Optec Leo for Epsilon

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Dan:
I also bought longer screws for mounting the focuser to the tube, the stock ones are a little short imho for the Optec.

thanks Dan. Do you remember the screw types/sizes by any chance?

while i'm certain clouds will oppressively blanket the sky when it gets here, I'm still anxious to have everything ready.

If any of you all would like to share your Autofocus settings, that would also be welcomed!

1.81 Dan Brown #... · view views · 1 like
Here is a link to what I bought, https://www.mcmaster.com/91698A725/ Dan Like

20.43 Chris White- Overcast Observatory #... · view views · 1 like
Dan: Alternatively, if you know that your collimation is good, just install the focuser and re-collimate by adjusting the focuser tilt adjuster. Dan This may off-center the optical axis which would be a problem for a full frame sensor. You should really collimate by adjusting the mirrors and not the drawtube angle. I always recommend that people lock the tilt feature on the focuser down and forget it exists. It really shouldnt be there in my opinion. When you install the focuser leave the 4 nuts a little bit loose. Install the tak tool and slide the focuser and flange into position where the crosshair is centered on the secondary spot. This will simplify collimation later as you will be aligning the center of the drawtube with the center of the secondary. This way you dont need to move the secondary itself. The holes in the OTA tube are slotted so you can position as desired and then tighten the nuts. Collimation is not that difficult with this scope, and you can use the tak tools to do it in the daytime. You will need to recollimate when replacing the focuser, and this is not to be feared. You will want to become familiar with collimation process and the mechanics of the scope. Epsilon is very well built. *** Also, the interior of the scope and the nuts are coated with a spray on flocking. It's delicate, so be careful not to scrape it too much when installing. For example, when you tighten the nuts, dont actually rotate the nuts... just hold them with a socket and use a screw driver to do the actual tightening. This will protect that flocking. Edited ... Like

20.43

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Dan:
Alternatively, if you know that your collimation is good, just install the focuser and re-collimate by adjusting the focuser tilt adjuster.
Dan

This may off-center the optical axis which would be a problem for a full frame sensor. You should really collimate by adjusting the mirrors and not the drawtube angle. I always recommend that people lock the tilt feature on the focuser down and forget it exists. It really shouldnt be there in my opinion.

When you install the focuser leave the 4 nuts a little bit loose. Install the tak tool and slide the focuser and flange into position where the crosshair is centered on the secondary spot. This will simplify collimation later as you will be aligning the center of the drawtube with the center of the secondary. This way you dont need to move the secondary itself. The holes in the OTA tube are slotted so you can position as desired and then tighten the nuts.

Collimation is not that difficult with this scope, and you can use the tak tools to do it in the daytime. You will need to recollimate when replacing the focuser, and this is not to be feared. You will want to become familiar with collimation process and the mechanics of the scope. Epsilon is very well built.

*** Also, the interior of the scope and the nuts are coated with a spray on flocking. It's delicate, so be careful not to scrape it too much when installing. For example, when you tighten the nuts, dont actually rotate the nuts... just hold them with a socket and use a screw driver to do the actual tightening. This will protect that flocking.

Edited ...

1.81 Dunk #... · view views · 1 like
My experience is from a 130 - so things were a little smaller/tighter, but: The instructions say to take the OTA off the mount when installing the replacement saddle, but for me I left the OTA on the mount, grabbed a chair and sat down next to my mount, flipped the OTA upside down (so that the focuser was pointing to the ground, scope pointing slightly down so no screws could fall into the tube and scratch the primary) and the replacement went well/easy. Just take your time. You do need a socket wrench with an extension as its a little tricky getting to the bolts at the back. Adding to Chris's comment above, I had to re-paint the nuts (got the mattest black I could find at the hobby shop) as I did scrape a bit of the flocking paint off. There's a reaaaaally long thread on here with pics of some of this process too which will help you: https://www.astrobin.com/forum/c/equipment-forums/takahashi-epsilon-160ed/setting-up-the-e160-ed-for-full-frame-imaging/ I had no issues with screws being too short, and collimation was straight-forward (I only had to to adjust the secondary). Like

1.81

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My experience is from a 130 - so things were a little smaller/tighter, but:

The instructions say to take the OTA off the mount when installing the replacement saddle, but for me I left the OTA on the mount, grabbed a chair and sat down next to my mount, flipped the OTA upside down (so that the focuser was pointing to the ground, scope pointing slightly down so no screws could fall into the tube and scratch the primary) and the replacement went well/easy.

