Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Reflectors

Pages: << 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | (show all)
AstroTatDad
Pooh-Bah
*****

Reged: 04/22/13

Loc: Los Angeles - San Diego
Re: Mega-mod thread for Zhumell dobs new [Re: petrus45]
      #5880977 - 05/23/13 07:51 PM

agree, if it wasn't for this thread and help I might not have even jumped in to picking up a Z8.

Post Extras: Print Post   Remind Me!   Notify Moderator  
kfiscus
Carpal Tunnel
*****

Reged: 07/09/12

Loc: Albert Lea, MN, USA
Re: Mega-mod thread for Zhumell dobs new [Re: AstroTatDad]
      #5881155 - 05/23/13 09:28 PM

I don't know how much activity a thread needs to get this special treatment. I'd love to have it be it's own forum.

Post Extras: Print Post   Remind Me!   Notify Moderator  
aznights
member
*****

Reged: 04/23/12

Loc: Glendale, AZ
Re: Mega-mod thread for Zhumell dobs new [Re: kfiscus]
      #5881804 - 05/24/13 09:07 AM

This is a great thread, but you guys are missing the most quintessential dob base mod that could ever be.

Behold...

http://imgur.com/7x42y


Post Extras: Print Post   Remind Me!   Notify Moderator  
tag1260
scholastic sledgehammer
*****

Reged: 10/07/12

Loc: Ohio, USA
Re: Mega-mod thread for Zhumell dobs new [Re: aznights]
      #5881831 - 05/24/13 09:27 AM

I'd probably try that on the OTHER side but with my luck I'd miss it in the dark and dump it on my eyepieces!!!

Post Extras: Print Post   Remind Me!   Notify Moderator  
newtoskies
Pooh-Bah


Reged: 07/15/12

Loc: SE Ma.
Re: Mega-mod thread for Zhumell dobs new [Re: aznights]
      #5881844 - 05/24/13 09:37 AM

Quote:

This is a great thread, but you guys are missing the most quintessential dob base mod that could ever be.

Behold...

http://imgur.com/7x42y




That is a cool idea and another cool mod for a Dob.

I don't see why they shouldn't make this a separate 'forum' as the 10" dob is very popular and the AD10 is always sold out. The 8 and 12" dobs could be included as well I think.


Post Extras: Print Post   Remind Me!   Notify Moderator  
kfiscus
Carpal Tunnel
*****

Reged: 07/09/12

Loc: Albert Lea, MN, USA
Re: Mega-mod thread for Zhumell dobs new [Re: newtoskies]
      #5882267 - 05/24/13 01:04 PM

Spill, barlow=shot glass

Post Extras: Print Post   Remind Me!   Notify Moderator  
Ian1957
member


Reged: 04/22/11

Loc: Cocoa,Fl
Re: Mega-mod thread for Zhumell dobs new [Re: aznights]
      #5882326 - 05/24/13 01:27 PM

Quote:

This is a great thread, but you guys are missing the most quintessential dob base mod that could ever be.

Behold...

http://imgur.com/7x42y



Very Good

Edited by Ian1957 (05/24/13 01:28 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
kfiscus
Carpal Tunnel
*****

Reged: 07/09/12

Loc: Albert Lea, MN, USA
Re: Mega-mod thread for Zhumell dobs new [Re: Ian1957]
      #5886333 - 05/26/13 10:45 PM

Has anyone added so many top-of-the-scope accessories that they ran out of altitude bearing adjustment. I've added quite a bit, but still have a little adjustment left. (I believe counterweights should be a last resort if they do nothing else.)

I've got a Telrad & 2" riser, 9x50 straight finder, customized longer Astrocrumb filterslide with 4 filters, flocking inside and out. (Most of the flocking is forward of the bearings.) I still may add a forward glare shield.

P.S. I hoping we can get enough traffic back here on this thread that the moderators will decide to make it a separate forum.


Post Extras: Print Post   Remind Me!   Notify Moderator  
beatlejuice
Pooh-Bah
*****

Reged: 04/05/11

Loc: Hamilton, ON,Canada
Re: Mega-mod thread for Zhumell dobs new [Re: kfiscus]
      #5886434 - 05/27/13 12:34 AM

Quote:

customized longer Astrocrumb filterslide with 4 filters




Ken, is that a metal tube? If so how did you secure the slide to the tube. ie. drill from the outside or inside? And if from the outside how did you measure and mark the points for drilling?
Thanks
Eric


Post Extras: Print Post   Remind Me!   Notify Moderator  
kfiscus
Carpal Tunnel
*****

Reged: 07/09/12

Loc: Albert Lea, MN, USA
Re: Mega-mod thread for Zhumell dobs new [Re: beatlejuice]
      #5886515 - 05/27/13 02:51 AM

Metal tube Z12. The job went flawlessly but was NOT for the faint-hearted. After I flocked the tube, I put the focuser and other forward equipment back on (not the cell). The fittings helped keep the Protostar flocking in place. I first rotated the spider 45 degrees. This went very smoothly but required one hole to go through the body tube's seam. I went slowly, used a sharp bit, and cleaned the hole with a Dremel.

