Less wobbly scope/stand!

[mjstarryeyed]

Hey folks, 

n00b here. I've been out and about with my 150p dobsonian Skywatcher for the last 2 years and had some sweet views of the moon. Tonight I used my 2x barlow with a 7mm eyepiece and saw the lunar surface in beautiful detail and also - got Mars!!! It was beautiful but also..so quick! My first time viewing a planet

Actually, I found it quite hard keeping Mars in my sights not only because of the speed but because of the lack of stability with the Skywatcher. Every time I moved it in azimuth, the eyepiece shakes. Not much but enough for distant Mars to become unobservable.

Any ideas on how to stabilise this particular scope? OR what I can move on to next? I have a small love affair with Jupiter so my ultimately my aim is to build up to being able to observe it and all of it's moons eventually.

Appreciate your thoughts! 

Thanks
MJ

Edited December 22, 2020 by mjstarryeyed

[Avocette]

If I am correct your magnification is around x343 which is in any circumstances is very high! Sometimes ‘less is more’ - you may find that taking the Barlow away may give you a more satisfyingly view over all.

By the way you are in the ‘imaging’ part of the forum - you might get quicker responses in the other parts of the forum.

[mjstarryeyed]

Oh thanks Avocette, have posted elsewhere and will look to delete this somehow. 

Also, I didn't start with the Barlow, the 7mm was more or less the same without. The moon was best at 15mm

[Ricochet]

It sounds like you might have the tension set too tight. There is a bolt that goes down through the centre of the rocker box and connects it to the base board that it turns on. By trial and error you will find that there is an optimum tightness level for the bolt. 

If that still does not give you satisfactory results some people like to cut a load of washers from the sides of plastic milk bottles. These washers are then added between the base board and rocker box on the connecting bolt. You want just enough washers in the stack so that the stack of washers starts to take some of the weight of the telescope. Again, it will require trial and error to determine the optimum number of washers in the stack for the smoothest motion.

Also, we have just had a conjunction of Jupiter and Saturn, meaning that they appear to be very close, and can even be seen at the same time in eyepieces with a suitably large field of view. For my location it is looking like tomorrow (24th) might be cloud free enough to have a look at them, so perhaps it is the same for you. They are both extremely low at the moment so you would need to find a location where you have a clear view to the south-west (i.e. nothing as high as a house for a few hundred metres) at about 4-5pm if you want to try to catch this event.

[Louis D]

You could also try putting anti-vibration pads under each foot of the baseboard.  They can help dampen vibrations to under a second.  You can cheap out and get great performance with Sorbothane pads such as these.  Just don't forget they're under each foot at the end of the night.  If you're on dirt or grass, there isn't much of a reason to use pads.

[Tiny Clanger]

17 hours ago, mjstarryeyed said:

Hey folks, 

n00b here. I've been out and about with my 150p dobsonian Skywatcher for the last 2 years and had some sweet views of the moon. Tonight I used my 2x barlow with a 7mm eyepiece and saw the lunar surface in beautiful detail and also - got Mars!!! It was beautiful but also..so quick! My first time viewing a planet

Actually, I found it quite hard keeping Mars in my sights not only because of the speed but because of the lack of stability with the Skywatcher. Every time I moved it in azimuth, the eyepiece shakes. Not much but enough for distant Mars to become unobservable.

Any ideas on how to stabilise this particular scope? OR what I can move on to next? I have a small love affair with Jupiter so my ultimately my aim is to build up to being able to observe it and all of it's moons eventually.

Appreciate your thoughts! 

Thanks
MJ

Mars is going to scoot across your view really fast with a 7mm and 2x barlow !

My 150 heritage dob is the sort that closes up, but has a similar turntable base. What I've found when looking at planets is that shifting the az with it in tiny increments is an art : it resists turning ( because of friction ) then when the force of my push overcomes that friction it's easy to overshoot, plus it takes a moment for the view to settle as the 'scope vibrates. I get more precise control by using a finger and thumb grip on the outer edge of the circular plate rather than any part of the telescope.

I believe some folk improve the 'glide' of dobsonian bases with teflon pads , but I've not done that myself so can't comment on how useful it is, I'm sure someone with the relevant experience will come forward.

I've used a 2x barlowed 8mm EP on the odd occasion, but find it a more comfortable view without the barlow, more time to actually view Mars before the 'scope needs adjusting. I've spent hours at a time watching Mars with my 150, and had good views of Saturn and Jupiter too when they were high in the sky in the summer , rings, moons and all ,so when Jupiter is favourably placed you should be able to see it too ! At the moment it may well be too low , and sets so soon after twilight you have to have an unobstructed view to the SW to stand a chance, but if there's a clear evening give it a try.

Heather

[Capt Slog]

1 hour ago, Tiny Clanger said:

Mars is going to scoot across your view really fast with a 7mm and 2x barlow !

My 150 heritage dob is the sort that closes up, but has a similar turntable base. What I've found when looking at planets is that shifting the az with it in tiny increments is an art : it resists turning ( because of friction ) then when the force of my push overcomes that friction it's easy to overshoot, plus it takes a moment for the view to settle as the 'scope vibrates. I get more precise control by using a finger and thumb grip on the outer edge of the circular plate rather than any part of the telescope.

I believe some folk improve the 'glide' of dobsonian bases with teflon pads , but I've not done that myself so can't comment on how useful it is, I'm sure someone with the relevant experience will come forward.

I've used a 2x barlowed 8mm EP on the odd occasion, but find it a more comfortable view without the barlow, more time to actually view Mars before the 'scope needs adjusting. I've spent hours at a time watching Mars with my 150, and had good views of Saturn and Jupiter too when they were high in the sky in the summer , rings, moons and all ,so when Jupiter is favourably placed you should be able to see it too ! At the moment it may well be too low , and sets so soon after twilight you have to have an unobstructed view to the SW to stand a chance, but if there's a clear evening give it a try.

Heather

A bit of Mr Sheen (other silicone based polishes are available   ) does wonders for stuff like this, and it makes curtain rails work a treat, too

Edited December 23, 2020 by Capt Slog

[Tiny Clanger]

1 minute ago, Capt Slog said:

A bit of Mr Sheen (other silicone based polished are available   ) does wonders for stuff like this, and it makes curtain rails work a treat, too

Thanks for that reminder, we used it on the moving bits of the long rotary trimmers in the photo finishing area when I worked as a photographer years ago, I'd forgotten all about it !

Heather

[mjstarryeyed]

The tension was definitely too tight, it's slightly better after adjusting, thank you @Ricochet! And thanks all of the other ideas, I know they will come in handy.

@Tiny Clanger, I'm looking into the Teflon pads too and also backing off the barlow for a bit 😆 Also, your explanation of shifting the az being an art is bang on, there's a little science to doing it without overshooting.

I've found a decent spot with a clear horizon for the now passed conjunction, only to be thwarted by a good bit of Yorkshire cloud. Tomorrow may be better, fingers crossed. Maybe I'll catch Santa doing some early rounds around Jupiter.

p.s. also realising why my arms are strong even though mostly in these days, carrying the dob base around is a decent workout!