35 replies to this topic

[Fiske]

I'm a fan of the Oberwerk XL-240/280 fork mount on the Manfrotto 161MK2B, show here with a 100XL-SD.

 

 

This setup is great for low to moderate magnifications, but for higher magnification views it is not ideally stable to be honest. The issue isn't this particular fork or mount (both are great), it's just a consequence of the design. Fork mounts tend to be somewhat wobbly for binocular telescopes in general, and the problem gets worse with larger instruments and higher magnifications.

 

So, as a happy new Oberwerk 127XL owner, I have started pondering alternative mount options. The Vinten video head route doesn't seem that inviting to me, but the iOptron AZ mount (which Oberwerk offers in a bundled package configured for the 127XL) seems promising. 

 

I found this Bino forum topic about the iOptron mount. I'm curious to know how well it handles higher magnification views (100-130x range, for example), if anyone on the forum has experience with that?

 

 

[aneeg]

I have this mount with a Mewlon 210. 300X no problem.

 

Arne

[Fiske]

I have this mount with a Mewlon 210. 300X no problem.

 

Arne

Arne, despite my love of all things binocular, I would not mind owning a Mewlon 210. 

[aneeg]

I understand that! I bought it for lunar and planetary work, But it excels on globulars and doubles, too. And faint fuzzies. And…, and…

 

Arne

[Fiske]

I understand that! I bought it for lunar and planetary work, But it excels on globulars and doubles, too. And faint fuzzies. And…, and…

 

Arne

Okay. Enough already! 

 

Seriously, congratulations on owning such a fine scope. 

[Fiske]

Thanks to Rick for his replies about fork stability and iOptron mounts in the BT 127 First Light topic. 

 

What I am considering is the iOptron AZ Pro 127XL bundle offered by Oberwerk. It includes a Bino-Bracket accessory for mounting larger binoculars and the Tri-tier pier/tripod combo for increased stability.

 

One question about using the mount is eyepiece height adjustment.

 

I found this helpful Astro-Jeff video with a lot of details about the Tri-tier. The Tri-tier can be set at various heights, but once set is not designed to be raised or lowered in use. Reflecting on that, it is pragmatically the same situation I'm in with the 161MK2B, because I would never raise the elevator column carrying something like 37 pounds (combined weight of the 127XL, XL-280 fork, and eyepieces). 

 

So height adjustment is down (or up) to my Starbound observer's chair anyway. 

Edited by Fiske, 10 October 2022 - 05:21 AM.

[oldmanrick]

Thanks to Rick for his replies about fork stability and iOptron mounts in the BT 127 First Light topic. 

 

What I am considering is the iOptron AZ Pro 127XL bundle offered by Oberwerk. It includes a Bino-Bracket accessory for mounting larger binoculars and the Tri-tier pier/tripod combo for increased stability.

 

One question about using the mount is eyepiece height adjustment.

 

I found this helpful Astro-Jeff video with a lot of details about the Tri-tier. The Tri-tier an be set at various heights, but once set is not designed to be raised or lowered in use. Reflecting on that, it is pragmatically the same situation I'm in with the 161MK2B, because I would never raise the elevator column carrying something like 37 pounds (combined weight of the 127XL, XL-280 fork, and eyepieces). 

 

So height adjustment would be down (or up) to my Starbound observer's chair. 

And depending on how you observe, you might be doing a lot of "up and down" adjusting of the Starbound!  I do more than I would like, even when using a working geared center column.

 

Rick

[Fiske]

I tend to delve into a starfield for an extended time, so although the StarBound height does get adjusted, that is punctuated by long periods of observing. Also, a nice thing about having a variety of binoculars and mounts is that if I want to roam widely and not worry about height adjustment I use a straight through binocular on a p-gram, or a smaller BT on the TR3 with the carbon elevator column, which I adjust more often than the crank elevator on the 161MK2B. 

 

Edited by Fiske, 09 October 2022 - 09:09 PM.

[duck2k]

My set up with my 127’s are the 161MK2B, and the Obie fork mount. Steady as a rock.

[Fiske]

What magnifications do you observe with, duck?