I used 4-40 cap head bolts and washers coming from the outside, threaded into 4-40 t-nuts imbedded into the Astrocrumbs rails inside. The 4 bolts that hold the focuser didn't want to let me get the rails close enough together. Kissing the rails with a Dremel sanding drum where each focuser bolt was solved that problem. When I knew the rails were spaced correctly (they have to be parallel), I drilled 4 holes in the rails (2 each) to use them as drill guides. I then held the rails in place, and carefully drilled the tiny bit (new and sharp) up through the rails and out through the body tube. After these pilot holes were done, I re-drilled them with the correct size bit for the bolts from the outside. All of this drilling was done with a vacuum running and a strong magnet inside a plastic bag to catch fillings. Let me know if I neglected to tell you anything important.


Post Extras: Print Post   Remind Me!   Notify Moderator  
beatlejuice
Pooh-Bah
*****

Reged: 04/05/11

Loc: Hamilton, ON,Canada
Re: Mega-mod thread for Zhumell dobs new [Re: kfiscus]
      #5886521 - 05/27/13 02:59 AM

Thank you very much Ken. Didn't think it would be anything but complex, but I will keep your response as a guide for when I decide to get the filter slide.
Thanks again,
Eric


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Nyctophobia, Maryland, USA
Re: Mega-mod thread for Zhumell dobs new [Re: kfiscus]
      #5887127 - 05/27/13 01:32 PM

Quote:

Has anyone added so many top-of-the-scope accessories that they ran out of altitude bearing adjustment. I've added quite a bit, but still have a little adjustment left. (I believe counterweights should be a last resort if they do nothing else.)




The easiest way I've found to add counterweights to a Dob, is with a fanny pack / sports pack filled with sealed plastic baggies of lead shot. Strap it below the OTA, close to the bottom end. If necessary to make sure the pack won't slip down the tube, place opposing Velcro strips on the back of the pack and on the OTA. I doubt very much if there is any easier, simpler, more compact and more logical way to add a counterweight to a Dob OTA.

Quote:

I've got a Telrad & 2" riser, 9x50 straight finder, customized longer Astrocrumb filterslide with 4 filters, flocking inside and out. (Most of the flocking is forward of the bearings.) I still may add a forward glare shield.




I've always fully flocked the interior of my Newt OTAs, including the focuser, for optimum results. Ray tracing doesn't necessarily tell you all possible sources of scatter. Light travels in waves and can be diffracted. A billiard ball ray-trace is not the whole story.

A forward glare shield - a dew/light shield - is easy to make. It not only cuts out ambient glare, but helps prevent dewing on the secondary.

To me, a built-in filter slide always seemed more trouble than it's worth. The only advantage I see is that you won't need a Barlow or OCA to come to focus, as you probably would with a filter wheel. On the other hand, filters in a slide are more open to scratches and dewing. Also, if you install a dew/light shield, it will be more difficult - maybe impossible - to reach inside to shift the filter slide.

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
kfiscus
Carpal Tunnel
*****

Reged: 07/09/12

Loc: Albert Lea, MN, USA
Re: Mega-mod thread for Zhumell dobs new [Re: Sarkikos]
      #5887250 - 05/27/13 02:43 PM

My filters are all safe, warm, and dust free (to a point) inside the solid tube. The advantage to the slide is I actually use the filters since they're ready to go without any hassle or danger of dropping or smudging with a fingerprint.

My beef with counterweights may come from my experience with R/C planes. If weight is needed for balance, better to cut weight somewhere or find something heavy that is already needed. Why add weight if heavy batteries can serve a dual purpose. With a 12" scope, I'm carrying enough already. I went to considerable effort to shed weight when I built this scope, I don't want to add 'dumb' weight if it can be avoided. My first scope in the 80's was on a homemade pipe EQ mount. Instead of a counterweight, I put a second scope on the other end...


