Small, Carbon, f5, 600mm Newt, is there such a thing ?

[Starflyer]

12 hours ago, Spaced Out said:

Thanks, I've looked into fitting Baader SteelTrack etc. The only focuser that will fit the tube diameter EASILY is a Moonlite (it has a specific 130PDS fitting kit), they're expensive and I've seen mixed reviews so I am little nervous of taking that route. Seems all other focusers will require some amount of bodging !

Having owned two Moonlites I wouldn't recommend them for imaging, especially if you may move to autofocus at some point in the future.

[Spaced Out]

2 minutes ago, Starflyer said:

Having owned two Moonlites I wouldn't recommend them for imaging, especially if you may move to autofocus at some point in the future.

Why is that ?

Whatever route I take I will definitely require a good focus motor.

[tooth_dr]

Hi Gary

I have a Moonlite crayford focuser on my scope and it handles the full imaging kit and focuses precisely with minimal tilting (I can’t seen any). It has the high res stepper motor and works with any software I’ve tried.  It works on autofocus too and plots a nice v curve.

 

[Spaced Out]

10 hours ago, tooth_dr said:

Hi Gary

I have a Moonlite crayford focuser on my scope and it handles the full imaging kit and focuses precisely with minimal tilting (I can’t seen any). It has the high res stepper motor and works with any software I’ve tried.  It works on autofocus too and plots a nice v curve.

 

Thanks mate, that's encouraging to hear. I'm guessing your imaging kit is heavy too (filter wheel etc) ?

Perhaps I am being too cautious about Moonlite ?

[Starflyer]

11 hours ago, Spaced Out said:

Why is that ?

Whatever route I take I will definitely require a good focus motor.

Repeatability was a big problem, constant tinkering to try and remove slippage but keep the smooth action.  I'm not talking about slippage you can physically see, but measurable with a micrometer and causing poor curves and poor focus.

I eventually cured most of the slippage by increasing the tension a lot, then the anodising on the barrel started wearing through underneath the bearings giving even worse results.

[johninderby]

I am surprised that Moonlite hasn’t moved on from the plain anodised finish on the drawtube. Baader now uses a diamond coated bearing surface on the drawtube that is very hard wearing. Rack & pinion is becoming common even on lower cost focusers.

Favourite is rhe FeatherTouch R&P but ££££££££££ 🙀

[Spaced Out]

20 minutes ago, johninderby said:

I am surprised that Moonlite hasn’t moved on from the plain anodised finish on the drawtube. Baader now uses a diamond coated bearing surface on the drawtube that is very hard wearing. Rack & pinion is becoming common even on lower cost focusers.

Favourite is rhe FeatherTouch R&P but ££££££££££ 🙀

If I could I'd fit a Baader SteelTrack Diamond but Moonlite is the only option I have for the little 130 PDS. 😐

[Spaced Out]

33 minutes ago, Starflyer said:

Repeatability was a big problem, constant tinkering to try and remove slippage but keep the smooth action.  I'm not talking about slippage you can physically see, but measurable with a micrometer and causing poor curves and poor focus.

I eventually cured most of the slippage by increasing the tension a lot, then the anodising on the barrel started wearing through underneath the bearings giving even worse results.

Thanks. I'm not liking the sound of 'slippage', do you mean the draw tube was actually slipping or was it sagging/tilting with the weight ? Was that with heavy gear ?

[johninderby]

FeatherTouch does focuser bases to order for any newt but over 100 quid for the base.. 😬

Then there is the cost of the focuser. 🙁

[Spaced Out]

22 minutes ago, johninderby said:

FeatherTouch does focuser bases to order for any newt but over 100 quid for the base.. 😬

Then there is the cost of the focuser. 🙁

Thanks. Agree about the cost, they are supposed to be top notch aren't they ? Couldn't find a base to fit the 130 PDS tho..... even if I could, it seems a bit crazy to spend that kind of money on a scope that only costs £160 !

[johninderby]

Just checked and the custom bases are sold byTelescope Express.

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p5390_Starlight-Newton-Basis-fuer-Feather-Touch-2----Ma-anfertigung.html

[johninderby]

Did find this focuser from TS that has an optional base that fits down to a 160mm dia. tube same as the 130 tube. Some interesting options as well.

https://www.teleskop-express.de/shop/product_info.php/info/p6522_TS-Optics-2--UNC-V-Power-Newton-Crayford-Focuser---short.html

Edited March 15, 2020 by johninderby

[Spaced Out]

11 minutes ago, johninderby said:

Did find this generic focuser base that fits down to 160mm dia tubes which means would fit the 130 tube which is 160mm dia. 

https://www.teleskop-express.de/shop/product_info.php/info/p3701_TS-Optics-Base-for-Newtonian-Focusers---fits-tubes-from-160-185mm-diameter.html

https://www.teleskop-express.de/shop/product_info.php/info/p6522_TS-Optics-2--UNC-V-Power-Newton-Crayford-Focuser---short.html

Thanks. I emailed TS optics last week about that base and that focuser (it looks interesting). Only drawback is that it involves re-drilling the tube to fit it and they told me.......

"It will not fit perfectly, it's a little wider, but there are no other possibilities. the curvature ratio will not correspond, but it's possible to fix it, even if it will not be a " aesthetic perfect" result"

It's something I would have considered but sounds like I would have to bodge it and I'm a bit nervous about cocking it up, I'm guessing it'll need precision placement...... Which brings me back to the Moonlite. 🤔

[johninderby]

This thread on CN might be of interest. 🤔

https://www.cloudynights.com/topic/493444-printing-crayford-baseplate-with-3d-printer/

[Starflyer]

2 hours ago, Spaced Out said:

Thanks. I'm not liking the sound of 'slippage', do you mean the draw tube was actually slipping or was it sagging/tilting with the weight ? Was that with heavy gear ?

It didn't sag, just slipped by various amounts at different altitudes.  I had a cooled canon 450D on it, probably around 1KG, I can't remember the exact weight, it certainly wasn't a huge heavy camera.

If it was my money I'd spend it on a second hand 70 - 80mm frac and reducer rather than trying to fix up the newt. You can always add diffraction spikes in processing or by using a cross of black thread across the frac's dew shield.

 

[tooth_dr]

3 hours ago, Spaced Out said:

Thanks mate, that's encouraging to hear. I'm guessing your imaging kit is heavy too (filter wheel etc) ?

Perhaps I am being too cautious about Moonlite ?

Yes.  Imaging kit includes reducer, EFW3 (big one with 7 x 2" filter carousel), and Atik 383L+, and necessary spacers.

[Skyline]

9 hours ago, johninderby said:

This thread on CN might be of interest. 🤔

https://www.cloudynights.com/topic/493444-printing-crayford-baseplate-with-3d-printer/

Designed in tinkercad. The only problem I got is that's printed in plastic as the original will be cnc machined.

[tooth_dr]

On 15/03/2020 at 09:15, Spaced Out said:

Thanks mate, that's encouraging to hear. I'm guessing your imaging kit is heavy too (filter wheel etc) ?

Perhaps I am being too cautious about Moonlite ?

Photo Gary:

 

[CraigT82]

The criticism you hear leveled at moonlight is that the drawtube slips under weight. Is it possible that when used with refractors which are pointed up with the focuser pointing down, this problem  is worse. However with newts where the focuser is pointed out to the side the full weight of the imaging train isn't trying to pull the drawtube out? Not sure 🤷‍♂️