 

[Fiske]

I came across another interesting iOptron video, from Matt Magilke, showing a mod he did to mount an APM 120 on his iOptron using a long dovetail plate, including an adjustable counterweight bar. It's well conceived to say the least. 

Edited by Fiske, 10 October 2022 - 07:19 AM.

[Mark Y.]

Fiske,obviously (as you know) I love "all" of you set ups and overall high quality collection.You've had a huge influence on my bank account...However,I have a question about the picture in post #8.....Do your neighbors kinda' bother you when you have such visibility in the spot you show?

 

I'd think everyone would want to come over for a gander.....Maybe a nosey dog as well.....I've seen your main viewing area and that's where I'd always want to be.....Just curious.

[Fiske]

Not one single time, Mark. 

 

You would always want to come over because you are an amateur astronomer. (We are relatively widely distributed in the general population.  )

 

A few times I have shared views with two of my neigbors -- during the last lunar eclipse and during the Jupiter/Saturn conjunction. But I more or less initiated the Jupiter/Saturn thing with one of my neighbors, and saw the other neighbor with binoclars watching the lunar eclipse and went over to join them. 

 

People mostly aren't interested in astronomy, which is hard for amateur astronomers to gasp I think. 

[ihf]

I think people are just trying to be polite. I always resisted inviting myself to the folks with big scopes on campsites. Maybe put out some signs: "Come, see the Moon!"

[Fiske]

I think people are just trying to be polite. I always resisted inviting myself to the folks with big scopes on campsites. Maybe put out some signs: "Come, see the Moon!"

But a passerby would inevitably call out, "We can see you from here." 

[Mark Y.]

I do remember one time,a few years ago,my pal had a big 12 inch S.C. in front of his house.We were looking at some nice star clusters.

 

Suddenly,a police patrol car pulls up and two cops get out,very suspicious as to what we were up to.We told them what this gadget was(not a rocket launcher) and  showed them what we were watching.

 

After 3 minutes we couldn't get them to leave!

[Fiske]

Kevin Busarow at Oberwerk and I have been chatting about the XL-280 fork azimuth motion with the 127XL on board, and he is shipping a tuned up fork with less stiction in the azimuth motion (synthetic grease, a teflon thrust bearing instead of the original brass thrust bearing, and newer two-level side plates). Images, details, and usage report to follow. 

 

Also, the Oberwerk iOptron AZ Pro 127XL bundle will be arriving in the not distant future. I mean, how else would I do three-way side by side views of the Perseus Double Cluster between the Kowa Highlander and the Oberwerk 100XL-SD and 127XL-SD? 

Edited by Fiske, 18 October 2022 - 03:21 PM.

[ihf]

You need six eyes, Fiske. Three pairs. There must be ways to grow two more pairs?

[Fiske]

You need six eyes, Fiske. Three pairs. There must be ways to grow two more pairs?

[SMark]

I do remember one time,a few years ago,my pal had a big 12 inch S.C. in front of his house.We were looking at some nice star clusters.

 

Suddenly,a police patrol car pulls up and two cops get out,very suspicious as to what we were up to.We told them what this gadget was(not a rocket launcher) and  showed them what we were watching.

 

After 3 minutes we couldn't get them to leave!

I had a near identical experience back in the winter of '81 up in Green Bay. I had recently finished my 8" Dob, and while squeezing my eyeball into my 6.8mm Ortho I heard a car stop, and then a hi-beam flashlight lit me up. "Is that a telescope?" So I gave the officer a quick tour of the solar system (Jupiter and Saturn) and he was happy and finally went on his way. He said he'd always wanted to look through a "big" telescope.

[Fiske]

The optimized XL-280 fork arrived last Friday (21 October 2022). Here is my original XL-280 fork. Note feline assistant ready to help with small machine screws and seasonally appropriate pumpkin.

 

 

The horizontal binocular mounting plate has been removed, to be installed on the replacement fork.

 

Here is a detail of the side plate, which is a newer shorter design (aprox 4-inch height). One issue Kevin realized with the XL-280 fork I had, which was converted from an XL-240 fork by installing wider horizontal plates, is that the shorter side plates that came with the XL-240 make the center of gravity on the 127XL half an inch too high, contributing to balance and vibration problems. 

 

 

Here is the replacement fork. The side plates are approximately 4.5 inches in height. The horizontal binocular mounting plate is connected to the lower slots, which lowers the binocular half an inch relative to the point of rotation. Kevin also replaced the original azimuth bearing grease with lighter synthetic grease and replaced the original brass thrust washer with a teflon washer. 

 

 

Here is the fork with the horizontal plate installed.

 

 

Clouds and (much needed) rain over the weekend prevented me from trying out the new fork until last night (Tuesday 25 October). I'm happy to report that azimuth motion stiction has been eliminated. (Kevin said changing the grease made the biggest difference.) Vibration at higher magnification views is better controlled now as well. I'm pleased with the motions of the optimized fork, and am content with 161MK2B / XL-280 configuration for the 127XL. From my perspective, 130x magnification (5mm eyepieces) is a practical maximum for the instrument. 

 

Seeing was better last night than it had been on my previous outing with the 127XL and I found the Pentax 5mm XW eyepieces usable. Working at 130x takes some practice, but I was able to navigate successfully despite the small FOV (0.54 degrees). Vibration damping is still a factor so patience and a light touch are helpful. 

 

The iOptron AZ Pro mount is scheduled for delivery tomorrow. Reports to follow. 

Edited by Fiske, 26 October 2022 - 08:02 AM.

[MrZoomZoom2017]

The optimized XL-280 fork arrived last Friday (21 October 2022). Here is my original XL-280 fork. Note feline assistant ready to help with small machine screws and seasonally appropriate pumpkin.

 

 

The horizontal binocular mounting plate has been removed, to be installed on the replacement fork.

 

Here is a detail of the side plate, which is a newer shorter design (aprox 4-inch height). One issue Kevin realized with the XL-280 fork I had, which was converted from an XL-240 fork by installing wider horizontal plates, is that the shorter side plates that came with the XL-240 make the center of gravity on the 127XL half an inch too high, contributing to balance and vibration problems. 

 

 

Here is the replacement fork. The side plates are approximately 4.5 inches in height. The horizontal binocular mounting plate is connected to the lower slots, which lowers the binocular half an inch relative to the point of rotation. Kevin also replaced the original azimuth bearing grease with lighter synthetic grease and replaced the original brass thrust washer with a teflon washer. 

 

 

Here is the fork with the horizontal plate installed.

 

 

Clouds and (much needed) rain over the weekend prevented me from trying out the new fork until last night (Tuesday 25 October). I'm happy to report that azimuth motion stiction has been eliminated. (Kevin said changing the grease made the biggest difference.) Vibration at higher magnification views is better controlled now as well. I'm pleased with the motions of the optimized fork, and am content with 161MK2B / XL-280 configuration for the 127XL. From my perspective, 130x magnification (5mm eyepieces) is a practical maximum for the instrument. 

 

Seeing was better last night than it had been on my previous outing with the 127XL and I found the Pentax 5mm XW eyepieces usable. Working at 130x takes some practice, but I was able to navigate successfully despite the small FOV (0.54 degrees). Vibration damping is still a factor so patience and a light touch are helpful. 

 

The iOptron AZ Pro mount is scheduled for delivery tomorrow. Reports to follow. 

Hey Fiske,

 

I believe I found one slight error in your post - it is the feline supervisor checking your work and not an assistant - right?  

 

Cheers,

Tim

[Fiske]

Hey Fiske,

 

I believe I found one slight error in your post - it is the feline supervisor checking your work and not an assistant - right?  

 

Cheers,

Tim

You nailed that one, Tim. 

[Rich V.]

The idea of multiple mounting height positions provided on the side plates seems to me to be an idea that should have been incorporated in the first place.  The ability to provide different mounting heights as needed for various binos relative to the alt axis seems necessary for a fork mount, IMO.

 

Glad you have a proper balance solution now, Fiske.

 

Rich

[MrZoomZoom2017]

You nailed that one, Tim. 

We have a feline supervisor in our home as well (Abby) which is why I had a sneaking suspicion.

 

So far it appears your work has the stamp of approval!  Now where are the cat-treats?  

 

Cheers,

Tim