Counterbalancing an AZ3? Will this work?

[lw24]

Hi all,

I've finally realised that I'm going to need some form of counterweights to balance my ST120 on my AZ3. I'm not very good at DIY, and will not attempt to purchase specific nuts and bolts and then make something in a shed. I want to be able to buy something that will work.

Earlier on, I read that the AZ3 was Syntas clone of the Vixen Alt-Az mount, but they didn't bother putting a counterweight system on. Seeing as Vixen did, surely I can buy a Vixen Dovetail Counterweight Adaptor, and use it on my AZ3?

Here it is

Will that work?

Cheers

[brianb]

Sorry but I don't think an AZ3 is ever going to work well with an ST120 ... it's OK with a 80mm frac or 90mm Mak but not suitable for anything much bigger IMHO.

[lw24]

It works fine when I mount the telescope further down the tube rings, and that's when I've got a barlow, eyepiece, and red dot finder at the bottom.

I'm just scared to add any heavier things to the bottom, so am trying to increase the weight of the telescope at the front end.

[JamesF]

Sorry but I don't think an AZ3 is ever going to work well with an ST120

It's what you get if you buy the ST120 with an alt-az mount though, so you've sometimes got to live with it.

I've noticed that the scope is sometimes a little "back end" heavy and push it forward through the rings to compensate. I've not looked to see if there's anywhere suitable for mounting a counterweight, but just because it's a copy of the Vixen design doesn't necessarily mean that the Vixen parts will fit without work.

I don't think it needs too much in the way of balancing weights though, so perhaps the simple solution might be to use some of those wrist- or ankle-weights and strap them behind the dewshield? The other solutions I can think of immediately definitely require knowing your way around a toolbox.

It may be possible to introduce a but more friction into the alt bearing, but mine seems fairly stiff as it is so I'm not certain that's a great idea.

James

[lw24]

I was thinking that some weights strapped around the dew sheild area might work.

Would these work?

They have adjustable velcro, so I could probably make them fit around the dew sheild.

Cheers!

[step_hen]

No reason why that vixen counterweight wont work, provided you have enough spare dovetail at the front to hang it down from, but as Brian says thats a lot of weight on the little AZ3 mount and an expensive adapter to boot to get it to balance.

Stephen

[lw24]

No reason why that vixen counterweight wont work, provided you have enough spare dovetail at the front to hang it down from, but as Brian says thats a lot of weight on the little AZ3 mount and an expensive adapter to boot to get it to balance.

Stephen

So just some simple wrist/ankle weights strapped onto the dew sheild area of the telescope might do the job a little better?

I'm also looking to change the standard aluminium legs to wooden tripod legs (TAL wooden tripod), for extra stability

[Carbon Brush]

The Skywatcher Altaz I used to have relied on a nyloc nut and washers to provide grip. With a lightweight scope you could leave the nut loose and everything was OK. with a heavier scope (ST102) you had to tighten the nut to hold off balance loads and the mount got very stiff.

What do I mean by off balance? Trying to use a 2" barlow. Or trying to use eyepieces with big differences in focus. Or worst of all, trying to hang 1Kg of DSLR on there.

I did add a home made adjustable counterweight bar to make the mount usable.

The mount was fine with a small scope - but that is all.

The saying about silk purse & sows ear comes to mind.

[lw24]

I said in my original post, I don't want to have to make anything myself, I'm just looking for simple things I can do to help it balance.

Would adding wrist/ankle weights to the front of the telescope help?

[JamesF]

I'd put them on the scope body itself rather than the dew shield, but I'd have thought something like that has to be worth a try and it's relatively cheap to write off if it doesn't work.

Sounds like the Vixen counterweight requires a dovetail bar which you don't have and would require a fair bit of work to sort out, so that seems like a non-starter.

If you're going to the lengths of replacing the legs and so on though, I'd have serious thoughts about just buying an entire heavier duty mount.

James

[lw24]

I don't have the funds to buy a whole new mount. If I wanted to buy a new mount, it has to be portable, and be an Alt-Az mount.

The only real contender is AZ4, but apparently, the aluminium legs aren't very good, and need replacing.

My budget is around £100, so a TAL Wooden Tripod = £80 and a couple of ankle/wrist weights = £15

Fits the budget nicely.

[russ]

Sorry but I don't think an AZ3 is ever going to work well with an ST120 ... it's OK with a 80mm frac or 90mm Mak but not suitable for anything much bigger IMHO.

I can now say through experience that's not true. We bought an AZ3 for my son's Skymax 127.....works like a charm. And less vibration, quicker damp down than the Porta we tried at SGL6. Probably because the scope is being held flat with low centre of gravity rather than held at one small point in a dovetail.

Only issue with the AZ3 is the stiff altitude movement to prevent it flipping back. It does need the weight mod for proper balance.

Weight is about the same for the Skymax 127 and Startravel 120, you don't need to waste money on a new mount. Just find a way of modding the AZ3.

[russ]

I don't have the funds to buy a whole new mount. If I wanted to buy a new mount, it has to be portable, and be an Alt-Az mount.

The only real contender is AZ4, but apparently, the aluminium legs aren't very good, and need replacing.

My budget is around £100, so a TAL Wooden Tripod = £80 and a couple of ankle/wrist weights = £15

Fits the budget nicely.

The AZ4 won't offer any better damp down times holding the ST120. I own both the AZ4 and the AZ3, the AZ3 is a real surprise. I've always overlooked it for the reasons Brian said. Just shows you really should use something before dismissing it.

