1. Topics
  2. Stowaway, 92TCC and corner stars

Stowaway, 92TCC and corner stars

Henry Kwok
 

Thank you all for the photos - I was a bit inpatient and started working on the screws before seeing your posts, and I think I was a little too enthusiastic with the Dremel such that a lot of the taper is now gone. I think now the contact point is at the top of the sloped edge... I hope it will be ok *fingers crossed*. I guess the screws have plenty of length and if need be I can always add back some taper.
ROBERT WYNNE
 

Tried to save and print this very well detailed drawing but was not able to download. Can you repost with a downloadable file? It would also be extremely helpful to have a table or list of the various lettered details and if you could a drawing of the basic set up from telescope w/wo TCC/FF to camera sensor. I know I'm asking a lot but it sure would save a lot of time feeling my way to nominal values. -Best, Robert

On 07/30/2022 6:00 AM M Hambrick <mhambrick563@...> wrote:


Henry

The 64.1 mm backfocus is dimension X in the sketch below.

Mike

ROBERT WYNNE
 

To what degree of accuracy should 3rd party "bolt on's" be machined? -Best, Robert

On 07/30/2022 8:33 AM Roland Christen via groups.io <chris1011@...> wrote:


If the machinist made your adapter in two setups it will definitely have tilt. You can measure that by using a micrometer and measure 3 points around the length of the adapter. If they vary by .001" it is enough tilt to affect the image.

Roland



-----Original Message-----
From: Henry Kwok <henry.ck.kwok@...>
To: main@ap-ug.groups.io
Sent: Sat, Jul 30, 2022 1:22 am
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars
Yeah... I am sure the scope and the 92TCC are not to blame. So it is most likely the custom adaptor which is made locally by a machinist and I am not sure what his precision is.

I think I will invest in both a tilt adjuster and also make a new custom adaptor. Can someone please verify what distance to specify with Precisionparts, if the camera + EFW + OAG take up 56 mm? Is it 8.1 mm, which is what I used with the current adaptor?

Roland Christen
 

Ideally the adapters need to be machined to zero tolerance, and that is easily achieved by machining the entire adapter in one operation. Machinists know how to do that but often won't do it that way since they do not understand the requirements of optical mechanics and so do it the easy way instead of the right way.

Rolando


-----Original Message-----
From: ROBERT WYNNE <robert-wynne@...>
To: main@ap-ug.groups.io; Roland Christen via groups.io <chris1011@...>
Sent: Mon, Aug 1, 2022 5:24 pm
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars

To what degree of accuracy should 3rd party "bolt on's" be machined? -Best, Robert
On 07/30/2022 8:33 AM Roland Christen via groups.io <chris1011@...> wrote:


If the machinist made your adapter in two setups it will definitely have tilt. You can measure that by using a micrometer and measure 3 points around the length of the adapter. If they vary by .001" it is enough tilt to affect the image.

Roland



-----Original Message-----
From: Henry Kwok <henry.ck.kwok@...>
To: main@ap-ug.groups.io
Sent: Sat, Jul 30, 2022 1:22 am
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars
Yeah... I am sure the scope and the 92TCC are not to blame. So it is most likely the custom adaptor which is made locally by a machinist and I am not sure what his precision is.

I think I will invest in both a tilt adjuster and also make a new custom adaptor. Can someone please verify what distance to specify with Precisionparts, if the camera + EFW + OAG take up 56 mm? Is it 8.1 mm, which is what I used with the current adaptor?

