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How to get an Evolution 8 onto a wedge?

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#1 Rac19

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Posted 30 June 2020 - 10:16 PM

I have tried two ways to do this.

 

1. Position the mount on the wedge with the OTA attached. With this method the mount + OTA is suspended by one screw, with 2 turns of thread engaged, for some time, while the whole thing is wiggled around to engage the other two screws.
 

2. Separate the OTA from the mount, secure tne mount on the wedge then engage the OTA dovetail and tighten the screw. This method is easier in many ways but it involves holding the OTA in one hand whilst engaging it in the dovetail and tightening the screw.

 

Both methods leave me concerned that, one day something, may be dropped while attempting to wrestle the 'scope onto the wedge.

 

I would be interested to hear how others do this.



#2 JohnBear

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Posted 30 June 2020 - 11:40 PM

How about: an observing partner or apprentice.


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#3 Rac19

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Posted 01 July 2020 - 01:26 AM

How about: an observing partner or apprentice.

I have had the same thought. To be really safe, it's a two person job. Unfortunately that's not an option.

 

I am leaning towards option 1, making sure that two full turns are engaged on the first bolt.



#4 Noah4x4

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Posted 01 July 2020 - 01:32 AM

Hi Richard, I was waiting to see how you got on with this.

 

The front screw will slot into the base and that provides enough support to free one hand to support mount/OTA whilst you pursue (1). But I reached a point where I left mine fully assembled as it all took too long once you add the tedious ASPA procedure. You might be more tolerant with better weather, but I got fed up with being beaten by cloud. I could just about manage the ten yards from my indoor mission control, but eventually the extra 15lbs weight was crippling. The Starsense on wedge bug was The final straw.

 

This was the point I gave up with wedge and choose Hyperstar and/or Short stacked exposures (also st f/6.3). After the Starsense on wedge bug was fixed, I did try wedge again to see if longer exposures made any difference. If I extended them to perhaps 60 minutes + then I guess that they might. But a maximum of 2 minutes was about my limit even with wedge, and whether two minutes × 1 exposure or two minutes comprising of multiple  ten second stacks it didn't seem to make too much difference. So I sold my wedge (n.b. it was not easy to find buyers and I had to drop price 50% from new and export it!). 



#5 Rac19

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Posted 01 July 2020 - 01:52 AM

Hi Richard, I was waiting to see how you got on with this.

 

The front screw will slot into the base and that provides enough support to free one hand to support mount/OTA whilst you pursue (1). But I reached a point where I left mine fully assembled as it all took too long once you add the tedious ASPA procedure. You might be more tolerant with better weather, but I got fed up with being beaten by cloud. I could just about manage the ten yards from my indoor mission control, but eventually the extra 15lbs weight was crippling. The Starsense on wedge bug was The final straw.

 

This was the point I gave up with wedge and choose Hyperstar and/or Short stacked exposures (also st f/6.3). After the Starsense on wedge bug was fixed, I did try wedge again to see if longer exposures made any difference. If I extended them to perhaps 60 minutes + then I guess that they might. But a maximum of 2 minutes was about my limit even with wedge, and whether two minutes × 1 exposure or two minutes comprising of multiple  ten second stacks it didn't seem to make too much difference. So I sold my wedge (n.b. it was not easy to find buyers and I had to drop price 50% from new and export it!). 

Hi Noah,

 

As per my post #3, I think that I have decided that option 1 is the lesser of two evils.

 

With regard to the pros and cons of using the wedge, I built myself a permanent pier from Besser blocks and, after a few sessions, the adjustments needed for polar alignment are very minor (almost unnecessary). I now leave the wedge on the pier, protected by a barbecue cover.

 

With PHD guiding, tracking is now very solid (such as I have never seen before) for both DSO and planetary imaging and there is no field rotation of course.

 

The big negative is having to wrestle with the 'scope to get it on and off the wedge.



#6 barbarosa

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Posted 01 July 2020 - 03:09 AM

The CPC 1100 weighs 65lbs and sedentary old guys can do that hanging the mount by one bolt trick. But there is an easier way, which should be dead simple for the Evolution 8 16 pound mount and 12 pound OTA.

 

Crank the wedge plate down as near to horizontal as it will go. Place the mount on the wedge and secure the bolts. Crank the plate back up to the correct angle. It works for the 65 pound CPC.



#7 Rac19

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Posted 01 July 2020 - 03:28 AM

The CPC 1100 weighs 65lbs and sedentary old guys can do that hanging the mount by one bolt trick. But there is an easier way, which should be dead simple for the Evolution 8 16 pound mount and 12 pound OTA.

 

Crank the wedge plate down as near to horizontal as it will go. Place the mount on the wedge and secure the bolts. Crank the plate back up to the correct angle. It works for the 65 pound CPC.

I guess the combined weight of the Evolution 8 mount + OTA Is less than maximum airline baggage allowance but the height to which it has to be lifted adds to any problem. Being at 33.75 degrees latitude, the 56.25 degree angle of the wedge adds to the difficulty.

 

The main reason for building the pier was to preserve polar alignment (at least approximately) between sessions so cranking the Dec axis down and back up isn't the answer for me. If the wedge had a servo motor with shaft encoder, maybesmile.gif.

 

Anyway, I think that I will be going with option 1 in the future.



#8 Don W

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Posted 01 July 2020 - 03:29 PM

Option 2.



#9 Rac19

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Posted 01 July 2020 - 04:54 PM

Option 2.

Having wrestled it off the wedge in one piece last night, I am having second thoughts about option 1. The phrase bear hug best describes it.  It's even more precarious getting it onto the wedge in one piece.



#10 barbarosa

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Posted 01 July 2020 - 06:26 PM

I guess the combined weight of the Evolution 8 mount + OTA Is less than maximum airline baggage allowance but the height to which it has to be lifted adds to any problem. Being at 33.75 degrees latitude, the 56.25 degree angle of the wedge adds to the difficulty.

 

The main reason for building the pier was to preserve polar alignment (at least approximately) between sessions so cranking the Dec axis down and back up isn't the answer for me. If the wedge had a servo motor with shaft encoder, maybesmile.gif.

 

Anyway, I think that I will be going with option 1 in the future.

Being at 38N I can empathize. May I suggest three more things.

 

A step or steps, and an platform on which to stand, that elevates you and makes the lift and extension easier and /or

a small table, even a bar stool, on which you can rest the mount as you position yourself for the lift

 

I used some combination of all of these to take a CPC1100 on and off first a tripod, then a pier and then a wedge on a pier.

 

For fast PA I highly recommend SharpCap Pro's polar alignment tool. £10/year.



#11 Rac19

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Posted 01 July 2020 - 07:09 PM

Being at 38N I can empathize. May I suggest three more things.

 

A step or steps, and an platform on which to stand, that elevates you and makes the lift and extension easier and /or

a small table, even a bar stool, on which you can rest the mount as you position yourself for the lift

 

I used some combination of all of these to take a CPC1100 on and off first a tripod, then a pier and then a wedge on a pier.

 

For fast PA I highly recommend SharpCap Pro's polar alignment tool. £10/year.

I have a 3 step ladder which am thinking of using for Option 2. The OTA isn't very heavy but the dovetail on the mount is at an awkward height when attached to the wedge.

 

I am still not sure which option I prefer. A servo motor powered Dec motor, as decided in post #7, is the most appealing but also the most unlikely.



#12 crn3371

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Posted 01 July 2020 - 09:31 PM

I’d be careful using a step ladder, even a short one, too easy to mis-step and finding your scope on the ground. A single raised box, yes. 



#13 Rac19

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Posted 01 July 2020 - 10:12 PM

I’d be careful using a step ladder, even a short one, too easy to mis-step and finding your scope on the ground. A single raised box, yes. 

Actually, I have some aerobics steps, that might be better, I can stack them (probably two high) to get a suitable height as a single step.

 

EDIT: I changed "can't stack" to "can stack". The IOS spell corrector strikes again.


Edited by Rac19, 02 July 2020 - 12:07 AM.


#14 whizbang

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Posted 01 July 2020 - 10:13 PM

Option 2.

 

I don't get the one handed part. 

 

I make the dovetail horizontal.  Then I hold the OTA underneath with two hands.  After I get the rail in the dovetail, I reach over and star tightening the dovetail knob while both arms and hands are still underneath supporting the tube.



#15 Rac19

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Posted 01 July 2020 - 10:45 PM

Option 2.

 

I don't get the one handed part. 

 

I make the dovetail horizontal.  Then I hold the OTA underneath with two hands.  After I get the rail in the dovetail, I reach over and star tightening the dovetail knob while both arms and hands are still underneath supporting the tube.

I use both hands initially, to engage the dovetail, but the moment comes when I have support tge OWA with my right hand while I tighten the dovetail with my left hand.



#16 Michael_Swanson

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Posted 01 July 2020 - 11:42 PM

I guess the combined weight of the Evolution 8 mount + OTA Is less than maximum airline baggage allowance but the height to which it has to be lifted adds to any problem. Being at 33.75 degrees latitude, the 56.25 degree angle of the wedge adds to the difficulty.

 

The main reason for building the pier was to preserve polar alignment (at least approximately) between sessions so cranking the Dec axis down and back up isn't the answer for me. If the wedge had a servo motor with shaft encoder, maybesmile.gif.

 

Anyway, I think that I will be going with option 1 in the future.

Hi Richard,

 

Reading this response, I had an idea.  Build yourself a platform that you place around the pier allowing you to step up onto the platform so that you are not lifting the scope so high.  In fact, make it tall enough to bring you up to the wedge so it is at waist height.  This should make it much easier to get the Evolution onto the wedge.  

 

I'm thinking something like a wooden box with a U shape cut that you slide the pier into.

 

EDIT - DOH!  I see David already suggested this :-)

 

Best regards,
Mike Swanson
https://www.NexStarSite.com


Edited by Michael_Swanson, 01 July 2020 - 11:43 PM.

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#17 Rac19

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Posted 02 July 2020 - 12:26 AM

Hi Richard,

 

Reading this response, I had an idea.  Build yourself a platform that you place around the pier allowing you to step up onto the platform so that you are not lifting the scope so high.  In fact, make it tall enough to bring you up to the wedge so it is at waist height.  This should make it much easier to get the Evolution onto the wedge.  

 

I'm thinking something like a wooden box with a U shape cut that you slide the pier into.

 

EDIT - DOH!  I see David already suggested this :-)

 

Best regards,
Mike Swanson
https://www.NexStarSite.com

Thanks Michael (and David). I think that I will try the aerobic steps, I doubt that I would want to stack more than two high (maybe three high). When I think that I have right height, I may well make something from weather resistant plywood.

 

I am leaning to option 2. Having the mount and 'scope hanging off a single, partially engaged bolt at 56.25 degrees while jiggling it all around, is quite precarious.

 

I did almost drop the OTA under similar circumstances (but nor on a wedge) a couple of years ago. I definitely don't want a repeat that experience.
 

As for whether or not using a wedge is worth the effort? So far my opinion is definitely yes. It will never match the precision of a high quality EQ mount but, with auto-guiding, the tracking precision is far superior to Alt/Az tracking. I think that it is even worthwhile for planetary imaging, just to keep the planet central in the frame. I have a lot to learn about longer exposures for DSO imaging but it is great to be able break the 30 second field rotation barrier.



#18 Noah4x4

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Posted 02 July 2020 - 03:31 AM

Hi Richard, sorry to discourage you, but I tried both Option 1 and Option 2 and found both a challenge. But my suggestion is what about trying a tripod adjustment?

 

The ideas offered about a box step make eminent sense. But why not simply put your tripod at its lowest elevation? If you are not doing any "visual" (I haven't looked though an eyepiece for a year), you don't need to extend your tripod to full height unless you are surrounded by low level obstructions.

 

But frankly, my experience of adding an OTA complete with StarSense and Finderscope (option 2) is fraught with more risk than adding the entire mount/OTA assembly (as under option 1). At least with 1 you only need to hook a single bolt into the slot, then you have reasonable security whilst you fiddle with the other two bolts. I don't want to alarm you, but....

 

It is during disassembly when you are tired, possibly frustrated if the night has not gone well, where things might go badly wrong.

 

What if you forget to disconnect the StarSense cable? I have twice accidently done this during daylight testing. in the first, my OTA suffered a tumble where I fortunately caught it but ended up with two tiny scratch marks on my corrector plate, but fortunately my kit survived and they have been of no consequence. I had another earlier incidence where in not dissimilar circumstances, I accidently dragged my mount off a table (fortunately no OTA attached) having tripped over the stupidly long original StarSense cable I had left attached and my mount dropped three feet onto a wooded floor. Fortunately, my mount landed upright on its base and escaped undamaged as its heavy base landed on my cable (perhaps fortunately, to cushion it) and it severed that as if guillotined. This is where I replaced it with a short coiled cable taken from an AVX.

 

Frankly, I don't think there is any comfortable way of handling a wedge and SCT OTA over 8". But lowering your tripod to avoid using steps might assist, and will add stability.


Edited by Noah4x4, 02 July 2020 - 03:33 AM.


#19 Rac19

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Posted 02 July 2020 - 04:24 AM

Hi Richard, sorry to discourage you, but I tried both Option 1 and Option 2 and found both a challenge. But my suggestion is what about trying a tripod adjustment?

 

The ideas offered about a box step make eminent sense. But why not simply put your tripod at its lowest elevation? If you are not doing any "visual" (I haven't looked though an eyepiece for a year), you don't need to extend your tripod to full height unless you are surrounded by low level obstructions.

 

But frankly, my experience of adding an OTA complete with StarSense and Finderscope (option 2) is fraught with more risk than adding the entire mount/OTA assembly (as under option 1). At least with 1 you only need to hook a single bolt into the slot, then you have reasonable security whilst you fiddle with the other two bolts. I don't want to alarm you, but....

 

It is during disassembly when you are tired, possibly frustrated if the night has not gone well, where things might go badly wrong.

 

What if you forget to disconnect the StarSense cable? I have twice accidently done this during daylight testing. in the first, my OTA suffered a tumble where I fortunately caught it but ended up with two tiny scratch marks on my corrector plate, but fortunately my kit survived and they have been of no consequence. I had another earlier incidence where in not dissimilar circumstances, I accidently dragged my mount off a table (fortunately no OTA attached) having tripped over the stupidly long original StarSense cable I had left attached and my mount dropped three feet onto a wooded floor. Fortunately, my mount landed upright on its base and escaped undamaged as its heavy base landed on my cable (perhaps fortunately, to cushion it) and it severed that as if guillotined. This is where I replaced it with a short coiled cable taken from an AVX.

 

Frankly, I don't think there is any comfortable way of handling a wedge and SCT OTA over 8". But lowering your tripod to avoid using steps might assist, and will add stability.

Hi Noah,

 

Thanks for the suggestions, but...

 

Because I am now using a pier, lowering the 'scope isn't an option, see below. I did just try the aerobic step stacked 3 high. It was still an easy step and brought the dovetail on the mount to a little above waist high. I might try it out tomorrow, it looks like cloud and even rain tonight.
 

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#20 Noah4x4

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Posted 02 July 2020 - 05:19 AM

Ah, I forgot your pier! Sorry. But what about this third option...

 

Might affixing the wedge base (with mount/OTA assembled) to pier be an easier option? At least it would then be laid on a flat surface rather than extreme lean. Yes, it would then require fresh Polar Alignment, but it might be easier/safer?

 

EDIT

What about a Telegizmo cover and leave it assembled? 


Edited by Noah4x4, 02 July 2020 - 05:31 AM.


#21 Rac19

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Posted 02 July 2020 - 06:55 AM

Ah, I forgot your pier! Sorry. But what about this third option...

 

Might affixing the wedge base (with mount/OTA assembled) to pier be an easier option? At least it would then be laid on a flat surface rather than extreme lean. Yes, it would then require fresh Polar Alignment, but it might be easier/safer?

 

EDIT

What about a Telegizmo cover and leave it assembled? 

The wedge is quite heavy actually so the combined weight of the mount + OTA + wedge would be considerable.

 

Leaving everything in place is an option that I have considered and I have had quote for a Telegizmos cover.

 

I'm not sure that I will ever be comfortable with leaving the mount outside even with such a cover. It doesn't snow here but summer can be very hot (we 47 degrees one day last summer) and condensation is always a consideration.

 

Leaving the wedge in place, with a cheaper (barbecue) cover, means that polar alignment is very close every time. There are only very small adjustments each time.
 

Anyway, the aerobic step definitely gets me to a more comfortable height and I am going to see how that works.The mini dovetails for StarSense and RACI finder make quite useful handles close to the centre of gravity. 

 

No matter what, care is needed when fitting the OTA to tge mount and when removing it.



#22 Rac19

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Posted 02 July 2020 - 07:27 AM

A couple of flights of fancy arising from this discussion.

 

I have often though that a telescopic pier that could be raised to rooftop height would be nice. The cost of constructing one with the required rigidity would be prohibitive of course.

 

Also, a servo motor (with shaft encoder) for the wedge Dec axis would make to assemble everything in that flat position then return to the correct latitude angle. It could be made accessible in CPWI for polar alignment. Wedges are expensive enough as they are I suppose.



#23 crn3371

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Posted 02 July 2020 - 11:40 AM

While you might not feel totally comfortable with a Telegizmo cover on the hottest of days, I’d try using one as much as possible as it would at least minimize the amount of times you have to wrestle with the mount.


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#24 Rac19

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Posted 02 July 2020 - 04:22 PM

While you might not feel totally comfortable with a Telegizmo cover on the hottest of days, I’d try using one as much as possible as it would at least minimize the amount of times you have to wrestle with the mount.

I must to admit that I have already been tempted to leave it out overnight at times.

 

I can't find a storage specification for the Evolution mount but for NUC mini PC it is -20 to +60 (degrees C), non-condensing of course. It's probably safe to assume 50 degrees for the Evolution, so it's a question of how successfully Telegizmos cover insulates and reflects solar radiation. I think that it would be quite effective.

 

Also the extreme temperatures are only for an hour or each time late in the afternoon.

 

Condensation remains something to think about. Ventilation and anti-condensation heaters are the usual remedies in industrial equipment.



#25 crn3371

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Posted 02 July 2020 - 06:27 PM

Plenty of Telegizmo threads, plenty of members leaving scopes out 24/7, some in pretty extreme conditions with good results. 




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