What the AZ4 does offer is smoother movements on both axis and no need to mod. But then it does cost £200 with the right tripod.

[lw24]

I think I'll go for some wrist/ankle weights, and strap them on near the front of the tube. Should do a bit to help, seeing as they are 2kg each.

[brianb]

Just shows you really should use something before dismissing it.

I did have one ... the balance issues with a 80mm frac were just about manageable, with anything much heavier there would be a real chance of the whole tripod tipping in some scope positions.

The T mounts are far superior in every respect. The SW Skytee 2 (with slow motions) mounted on an HEQ5 or EQ6 type steel pipe leg tripod would be very satisfatory indeed with a ST120 on it (and you could mount a smaller frac or a Mak up to about 125mm as well).

Seriously.

A rickety mount is the best way to get fed up with a scope. Mount the scope properly - or overmount it - and enjoy using it.

[lw24]

I've already said, I don't have the funds available...

[tinvek]

can;t see why some form of counter balance won't work, i wouldn't recomend it but i needed to take a reasonable sized scope to work one night and didn;t wan to mess round aligning an EQ mount durring our half hour dinner break (is it really dinner at midnight?) so i tried my skywatcher 150p on my AZ3 and it wasn't that bad once i'd got it balanced (though i did leave the legs retracted)

if you want to just try and see how well a counter balance works, try hanging something from the end of the scope, if it works ok then wrist weights may be a simple answer,

there was a post somewhere of how someone made a counter balance rod and bracket for their AZ 3, if you've got access to a drill. saw and a vice you could probably put something together very cheaply.

[russ]

I did have one ... the balance issues with a 80mm frac were just about manageable, with anything much heavier there would be a real chance of the whole tripod tipping in some scope positions.

The T mounts are far superior in every respect. The SW Skytee 2 (with slow motions) mounted on an HEQ5 or EQ6 type steel pipe leg tripod would be very satisfatory indeed with a ST120 on it (and you could mount a smaller frac or a Mak up to about 125mm as well).

Seriously.

A rickety mount is the best way to get fed up with a scope. Mount the scope properly - or overmount it - and enjoy using it.

There is absolutely nothing rickety about the AZ3 with the 127 Mak on board. With a simple mod the tipping issue can be overcome and you are left with a good AltAz solution. Damp down times are very similiar to the AZ4.

Yes it won't match a Skytee 1/2, Giro etc but it's been said a number of times (and in capitals) he doesn't have £300 or anywhere near it!!!!!!!!!!!!

[JamesF]

There is absolutely nothing rickety about the AZ3 with the 127 Mak on board. With a simple mod the tipping issue can be overcome

What mod did you do?

James

[lw24]

I've just about managed to spare some cash for a new mount (£140), and therefore I am going to buy an AZ4 with the Aluminium Legs, due to cost, lightness and portability.

I can always upgrade the legs at a later stage.

[russ]

What mod did you do?

James

At the moment i've done a cheat mod, not the proper mod like Anthony has done. I've put a longer dovetail that extends in front of the scope and onto that put my MkI dob counterweight. My neighbour is positive she can have a proper bracket made, so should end up with a properly modded AZ3.

Everyone has different ideas of what works and doesn't. We're happy with the AZ3, especially considering the cost. Rickety is a word i would use to describe using an EQ1/2 but not the AZ3.

I've just about managed to spare some cash for a new mount (£140), and therefore I am going to buy an AZ4 with the Aluminium Legs, due to cost, lightness and portability.

I can always upgrade the legs at a later stage.

AZ4 is very nice to use. Don't be shocked if it doesn't reduce the damp down times compared to the AZ3 but the movement in both axis is very smooth. And the steel tripod makes a big difference when you upgrade later.

[NGC 1502]

Adding weights to the optical tube will only balance the scope when

it is horizontal with the AZ3, as the pivot point is below the tube.

To balance the tube when it is pointed up, requires a counterbalance

below the pivot point. That is why Vixen made a heavier duty alt-az

mount called the Custom D, with just such a counterweight, as in

the link here (scroll down for pics)

Two Fast and Useful Alt/Az Mounts: The Vixen Custom D Alt/Az Mount and Tele Vue Gibraltar Mount - Review

Regards, Ed.

[lw24]

AZ4 is very nice to use. Don't be shocked if it doesn't reduce the damp down times compared to the AZ3 but the movement in both axis is very smooth. And the steel tripod makes a big difference when you upgrade later.

The problem with the ST120 on the AZ3 wasn't the stability of the tripod legs, just the balance of the Altitude, so the Aluminium legs should be fine for now.

Also, it says that telescope tubes are mounted to the AZ4 via a standard vixen-type dovetail bar. What dovetail would I need for my ST120? I only have tube rings at the moment, so I think I need to buy a dovetail bar.

Would something like this work?

Cheers

[russ]

The problem with the ST120 on the AZ3 wasn't the stability of the tripod legs, just the balance of the Altitude, so the Aluminium legs should be fine for now.

Also, it says that telescope tubes are mounted to the AZ4 via a standard vixen-type dovetail bar. What dovetail would I need for my ST120? I only have tube rings at the moment, so I think I need to buy a dovetail bar.

Would something like this work?

Cheers

The Skywatcher Medium dovetail bar would be perfect for the AZ4:

Dovetail bars - Skywatcher Dovetail Mounting Plates

[lw24]

Ok, cheers, got everything sorted now!