Just take your time. You do need a socket wrench with an extension as its a little tricky getting to the bolts at the back.

Adding to Chris's comment above, I had to re-paint the nuts (got the mattest black I could find at the hobby shop) as I did scrape a bit of the flocking paint off.

There's a reaaaaally long thread on here with pics of some of this process too which will help you: https://www.astrobin.com/forum/c/equipment-forums/takahashi-epsilon-160ed/setting-up-the-e160-ed-for-full-frame-imaging/

I had no issues with screws being too short, and collimation was straight-forward (I only had to to adjust the secondary).

3.81 Nick Grundy #... · view views
Hi All, I feel like I'd just turned a corner on this epic journey. Once I finally installed the Leo, it seemed to have a faulty mechanical issue to get to home. Optec was impressive with support though. (no issues, no BS, just wanted to get it right for me) I got the replacement a few days ago. I've got the scope out tonight and I feel like i'm crazy because I can't retract enough to get in focus. I'm at 57mm backfocus with the optical train out from the corrector. I installed the focuser checked collimation after. (all looked good so far) But now I'm bottomed out at 100 on the focuser. Any thoughts? It's the Optec Leo kit for the 160 that I installed. Did I miss something? Like

3.81

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Hi All, I feel like I'd just turned a corner on this epic journey. Once I finally installed the Leo, it seemed to have a faulty mechanical issue to get to home. Optec was impressive with support though. (no issues, no BS, just wanted to get it right for me) I got the replacement a few days ago.

I've got the scope out tonight and I feel like i'm crazy because I can't retract enough to get in focus. I'm at 57mm backfocus with the optical train out from the corrector. I installed the focuser checked collimation after. (all looked good so far)

But now I'm bottomed out at 100 on the focuser. Any thoughts? It's the Optec Leo kit for the 160 that I installed. Did I miss something?

1.81 Dunk #... · view views · 1 like
Nick Grundy: Hi All, I feel like I'd just turned a corner on this epic journey. Once I finally installed the Leo, it seemed to have a faulty mechanical issue to get to home. Optec was impressive with support though. (no issues, no BS, just wanted to get it right for me) I got the replacement a few days ago. I've got the scope out tonight and I feel like i'm crazy because I can't retract enough to get in focus. I'm at 57mm backfocus with the optical train out from the corrector. I installed the focuser checked collimation after. (all looked good so far) But now I'm bottomed out at 100 on the focuser. Any thoughts? It's the Optec Leo kit for the 160 that I installed. Did I miss something? Backfocus should be 56.2mm Like

1.81

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· 1 like

Nick Grundy:
Hi All, I feel like I'd just turned a corner on this epic journey. Once I finally installed the Leo, it seemed to have a faulty mechanical issue to get to home. Optec was impressive with support though. (no issues, no BS, just wanted to get it right for me) I got the replacement a few days ago.

I've got the scope out tonight and I feel like i'm crazy because I can't retract enough to get in focus. I'm at 57mm backfocus with the optical train out from the corrector. I installed the focuser checked collimation after. (all looked good so far)

But now I'm bottomed out at 100 on the focuser. Any thoughts? It's the Optec Leo kit for the 160 that I installed. Did I miss something?