ROBERT WYNNE
 

I know how to do it. The best way is on a Swiss Screw machine. If you're reduced to a CNC lathe then parting off the component as the last operation is the conventional way to go. Dimension speak: Ideally vs nominally; any difference? I can recall a 3rd shift lathe operator who used to do it the "easy way" and got 3 more parts per shift. A mystery until I figured out he was taking the parted off but incompletely faced component to a manual lather for the final cut while keeping the CNC lathe running unattended. Luckily the end face of the parted off end was not tightly toleranced. As for myself I've never gotten any better than +- 100 microns, even turning on an isolation table. -Best, Robert

On 08/01/2022 4:01 PM Roland Christen via groups.io <chris1011@...> wrote:


Ideally the adapters need to be machined to zero tolerance, and that is easily achieved by machining the entire adapter in one operation. Machinists know how to do that but often won't do it that way since they do not understand the requirements of optical mechanics and so do it the easy way instead of the right way.

Rolando


-----Original Message-----
From: ROBERT WYNNE <robert-wynne@...>
To: main@ap-ug.groups.io; Roland Christen via groups.io <chris1011@...>
Sent: Mon, Aug 1, 2022 5:24 pm
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars
To what degree of accuracy should 3rd party "bolt on's" be machined? -Best, Robert
On 07/30/2022 8:33 AM Roland Christen via groups.io <chris1011@...> wrote:


If the machinist made your adapter in two setups it will definitely have tilt. You can measure that by using a micrometer and measure 3 points around the length of the adapter. If they vary by .001" it is enough tilt to affect the image.

Roland



-----Original Message-----
From: Henry Kwok <henry.ck.kwok@...>
To: main@ap-ug.groups.io
Sent: Sat, Jul 30, 2022 1:22 am
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars
Yeah... I am sure the scope and the 92TCC are not to blame. So it is most likely the custom adaptor which is made locally by a machinist and I am not sure what his precision is.

I think I will invest in both a tilt adjuster and also make a new custom adaptor. Can someone please verify what distance to specify with Precisionparts, if the camera + EFW + OAG take up 56 mm? Is it 8.1 mm, which is what I used with the current adaptor?

ROBERT WYNNE
 

While we are on Stowaway details; What is the correct way to mount a Baader Guidescope to a Stowaway? -Best, Robert

On 08/01/2022 3:22 PM ROBERT WYNNE <robert-wynne@...> wrote:


Tried to save and print this very well detailed drawing but was not able to download. Can you repost with a downloadable file? It would also be extremely helpful to have a table or list of the various lettered details and if you could a drawing of the basic set up from telescope w/wo TCC/FF to camera sensor. I know I'm asking a lot but it sure would save a lot of time feeling my way to nominal values. -Best, Robert

On 07/30/2022 6:00 AM M Hambrick <mhambrick563@...> wrote:


Henry

The 64.1 mm backfocus is dimension X in the sketch below.

Mike

Roland Christen
 

It should also be done using solid stock so that you don't end up with triangular parts.

Roland

-----Original Message-----
From: ROBERT WYNNE <robert-wynne@...>
To: main@ap-ug.groups.io; Roland Christen via groups.io <chris1011@...>
Sent: Mon, Aug 1, 2022 7:34 pm
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars

I know how to do it. The best way is on a Swiss Screw machine. If you're reduced to a CNC lathe then parting off the component as the last operation is the conventional way to go. Dimension speak: Ideally vs nominally; any difference? I can recall a 3rd shift lathe operator who used to do it the "easy way" and got 3 more parts per shift. A mystery until I figured out he was taking the parted off but incompletely faced component to a manual lather for the final cut while keeping the CNC lathe running unattended. Luckily the end face of the parted off end was not tightly toleranced. As for myself I've never gotten any better than +- 100 microns, even turning on an isolation table. -Best, Robert
On 08/01/2022 4:01 PM Roland Christen via groups.io <chris1011@...> wrote:


Ideally the adapters need to be machined to zero tolerance, and that is easily achieved by machining the entire adapter in one operation. Machinists know how to do that but often won't do it that way since they do not understand the requirements of optical mechanics and so do it the easy way instead of the right way.

