29 replies to this topic

[Panotaker]

I was getting ready to finally order the Astrotrac Wedge for my little Questar, but I forgot the name of it. So I googled "small portable telescope wedge" and this new wedge from Sky Tracker showed up. It has fine adjustments for up and down, and left and right, just like the Astrotrac, which is the main feature I was looking for, so I can do a more precise polar alignment. It's about the same size as the Astrotrac, just not as pretty. The best part, is that it only cost $65.00. So I took a chance and ordered it from B&H Photo, and it arrived today. It screws right on to my Manfrotto tripod. It comes with a removable dove tail plate where the scope mounts to. Only problem is that the screw on the dovetail plate is 3/8 inch, and the Questar base is 1/4 inch. So I had to get a converter screw and 5 fat washers to mount the scope. So I have the worlds cheapest tristand! It's cloudy here tonight, so I haven't tried it outside yet, but it is rock solid, and I am able to do fine tuning on the wedge on both up and down and left and right. It also has a built in bubble level. If you are looking for a good wedge, and have a good heavy duty tripod, I encourage you to buy one of these wedges.

[joseph daukantas]

Not the best way to mount you Q, two weak points, head to tripod, Q to head will cause strain on bottom plate of Q.

 

Joe D.

[RobertPettengill]

This looks like an interesting find.

 

The mount that this is designed for has an advertised capacity of 11 pounds - it's designed for a big DSLR rather than a scope.  With the 2 pound weight of the mount that gives the wedge a capacity of 13 pounds which seems OK for  the 7 pound Questar by itself or with a light camera.

 

The balance point of the Questar is well away from the screw mount in the base plate - often  at or just outside the outer edge of the base plate depending on your latitude.  This makes any tripod mount that places the Questar mounting screw in the center of the tripod unbalanced for the Questar.  It will also put extra strain on the wedge (this one doesn't have a lot of extra capacity).

 

Given the screw thread incompatibility and the clearance problems with the dovetail clamp screw a good solution would be a mounting plate with a thread for the 3/8" dovetail mount near the balance point of the Q and a separate 1/4" 20 camera thread screw for the  Q.  The plate could be large enough to provide good support for the Questar's base plate.  Drilled out for access to the PG port and for weight reduction, the adapter plate wouldn't be difficult to make and would look attractive.

 

Do you have any information on the materials?  Is it alloy or mostly steel (does it disturb a compass held near by)?

 

;rob

[Mike E.]

Here is a simple addition I made to the dovetail plate from a video tripod we acquired to support our Questar.......

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[Panotaker]

Like I said. I just got it yesterday, and quickly mounted it on my tripod and took a picture of it to let every one know that it will work, and that it doesn't cost a lot of money. You guys can mount it any way you want. I just wanted to show the wedge. I will probably come up with a different way to mount the Questar on the wedge, but it works just fine the way it is. As far as the wedge screwing straight to the tripod, well, that's the way it was designed, to put on top of a tripod, but if you come up with a different way to mount it, that is fine too. The wedge works fine, and it's just another alternative to the Astrotrac. I don't know what kind of metal is made out of, I'll have to find a magnet to find out, but I'm betting its aluminum since it is pretty light.

[ChristianG]

Hi.

 

I think the main mounting issue as mentionned above is that the bottom plate of the Questar is very thin, flexible, and was never intended to support anything. If the telescope is mounted on the tripod head's usual small plate (often topped with cork or rubber) designed to hold a camera using the 1/4-20 threaded hole, there will be considerable flex. Questar are intended to be supported by the periphery of the base. So instead of using a stack of washers as on your photo, one would better use a metal plate that extend just a bit past the outside diameter of the base (diameter 7.25"). It does not have to be very wide, an aluminum plate 1/4" thick and something like 3" X 8" is more than sufficient. Cheers!

 

--Christian

[Panotaker]

I think newer Questars are different than the one I have. Mine is a 1959 model that didn't even have a tripod mount. I had sent my Questar back to the factory and they installed a custom tripod mount on it for me, so mine is solid as a rock since it doesn't  mount to the bottom sheet metal like some of the newer ones do. So maybe that is the difference. Mine doesn't flex at all and its rock solid. So that is why I see others using a big aluminum plate on the bottom of the Questars, to keep them from flexing. I don't have that problem with mine, since my tripod socket is not part of the thin sheet metal. 

[Panotaker]

I had a chance to play with the new wedge this weekend. The top of the wedge is the same size as a CG5 dovetail and it fits in there nice and snug. 

 

So I used one that I had laying around and screwed that on to the bottom of the Questar so it covers it from end to end. It is very solid now and that will have to do until I get a wider aluminum plate, but it's not really needed. 

 

[Mike E.]

Looks good. In all practicality, going any wider isn't going to increase the stability of the wedge is it ?

 

Edit: And the attachment bolt head extending below your dovetail helps to prevent it from slipping down the slot. I added a socket head screw for the same reason, which can be seen in my first photo.

Edited by Mike E., 15 November 2015 - 07:59 PM.

[Bomber Bob]

A vintage Davis & Sanford "floating action" tripod came with my 1958 Questar, and I couldn't be happier with it.  Oversized mounting plate holds the Q's base securely, and the hydraulic center post makes it easy to set a comfortable seated height.  And the retracting wheels mean I can glide around the patio or pool deck to dodge trees.