Backfocus should be 56.2mm

3.81 Nick Grundy #... · view views
Dunk: Backfocus should be 56.2mm I could be wrong on this one, but I calculated about 57.2mm to be ideal given that my filters are 3mm. (they say to add 1/3 of your filter thickness to the optical train) Is that incorrect?? Should this be a factor though. I was guessing this is all prior to the corrector. Like

1.81 Dunk #... · view views
Nick Grundy: Dunk: Backfocus should be 56.2mm I could be wrong on this one, but I calculated about 57.2mm to be ideal given that my filters are 3mm. (they say to add 1/3 of your filter thickness to the optical train) Is that incorrect?? Should this be a factor though. I was guessing this is all prior to the corrector. Are you sure your filters are not 3nm (which is not the thickness of the filter)? My filters are 1mm thick, so I add 0.3mm to the calculation… Like

1.81

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Nick Grundy:
Dunk:
Backfocus should be 56.2mm

I could be wrong on this one, but I calculated about 57.2mm to be ideal given that my filters are 3mm. (they say to add 1/3 of your filter thickness to the optical train) Is that incorrect??

Should this be a factor though. I was guessing this is all prior to the corrector.

Are you sure your filters are not 3nm (which is not the thickness of the filter)? My filters are 1mm thick, so I add 0.3mm to the calculation…

3.81 Nick Grundy #... · view views
here's what i'm using https://agenaastro.com/chroma-h-alpha-8nm-imaging-filter-50mm-round-unmounted.html It says the glass substrate is 3mm thick. My assumption is that is the glass itself. (even though the bandpass is 8nm) Anyone smarter, please chime in, but the 8nm is the FWHM size of the bandpass for the targeted emission line. Totally different. But in fairness, it is late so I could be a couple beverages too late for clear logic ;-) Like

3.81

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here's what i'm using

https://agenaastro.com/chroma-h-alpha-8nm-imaging-filter-50mm-round-unmounted.html

It says the glass substrate is 3mm thick. My assumption is that is the glass itself. (even though the bandpass is 8nm)

Anyone smarter, please chime in, but the 8nm is the FWHM size of the bandpass for the targeted emission line. Totally different. But in fairness, it is late so I could be a couple beverages too late for clear logic ;-)

1.81 Dunk #... · view views · 1 like
Nick Grundy: here's what i'm using https://agenaastro.com/chroma-h-alpha-8nm-imaging-filter-50mm-round-unmounted.html It says the glass substrate is 3mm thick. My assumption is that is the glass itself. (even though the bandpass is 8nm) Anyone smarter, please chime in, but the 8nm is the FWHM size of the bandpass for the targeted emission line. Totally different. But in fairness, it is late so I could be a couple beverages too late for clear logic ;-) You are correct, it does say 3mm. It also says that filter is for F4 and slower. Chroma though so…. $$$ 😀 (I’m on my 2nd glass of wine too) back to your problem though: you say “this is all prior to the corrector” - the 56.2 is from where the corrector ends to the camera sensor (i.e. you can ignore the corrector completely in the calculation). also, the optec does not change any of this as it’s identical in backfocus with and without. heres how I have mine setup: Like

1.81

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Nick Grundy:
here's what i'm using

https://agenaastro.com/chroma-h-alpha-8nm-imaging-filter-50mm-round-unmounted.html

It says the glass substrate is 3mm thick. My assumption is that is the glass itself. (even though the bandpass is 8nm)

Anyone smarter, please chime in, but the 8nm is the FWHM size of the bandpass for the targeted emission line. Totally different. But in fairness, it is late so I could be a couple beverages too late for clear logic ;-)

You are correct, it does say 3mm. It also says that filter is for F4 and slower. Chroma though so…. $$$ 😀

(I’m on my 2nd glass of wine too)

back to your problem though: you say “this is all prior to the corrector” - the 56.2 is from where the corrector ends to the camera sensor (i.e. you can ignore the corrector completely in the calculation).

also, the optec does not change any of this as it’s identical in backfocus with and without.

heres how I have mine setup:

20.43 Chris White- Overcast Observatory #... · view views · 1 like
Nick Grundy: Hi All, I feel like I'd just turned a corner on this epic journey. Once I finally installed the Leo, it seemed to have a faulty mechanical issue to get to home. Optec was impressive with support though. (no issues, no BS, just wanted to get it right for me) I got the replacement a few days ago. I've got the scope out tonight and I feel like i'm crazy because I can't retract enough to get in focus. I'm at 57mm backfocus with the optical train out from the corrector. I installed the focuser checked collimation after. (all looked good so far) But now I'm bottomed out at 100 on the focuser. Any thoughts? It's the Optec Leo kit for the 160 that I installed. Did I miss something? Nick, if you can't move the focuser in enough to reach focus you need to lower the focuser. Underneath is a gold ring. This locks the height. Thread the pieces together more to lower the entire focuser and lock with the ring. If you Are already bottomed out there are two more things you can do. 1) loosen the 4 bolts where the focuser flange bolts to the ota and slide the entire assembly towards the primary. The holes on the ota are slotted, so you can choose position. Moving the focuser closer to the primary will require you to re-enter the secondary under the focuser. By moving the secondary closer to the primary you will push the focal plane further out. You should check to make sure the secondary is centered under the focuser anyway. 2) instead of moving the focuser you can move the primary closer to the secondary. This will do the same thing with the focal plane, however the primary travel may be limited depending on your setup. Most likely, the original idea I gave you will solve your problem. Edited ... Like

20.43

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· 1 like

Nick Grundy:
Hi All, I feel like I'd just turned a corner on this epic journey. Once I finally installed the Leo, it seemed to have a faulty mechanical issue to get to home. Optec was impressive with support though. (no issues, no BS, just wanted to get it right for me) I got the replacement a few days ago.

I've got the scope out tonight and I feel like i'm crazy because I can't retract enough to get in focus. I'm at 57mm backfocus with the optical train out from the corrector. I installed the focuser checked collimation after. (all looked good so far)

But now I'm bottomed out at 100 on the focuser. Any thoughts? It's the Optec Leo kit for the 160 that I installed. Did I miss something?

Nick, if you can't move the focuser in enough to reach focus you need to lower the focuser. Underneath is a gold ring. This locks the height. Thread the pieces together more to lower the entire focuser and lock with the ring.

If you Are already bottomed out there are two more things you can do.

1) loosen the 4 bolts where the focuser flange bolts to the ota and slide the entire assembly towards the primary. The holes on the ota are slotted, so you can choose position. Moving the focuser closer to the primary will require you to re-enter the secondary under the focuser. By moving the secondary closer to the primary you will push the focal plane further out. You should check to make sure the secondary is centered under the focuser anyway.

2) instead of moving the focuser you can move the primary closer to the secondary. This will do the same thing with the focal plane, however the primary travel may be limited depending on your setup.

Most likely, the original idea I gave you will solve your problem.

Edited ...

3.81 Nick Grundy #... · view views
Chris White- Overcast Observatory: Underneath is a gold ring. This locks the height. Thread the pieces together more to lower the entire focuser and lock with the ring. thanks Chris! I will give that a try. I left that portion exactly as I received it so hopefully there's some room to bring it closer Like

7.78 JohnHen #... · view views
Hi Nick could you provide some background on the light leaks in the stock focuser? Is this a known problem with the Epsilon focuser? Thanks, John Like

3.81 Nick Grundy #... · view views · 1 like
light leaks in the stock focuser? I think it's known issue. I never saw it in actual images, but I tested it myself with a flashlight. there was definitely an angle where light from the flashlight on one side would be shown in the image preview. There was actually someone that made a light collar to fix it. https://www.thingiverse.com/thing:5402209 I tried that and it needs a little adjusting, but I could see it helping. I ended up pulling the trigger on the Leo because I wanted backlash free focusing. The ZWO EAF was doing ok, but I was a little worried about the focuser tube shifting a bit under a heavier load. Like

3.81

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light leaks in the stock focuser?

I think it's known issue. I never saw it in actual images, but I tested it myself with a flashlight. there was definitely an angle where light from the flashlight on one side would be shown in the image preview.

