What happens you overload a mount - EQ5, HEQ5, NEQ6 etc

[stem1989]

Obviously its not going to start smoking and burst into flames when you start slewing,

but whats the long term damage that can be done for overloading past the stated requirements by 20-30%.

Obviously it depends on how much you overload them by and for how long, what your using it for (visual, imaging etc)

but just as a general rule of thumb, do the gears wear down? is it just 'unsteady'? easily knocked out of alignment etc?

Do piers or a better tripod 'up' the payload?

I don't plan on doing this, I was just curious as to what would happen to the mounts accuracy and life? They have these limits for a reason right

[matsey]

This is something I'd be really interested in understanding as well, again out of curiosity and a general desire to increase my understanding of how everything works !

I think I've read somewhere a few times that tracking accuracy (for imaging) is adversely affected by an overloaded mount, but I certainly don't understand the technicalities behind why that would be the case.

I will await the knowledgeable responses with much interest

[billhinge]

When I didn't properly balance my C11 on a CG5 Dec axis, the motor will turn one way supported by gravity but not the other way working against gravity.

Haven't had a problem with the RA axis but guess it would be similar result

An example of why good balance is important and why you shouldn't rely on the thick tar grease of the original mount to simulate balance

[michael.h.f.wilkinson]

The main problem is not so much damage, but instability. As you increase the mechanical load, vibrations become harder and harder to dampen out properly, and the image at the EP bounces around uncontrollably (long before things come crashing down). Many scopes have been sold on inadequate mounts, and the same mount (or clones) get very different load ratings from different sellers. It all has to do with what the seller thinks is acceptable (or what he thinks can get away with). Weight is actually not the best measure, as the length of the scope comes into play as well (long scopes of a given weight have a higher moment of inertia than short ones, which means you can put a bigger SCT than Newtonian on a given mount). The Great Polaris mount has a rating from Vixen of 6-7 kg (or rather: a 4" refractor, 6" Newtonian, or 8" SCT, which makes more sense), whereas the Synta clones (EQ5) gets a rating of 10 kg. The Vixen origina is generally considered to be the sturdier mount.

[Jessun]

Long term damage is that you'll wear out the gear, and backlash will increase. This will happen over time with any geared mount - the term 'wear in' the gears even pops up here and there.

How much faster will it happen? Clue less. But these are solid gears and they do few hours and complete very few revolutions during use in comparison to, say the gears of your power drill.

Also an unbalanced load is far worse than a balanced heavy load. If you're off by too much most motors will cut off as they normally have protection built in.

The results will tell if you have a problem long before the gears do - ie too big a tube will be tossed around in the lightest of gusts and the mount can't keep it in check. Observation and photography becomes frustrating.

/Jesper

[Dark Matter]

Guys,

I'd like to wade in here and say, I've got an EQ6 Pro and it carries ~25-30 kgs of camera gear (two-three Canon and 1 Nikon pro DSLR's and lenses up to 500mm) and a 60mm guide scope.

After 12 months of heavy usage, the mount shows NO sign of wear, so much so the mount still gives up to 15 mins. unguided tracking. I have no slop in RA/Dec and backlash in Dec has been trimmed down to virtually zero.

Mind you, a PEC is always done and employed prior to every photo session. I control the mount via SKY X using ASCOM.

In regards to balance, while I can feel just a tad resistance on the RA axis (that's to be expected with this payload) the balance in both axis is spot on.

One way to check your GEM balance, is to do in the hottest part of the day. This is to allow the grease to thin out and bearings run a lot better.

Never try and balance a GEM at night. Once the grease thickens up due to cold, it can give you a false balance reading.

In toto, the EQ6 Pro IMHO, could when balanced up properly, a C14 OTA.

[PDW]

In engineering terms the mounts we use are very lightly loaded - just rotating a well balanced small mass at a fraction of 1 rpm using fractional horsepower motors. Relatively substantial increases in that small mass will be of no consequence.