 

[Panotaker]

Looks good. In all practicality, going any wider isn't going to increase the stability of the wedge is it ?

 

Edit: And the attachment bolt head extending below your dovetail helps to prevent it from slipping down the slot. I added a socket head screw for the same reason, which can be seen in my first photo.

No, it's already rock solid with the CG5 dovetail. It might make it look a little prettier, but it's already super stable. Yes, the bolt head prevents it from slipping down. The tripod is a Bogen Manfrotto 3236 which is pretty strong and light. I use it for Birding with my TV85 and a Bogen video head. The wedge is not magnetic. I held a compass next to it and the needle didn't move. The bolts are not magnetic either. It's really a bargain at twice the price.

[RobertPettengill]

After figuring out that Ralph was also in Austin, we had a very nice lunch talking things Questar.  I also got an opportunity to examine the Sky-Watcher Star Adventurer Equatorial Wedge Base first hand and was very impressed.  The construction appeared to be entirely of cast aluminum with stainless steel screws showing disturbance of the compass we passed near it.

 

It does require an adapter to mount the Questar which can be as simple as a Vixen dovetail long enough to span the Questar base.  With just the dovetail the Questar seemed rock solid for visual observation.  The 5m of focal length I use images of Jupiter will be a more sever test.  for Any wedge other than the Tristand wedge will also require similar accommodation.

 

I ordered one right away and will report back it it works as well for imaging as I expect.

 

;rob

[Panotaker]

Nice meeting you yesterday Rob. We need to get together again soon. I got a chance to use the new wedge last night and it worked out perfect. I used the Painless Polar alignment method posted on the yahoo group here https://groups.yahoo...olar Alignment/ With the fine adjustments on the wedge, both up and down and left and right, I was able to get a very good polar alignment, and the setting circles where very accurate. The scope is rock solid and has no vibration on my Bogen tripod. It is very light weight too, so I can take the whole setup outside in one trip. If you need a good wedge, and have a stable photo tripod, I highly recommend this wedge.

[RobertPettengill]

I received my Sky-Watcher wedge and mounted my Questar with a Celestron CG-5 mounting plate.  I was very pleased other than for one problem.  The dovetail mounting plate I have has a slight crown on top and las a result there is a slight side to side rock even when everything is tightened up.  I suspect that it would not be a problem with a dovetail that doesn't have the crown or perhaps  Ralph's Questar retrofit camera mount is a little less susceptible to this problem.

 

I plan to fab a mounting plate that will provide contact all around the edge of the Questar and mount that to the dovetail bar with 4 screws.  I believe that this will be a very solid mount with this wedge.

 

;rob

[Panotaker]

So what exactly is not flat, the dovetail bar you have, or the the top of the wedge where the dovetail fits into. I got extra dove tail bars if it's the bar, or you can always grind it flat. If you need any help or need me to look at it, let me know.

 

Ralph

[RobertPettengill]

I believe that it is the top of the dovetail bar.  I think I have an approach, but am busy with holiday stuff right now. Thanks,  I'll get back to you if I need a hand.

 

;rob

[Panotaker]

Here is my Wedge in action. I take the whole thing outside in one trip. Do a quick Painless Polar Alignment, and I am good to go.

[nicolasM]

Hello, 

 

I am considering this Skywatcher wedge. After few weeks of testing, are satisfied by the stability?

 

Thanks, 

[Panotaker]

Yeah, Im super satisfied with it. I haven't had any problems. It's rock solid for me.

[Piggyback]

Found this solution for my Questar 3,5" Duplex Powerguide II.

I use my unmodified Meade ETX 125 #884 tripod and wedge to attach the center bore of the Q3.5. Note that weight is distributed over 75% of ground plate area. Just by coincidence there is enough space left on the rim for the Powerguide-cable to plug in. Works great for me.

 

 

[Piggyback]

Close up shot of my setup

 

 

[Piggyback]

And here is the culprit. Cast iron tripod legs seem to be prone to cracking. 

 

 

[Piggyback]

Close up of the ground base connection for Powerguide 2 cable.

 

 

[mtr1]

Hi -- 

At NEAF a few folks convinced me that the Star Tracker can be a very effective portable mount for wide field astrophotography, and I decided to try it out.  This gave me an excuse to acquire one of the wedges as described above by Panotaker.  I like it a lot for the Questar, which I mounted by adding a Vixen Dovetail plate in more or less the same fashion as he has done.  Here's what it looks like with my Questar set up for guided imaging:

 

I made one modification to have it fit properly.  The dovetail knob I've highlighted is too wide and interferes with the Questar base.  I think this is causing the improper fit for the dovetail described by Rob.  So I used my Dremel to grind off some of the plastic from the knob, reducing its diameter so that it can fit under the base (just a millimeter or two from each protuberance of the knob).  This allows for a solid fit.  The wedge is easy to adjust for polar alignment.  I used it two nights ago for my ongoing field test of the PG3 and it was stable enough for me to rattle off a series of 20 minute exposures of M64: 

 

https://www.flickr.c.../in/dateposted/

 

Note that it was a bit hazy so I'm a little disappointed in the level of detail I achieved for the galaxy, but as you can see the stars are decent.  

 

Regards,

Mauri

[Steve's 50th]

That Sky Watcher wedge gives a lot of bang for the buck! I wish I'd found it before I spent much more for the AstroTrac wedge!