There was actually someone that made a light collar to fix it. https://www.thingiverse.com/thing:5402209

I tried that and it needs a little adjusting, but I could see it helping. I ended up pulling the trigger on the Leo because I wanted backlash free focusing. The ZWO EAF was doing ok, but I was a little worried about the focuser tube shifting a bit under a heavier load.

20.43 Chris White- Overcast Observatory #... · view views · 2 likes
Nick Grundy: light leaks in the stock focuser? I think it's known issue. I never saw it in actual images, but I tested it myself with a flashlight. there was definitely an angle where light from the flashlight on one side would be shown in the image preview. There was actually someone that made a light collar to fix it. https://www.thingiverse.com/thing:5402209 I tried that and it needs a little adjusting, but I could see it helping. I ended up pulling the trigger on the Leo because I wanted backlash free focusing. The ZWO EAF was doing ok, but I was a little worried about the focuser tube shifting a bit under a heavier load. 4um steps are not fine enough for epsilon either. The leo has 0.08um steps, and as you mentioned... no backlash. @Bill Long - Dark Matters Astrophotography let me borrow an eaf while my LEO was on order and it was functional but between that and the stock focuser it was not precise enough for my standards. Like

20.43

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· 2 likes

Nick Grundy:
light leaks in the stock focuser?

I think it's known issue. I never saw it in actual images, but I tested it myself with a flashlight. there was definitely an angle where light from the flashlight on one side would be shown in the image preview.

There was actually someone that made a light collar to fix it. https://www.thingiverse.com/thing:5402209

I tried that and it needs a little adjusting, but I could see it helping. I ended up pulling the trigger on the Leo because I wanted backlash free focusing. The ZWO EAF was doing ok, but I was a little worried about the focuser tube shifting a bit under a heavier load.

4um steps are not fine enough for epsilon either. The leo has 0.08um steps, and as you mentioned... no backlash.

@Bill Long - Dark Matters Astrophotography let me borrow an eaf while my LEO was on order and it was functional but between that and the stock focuser it was not precise enough for my standards.

3.81 Nick Grundy #... · view views
Chris White- Overcast Observatory: Underneath is a gold ring. This locks the height. this is definitely feeling like a dumb question, but ..... Is there some trick to loosening the gold lock ring? I'm putting some force in it, but figured I'd ask before I get crazy Like

20.43 Chris White- Overcast Observatory #... · view views · 1 like
Nick Grundy: Chris White- Overcast Observatory: Underneath is a gold ring. This locks the height. this is definitely feeling like a dumb question, but ..... Is there some trick to loosening the gold lock ring? I'm putting some force in it, but figured I'd ask before I get crazy Not that I recall. Remove the focuser from the base by loosening the three grub screws on the lower flange. That will give you better access. Like

20.43

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Nick Grundy:
Chris White- Overcast Observatory:
Underneath is a gold ring. This locks the height.

this is definitely feeling like a dumb question, but .....

Is there some trick to loosening the gold lock ring? I'm putting some force in it, but figured I'd ask before I get crazy

Not that I recall. Remove the focuser from the base by loosening the three grub screws on the lower flange. That will give you better access.

3.81 Nick Grundy #... · view views
thanks! I was able to adjust but I had to unscrew the whole insert just to get to the gold ring. Looking good now and just fussing my Nina AF settings. Is anyone using Nina and willing to share their AF settings? I'm guessing, but there should be no backlash? Like

20.43 Chris White- Overcast Observatory #... · view views
Nick Grundy: thanks! I was able to adjust but I had to unscrew the whole insert just to get to the gold ring. Looking good now and just fussing my Nina AF settings. Is anyone using Nina and willing to share their AF settings? I'm guessing, but there should be no backlash? for hocus focus?. I don't use Nina otherwise. For analysis use: 10s exposures 1000 step size 4 steps out at start use a high camera gain lum filter Zero backlash Like

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