A neat way to add Telrad or Rigel quickfinder aligning with RACI

[starhiker]

I have been experiencing difficulty to use the RACI on my dob for star hopping. Though its FOV is 5 degree, I just realised that it is much harder than using a binocular to star hop. Probably a bortle 6 sky might be another reason to cause the difficulty. Now I learnt that a Telrad or Rigel quickfinder should help a lot. While i am still thinking which one I should get, I read that I have to use a double-side tape to attach the base on both choices. I am just wondering if there is a neat way to attach it, like some dual mount on top of the existing RACI mount. Thanks.

I read that either Telrad or Rigel can be a good choice with some pros and cons, like light weight and the height of Rigel or an extra 4 degree circle of Telrad. But any comments on the choice is also welcomed  

[cajen2]

I used a Quickfinder for a while but found the tape wasn't good enough - I have to store my scope almost vertically and the QF kept falling off! I now use a red dot finder like a gunsight, without bothering with the red dot. It gets me close enough to use the RACI.

[cajen2]

There's a dual finder bracket that I might invest in:

https://www.widescreen-centre.co.uk/ts-dual-finder-scope-mounting-bracket.html

Edit: in fact, I've just ordered one!

Edited October 31, 2022 by cajen2

[Carbon Brush]

In principle there is nothing wrong with using a double sided tape. However, it can go wrong.
If the tape is really old it won't work too well - like when you buy a used finder and the spare tape is offered.
A second, and more common cause of failure is resdues on the scope. In extreme, leftover Mr Sheen or similar will prevent adhesion.
A quick wipe with a bit of IPA, Baader fluid or moist specs lens cleaner will remove 'leftovers'.
I have been using double sided tapes in work for 40+ years and if applied correctly, the problems are with removal, not adhesion.

There lots of pros and cons with both finders. These have been discussed in other threads on SGL.
In part it is personal preference, also influenced by OTA size. What scope do you have?

HTH, David.

Edited October 31, 2022 by Carbon Brush

[AstroMuni]

1 hour ago, starhiker said:

I read that either Telrad or Rigel can be a good choice with some pros and cons

Its just personal choice.

I am just listing the Pros & Cons of Telrad here.

Pros:

Larger FOV, easier to view

AA batteries ( I have listed this as a Pro as I normally have AA batteries lying around rather than button cells)

Cons:

Larger than Rigel and takes up more space on OTA

Heavier than Rigel

 

There is a good discussion here https://www.cloudynights.com/topic/17315-telrad-vs-rigel-quickfinder/

 

 

 

[starhiker]

Thanks @cajen2 for showing me the dual finder mount. I guess it works fine for RDF. Does it work for Rigel or Telrad too?

@Carbon Brush, thanks for the comments for how to keep the double-sided tape tight. My concern is exactly what @cajen2 mentioned about it may fall unexpectedly. It is a tape after all. But if there is no better way, I will use the tape. It is still better than drilling a hole and fixing it. 😀

I guess space is not an issue as mine is a 8" dob. 

@AstroMuni, a larger FOV for Telrad is not what I am aware of. I thought they are the same as both are zero magnification. If this is so, I may lean towards Telrad.

 

 

[AstroMuni]

23 minutes ago, starhiker said:

I thought they are the same as both are zero magnification.

The telrad projects an additional ring of 4deg (besides the 0.5 & 2deg which the Rigel also has). HTH.

Edited October 31, 2022 by AstroMuni

[cajen2]

24 minutes ago, starhiker said:

Thanks @cajen2 for showing me the dual finder mount. I guess it works fine for RDF. Does it work for Rigel or Telrad too?

@Carbon Brush, thanks for the comments for how to keep the double-sided tape tight. My concern is exactly what @cajen2 mentioned about it may fall unexpectedly. It is a tape after all. But if there is no better way, I will use the tape. It is still better than drilling a hole and fixing it. 😀

I guess space is not an issue as mine is a 8" dob. 

@AstroMuni, a larger FOV for Telrad is not what I am aware of. I thought they are the same as both are zero magnification. If this is so, I may lean towards Telrad.

 

 

I'll let you know if it'll mount a RQ when it arrives. It should just fit into the existing mount for my RACI. No idea about mounting a Telrad - never had one.

The only issue with putting a Quickfinder on it is that it'd be pretty high. I intend to use the RACI and a Baader RDF on it.

[bosun21]

I have a Rigel quickfinder on my 8” dobsonian alongside my RACI and starsense unit (overkill) I also had trouble with the Rigel coming loose after a month or so despite buying good quality tape and cleaning the adhesion site. I ended up buying a triple dovetail base and modifying the Rigel to accept a finder shoe. Problem solved . I also have a telrad on my Maksutov which I love and deem it to be superior to the Rigel.

