Useful 3D printed parts for the Exos-2


Mike Leemhuis
 

Many of the early problems I had with my Exos-2 mount and ES 102CF OTA have been related to cables getting snagged or unplugged.  A snagged cable can cause the RA or DEC steppers to break phase and a loose USB connection will cause a loss of communication with the PMC-eight box.  These problems cause a lot of frustration and loss of valuable astrophotography time trying to find the problem then reconnecting and re-homing.  I should point out that I control my mount using CDC with my desktop computer inside my house and a 20 meter USB cable running to the telescope out in my front yard.  

I have pretty much solved these problems with several 3D printed parts that I designed.  A short description of each of these parts is included below along with a link to a more detailed description and a printable .stl file on thingiverse.com.  

1. A tray to hold my iPhone 7 parallel to the axis of the OTA so I can get fairly close polar alignment using the iOptron Polar Scope Align Pro
https://www.thingiverse.com/thing:3120190

2. A USB cable clamp to make sure this cable does not disconnect. 
https://www.thingiverse.com/thing:3120150

3. A 2 inch diameter snap-on leg clamp to control the stepper and/or heater cables.  I include a variation of this clamp which includes a simple power distribution panel.
https://www.thingiverse.com/thing:3120125

4. A leg clamp that firmly grips the Exos-2 leg and has a feature to slide on the PMC-eight box.  This replaces the aluminum block and velcro strap that comes with the PMC-eight.
https://www.thingiverse.com/thing:3120066

Anyway, I wanted to share these parts with all of you.  If you have a 3D printer, know someone who does or want to use the 3D printing services that exist online, you can print these and hopefully avoid some of the problems that I have dealt with.

Hope this helps!


Mike Leemhuis


Cyril Bonnett
 

I have used a jubilee clamp with a piece of inner tube rubber to clamp the aluminium block to the leg.


 

Heh...    :-)
 
I don't like that velcro strap, either.  Much too inclined to sneak down the leg and past the spreader, with my PMC-8 sliding towards the ground while the legs are shifting around, as I level the mount.  
 
The plan (it's on my list...) is to put a wooden block on the spreader, with the aluminum wedge attached to its side, such that the PMC-8 box is held vertically, off the side of the spreader, and well above the ground.   
 
- Bob
    
 


W. Christopher Moses
 

I fully agree.  That is the only piece of the G-11 that seems sub-par.  Beside the sinking movement, I want everything on my mount ROCK SOLID.  Cables, cameras, etc....all the way down to the little things.


I was in a hurry.  I just used some of that quick drying clay-like stuff .  Molded it around the leg and then flattened the other side.  I keep meaning to measure the diameter and then 3d print a better solution.  If anyone knows the OD, let me know and I'll give it a shot.

On Thursday, September 27, 2018, 7:07:40 PM EDT, Robert Hoskin <devonshire@...> wrote:


Heh...    :-)
 
I don't like that velcro strap, either.  Much too inclined to sneak down the leg and past the spreader, with my PMC-8 sliding towards the ground while the legs are shifting around, as I level the mount.  
 
The plan (it's on my list...) is to put a wooden block on the spreader, with the aluminum wedge attached to its side, such that the PMC-8 box is held vertically, off the side of the spreader, and well above the ground.   
 
- Bob
    
 


Mike Leemhuis
 

If someone can tell me the G11 leg diameter I’d be happy to add a variation to my 2” EXOS 2 3D design that I published yesterday. 

Mike Leemhuis. 


On Sep 27, 2018, at 7:16 PM, Winfield Moses via Groups.Io <chris_moses@...> wrote:

I fully agree.  That is the only piece of the G-11 that seems sub-par.  Beside the sinking movement, I want everything on my mount ROCK SOLID.  Cables, cameras, etc....all the way down to the little things.


I was in a hurry.  I just used some of that quick drying clay-like stuff .  Molded it around the leg and then flattened the other side.  I keep meaning to measure the diameter and then 3d print a better solution.  If anyone knows the OD, let me know and I'll give it a shot.

On Thursday, September 27, 2018, 7:07:40 PM EDT, Robert Hoskin <devonshire@...> wrote:


Heh...    :-)
 
I don't like that velcro strap, either.  Much too inclined to sneak down the leg and past the spreader, with my PMC-8 sliding towards the ground while the legs are shifting around, as I level the mount.  
 
The plan (it's on my list...) is to put a wooden block on the spreader, with the aluminum wedge attached to its side, such that the PMC-8 box is held vertically, off the side of the spreader, and well above the ground.   
 
- Bob
    
 

--

Mike Leemhuis


W. Christopher Moses
 

Well, that sounds much easier than me doing it!  
I just got back from a trip and am still catching up on messages.  I'll go fin my micrometer!

