SLT Mount noisier in alt movement?

[johnnyp]

Hi all, Im Enjoyin my newly purchased nexstar slt 102, but just a slight niggle with the noise of slewing when moving in altitude. Azimuth seems smoother and somewhat quieter, while alt is more of a slightly louder grinding noise.

Does this sound like the norm with the slt mount? Or should the sound be uniform in both alt/az movement?

Advice Welcome

Cheers

John

[BrownClaw]

Just a quick thought; is the OTA well within the weight limit for the mount? It might be trying harder than it should be if not

[brianb]

Balance? A heavy eyepiece might load the alt motor ... best to balance the scope reasonably well "fore & aft" by sliding the dovetail along to the centre of gravity, which is easy enough to check when you have the tube dismounted.

[johnnyp]

Just a quick thought; is the OTA well within the weight limit for the mount? It might be trying harder than it should be if not

Hi Brownclaw, The OTA is the standard one so shouldnt b a problem

Thanks for the reply

[johnnyp]

Balance? A heavy eyepiece might load the alt motor ... best to balance the scope reasonably well "fore & aft" by sliding the dovetail along to the centre of gravity, which is easy enough to check when you have the tube dismounted.

Hi, only used the standard eyepieces as yet so dont think this is the problem. The scope seems balanced etc. Just noisier when moving in alt compared to azimuth. But i have nothin to compare it to so not sure if if it is normal or not.

cheers

[johnnyp]

Any body with the slt mount shed any light on it being noisy in altitude? its sounding like its going to give up the ghost lol

[ringz]

Jonnyp,

It's no good assuming that you have the scope balanced, you have to check it.

Take the mount, with all the eyepieces/finder etc fitted,

Place on a flat surface such as a table with the dovetail flat on the table,

Then use something like a pencil underneath the dovetail and move it until you get the scope balanced.

Mark where the pencil is.

Now mount the scope with the mark in the centre of the dovetail bracket.

Now see what the scope sounds like.

--

Martyn.

[jgs001]

I don't recall mine being significantly noisier in Alt than in Az, but it's possible that given the design, the noise of the motor will be more noticeable. I do know I had to work on the balance of mine a little, and fit the scope further forward than you would expect, although I've never used it with the little 60mm frac that came with the mount. The dovetail on that is short and fixed, so if you're's is the same, it's likely you have very little adjustment in balance.

[dph1nm]

The noise is certainly different in the two directions. I can't remember which is loudest though. I can check this evening ...

NigelM

[johnnyp]

I don't recall mine being significantly noisier in Alt than in Az, but it's possible that given the design, the noise of the motor will be more noticeable. I do know I had to work on the balance of mine a little, and fit the scope further forward than you would expect, although I've never used it with the little 60mm frac that came with the mount. The dovetail on that is short and fixed, so if you're's is the same, it's likely you have very little adjustment in balance.

The dovetail is short and fixed as you mention so not much room for adjustment.

[johnnyp]

The noise is certainly different in the two directions. I can't remember which is loudest though. I can check this evening ...

NigelM

Ok that would be most helpful. It is working of course, just sounds like its grinding and struggling somewhat.

[johnnyp]

Jonnyp,

It's no good assuming that you have the scope balanced, you have to check it.

Take the mount, with all the eyepieces/finder etc fitted,

Place on a flat surface such as a table with the dovetail flat on the table,

Then use something like a pencil underneath the dovetail and move it until you get the scope balanced.

Mark where the pencil is.

Now mount the scope with the mark in the centre of the dovetail bracket.

Now see what the scope sounds like.

--

Martyn.

I think i understand that, but the mount sounds the same without the scope even fitted. I will have a go at balancing the scope like you state though.

[dph1nm]

Hmm - well I have given it a listen. I wouldn't say there was much difference in volume, but the tone is quite different. My azimuth sounds quite tinny, whereas the altitude has more bass tone to it (more of a growl). I did have trouble with my azimuth motor (as did a friend of mine), and it has been replaced - but the symptoms were basically variable speed of movement (and hence change in pitch of the motor noise) when you kept the button pressed down. I think if the noise is constant then you are probably OK. A quiet mount it is not!

NIgelM

[Brinders]

I have the SLT mount and have to say it is quite noisy when slewing, but very quiet when tracking (just a quiet ticking noise, a little like a clock). The noise from both motors when slewing is about the same in volume but of higher pitch from the altitude motor compared to the azimuth one.

Brinders

[johnnyp]

Hmm - well I have given it a listen. I wouldn't say there was much difference in volume, but the tone is quite different. My azimuth sounds quite tinny, whereas the altitude has more bass tone to it (more of a growl). I did have trouble with my azimuth motor (as did a friend of mine), and it has been replaced - but the symptoms were basically variable speed of movement (and hence change in pitch of the motor noise) when you kept the button pressed down. I think if the noise is constant then you are probably OK. A quiet mount it is not!

NIgelM

I think change in the speed of motor is my problem also as over the last couple of days its has become more noticeable. The noise is certainly not consistent! Off to the supplier anyway me thinks.

Thanks for your help mate.

John