CHRlS

1 hour ago, John said:

The thickness of a Sainsbury's 4 pint plastic milk carton 🙂

 

For some reason I was thinking you meant a 100mm metal washer

2 hours ago, doublevodka said:

How about https://www.firstlightoptics.com/misc/stellalyra-roller-bearing-for-dobsonian-telescopes-8-to-16-aperture.html

I've not used one myself, but the Stellalyra dob owners seem pretty happy so I'd imagine it's pretty good 🤷‍♂️

It has good reviews on flo.

17 hours ago, Zermelo said:

Excellent. Many people use a combination of red dot and optical finder. With Goto, I tend to use just the optical finder.

I rely on goto a little too much. I realised I'd be using both a red dot finder and the findercope so I've bought a double findercope shoe.

18 hours ago, Carbon Brush said:

I have used a few of the 'chipboard' type dob mounts. They always benefit from a bit of care.
These mounts are made in quantity to a loose spec. With any luck tension adjustment only gives a good enough result.
On a used scope, dismantle the base (a couple of spanners) and give it a clean up. Then reassemble with a very little bit of Mr Sheen type spray, or silicon grease, or petroleum jelly.
I have been amazed at how much muck can accumulate in there and been pleased with the improvement after cleaning.
The milk carton washer mentioned by @john is another good mod.
 

I guess cleaning it and lubricating is the first thing to do and add a milk carton washer whilst it's unassembled.

18 hours ago, John said:

I have owned 2 of these but at least 10 years apart !

I picked up the latest one a couple of months ago. It is the 200P Classic model pretty much unused.

I was expecting some stickyness (for want of a better term) on the azimuth axis and when I first lighted the scope, it was there. The scope was useable but frustrating at high power because it was all to easy to apply too much push in azimuth to get it moving, overshoot the target, then do the same coming back the other way !

I tried different tensions on the central nut and bolt but that didn't really help. I then reminded myself of the old "milk carton washer" modification that I had used all those years back with my other 200P dob. 

For this new scope I found that adding a single large washer (about 100mm in diameter and with a 12mm hole in the centre for the bolt) made a noticeable difference in reducing the "sticktion" to a low and acceptable (for me) level while retaining stability in the mount base. I put my milk carton washer between the bottom board and the stock white teflon washer. I then bolted the mount base back together and applied enough torque to the central locking nut to hold things together in a stable manner. 

I think the way this works is that the additional thickness of the DIY washer takes a little of the weight off the 3 teflon pads that are used as the azimuth bearing. Some people find more than one DIY washer is needed but in my case one did the trick. 

I realise that other people use lazy susan type bearings and other approaches and those undoubtedly work for them. Different people have different preferences for ease of movement etc so this is why there is not 100% agreement on the best approach. People find what works for them 🙂

I have found the milk carton washer modification has worked for me 3 times now - I also owned a 10 inch Skywatcher dob a few years back and did the same thing on that - 2 washers needed with that one I recall.  

I have also owned dobs with lazy susan type bearings as standard and those needed some friction adding to the motion to get it to suit my tastes. 

 

 

 

I was thinking more than likely going down the milk carton washer route, well start off with that anyway as it's the cheapest! Do you know the thickness of the washer you added?

Hi,

I know this has been debated quite a lot over the years, but the reading I've done seems to be inconclusive with some saying something works whilst other saying something else works and none of them work and so on and so forth.

What I'm talking about is how stiff the azimuth direction is on the dobsonian base. Whilst observing at high magnification, it is all but to easy to nudge the target out of the field of view.

If you have one, what has worked for you?

Thanks.

@Zermelo I've just came back inside after splitting 65 piscium, aswell as a couple of others. The 9x50 findercope was the key to finding it pretty much instantly. It's definatley different to using a red dot finder!

8 hours ago, M40 said:

I always carried mine in two parts for a couple of reasons; I had four steps and about 5M of uneven paving to traverse plus I am very good at finding trip hazards 🤦‍♂️ enjoy your new telescope 👌

Come to think of it I'm good at finding trip hazards too

Hi,

I have bought a used skyliner 200p dob and was wondering whether carrying it whilst fully assembled is OK or would it damage the bolts/threads/handles over time? I would only be taking it in and out of the shed and walking it a few yards.