On Thursday, September 27, 2018, 7:26:12 PM EDT, Mike Leemhuis <skislalom1@...> wrote:


If someone can tell me the G11 leg diameter I’d be happy to add a variation to my 2” EXOS 2 3D design that I published yesterday. 

Mike Leemhuis. 


On Sep 27, 2018, at 7:16 PM, Winfield Moses via Groups.Io <chris_moses@...> wrote:

I fully agree.  That is the only piece of the G-11 that seems sub-par.  Beside the sinking movement, I want everything on my mount ROCK SOLID.  Cables, cameras, etc....all the way down to the little things.


I was in a hurry.  I just used some of that quick drying clay-like stuff .  Molded it around the leg and then flattened the other side.  I keep meaning to measure the diameter and then 3d print a better solution.  If anyone knows the OD, let me know and I'll give it a shot.

On Thursday, September 27, 2018, 7:07:40 PM EDT, Robert Hoskin <devonshire@...> wrote:


Heh...    :-)
 
I don't like that velcro strap, either.  Much too inclined to sneak down the leg and past the spreader, with my PMC-8 sliding towards the ground while the legs are shifting around, as I level the mount.  
 
The plan (it's on my list...) is to put a wooden block on the spreader, with the aluminum wedge attached to its side, such that the PMC-8 box is held vertically, off the side of the spreader, and well above the ground.   
 
- Bob
    
 

--

Mike Leemhuis


Wes Mcdonald
 

Mike 

You. Are. The. Man.   

The ioptron app looks like a gem.  Loaded it up last night.  Man.  But the icing on the cake are your 3d printed parts.  I just ordered a full set from 3d Hubs.  2x clamps, pmc 8  mount, tray, and power distribution. ...in grey nylon...85$ delivered.  Fantastic.  If ABS the price would have been $30.  

Jerry, that pmc 8 clamp and cable clamps would be a nice addition to the product.  The tray also.  The tools in the ioptron app would be a great addition to explorestars...maybe the author would sell you rights to them.

Wes


Jerry Hubbell - Explore Scientific VP Engineering
 
Edited

There is a somewhat quick way to do a polar alignment that uses the inherent accuracy of the mounts pointing to do a physical alignment that I have not really talked about. It really is a very simple procedure that I would like some feedback on. I think we get hung up some on using external camera systems and other programs or applications that solve this issue, but all you really need is your mount and your telescope. You can use a regular higher power eyepiece, anything less than 10 mm, or you can use a cross-hair eyepiece to make it a little better. 

So this is the procedure:
1.  Set up your mount and level it
2.  Make sure the mounts RA and DEC axis are zeroed and in the PARK position (the axis alignment arrows on the body of the mount, or equivalent, are aligned).
3.  IF you can see Polaris, point your mount using the Altitude and Azimuth mount adjustments so that when your telescope is PARKED, you can see Polaris in your eyepiece.
4.  ALTERNATIVELY, using a compass, point the mount towards the NCP compensating for the magnetic declination
5.  ALTERNATIVELY, using a level program on your phone, adjust the Altitude mount adjustment to set it to your Latitude value.
6.  Start the ExploreStars application and connect to the PMC-Eight
7.  Select an appropriate bright star from the alignment star list and slew to the star.
NOTE:  The following adjustment technique relies on the inherent raw pointing accuracy of the mount which includes any errors due to Cone Angle and other sources of flexure in the system.
8.  Using the Altitude and Azimuth mount adjustments, center the alignment star in your eyepiece. 
9.  The mount should be within 5 arc-minutes of the NCP now.
This is a formal explanation of the technique I have done in the field as a quick and dirty way to get the alignment close enough for visual use. It may also be good enough for astrophotography depending on the inherent accuracy of the mount, i.e., the G11 may get you closer than the EXOS 2 would.

Please report back on your success, or failure using this technique.


Jerry Hubbell
Director Electrical Engineering

Explore Scientific, LLC.
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811
www.explorescientificusa.com



Larry White
 

I used an adjustable hose clamp.  I opened it all the way open and ran it over the top of the Velcro.  I wrapped the Velcro around the tripod leg and tightened the hose clamp over the Velcro.  Works great and didn’t starch the leg.

 

Sent from Mail for Windows 10

 


From: ESPMC-Eight@groups.io <ESPMC-Eight@groups.io> on behalf of Winfield Moses via Groups.Io <chris_moses@...>
Sent: Thursday, September 27, 2018 6:39:31 PM
To: ESPMC-Eight@groups.io
Subject: Re: [ESPMC-Eight] Useful 3D printed parts for the Exos-2
 
Well, that sounds much easier than me doing it!  
I just got back from a trip and am still catching up on messages.  I'll go fin my micrometer!