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Nyctophobia, Maryland, USA
Re: Mega-mod thread for Zhumell dobs new [Re: kfiscus]
      #5887331 - 05/27/13 03:38 PM

Yes, if you can find some weight to cut where you can cut it. Not always possible, or even if possible, not usually the best way to go.

For instance, I like having a 70mm RACI optical finder. It makes finding DSO easy and it doubles as a rich field scope. So the 70mm is staying. It wouldn't make sense to mount it toward the bottom of the OTA. And I can't shift the OTA any lower in the Dob mount without striking the floor of the mount. So therefore I need a weight near the bottom of the OTA to counterbalance.

You don't have to have everything pre-attached to the OTA. Put the OTA on the Dob mount then add accessories and weights as needed. That way you can reduce the carrying weight of the OTA.

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Nyctophobia, Maryland, USA
Re: Mega-mod thread for Zhumell dobs new [Re: kfiscus]
      #5887333 - 05/27/13 03:39 PM

Quote:

My filters are all safe, warm, and dust free (to a point) inside the solid tube. The advantage to the slide is I actually use the filters since they're ready to go without any hassle or danger of dropping or smudging with a fingerprint.




That's funny. IME, those are all advantages of having filters in a filter wheel.

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tim L
Carpal Tunnel
*****

Reged: 12/17/08

Loc: Missouri
Re: Mega-mod thread for Zhumell dobs new [Re: kfiscus]
      #5889130 - 05/28/13 03:01 PM

Quote:

I don't know how much activity a thread needs to get this special treatment. I'd love to have it be it's own forum.




Ken,
I think about the best to hope for would be for this thread to be included in list of "Best of" links at the top. When new fora have been suggested in the past, there's usually a reluctance to do so to keep the site from becoming more fragmented than it already is.

Glad this thread has been a good place for everyone to share ideas!

Clear skies,


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tim L
Carpal Tunnel
*****

Reged: 12/17/08

Loc: Missouri
Re: Mega-mod thread for Zhumell dobs new [Re: kfiscus]
      #5889151 - 05/28/13 03:10 PM

Quote:

Has anyone added so many top-of-the-scope accessories that they ran out of altitude bearing adjustment. I've added quite a bit, but still have a little adjustment left. (I believe counterweights should be a last resort if they do nothing else.)

I've got a Telrad & 2" riser, 9x50 straight finder, customized longer Astrocrumb filterslide with 4 filters, flocking inside and out. (Most of the flocking is forward of the bearings.) I still may add a forward glare shield.





I don't know if this link has been included in the thread yet, but it should be. Andrew J. De Luca describes (with pictures) how he improved the altitude clutches on his Z12.

The Alt clutches on my Z10 seem to have lost some of their range over time. I can still get them to grip tight, but they don't have as much "medium grip" range as they used to. I may have to try this mod sometime.


Post Extras: Print Post   Remind Me!   Notify Moderator  
kfiscus
Carpal Tunnel
*****

Reged: 07/09/12

Loc: Albert Lea, MN, USA
Re: Mega-mod thread for Zhumell dobs new [Re: Tim L]
      #5891312 - 05/29/13 08:48 PM

I had read that link before and it is a good one. If a guy bought the tool do you think there would be a market for more of those PVC rings? I see no sense in everybody in need of this tweak buying the tool or hacking their own pcs. My bearings still tighten okay and the scope is well balanced. I might make a pair of skinny PVC rings for myself and sell pairs of rings to others...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Tim L
Carpal Tunnel
*****

Reged: 12/17/08

Loc: Missouri
Re: Mega-mod thread for Zhumell dobs new [Re: kfiscus]
      #5891937 - 05/30/13 08:21 AM

Ken,
I still don't quite understand how the bearing mod works, since I've never torn mine apart. But if you made a pair of PVC rings, I might buy a set from you.


Post Extras: Print Post   Remind Me!   Notify Moderator  
kfiscus
Carpal Tunnel
*****

Reged: 07/09/12

Loc: Albert Lea, MN, USA
Re: Mega-mod thread for Zhumell dobs new [Re: Tim L]
      #5892401 - 05/30/13 01:10 PM

If I understand the link, the PVC is just a thin spacer allowing more pressure to be applied to the felt disk when the knob is tightened. My bearings are tight and still functioning, but the knobs won't turn much more. I'm not pursuing this until/unless my bearings need it.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: << 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | (show all)


Extra information
22 registered and 24 anonymous users are browsing this forum.

Moderator:  ausastronomer, Knuklhdastrnmr, Phillip Creed, JayinUT 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 45306

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics