Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

SW 180mm Mak just ordered

  • Please log in to reply
70 replies to this topic

#51 Tyson M

Tyson M

    Gemini

  • *****
  • Posts: 3101
  • Joined: 22 Jan 2015
  • Loc: 53 degrees North

Posted 10 February 2019 - 01:05 PM

The problem is i can't really tell which of those ML focusers i should buy, many models and i don't know what accessories to buy, i want to start buying one first for my 8" Newt, then later i can think about for my 7" Mak but not necessary, but i still look at different models even if it says focuser for Newt i still don't know which model exactly and what accessories and i don't know if it is compatible with my scope or not as i really don't like at all to modify my scope or drill it to match the focuser dimensions, and definitely i can't tell which one i can use for the Mak as there is nothing written about that.

Send an email to Rob @ moonlite and he will take it from there.

 

Basically you want a 2" SCT threaded moonlite with a short draw tube length.



#52 TareqPhoto

TareqPhoto

    Skylab

  • -----
  • Posts: 4075
  • Joined: 20 Feb 2017
  • Loc: Ajman - UAE

Posted 10 February 2019 - 01:11 PM

Send an email to Rob @ moonlite and he will take it from there.

 

Basically you want a 2" SCT threaded moonlite with a short draw tube length.

Ok, so i will focus more on that 2" SCT focuser for my 7" Mak, i will send Rob an email, but i want to start with a focuser for Newt first, 8" f5 one, even if i just need to change the focuser tube and not the base, but not sure if the stock one can be compatible with ML focuser without base for it.

 

Thank you very much!



#53 Tyson M

Tyson M

    Gemini

  • *****
  • Posts: 3101
  • Joined: 22 Jan 2015
  • Loc: 53 degrees North

Posted 10 February 2019 - 01:24 PM

I had an issue with an 8" f6 XT8plus dob.

 

If your scope's focuser base is not compatible with moonlite, Rob makes universal bases to attach to any scope after you remove the stock base but keep the screws



#54 TareqPhoto

TareqPhoto

    Skylab

  • -----
  • Posts: 4075
  • Joined: 20 Feb 2017
  • Loc: Ajman - UAE

Posted 10 February 2019 - 02:34 PM

I had an issue with an 8" f6 XT8plus dob.

 

If your scope's focuser base is not compatible with moonlite, Rob makes universal bases to attach to any scope after you remove the stock base but keep the screws

I will keep that in mind, thanks again.

 

So, what did you do with that 180mm stock focuser which is to the side on the back to move the mirror?



#55 Peter Besenbruch

Peter Besenbruch

    Fly Me to the Moon

  • *****
  • Posts: 6883
  • Joined: 21 Aug 2014
  • Loc: Oahu

Posted 13 February 2019 - 12:26 AM

I just ordered the GSO 2 speed, standard, SCT focuser. I'm pretty familiar with the refractor version. They are quite good.



#56 TareqPhoto

TareqPhoto

    Skylab

  • -----
  • Posts: 4075
  • Joined: 20 Feb 2017
  • Loc: Ajman - UAE

Posted 13 February 2019 - 01:22 AM

I just ordered the GSO 2 speed, standard, SCT focuser. I'm pretty familiar with the refractor version. They are quite good.

I bought similar to that focuser, from TPO, for my ST80, yes, very nice focuser, solid enough, but i am not sure if i can find a compatible one from GSO for my Mak rather than Moonlite one, i just feel i don't want to spend much for the Mak as i also want to buy focuser for my Newt, so it will cost me a lot if i buy new focuser for each scope i have, and for planetary i really feel it is not very very critical as with stars, in the screen i am able to focus on the moon and the planets good enough.



#57 Peter Besenbruch

Peter Besenbruch

    Fly Me to the Moon

  • *****
  • Posts: 6883
  • Joined: 21 Aug 2014
  • Loc: Oahu

Posted 13 February 2019 - 01:56 AM

TPO is Oceanside's house brand. Much of the TPO stuff is rebadged GSO. Any standard, 2" threaded, SCT accessory will fit the 180mm Maksutov. The only conflict that comes is when you want to rotate the GSO focusing knobs into the same position as the Maksutov focusing knob. That's easy enough to work around.

 

This focuser is the one I got. This is a longer, heavier duty version that probably won't have conflicting focus knobs. I also found this article informative.



#58 TareqPhoto

TareqPhoto

    Skylab

  • -----
  • Posts: 4075
  • Joined: 20 Feb 2017
  • Loc: Ajman - UAE

Posted 13 February 2019 - 07:23 AM

TPO is Oceanside's house brand. Much of the TPO stuff is rebadged GSO. Any standard, 2" threaded, SCT accessory will fit the 180mm Maksutov. The only conflict that comes is when you want to rotate the GSO focusing knobs into the same position as the Maksutov focusing knob. That's easy enough to work around.

 

This focuser is the one I got. This is a longer, heavier duty version that probably won't have conflicting focus knobs. I also found this article informative.

I will go with that linear bearing one, that version i bought for my ST80 anyway, and i remember i think almost same price too or slightly cheaper from TPO, so i will choose that and i hope you are right that it can fit into my Maksutov.

 

Thank you very much



#59 Rock22

Rock22

    Ranger 4

  • *****
  • Posts: 304
  • Joined: 28 Aug 2017
  • Loc: Diamond Bar, California

Posted 13 February 2019 - 01:30 PM

I will go with that linear bearing one, that version i bought for my ST80 anyway, and i remember i think almost same price too or slightly cheaper from TPO, so i will choose that and i hope you are right that it can fit into my Maksutov.

 

Thank you very much

I have the GSO linear bearing 2" Crayford for my 180mm mak.  If it hasn't already been mentioned, you will need an SCT adapter like the one from ScopeStuff (item #SMSA).  Then, you just screw on the focuser.  You would use the primary mirror focuser on your mak to get to near focus, and then use the Crayford to do fine focusing.  Works great.



#60 Peter Besenbruch

Peter Besenbruch

    Fly Me to the Moon

  • *****
  • Posts: 6883
  • Joined: 21 Aug 2014
  • Loc: Oahu

Posted 13 February 2019 - 02:31 PM

I will go with that linear bearing one, that version i bought for my ST80 anyway, and i remember i think almost same price too or slightly cheaper from TPO, so i will choose that and i hope you are right that it can fit into my Maksutov.

Yes, you do astrophotography, so the heavier duty model makes sense.



#61 Peter Besenbruch

Peter Besenbruch

    Fly Me to the Moon

  • *****
  • Posts: 6883
  • Joined: 21 Aug 2014
  • Loc: Oahu

Posted 13 February 2019 - 02:36 PM

I have the GSO linear bearing 2" Crayford for my 180mm mak.  If it hasn't already been mentioned, you will need an SCT adapter like the one from ScopeStuff (item #SMSA).

I don't think so. TareqPhoto's model is quite recent, so I think it comes with standard SCT threading. I use one of the Scopestuff adapters on my 90mm Mak. It does the job.


  • Tyson M likes this

#62 TareqPhoto

TareqPhoto

    Skylab

  • -----
  • Posts: 4075
  • Joined: 20 Feb 2017
  • Loc: Ajman - UAE

Posted 13 February 2019 - 03:22 PM

I have the GSO linear bearing 2" Crayford for my 180mm mak.  If it hasn't already been mentioned, you will need an SCT adapter like the one from ScopeStuff (item #SMSA).  Then, you just screw on the focuser.  You would use the primary mirror focuser on your mak to get to near focus, and then use the Crayford to do fine focusing.  Works great.

Great, that is a big help, i hope i can get that sooner or later, but not very soon.

 

I am going to use my Mak these days as the sky is getting clear, wish if i knew about this focuser and that adapter last year so it may make the life easier for me, but i am not in rush, good i know which items now so i just wait a good budget coming so i can use little for this Mak.

 

Thank you very much!



#63 TareqPhoto

TareqPhoto

    Skylab

  • -----
  • Posts: 4075
  • Joined: 20 Feb 2017
  • Loc: Ajman - UAE

Posted 13 February 2019 - 03:29 PM

Yes, you do astrophotography, so the heavier duty model makes sense.

Exactly, even if i don't do astrophotography it is just always good to have like extra safety no matter what, after all even if i will use it for visual then i am thinking to buy TV eyepieces and some can be heavy and with quality diagonal then that may give almost same weight or similar to imaging setup, after all i am using this Mak only for planetary imaging so only those small cameras, and small or standard filter wheel, not too much expensive the linear version than one without anyway.

 

I don't think so. TareqPhoto's model is quite recent, so I think it comes with standard SCT threading. I use one of the Scopestuff adapters on my 90mm Mak. It does the job.

Yes, it is recent, but i didn't know that recent one is likely same as standard SCT threading, i bought it last year, and i really don't know if SW upgraded it already as they included the new or green dovetail to the scope which i believe it is new copies, i really don't know how was the older models anyway, if any pictures around between older models and recent then i can confirm or tell before i do anything.

 

Thanks!

 

I did see some also replaced that Mak stock focuser knob with something from Feathertouch knob, i still don't know how this can be different than using the central focuser instead without moving the mirror, i mean which one can be easier for focusing anyway, and which should give better result if there is different results anyway, as choosing or that is always or only about which can make things easier or having less issues anyway.



#64 Peter Besenbruch

Peter Besenbruch

    Fly Me to the Moon

  • *****
  • Posts: 6883
  • Joined: 21 Aug 2014
  • Loc: Oahu

Posted 14 February 2019 - 10:04 PM

Exactly, even if i don't do astrophotography it is just always good to have like extra safety no matter what, after all even if i will use it for visual then i am thinking to buy TV eyepieces and some can be heavy and with quality diagonal then that may give almost same weight or similar to imaging setup, after all i am using this Mak only for planetary imaging so only those small cameras, and small or standard filter wheel, not too much expensive the linear version than one without anyway.

I just got the GSO focuser for my Mak, and it just bolted on. My scope is a year or two older than yours. The basic GSO is built like a tank, and adds about a full inch to the light path.  I get just under 2" of travel. Very smooth.

 

I did see some also replaced that Mak stock focuser knob with something from Feathertouch knob, i still don't know how this can be different than using the central focuser instead without moving the mirror, i mean which one can be easier for focusing anyway, and which should give better result if there is different results anyway, as choosing or that is always or only about which can make things easier or having less issues anyway.

I have seen Feathertouch motorized focus knob replacements. I got the GSO in part because of the mirror image shift. The Feathertouch won't fix that issue.


Edited by Peter Besenbruch, 14 February 2019 - 10:36 PM.


#65 jjack's

jjack's

    Messenger

  • -----
  • Posts: 463
  • Joined: 01 Apr 2012
  • Loc: normandy

Posted 15 February 2019 - 03:43 AM

All these accessories reduce your aperture cause of the primary pipe baffle. Do you really want to tranform your 7.1"scope into a 6" one with more obstruction ?



#66 TareqPhoto

TareqPhoto

    Skylab

  • -----
  • Posts: 4075
  • Joined: 20 Feb 2017
  • Loc: Ajman - UAE

Posted 15 February 2019 - 07:27 AM

I just got the GSO focuser for my Mak, and it just bolted on. My scope is a year or two older than yours. The basic GSO is built like a tank, and adds about a full inch to the light path.  I get just under 2" of travel. Very smooth.

 

I have seen Feathertouch motorized focus knob replacements. I got the GSO in part because of the mirror image shift. The Feathertouch won't fix that issue.

Ok, then GSO focuser it is, thanks!



#67 TareqPhoto

TareqPhoto

    Skylab

  • -----
  • Posts: 4075
  • Joined: 20 Feb 2017
  • Loc: Ajman - UAE

Posted 15 February 2019 - 07:28 AM

All these accessories reduce your aperture cause of the primary pipe baffle. Do you really want to tranform your 7.1"scope into a 6" one with more obstruction ?

???



#68 De Lorme

De Lorme

    Surveyor 1

  • *****
  • Posts: 1948
  • Joined: 30 Dec 2008

Posted 15 February 2019 - 05:13 PM

The way you can find if your losing aperture is to focus your scope at infinity{during the day}on a very far away object with the focuser, diagonal and eyepiece you'll be using at night. Then don't move the focuser and get about 8" from a wall or tape

a sheet of white paper onto the dew shield. Then have someone shine a small flash light through the eyepiece and and you measure the size of the light that's on the paper.


  • Tyson M likes this

#69 Tyson M

Tyson M

    Gemini

  • *****
  • Posts: 3101
  • Joined: 22 Jan 2015
  • Loc: 53 degrees North

Posted 16 February 2019 - 12:54 PM

The way you can find if your losing aperture is to focus your scope at infinity{during the day}on a very far away object with the focuser, diagonal and eyepiece you'll be using at night. Then don't move the focuser and get about 8" from a wall or tape

a sheet of white paper onto the dew shield. Then have someone shine a small flash light through the eyepiece and and you measure the size of the light that's on the paper.

 

All these accessories reduce your aperture cause of the primary pipe baffle. Do you really want to tranform your 7.1"scope into a 6" one with more obstruction ?

I have seen this comment pop up every now and then, so I decided to test it using De Lorme's method.

 

I focused as far as I can, down the neighborhood block on a tree with berries.  With the 40 XL I noticed no vignetting.  I focus by using course focus of the scope itself moving the mirror first, then the fine focus knob of the moonlite to dial it in.

 

After finding focus this manner with the draw tube barely extented, I locked it in place and took it to a white wall. 

 

I shone a bright flashlight in the eyepiece and measured the illuminated disk 8" away from the wall and measured 7.1 or 180mm.

 

Even racking out the focuser more an inch or so I didnt notice much of a difference of the illuminated disk, so its likely one could use the focuser without touching the main focus knob on the scope.  It does not appear to be clipping the aperture in the range of motion most likely to be used in with a dual speed focuser.


  • Peter Besenbruch and Rock22 like this

#70 De Lorme

De Lorme

    Surveyor 1

  • *****
  • Posts: 1948
  • Joined: 30 Dec 2008

Posted 16 February 2019 - 08:43 PM

Tyson M,

 

I was concerned about losing light when using my Binotron binoviewers{with a A 37 OCS} so It's why I measured.  To my surprise it measured 7" with the Binotrons and a 2" diagonal.  Take a look at this post " Binoviewers with a Mak Cass with specifically looking at post 25,17,29.

 

https://www.cloudyni...ss#entry7672507

 

 

Eddgie has repeatedly said that sct's would most definitely lose aperture when using the a 2spd focuser and highly recommended using a OCS to bring back the focus to it's original position when viewing it planets.

 

Here's the post{#4} I found on how to collimate a 7"  SW Mak Cass. 

https://www.cloudyni...ss#entry7672507

 

This really worked to. Could not believe just how easy it was. Make sure you point the telescope up though so you don't get mirror flop and lose collimation. When the sky clears I'll use a star to tweak though.


Edited by De Lorme, 16 February 2019 - 08:44 PM.


#71 precaud

precaud

    Aurora

  • *****
  • topic starter
  • Posts: 4834
  • Joined: 05 Dec 2012
  • Loc: north central New Mexico

Posted 04 May 2019 - 05:55 PM

Reviving this thread from last year.  Read through a bit, and it is entirely too positive. There must be something about this scope (besides mirror shift) that needs improvement... time to raise some stink.

 

One of the things I've been stymied by is the inability to see any fringes on the supplied diagonal's mirror using a contact flat. The reflectivity is so high, the fringes are invisible. This means that I can't test the mirror surface flatness against a reference, and am left to using more subjective methods.

 

A couple days ago I was doing some daytime terrestrial viewing of objects on nearby power poles. One of the experiments was to check out the relative difference in sharpness and contrast between the 7 diagonals I have on hand; 2 prisms and 5 mirrors. I did this using the 180 Mak at high magnifications (300X and 400X) and swapping in the various diagonals, making note of the features on a small white ceramic fixture with black logo and print on it, against the background of the textured power pole and behind it, the blue sky. (We have plenty of clear blue sky during the day; the clouds roll in early evening...)

 

Both prisms won the test, with two of the mirrors not far behind. The loser was the diagonal supplied with the Mak. Despite its high reflectivity, its contrast and sharpness was worse than the others at these high mags. Not horrible, but noticeable.

 

Having just finished remounting the secondary of my SW350 dob with excellent results, it seemed prudent to look at how the mirror is mounted in this diagonal. I had taken a quick peek a few months ago and it looked like it was siliconed in place with the usual three dabs. But on closer inspection, I see that's not the case. See the pic below.

 

The mount consists of three rubber standoffs (aka feet or bump-ons) about 3/8" in diameter, stuck to the mirror with 2-sided tape. These then are glued (with red silicone, I presume, but who knows?) to the diagonal's back plate.

 

Maybe it's not as bad as it could be because of the 3-point mount. But I have yet to see a mirror perform well when 2-sided tape is used to secure it in any way.

 

So this project will be to remove the rubber feet, remount it properly, and do the test again. Based on past results, I am betting it will bring the performance of this diagonal right up there with the best of the mirrored ones.

 

Attached Thumbnails

  • diaglue.jpg



CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics