Focuser load on FC100DC

[MalcolmM]

I have removed a tube on my 100DC in order to shorten the light path so that I have the option to use my Binoviewers natively, without a GPC. See photo with the tube marked in red.

This means for normal eyepiece viewing I have an extension tube attached on the other side of the focuser, to lengthen the light path again! This is also used when Binoviewing with a GPC when I want higher magnification for lunar/planetry. See pic.

When Binoviewing in this configuration, the weight is now much further out from the focuser and therefore is putting more load on the focuser. I can feel the focuser is stiffer in this scenario, especially if the scope is at an angle and I am focusing in (raising the draw tube).

My question (eventually!) is, might this be overloading the focuser? I have not been able to Google any specs along these lines. What's your thoughts?

Malcolm 

[Franklin]

Tak focusers are built like tanks, can't see it being a problem apart from the stiffer movement. Nice set-up!

[JeremyS]

Will be fine Malcolm. The “stiffness” is just the extra work being done, especially when scope pointed up, due to gravity 

[MalcolmM]

Thanks @Franklin and @JeremyS for your reassuring replies! It's far too nice a scope to have to endure any needless stress and strain 🙂 That's for me to soak up!

Malcolm

[HollyHound]

I had my DC in that configuration for a short while before I got the DZ… it was also had a slightly stiffer focus action, but never felt it was overloaded 🤞

It’s great in this configuration if you love binoviewing 😃

[Stu]

Personally I think it’s a disaster and you MUST get a Feathertouch replacement 😉😉

More seriously, this was discussed a while back with @mikeDnight and he did a similar thing successfully so I’m sure you will be fine. The nice thing about these Taks is they do seem to have plenty of inwards focus on the tubes so this sort of thing is possible.

[Space Hopper]

Its nice to have the versatility to be able to remove that section and have all that extra backfocus.

Not many scopes have that option, and i think its sound thinking from Takahashi. More manufactures should do it. Versatile and all bases covered.

I'm sure you'll be fine putting a load onto it ; those rack and pinions can take a fair old load.

Nice scope, and really well made like all Taks.

I had a good look at  RVOs Taks on display at last weekends IAS. Very nice indeed.

 

[MalcolmM]

23 minutes ago, HollyHound said:

I had my DC in that configuration for a short while before I got the DZ… it was also had a slightly stiffer focus action, but never felt it was overloaded 🤞

It’s great in this configuration if you love binoviewing 😃

Binoviewing is a bit of a faff compared to mono but every time I do it I wonder why I bother with mono! Usually I start out mono and if I have the time and seeing is good I move to binoviewing!

Malcolm 

[MalcolmM]

13 minutes ago, Stu said:

Personally I think it’s a disaster and you MUST get a Feathertouch replacement 😉😉

I have so far resisted the temptation! It's a vanity thing. I just love the way they look out of the box and want to try and keep them pure Tak! Though native binoviewing does require a couple of Baader bits which pains me greatly

Malcolm 

[Space Hopper]

28 minutes ago, HollyHound said:

I had my DC in that configuration for a short while before I got the DZ… it was also had a slightly stiffer focus action, but never felt it was overloaded 🤞

It’s great in this configuration if you love binoviewing 😃

Hope you don't mind me butting in, and not wanting to take the topic off course but,

how do you find the DZ compared to your earlier DC ??  Much difference apart from the extra 80mm fl ?

[HollyHound]

49 minutes ago, Space Hopper said:

Hope you don't mind me butting in, and not wanting to take the topic off course but,

how do you find the DZ compared to your earlier DC ??  Much difference apart from the extra 80mm fl ?

I'll be completely honest and say that so far, I haven't seen anything in the DZ that wasn't seen in the DC and the views are very much the same (so far)... I'm sure that on a perfect night of seeing, that the DZ will likely get just that bit more detail out that the DC can't, but that hasn't happened (for me) yet 🤔

The extra 60mm focal length is useful, and being f/8, it really does sharpen up the edges on a few of my eyepieces (notably the XW14 and 20), but again these were quite fine already

What is massively different though is ergonomics...

The DZ is significantly heavier than the DC, but I'm using it on an AZ75 or AZ100 and it's not my grab and go scope (the FC-76DCU does that), so not an issue anyway.

It has a focuser with a much longer travel (no need to worry about spacers quite so much) and it feels a tiny bit more robust.  I also love the metal rather than plastic focuser wheels, although this is really nothing important.

The sliding dew-shield is very convenient when carrying it in and out, and seems to be much deeper, so should give more dew protection.

If you want to have that extra bit of optical perfection, for when it might just be usable, then by all means get the DZ, but you're losing very little (or nothing on normal nights) with the DC, and might also be able to use a lighter mount too 👍