates standing and seated observing without having to change tripod height.)
Counterweights: Optional extra; Skywatcher/Vixen counterweights fit.
Counterweight bar: 20 mm tube (for SW/Vixen)
Tripod mount: M10 standard; optional 3/8" and 5/8" adapters
Binoc mount: 1/4" and 3/8"
Degrees of motion: 4
Centre of mass adjustment: No (My Miyas would not balance longitudinally, even with the mount-arm fulcrum tightened as much as I could by hand)
Price: $239 + shipping

 

Skymount/Paragon

Arm length (between fulcrums): 43 cm
Arm material: Steel, 24.5 x 24.5 mm box section
Rated payload: 6 lbs (However, counterweight does not balance very light binos or those weighing over about 4.5 lbs (2.2. kg) properly, but tightening the fulcrums with the hand-knobs enables heavier weights to be mounted. )
Vertical range of motion: 62 cm
Counterweights: 8 lbs, fixed to bar.
Counterweight bar: Solid, 12.25 mm
Tripod mount: 3/8" with 1/4" adaptor
Binoc mount: 1/4" L-bracket provided; horizontal bracket (for binoculars with a mounting post) is an optional extra costing about $30)
Degrees of motion: 3 (essentially, you are limited to looking over the tripod)
Centre of mass adjustment: No
Price: £114.99

I hope someone finds these comparisons useful.