On Thursday, September 27, 2018, 7:26:12 PM EDT, Mike Leemhuis <skislalom1@...> wrote:


If someone can tell me the G11 leg diameter I’d be happy to add a variation to my 2” EXOS 2 3D design that I published yesterday. 

Mike Leemhuis. 


On Sep 27, 2018, at 7:16 PM, Winfield Moses via Groups.Io <chris_moses@...> wrote:

I fully agree.  That is the only piece of the G-11 that seems sub-par.  Beside the sinking movement, I want everything on my mount ROCK SOLID.  Cables, cameras, etc....all the way down to the little things.


I was in a hurry.  I just used some of that quick drying clay-like stuff .  Molded it around the leg and then flattened the other side.  I keep meaning to measure the diameter and then 3d print a better solution.  If anyone knows the OD, let me know and I'll give it a shot.

On Thursday, September 27, 2018, 7:07:40 PM EDT, Robert Hoskin <devonshire@...> wrote:


Heh...    :-)
 
I don't like that velcro strap, either.  Much too inclined to sneak down the leg and past the spreader, with my PMC-8 sliding towards the ground while the legs are shifting around, as I level the mount.  
 
The plan (it's on my list...) is to put a wooden block on the spreader, with the aluminum wedge attached to its side, such that the PMC-8 box is held vertically, off the side of the spreader, and well above the ground.   
 
- Bob
    
 

--

Mike Leemhuis


Peter Turner
 
Edited

Hi Jerry,

Thanks for the routine.  I'm fairly sure that the iphone's compass compensates for magnetic declination.  Here in Phoenix we have a magnetic declination of 12 degrees.  When I use the compass on the iphone's Utility app, it points to within a degree or two of Polaris.

Mike I'm impressed with your parts especially the cable holder and PMC-8 box holder.  They look like "must haves".  I just ordered the PMC-8 holder from 3D-Hubs.  I chose PETG as the material - have to see how strong it is.

Pete


Mike Leemhuis
 

Thanks Pete.  I'm glad you are finding my designs useful.  If you or anyone can think of any improvements or suggestions for other useful parts, I'd be glad to consider them.

Thanks to all,
Mike


On Fri, Sep 28, 2018 at 8:28 PM Peter Turner via Groups.Io <peteturner07=yahoo.com@groups.io> wrote:

[Edited Message Follows]

Hi Jerry,

Thanks for the routine.  I'm fairly sure that the iphone's compass compensates for magnetic declination.  Here in Phoenix we have a magnetic declination of 12 degrees.  When I use the compass on the iphone's Utility app, it points to within a degree or two of Polaris.

Mike I'm impressed with your parts especially the cable holder and PMC-8 box holder.  They look like "must haves".  I just ordered the PMC-8 holder from 3D-Hubs.  I chose PETG as the material - have to see how strong it is.

Pete


--

Mike Leemhuis


Mike Leemhuis
 

I might add that PETG is a great all around material for 3D-printing.  It's doesn't split or shrink while printing and can handle flexing.  It's very similar to ABS strength-wise but much easier to print.  Nylon is great for toughness and flexibility but very difficult to print and it's hydroscopic (absorbs moisture).  It's overkill for these kinds of parts.  PLA is barely adequate for parts under load. It's brittle and can deform if left in a hot car.  I wouldn't recommend it.  I've designed hundreds of plastic parts and PETG is the best material I've found thus far for parts like these.  Just my 2 cents!

Mike



On Fri, Sep 28, 2018 at 8:43 PM Mike Leemhuis <skislalom1@...> wrote:
Thanks Pete.  I'm glad you are finding my designs useful.  If you or anyone can think of any improvements or suggestions for other useful parts, I'd be glad to consider them.

Thanks to all,
Mike


On Fri, Sep 28, 2018 at 8:28 PM Peter Turner via Groups.Io <peteturner07=yahoo.com@groups.io> wrote:

[Edited Message Follows]

Hi Jerry,

Thanks for the routine.  I'm fairly sure that the iphone's compass compensates for magnetic declination.  Here in Phoenix we have a magnetic declination of 12 degrees.  When I use the compass on the iphone's Utility app, it points to within a degree or two of Polaris.

Mike I'm impressed with your parts especially the cable holder and PMC-8 box holder.  They look like "must haves".  I just ordered the PMC-8 holder from 3D-Hubs.  I chose PETG as the material - have to see how strong it is.