Rolando


-----Original Message-----
From: ROBERT WYNNE <robert-wynne@...>
To: main@ap-ug.groups.io; Roland Christen via groups.io <chris1011@...>
Sent: Mon, Aug 1, 2022 5:24 pm
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars
To what degree of accuracy should 3rd party "bolt on's" be machined? -Best, Robert
On 07/30/2022 8:33 AM Roland Christen via groups.io <chris1011@...> wrote:


If the machinist made your adapter in two setups it will definitely have tilt. You can measure that by using a micrometer and measure 3 points around the length of the adapter. If they vary by .001" it is enough tilt to affect the image.

Roland



-----Original Message-----
From: Henry Kwok <henry.ck.kwok@...>
To: main@ap-ug.groups.io
Sent: Sat, Jul 30, 2022 1:22 am
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars
Yeah... I am sure the scope and the 92TCC are not to blame. So it is most likely the custom adaptor which is made locally by a machinist and I am not sure what his precision is.

I think I will invest in both a tilt adjuster and also make a new custom adaptor. Can someone please verify what distance to specify with Precisionparts, if the camera + EFW + OAG take up 56 mm? Is it 8.1 mm, which is what I used with the current adaptor?

ROBERT WYNNE
 

You can always add more taper as the screws are somewhat longer than needed. But recovering the correct angle of the tip will present a problem if done by hand. The angle of the tip is such that it must mate to the bevel edge without damaging the beveled edge. Otherwise you will end up with dimpled rounds on the beveled edge. Or if made with a a too sharp angle you will only dimple the barrel all over again! Some things are easier said than done. -Best, Robert

On 07/31/2022 12:47 AM Henry Kwok <henry.ck.kwok@...> wrote:


Thank you all for the photos - I was a bit inpatient and started working on the screws before seeing your posts, and I think I was a little too enthusiastic with the Dremel such that a lot of the taper is now gone. I think now the contact point is at the top of the sloped edge... I hope it will be ok *fingers crossed*. I guess the screws have plenty of length and if need be I can always add back some taper.

ROBERT WYNNE
 

What is the correct angle for the taper? -Best, Robert

On 07/30/2022 6:15 PM Gary Saunders <bonview@...> wrote:


The one on the right in this photo is grounded down. The left and center are not. I ‘m not sure if you can make it out.

I used sandpaper on a flat surface to remove the tip. Its not much that needs to be remove. I did do all three.


Gary Saunders


Sent from Mail for Windows 10


From: Henry Kwok
Sent: Friday, July 29, 2022 11:48 PM
To: main@ap-ug.groups.io
Subject: [ap-ug] Stowaway, 92TCC and corner stars


Hello,

Questions about trying to get good corner stars with my Stowaway + 92TCC.

I have been trying to get good corner stars with my Stowaway + 92TCC + APS-C size QHY268m camera. No matter what I tried the corner stars are ever slightly malformed. The same camera / FW / OAG are used interchangably with my AP130GT + 67PF flattener with no problem, via two different custom adaptors to get the required back focus distances for the two set ups. I can tweak the corner star shape a bit by manually fine tuning the focus while watching the corners, but it is not going to be good enough for auto focus. I am not sure if I am expecting too much of the 92TCC, as it is supposed to be able to cover an APS-C size sensor. I don't know if there are other things to try, or whether I should just buy a the 92FF and accept a slower speed.

Just a bit of sanity check:
- The back focus of 64.1 mm for 92TCC, where is it measured from?  With the custom adaptor I designed and had made, I asked for a effective length of 8.1 mm, measured from the very end of the 92TCC (i.e. the female 2.7" thread portion of the adaptor which goes onto the 92TCC does not contribute to the effective length). With that this gives me 64.1-8.1=56 mm, which is the amount taken up by my camera+OAG+FW.

- Is the 92TCC designed to give pinpoint corner stars using a APS-size sensor with pixel size of only 3.75 micron? Or am I asking too much of it? Would a 92FF mitigate the corner problem?

- The fact that the star shape can be tweaked with focus, does it suggest that the problem may be to do with spacing? or is it tilt (given the AP130GT with 67PF is slower it may not manifest).  How do I isolate the problem?