 

[starhiker]

14 minutes ago, bosun21 said:

I have a Rigel quickfinder on my 8” dobsonian alongside my RACI and starsense unit (overkill) I also had trouble with the Rigel coming loose after a month or so despite buying good quality tape and cleaning the adhesion site. I ended up buying a triple dovetail base and modifying the Rigel to accept a finder shoe. Problem solved . I also have a telrad on my Maksutov which I love and deem it to be superior to the Rigel.

 

 

Thanks for the picture! This is some sort of alignment I am looking for!

[starhiker]

29 minutes ago, cajen2 said:

I'll let you know if it'll mount a RQ when it arrives. It should just fit into the existing mount for my RACI. No idea about mounting a Telrad - never had one.

The only issue with putting a Quickfinder on it is that it'd be pretty high. I intend to use the RACI and a Baader RDF on it.

Looking around the choice of RDF, it comes with a better looking than either Rigel and Telrad. I may need to read around the past discussion about why people don't take it as the first choice..

[cajen2]

Just now, starhiker said:

Looking around the choice of RDF, it comes with a better looking than either Rigel and Telrad. I may need to read around the past discussion about why people don't take it as the first choice..

Some people don't like having a red dot superimposed on the view - it tends to hide the target, whereas a RQ or Telrad have rings. I don't have a problem with my Baader RDF as I can adjust the brightness. Anyway, it's often enough to get the target in view without using the dot - like a gunsight. 9 times out of 10, that puts it in the FOV of my RACI.

[Guest]

26 minutes ago, bosun21 said:

I have a Rigel quickfinder on my 8” dobsonian alongside my RACI and starsense unit (overkill) I also had trouble with the Rigel coming loose after a month or so despite buying good quality tape and cleaning the adhesion site. I ended up buying a triple dovetail base and modifying the Rigel to accept a finder shoe. Problem solved . I also have a telrad on my Maksutov which I love and deem it to be superior to the Rigel.

 

Now your just showing off. 

[bosun21]

40 minutes ago, cajen2 said:

I'll let you know if it'll mount a RQ when it arrives.

I had to modify my RQ base to allow it to accept a standard finder shoe.

[cajen2]

1 minute ago, bosun21 said:

I had to modify my RQ base to allow it to accept a standard finder shoe.

What did you have to do to it? Idle curiosity only, since I'll be using the RDF.

Edited October 31, 2022 by cajen2

[Guest]

You know you could just get a setting circle and angle gauge.  Instant GPS for your scope. 

[bosun21]

Just now, cajen2 said:

What did you have to do to it?

Have a look at my photos earlier in the thread 

[bosun21]

2 minutes ago, cajen2 said:

What did you have to do to it?

I just fitted a countersunk screws through the base after drilling a hole. I then slid a spacer over the screw, then the shoe itself and tightened it all with a nyloc nut. HTH

[bosun21]

6 minutes ago, cajen2 said:

What did you have to do to it? Idle curiosity only, since I'll be using the RDF.

I have the same RDF on my refractor, and I love it. It’s so easy and quick to use along with the Baader quality.

[wulfrun]

I bought a s/hand 150PL that came with a Telrad base already on it, previous owner(s) had obviously been unwilling to try removing it. So, obviously, I bought a Telrad to go on it. The base has been on for an unknown number of years and shows no sign of coming off without a determined effort (I'll not be trying). I'd say it's unlikely to give way if you attach it properly.

One thing the Telrad is susceptible to is dew - the glass dews up fairly easily. You'll need some sort of cover for it, when not actually being used. A suitably-velcroed and shaped piece of foam sheet will do fine.

[Louis D]

My refractor night-time finder setups:

RACI/GLP/QuikFinder

RACI/SkEye/QuikFinder

On my Dob, the Telrad sits on its own base due to its sheer size/bulk.

[bosun21]

6 minutes ago, wulfrun said:

One thing the Telrad is susceptible to is dew

I bought a little clip in (adhesive) dew heater for mine from “Dew Control” and it works  great.

[wulfrun]

1 minute ago, bosun21 said:

I bought a little clip in (adhesive) dew heater for mine from “Dew Control” and it works  great.

Yes, I know about those and thought about one, or making one (easy enough). Reliance on battery-power was the only reason I went for a simple slide-on foam protector - the no-power option!

[bosun21]

18 minutes ago, wulfrun said:

Yes, I know about those and thought about one, or making one (easy enough). Reliance on battery-power was the only reason I went for a simple slide-on foam protector - the no-power option!

As long as it works, that’s what counts. I was thinking about making one for my secondary mirror on my Stella Lyra dobsonian. The holder is shaped in a way that eliminates the standard secondary heaters on sale. In the interim I am using a standard 8” Astro Essentials dew shield which seems to be coping with the dew.

[starhiker]

1 hour ago, Mike Q said:

You know you could just get a setting circle and angle gauge.  Instant GPS for your scope. 

Such a DIY project is definitely a good idea for someone who has less clumsy hand as me..