Pete


--

Mike Leemhuis


Peter Turner
 
Edited

Hi Mike,

Thanks for the update on PTEG.  Not knowing much about the 3D printer world I did some research on the different materials.  PTEG seemed to be better than ABS or PLA and certainly was much less expensive than Nylon.  After I've had more experience with the mount I may take you up on ideas.  One question, how do your cable parts work with the standard Dec and RA cables.  It didn't look in the picture as if you were using them.

Pete


Mike Leemhuis
 
Edited

Hi Pete.  I'll attach a picture of the clip part assuming that's the part you're talking about.  This part has a space at the bottom of the U that can control up to about 4 standard sized cables.  This would include the Dec and RA cables and perhaps 2 heater cables.  It clips onto the 2 inch diameter EXOS 2 leg to restrain the wires.  You then leave a loop in the wires so that the OTA can swing to all positions.  I hope that makes sense.  Let me know if I'm not understanding your question correctly.
 
Thanks,
Mike
 

On Sat, Sep 29, 2018 at 1:34 AM Peter Turner via Groups.Io <peteturner07=yahoo.com@groups.io> wrote:

[Edited Message Follows]

Hi Mike,

Thanks for the update on PTEG.  Not knowing much about the 3D printer world I did some research on the different materials.  PTEG seemed to be better than ABS or PLA and certainly was much less expensive than Nylon.  After I've had more experience with the mount I may take you up on ideas.  One question, how do your cable parts work with the standard Dec and RA cables.  It didn't look in the picture as if you were using them.

Pete

 

 


--

Mike Leemhuis


Peter Turner
 

Your explanation is perfect.  I was looking at the wrong picture.

Pete


Peter Turner
 

Mike,

I just received my first part from 3D Hubs; the PMC-8 controller box holder.  It fits perfectly!.  Now to go down to ACE hardware and get some nuts and bolts to secure it to the leg.  Can't wait to get the iPhone holder and cable clamps which are being done by a different 3D Hub manufacturer.  I wasn't smart enough to order all three at the same time.  Their turn-around time is great.


Mike Leemhuis
 

That’s great to hear Pete. FYI, I used metric M3-35 screws for my design but english 4-40 by 1.5 inch screws should work fine too. 

Keep me updated. 

Mike


On Oct 2, 2018, at 6:18 PM, Peter Turner via Groups.Io <peteturner07@...> wrote:

Mike,

I just received my first part from 3D Hubs; the PMC-8 controller box holder.  It fits perfectly!.  Now to go down to ACE hardware and get some nuts and bolts to secure it to the leg.  Can't wait to get the iPhone holder and cable clamps which are being done by a different 3D Hub manufacturer.  I wasn't smart enough to order all three at the same time.  Their turn-around time is great.

--

Mike Leemhuis


Peter Turner
 


Here's a part that I thought of while out the other night.  Currently the EXOS 2GT / PMC-8 has an eyepiece holder in the tripod for 1 - 2" ep and 2 - 1.25" eps.  An eyepiece holder extension that fitted in to the current holder and expanded the number of eyepieces to six 1.25" holes and three 2" holes would be great.  I have no idea how difficult this would be, but have not seen anything like it on Thingiverse or Yeggi.  I've attached a mockup drawing of my thoughts.


Mike Leemhuis
 
Edited

Hi Pete,
 
Just wanted to let you know that I designed an add-on tray for the EXOS2 based on your suggestion.  This tray will hold two additional 1.5" eyepieces and one 2".  I will be adding similar trays soon that will add either two 2" or three 1.5" eyepieces.    I made  a few of these as I debugged the design and they seem to work very well.  I am limited to a 6 inch print area so I wasn't able to make the size you showed. I did add a feature though so that three of these trays could be screwed together to form a complete circle similar to your design.  Let me know if this is what you were thinking.
 
Here is the link to the file on thingiverse.com:
 
Mike Leemhuis

On Tue, Oct 2, 2018 at 7:39 PM Peter Turner via Groups.Io <peteturner07=yahoo.com@groups.io> wrote:

Here's a part that I thought of while out the other night.  Currently the EXOS 2GT / PMC-8 has an eyepiece holder in the tripod for 1 - 2" ep and 2 - 1.25" eps.  An eyepiece holder extension that fitted in to the current holder and expanded the number of eyepieces to six 1.25" holes and three 2" holes would be great.  I have no idea how difficult this would be, but have not seen anything like it on Thingiverse or Yeggi.  I've attached a mockup drawing of my thoughts.

 

 


--

Mike Leemhuis


Peter Turner
 

Wow Mike!  What response.  And, having the ability to do one, two or three trays is an impressive upgrade to my idea.  Thank you so much.  I'm assuming that for more than one tray we should cut of the existing screw holes and drill holes in the side of the adjoining trays?

Pete