Corner star shape bothers me, even though it is probably not important for most compositions, and I am keen to get to the bottom of it.

Thank you                                                                                                                      

 
ROBERT WYNNE
 

It's because the set screws are not intended to "bottom out" on the barell circumference at all. The bevel of the set screw is intended to mate with the angled face of the adapter thus both pushing and locking it into place. -Best, Robert

On 07/30/2022 12:45 PM Henry Kwok <henry.ck.kwok@...> wrote:


I have been plowing through the forum here of topics on 92TCC/Stowaway, and I have come across a few more posts relating to tilt:

(1) On 10/26/2021, Roland replied in a thread: "It is possible for the camera adapter dovetail attachment to be tilted – you can check that visually. Make sure that it seats flat against the focuser end when you tighten the three thumb screws."

Can you please tell me how to ensure the TCC is sitting flat? To the naked eye it seems to be well seated. Do you need to install the TCC with the scope vertical?

(2) Mike Hambrick replied in the same thread with illustration: "I believe that the root cause of this issue is that the lock screw holes in the Doveloc adapter are drilled in the wrong location (too close to the back face by about 0.030"). However, you can correct this issue by filing the sharp tip off of the lock screws so that only the tapered part makes contact with the angled shoulder of the 92TCC." 

I don't understand the last sentence: "iling the sharp tip off of the lock screws so that only the tapered part makes contact with the angled shoulder of the 92TCC."

(3) In another tread, Mark posted again: "As for other comments, pay attention to the locking screws that hold the 92FF or 92TCC into the Doveloc adapter. If you see any indentions in the bottom of the groove of your 92FF or 92TCC it means that the lock screws are not properly holding the corrector in position. You will need to slightly blunt the tips of the locking screws with a file so that the tapered section of the locking screws is making contact with the tapered section of the groove in the 92FF or 92TCC."

If I understand it correctly, I should grind the tip so that the point of contact between the screw and the TCC is on the sloped edge of the groove, not the bottom of the groove. Is this correct?

Sorry for the questions. I am not very mechanical minded and found it difficult to picture why this matters and how the solution work.

ROBERT WYNNE
 

Could you use a feeler gage (the thinnest) to determine if any gap remains after mating the two? -Best, Robert

On 07/30/2022 12:55 PM Roland Christen via groups.io <chris1011@...> wrote:



I guess this could potentially be the problem?
Yes, this is the problem. When you flatten the tips, install the TCC and tighten the 3 screws evenly. Then check that the TCC body is tight against the mating adapter all the way around the circumference. There should be no airgap between them.

Roland

-----Original Message-----
From: Henry Kwok <henry.ck.kwok@...>
To: main@ap-ug.groups.io
Sent: Sat, Jul 30, 2022 2:13 pm
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars
Hello Roland,

Yes, the thumb screws holding the TCC in the DOVELOC are indeed pointed. In fact, they are so pointed that they make small marks on the TCC itself. See photos attached. I guess this could potentially be the problem? I am actually hoping that it is, as it may be an easy fix...

It would be very nice if you can send me a set of new ones, but I am now back in New Zealand (I was living in NYC up until recently) and the only way you can send me a set is by UPS/Fedex as USPS is currently not sending to NZ due to the pandemic.

In the mean time, I may try to grind the screws a bit to see if this will help. How much shall I grind them by? Can you please post a photo of what the screws should look like? Should the tips be completely flat? Shall I invest in some teflon tip screws that AgenaAstro sells?

 

ROBERT WYNNE
 

Yes, but the forces applied by each are applied differently. The screw on the left is more properly called a set screw. The screw on the right uses the bevel to snug the two components into place rather than tighten onto the circumference of the barrel. -Best, Robert

07/30/2022 1:11 PM Wenhan Chang <sjtu.wenhan@...> wrote:


Hi Henry,

Here is a photo comparing the locking screws for diagonal/eyeypiece (left) and for 92FF/TCC (right), both from AP. Unlike screws for eyepiece, the 92TCC screw doesn't need to be too flat.