Thanks.

3 hours ago, Zermelo said:

I also observed 65 Psc on Friday.  Yes, Pisces is a bit devoid of waypoints if you're star-hopping, especially in brighter skies.

What scope are you using, and what finder(s) do you have?  I have a goto mount and RACI finder, and it's usually quite simple to match the starfield in the finder to a chart, unless I'm close to a bright moon. I'm not familiar with the app incarnation of Stellarium, but in SkySafari you can flip the chart E-W and N-S to match the view in your optical finder or scope.

If I had to star-hop then, yes, Delta Andromeda and straight down to the horizon, a little more than my finder's FOV.

I'm using a heritage 130p and I was using the az gti mount as a manual mount. I'm used to using the goto but want to search manually as much as I can for this list of doubles. The finder is just a simple red dot finder. I guess using my 25mm would act as my finder? My sky is heavily affected by light pollution, hence the reason to do some double star observing.

In stellarium there is the option to flip horizontal, I'm guessing this is East and west. The other option is to flip vertical, so this would be north to south. If a newtonian view is rotated 180 degrees does that just mean it is flipped upside down?

What scope and finder did you use? Was it easily split?

Hi, 

I've got Stellarium on my phone and was wondering what orientation I should have it set as. Currently I have no settings on for when I look at the sky using the naked eye, but when I look through a reflector, what should the flip view be? Horizontal, vertical or both? I would have tried to work it out myself tonight but it look as though it's going to be cloudy.

Thanks.

Hi,

I've downloaded a copy of the astronomical society double star list and thought I'd give it a try. I've already got stuck on the second star in the list.

The area around 65 piscium is rather sparce, both in the sky and in the star chart.

I started at Delta Andromedae and made a triangle using this star, Epsilon Andromedae and 28 Andromedae.

I then get confused with the orientation of the view I see through the scope compared to what I see on Stellarium.

I think I'm meant to go south from Delta down to the first brightish star seeable. 

Using a 130mm f5 reflector I was unable to split it, but I'm not sure it was the right star.

Any advice would be greatly appreciated.

Hi, 

Until I've decided on which manual mount I'm going to buy, I'll be using my az gti mount as a quick grab and go mount. By slacking off the clutches and manually moving the scope around, will this damage the mount in any way? The altitude seems to really smooth but the azimuth seems a bit tougher to move.

Thanks.

19 minutes ago, Carbon Brush said:

My experience has been that cool down time does matter - but how much?
If you were to carry your scope/mount/tripod in one lump from from a 23C room to a 0C outside and expect to immediately count Jupiters bands, GRS, etc, yes it matters.

Storing the scope in a cooler room, or a shed, or garage, or in a (not recently driven) car will help.

In practice we tend to carry things out separately and assemble outside. It takes longer, eating into cool down time.
Then of course we tend to look at an 'easy' target, low magnification, to check the scope is all OK, finder aligned, and the sky is as clear as we thought.
Finally we get around to viewing something at high magnification.
The quickest setup is of course a manual dob. Anything with goto has the levelling and alignment time.

HTH, David.
 

I guess I've been blessed with the heritage, being able to just grab it out the shed and being able to start using it straight away, especially with it being a flex tube. 

2 hours ago, Zermelo said:

I agree with the above. My 127 will usually be OK in around half an hour. Obviously, it depends on the difference in inside and outside temperatures on the day, and perhaps how fast the external temperature is falling. If I think I might be observing later, I just sit the Mak outside the back door to cool, and leave the setting up until I'm sure.

I like the idea of leaving just the scope outside just in case.

3 hours ago, bosun21 said:

Maks definitely require cool down time to get the best from them. My SW 150 needs at least 1 - 1 1/2 hours if taken from the house directly to outside before it's ready to use. Of course I could use it before this but the heat in the tube is seen as a shimmering image. I also previously owned a 127 which could be ready in about 45 minutes give or take. Once cooled the images are crisp

Perhaps I could cut that time in half by storing it in the shed rather than a house.

