A Synta EQ3-Class Mount Unveiled

[Alan64]

I've had a Celestron CG-4 equatorial for over two years now, but have yet to use it.  Before putting it to use, I've been wanting all along to get it just right, so recently I began its refurbishment.  First, the cleaning and removal of the factory grease throughout.  The mount-head prior to disassembling; click on the images for a larger view...

 

First, the declination axis...

 

 

The factory grease wasn't as bad, or glue-like, as I had anticipated...

In any event, all of it was removed with the aid of charcoal-lighter fluid, and replaced with Super Lube, a Teflon-based grease.  In addition, all bearing surfaces were polished with #0000 steel wool and lemon oil.  It turned out that the surfaces didn't really require polishing, but it was performed nonetheless.  Unsurprisingly yet disappointingly, no ball or roller bearings were found within either of the axes.

 

Removal of the RA axis' aluminum lock-ring required soaking of the joint with acetone to dissolve the "super glue", loosening its set-screws, inserting a larger hex-key into one of the set-screws' pilot-holes to immobilise, then unscrewing the lock-ring by cranking the counterweight shaft clockwise...

  

The RA axis and its worm-assembly exploded, with more washers for the axis instead of ball or roller bearings...

Perhaps the finest component within: the RA axis' worm-gear...

Reassembly of the RA axis...

The worm assemblies of both axes are fully adjustable...

 

The polar scope's micro-printed reticle...

The axes' setting circles are not practical, and will not be used...

 

Next, the tripod...

[Alan64]

Shortly after purchasing the mount, I just had to have the pier-extension in addition...

But I've always disliked it because it's simply too tall, and at 16".  So, I had it cut down to 8"...

...then painted it...

I also cut the tubular-steel legs down, removing 7.25" from each...

Where the legs attach to the mount-base, Synta used twelve of these leatherette(plastic) washers to stiffen the movements of same, and four per leg...

Instead of re-using them, I made six washers from .008" thick bronze sheet, and for two per leg...

Stainless steel lock-washers were added in addition to the lock-nuts and flat-washers...

The tripod can now be picked up without the legs folding together, yet each leg is easily folded when required.  The full retracted height of the tripod...

Instead of this, which I deem unnecessary for the now-compact EQ3-class mount...

...an oil-black socket-cap screw and washer, along with a stainless-steel flat-washer, makes for an easier breaking-down of the mount after an observing session.  Said screw threads well into the pier-extension's adaptor, and unlike that illustrated above...

I am more than happy to do without the eyepiece tray in exchange for said convenience.  Granted, when mounting the larger of my telescopes, the "thingy" may be required, but it will have to be machined in order to thread well into said adaptor.

To better secure the tripod and mount-head to the pier-extension, longer socket-cap screws, along with locking and flat washers, all of stainless steel, were sourced.  In the case of the screws, a trip to two vendors within my county was required, and for a total of six...

 

Finis...

Thank you for looking.

[Alan64]

I once had a Vixen GPDX.  It had come equipped with an 8 lb. counterweight, which had been slowly rusting since 2005 when the mount itself was destroyed...

[wimvb]

Great write-up. Reminds me of my struggles with my SW EQ3 Pro mount. You seem to have the advantage of not living near the maximum latitude of this mount. I also had to replace the Alt bolts and add an additinal wedge to the Alt adjustment "wedge". The south-side Alt-bolt bends itself below the existing wedge when you try to adjust it to northern latitudes.

How does the mount perform now?