Spile

7 hours ago, Planetarian said:

Since you've flocked the tube, have you noticed lint from the flocking paper being collected on the mirror surfaces? I'm planning to flock mine, but a bit worried about residue.

I did my OTA with black velour last year and there has been no shedding of material.

A simple multimeter is a very useful tool to have at hand and will make it easy to identify + and -.

I decided that it would be nice to have my Telrad next to my right-angle finder and mount it on a dovetail. 

The first step was to buy a used multiple-finder mount from this forum. 

Adapters that convert the Telrad base to a finder dovetail are available in the US but equivalents in the UK are difficult to find and are expensive for what they are.

 I decided on the DIY approach and a simple off-cut of wood did the job nicely at minimal cost...

From my younger days…

11 hours ago, John said:

No, the laser collimator as a whole goes on the V-block, provided that it is a symmetrical unit such as the one I posted a link to earlier in this thread.

@steppenwolf / Steve Richards shows a simple approach here:

 

Sorry but you have misunderstood my point. I don’t need to to remove my laser collimator from the focuser to find out if it’s no collimated or it’s nots correctly registered.

V blocks mean that I’d need to remove the laser. The rotation method in situ means I don’t. That works for me.

If you want to check a laser is collimated and registered in the focus tube, rotate it and see if the dot “walks” around the donut. Basically it shouldn’t.

9 hours ago, John said:

The original poster has one of these:

 

I do apologise. I have no idea why I got that from.

I can’t see anything different to what I see through the same telescope. Can you crop to the part you are referring to?

Cleaning the primary mirror of the 200P is very straightforward. If there is a challenge it’s prising out the mirror assembly as it is a tight fit in the ota. If you believe there is something missing or unclear in my guide, then let me know and I will update it.

As for collimation and concentricity of the secondary... The outer edge should be circular and concentric. It’s the reflection (it’s dark because it’s looking at the inside of the sight tube) of the secondary that is offset but it is still circular.

If the secondary is centred but still not quite circular and assuming your focuser is square to the main tube, you can either leave it as is and move onto the primary or you can keep tweaking to get it circular. I find loosening the assembly so it’s in my palm allows me to confirm there is a position that is just right.

As for which guide is right for you, I’d recommend reading as many as you can and picking out the parts that make sense to you. I came up with a=b nomenclature because using diagrams worked for me but were all learn in different ways so find one that works for you. Writing your own guide could be your salvation…

10 hours ago, a6400 said:

Thanks but the issue is being able to remove the primary and assemble it back safely.

I've seen some guides on cleaning already.

I'm trying to collimate with a cheshire with a crosshair but this scope has different kind of spiders so I can't really align it with the crosshair.

Read the guide on cleaning because it goes through the disassembly process too.

As for collimation as my guide says the reference points are the outside of the secondary, primary donut and edge of focuser. The cross hairs of the Cheshire are a reference point in respect of the centre mark. 

If the price and condition was right I would be happy with any make. Otherwise I would recommend the StellaLyra/Apertura.

I’ve written guides on cleaning mirrors and collimation (link below). Please try them out and if you have any questions, I’d be happy to help you.

First of all I think going for a Dobsonian is the right direction of travel. If you’re getting something larger than 8” I’d go and see one first as the size and weight may come as a surprise. Don’t worry about extras until you have started using your telescope and developed your skills. Allow time for this. The exception would be a copy of Turn Left at Orion and maybe a collimation cap. Finally, my blog has a number of resources and tips you may find useful.

I’ve a spreadsheet of 500 double stars that you can download off my blog. They are given a 1 to 5 rating which you may or may not agree with.  

If this could be run an an esp32 cam it would make a cost effective wireless project.

14 minutes ago, michaelmorris said:

No I moved out of Worcester 4 years ago.

I was thinking Bromsgrove.

I updated/upgraded my Skywatcher 200P over a period of a couple of years and it was pretty straightforward. I now have the equivalent of the StellaLyra.

14 hours ago, wookie1965 said:

It was more to do with the soft metal of the secondary holder how the indents can get so deep when the 3 bolts are not screwed right in I don't know. But I had the same problem on my Skywatcher 6" and 8" that's how I knew what to do. 

Thank you once again I really do appreciate it. 

I’ve read of others who had this issue and successfully deployed the milk bottle trick. Thankfully my Skywatcher is not affected at the moment.

I was diagnosed type two ten years ago and as a result of a low carb diet I was able to reverse it. I have a check up every couple of years but I have a target weight that I keep below and that makes all the difference. Reducing processed food rather than fats made all the difference for me.

I am pleased that you have sorted your mirrors. I also found that loosening the whole secondary assembly allowed me to actually visualise the intended result. 

On 10/09/2023 at 13:44, Spile said:

Its a lot better...

I agree. I’d just check the primary with a cap to make sure it’s centred.

Its a lot better...

A little bit of tilt should do it.

Here you go...