Hope it helps.

Best,
Wenhan

M Hambrick
 

Hi Robert

Give me a day or so to pull out the drawing onto a separate file. I have a lot of other "junk" on the file, otherwise I would just post the whole thing. I do all of these drawings on an Excel spreadsheet using the drawing toolbar. It is quite accurate.

Mike
Henry Kwok
 

Hello Roland
can I please take up your offer for a new set of screws
Filed down correctly? I think I have overdone the filing on mine and the screw is now contacting the top edge of the sloped sidewall. I would rather someone in the know make me a set rather than damaging the TCC anymore. Darleen should have my NZ contact details. Thanks. Henry
Roland Christen
 

Please send an e-mail directly to AP so we can process this properly. Daleen will send you new screws. I may be in and out tomorrow, so best to contact directly.

Roland

-----Original Message-----
From: Henry Kwok <henry.ck.kwok@...>
To: main@ap-ug.groups.io
Sent: Mon, Aug 1, 2022 11:32 pm
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars

Hello Roland
can I please take up your offer for a new set of screws
Filed down correctly? I think I have overdone the filing on mine and the screw is now contacting the top edge of the sloped sidewall. I would rather someone in the know make me a set rather than damaging the TCC anymore. Darleen should have my NZ contact details. Thanks. Henry

ROBERT WYNNE
 

Never tried to chince on high end/high reliability components using tube stock as I'm certain you do the same. Swiss screw lathe machining as far as I know can only be done with round stock. With a Swiss screw lathe you would run a real chance of out of round components turning with tube stock and if long you would need to couple a live center at some point. Since I've not any experience with anything but solid rounds I don't understand the "triangular part" comment. Plus it's been many years since I ran a machine shop. I may be outdated. -Best, Robert 

On 08/01/2022 5:54 PM Roland Christen via groups.io <chris1011@...> wrote:


It should also be done using solid stock so that you don't end up with triangular parts.

Roland

-----Original Message-----
From: ROBERT WYNNE <robert-wynne@...>
To: main@ap-ug.groups.io; Roland Christen via groups.io <chris1011@...>
Sent: Mon, Aug 1, 2022 7:34 pm
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars
I know how to do it. The best way is on a Swiss Screw machine. If you're reduced to a CNC lathe then parting off the component as the last operation is the conventional way to go. Dimension speak: Ideally vs nominally; any difference? I can recall a 3rd shift lathe operator who used to do it the "easy way" and got 3 more parts per shift. A mystery until I figured out he was taking the parted off but incompletely faced component to a manual lather for the final cut while keeping the CNC lathe running unattended. Luckily the end face of the parted off end was not tightly toleranced. As for myself I've never gotten any better than +- 100 microns, even turning on an isolation table. -Best, Robert
On 08/01/2022 4:01 PM Roland Christen via groups.io <chris1011@...> wrote:


Ideally the adapters need to be machined to zero tolerance, and that is easily achieved by machining the entire adapter in one operation. Machinists know how to do that but often won't do it that way since they do not understand the requirements of optical mechanics and so do it the easy way instead of the right way.

Rolando


-----Original Message-----
From: ROBERT WYNNE <robert-wynne@...>
To: main@ap-ug.groups.io; Roland Christen via groups.io <chris1011@...>
Sent: Mon, Aug 1, 2022 5:24 pm
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars
To what degree of accuracy should 3rd party "bolt on's" be machined? -Best, Robert
On 07/30/2022 8:33 AM Roland Christen via groups.io <chris1011@...> wrote:


If the machinist made your adapter in two setups it will definitely have tilt. You can measure that by using a micrometer and measure 3 points around the length of the adapter. If they vary by .001" it is enough tilt to affect the image.

Roland



-----Original Message-----
From: Henry Kwok <henry.ck.kwok@...>
To: main@ap-ug.groups.io
Sent: Sat, Jul 30, 2022 1:22 am
Subject: Re: [ap-ug] Stowaway, 92TCC and corner stars
Yeah... I am sure the scope and the 92TCC are not to blame. So it is most likely the custom adaptor which is made locally by a machinist and I am not sure what his precision is.

I think I will invest in both a tilt adjuster and also make a new custom adaptor. Can someone please verify what distance to specify with Precisionparts, if the camera + EFW + OAG take up 56 mm? Is it 8.1 mm, which is what I used with the current adaptor?


ROBERT WYNNE
 

Excel! I thought you were using Solidworks or some other high end drafting software. You are a prince of the Excel spreadsheet! I once was introduced to a legal firm that did all its communications work on one continuous spreadsheet. They would compile spreadsheets as they used up all the space on one worksheet. Each cell would contain a communcation arranged in chronological order. The whole arrangement had multiple tabs at the bottom of the spreadsheet to add once the spreadsheet filled. Never seen anything like it to keep a company's documents in order. -Best, Robert

On 08/01/2022 7:32 PM M Hambrick <mhambrick563@...> wrote:


Hi Robert

Give me a day or so to pull out the drawing onto a separate file. I have a lot of other "junk" on the file, otherwise I would just post the whole thing. I do all of these drawings on an Excel spreadsheet using the drawing toolbar. It is quite accurate.

Mike

M Hambrick
 

Hi Robert

Here is the Excel version of my drawing file.

I learned how to make my drawings on Excel out of frustration from trying to make drawings on Powerpoint. I discovered that it was possible to make really accurate and detailed drawings on Excel, then just cut and paste them onto my Powerpoint slides.

I format the spreadsheet rows and columns so that they are the same size in number of pixels. For my version of Excel and screen resolution a row height of 15.00 and column width of 2.00 gives a 25 X 25-pixel grid. if you draw an object like a line, you can select it and use the arrow keys to move it. You can use the size and position menu to tweak the size and angular position of objects.

The Format toolbar has the drawing tools.

As for the drawings themselves, I started making them to document the position of the dovetail slides and counterweights for my different imaging setups. I have three different imaging scopes: The Stowaway, a Tele-Vue NP101is, and a 180EDT. There is a set of drawings for each system, and as you can see on these drawings, multiple setups for each.

I have been using a separate guide scope and camera in a piggyback arrangement since I started out, but I have decided that the piggyback arrangement may be causing a lot of differential flexure, so last year I converted all of my imaging systems over to side-by-side. It is more complicated, but easier to get precisely balanced, and hopefully less prone to flexure.

So far, the only system I have actually used for imaging in the side-by-side arrangement is the 180EDT. Based on the results I have seen so far; I have concluded that I need to switch to an off-axis guiding system. I am currently working on getting the 180EDT set up for that.

I also want to try my luck at building a pointing model, but I am not sure how well a model will work with my portable setup that I set up and take down every night.

Of course, I am hopeful that I will be lucky enough to have my name drawn for one of the new 110 GTX scopes so that I can make another set of drawings.

Mike

?
Telescope _ Camera Sketches, Stowaway, 220802.xlsx

ROBERT WYNNE
 

There's a lot of work and devotion to this singularly unique approach to drafting components. What drove you to Excel other than disatisfaction with Powerpoint rather than off the shelf drafting software? In my past, the corporate classes taught diferent software for those working in applicable disciplines. I stopped Excel training at regression analysis (I think I was getting slightly in over my head) while I decided it might be to my advantage to learn rudimentary drafting software. That began with a 2D program called Canvas, then onto CADKEY which was not widely used by most of my vendors and finally and most satisfying SolidWorks. SW is a true 3D software and allows finite element analysis so you can determine when your component will fail among many other features. That and it plugs in neatly to most CNC software eliminating the need to translate drawing specs to machine programming. But I certaintly never thought Excel could be as productive as you have made it. You must have very high abstract relational reasoning to arrive at this solution to drafting. -Best, Robert

On 08/03/2022 7:58 PM M Hambrick <mhambrick563@...> wrote:


Hi Robert

Here is the Excel version of my drawing file.

