GoTo Mount Care

[Darrel999]

I've just got my hands on a Star Adventurer GTi and I'm looking forward to some clear skies so I can put it thru its paces.  I see from the handbook that it should not be transported fully assembled. I'm wondering why this is so - I'd have thought that if the clutches were tight no harm could come to the mechanism? With my old Eq3/2 mount I'd keep it in the kitchen ready to go before carrying the whole thing outdoors - no harm seems to have come to it. 

[AstroMuni]

2 hours ago, Darrel999 said:

I've just got my hands on a Star Adventurer GTi and I'm looking forward to some clear skies so I can put it thru its paces.  I see from the handbook that it should not be transported fully assembled. I'm wondering why this is so - I'd have thought that if the clutches were tight no harm could come to the mechanism? With my old Eq3/2 mount I'd keep it in the kitchen ready to go before carrying the whole thing outdoors - no harm seems to have come to it. 

I think the reference to transport is intended for long journeys, not a short trip from indoors to outdoors.

[StevieDvd]

Easier for them to say that than to say:

• Check your clutches/clamps. cameras or eyepieces are tightened/in firmly.
• Avoid obstacles and trip hazards.
• Don't do it while under the influence of drugs/alcohol.
• Don't rush to catch a briefly cloud free sky!
• And of course don't blame us or expect a free replacement.

🤭

[Darrel999]

Fair enough!

[AstroKeith]

It is 'safer' to undo the clutches, even for a short move.

Otherwise any out of balance forces will go straight to your gear teeth. It doesnt take much to move the worm gear laterally and the next thing you know is an increase in backlash.

[newbie alert]

It's because if you carry the whole mount with counterweights etc you're putting stress on the gears no matter how tight the clutches are.. and clutches shouldn't also be done up that tight anyway , that can push the ring gears to one side..

If you think of how much of a turn of the worm grub screw changes the setting of the worm placement it shows how much is needed to alter the mechanics of the mount

[Darrel999]

Thanks for replies - makes sense

[Grant]

A lot of mounts recommend transporting with the clutches unlocked as AstroKeith mentions to avoid any sharp jolts to the gears causing damage.

I wouldn’t consider moving it fully assembled from inside to outside to be the same as transporting it though - assuming everything is assembled correctly and balanced and you are careful carrying it then it should be fine.

Ive always carried my imaging rigs fully assembled outside unless they are too heavy to do in one trip - makes settings up much quicker and also, in the event of an unexpected shower much quicker to get into safety!

[AstroKeith]

I think that some people arent are of what the clutch action is on such mounts.

Locking or tightening the clutch isn't locking the rotating axis to the mount, even if that is what it feels like.

its locking the rotating axis to the drive gear. Thus when 'locked', the drive gear takes all the strain.

When carrying a fully loaded (but balanced) mount that is locked, just turning a corner creates angular momentum that the worm gear has to resist. Often the main gear is only 50 or 75mm in diameter. Do the maths and you will find that kg 's of force are sent to the little bearings at either end of the worm gear shaft. These bearings are the ones that directly affect backlash. A typical balanced mount has scope and counterweights some distance from the axis of rotation. This is where the high angular momentum comes from.

I serviced dozens of mounts. Many are well engineered and can take reasonable loads on the worm shaft or belts. Most of the newer, lightweight mounts are not.

[Mike Murphy]

Any thoughts about the polar scope illuminator on the SW GTi? I would be interested in knowing the design criteria, method and possibly who? Having using a number of devices that were properly thought out I come to this. What the…. A bit like like someone shining a light in your objective while you are at the eyepiece! Any knowledge where the initial concept comes from? UK, US or China? Perhaps the illuminator design was dropped on an intern?

Just wondering

[StevieDvd]

Have you tried adjusting the led brightness in the Synscan app?

[Mike Murphy]

Yes, it makes no difference. The reticle is not illuminated because the light source (led) is nowhere near the reticle. Going to do without illumination.