3 hours ago, davidc135 said:

Although there are dissenting voices the majority of experienced observers who have wrapped their Maks in insulating reflectix claim very positive results. But it sounds that it would be barely needed. Still, for pennies, why not try it.

David

For the cost, maybe every little helps 

4 hours ago, SwiMatt said:

As a proud owned or a Mak 127, I never noticed excessive cool down times. I was also scared about it before I bought it, but it has not been an issue so far.

My typical observing routine is to walk 10-15 minutes to my observation spot with the Mak in a backpack, set up, and start right away on brighter objects until dark adaptation kicks in. In my experience, by the time I'm dark adapted, the Mak is ready to go. Also the few times I observe from my balcony (taking the scope directly from my apartment outside) I didn't notice problems. Also, I'm a noob, and I suspect that more experienced people might have more fine tuned experiences about this...

I guess I probably wouldn't notice the difference either as I still class myself as a noob. If you can use it straight away on your balcony, I guess taking mine out from an unheated shed would be even better?

4 hours ago, NGC 1502 said:

If it were my choice-

Skymax 127 for Lunar/Planetary and keep the ST80 for a wider view.  Those 2 scopes nicely complement each other.

Cooldown for the 127 should not be long with the suggestion already mentioned. 
 

Option 2.  Have another try at making a shield for the H 130, and live with the helical focuser. Many have fixed the focuser with PTFE (plumber’s) tape.

Ed.

I might have to have a look at a new shroud even if I get the skymax, I would then have a different types of  telescopes rather than two of the same.

4 hours ago, RobertI said:

If it’s lunar and doubles, I would think the Skymax 127 would give the nicest results, but understand that cool down might be an issue if you do short spur of the moment observing. Can you store the scope outside in a shed or garage to keep it closer to ambient temperature? 

I would keep the scope in the shed so I guess that would help.

Hi,

I currently own 2 telescopes, a skywatcher 130p heritage and a skywatcher st80. I use the former as my visual scope, from now on it's going to be for lunar and double stars. The only downside is it is a flex tube, allowing light in through the mid section. I keep making shrouds but they don't last. I also prefer a rack and pinion focuser compared to the helical focuser that the heritage is supplied with. The latter is what I use for e.a.a. The only downside I have found is it's too small for visual but perfect for e.a.a. Unfortunately I broke the dob base so I use a skywatcher az gti with both scopes. I'm looking to buy a new mount and tripod, this time with slo mo controls. I would then have a goto and a manual mount. The price of the mount and tripod is £259. For an extra £66 it would come with the same scope as my heritage but not having a helical focuser or a flextube construction. For an extra £130  it would come with an st102, a bit bigger than my st80 but not sure if it would compete with the 130mm reflector. Finally, for an extra £239 it would come with a skymax 127. This one seems to be calling out to me but my observing seems to be spur of the moment.  The only problem with the skymax that is stopping me buying it is the cool down time. I've never used this type of scope before so I have nothing to compare it with, unlike the other two.

In my situation which one would be the best thing to go for?

Thanks.

50 minutes ago, lunator said:

Chris, it is a lovely double.

There are lots of colourful pairs. Almach and Albireo are 2 showpiece pairs.

Cheers

Ian

I think I've set the bar high, picking out show piece stars for my first targets.

2 hours ago, Spile said:

It’s a fine double and great colour contrast too. Doubles are good friends for those of us with light polluted skies.

I do have light polluted skies, so double stars seem to be goods targets to observe.

2 hours ago, Zermelo said:

Yes, Almach is a perennial favourite. Regarding the astigmatism in your eyesight, you should find that it is less of a problem with higher magnifications (it actually depends on the size of the "exit pupil" of the light entering your eye).

It will now stay on my target list for anytime it's visible. I've just read a little on pupil size and now understand why it's worse at lower magnifications. 

2 hours ago, Mr Spock said:

It's a very pleasing sight. Doubles can be very absorbing. There are quite a few eyepieces with 20mm of eye relief, I'm sure glasses wearers can recommend some.

I think it's fair to say that it can be addictive, especially the different coloured ones.