I learned how to make my drawings on Excel out of frustration from trying to make drawings on Powerpoint. I discovered that it was possible to make really accurate and detailed drawings on Excel, then just cut and paste them onto my Powerpoint slides.

I format the spreadsheet rows and columns so that they are the same size in number of pixels. For my version of Excel and screen resolution a row height of 15.00 and column width of 2.00 gives a 25 X 25-pixel grid. if you draw an object like a line, you can select it and use the arrow keys to move it. You can use the size and position menu to tweak the size and angular position of objects.

The Format toolbar has the drawing tools.

As for the drawings themselves, I started making them to document the position of the dovetail slides and counterweights for my different imaging setups. I have three different imaging scopes: The Stowaway, a Tele-Vue NP101is, and a 180EDT. There is a set of drawings for each system, and as you can see on these drawings, multiple setups for each.

I have been using a separate guide scope and camera in a piggyback arrangement since I started out, but I have decided that the piggyback arrangement may be causing a lot of differential flexure, so last year I converted all of my imaging systems over to side-by-side. It is more complicated, but easier to get precisely balanced, and hopefully less prone to flexure.

So far, the only system I have actually used for imaging in the side-by-side arrangement is the 180EDT. Based on the results I have seen so far; I have concluded that I need to switch to an off-axis guiding system. I am currently working on getting the 180EDT set up for that.

I also want to try my luck at building a pointing model, but I am not sure how well a model will work with my portable setup that I set up and take down every night.

Of course, I am hopeful that I will be lucky enough to have my name drawn for one of the new 110 GTX scopes so that I can make another set of drawings.

Mike

Cheng-Yang Tan
 

Hi Mike,
   Your drawings in Excel look excellent. I thought you had drawn them in a CAD program! Personally, I wouldn't use Excel to draw anything, because I have other drawing tools. But it's interesting to see that Excel is capable of doing it.

cytan

On Wednesday, August 3, 2022 at 09:58:36 PM CDT, M Hambrick <mhambrick563@...> wrote:


Hi Robert

Here is the Excel version of my drawing file.

I learned how to make my drawings on Excel out of frustration from trying to make drawings on Powerpoint. I discovered that it was possible to make really accurate and detailed drawings on Excel, then just cut and paste them onto my Powerpoint slides.

I format the spreadsheet rows and columns so that they are the same size in number of pixels. For my version of Excel and screen resolution a row height of 15.00 and column width of 2.00 gives a 25 X 25-pixel grid. if you draw an object like a line, you can select it and use the arrow keys to move it. You can use the size and position menu to tweak the size and angular position of objects.

The Format toolbar has the drawing tools.

As for the drawings themselves, I started making them to document the position of the dovetail slides and counterweights for my different imaging setups. I have three different imaging scopes: The Stowaway, a Tele-Vue NP101is, and a 180EDT. There is a set of drawings for each system, and as you can see on these drawings, multiple setups for each.

I have been using a separate guide scope and camera in a piggyback arrangement since I started out, but I have decided that the piggyback arrangement may be causing a lot of differential flexure, so last year I converted all of my imaging systems over to side-by-side. It is more complicated, but easier to get precisely balanced, and hopefully less prone to flexure.

So far, the only system I have actually used for imaging in the side-by-side arrangement is the 180EDT. Based on the results I have seen so far; I have concluded that I need to switch to an off-axis guiding system. I am currently working on getting the 180EDT set up for that.

I also want to try my luck at building a pointing model, but I am not sure how well a model will work with my portable setup that I set up and take down every night.

Of course, I am hopeful that I will be lucky enough to have my name drawn for one of the new 110 GTX scopes so that I can make another set of drawings.

Mike

21 - 40 of 58