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Sterope project - design and build a compact 16" binoscope

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#51 brucesdad13

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Posted 15 June 2016 - 10:23 PM

Do you know I spent as much as I did on the XCarve on some software called BobCAD CAM. To be honest.. it's very complicated and I almost always just use Easel which comes free with X-Carve for carving shapes. The reason I bought a pro CADCAM software is I figured if I got good enough I could upgrade milling machines. From what I see you cutting on your build threads I think Easel would suffice. You can use a simple web GUI to drag primitive shapes on and subtract add them together. If you wanted to make your original Merope base for example with the little bumps that just out... or the mirror retaining disc... forget what you called it... just draw a big circle.. .subtract a circle out of the middle... add three circles... you can also import a drawing from Illustrator which you so love and vectorize it in Easel. I wish I had not spent the money on the fancy software.

 

You're right. I'm sold.

Which software should I buy?



#52 brucesdad13

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Posted 15 June 2016 - 10:45 PM

You might also try Autocad Fusion 360. It's a new approach at integrating design, simulation, and CAM in one package. Free for personal use. I spent a short time goofing around in it. My problem is I'm not certain which is best for me. I see the great things people are designing in SolidWorks, SketchUp, etc etc... I was amazed at what you do in Illustrator in 2D but somehow seeing it in your mind in 3D. Anyways, suggest Easel plus Illustrator imports from your existing designs.


Edited by brucesdad13, 15 June 2016 - 10:45 PM.


#53 brucesdad13

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Posted 15 June 2016 - 10:51 PM

Thanks, ordered them! :) Hopefully they get here before Stellafane.

 

 

Also, I can't seem to find double flanged track wheels or roller bearings or whatever it is that you used to attach bicycle wheels to Merope. Ideas? Everything I find costs $30 or more ea.

 

Pulleys. Here.

 



#54 brucesdad13

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Posted 15 June 2016 - 11:16 PM

Ok... I know some people will think I'm posting too much. I should probably go work on my own 'scope but here's a video of a guy designing in Adobe Illustrator and carving with X-Carve via Easel https://www.youtube....h?v=s0nOHB2gqYQ



#55 Oberon

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Posted 16 June 2016 - 12:03 AM

 

Jonathan, seriously look at this unit I got in December. I bought the 1000mm x 1000mm package. It is probably less than what you've spent on a few eye pieces for Sterope. https://www.inventab...ologies/x-carve (full disclosure I have no connections with Inventables just a happy customer).

 

Hi BD with Merope I used PVA glue (external grade) when gluing timber to timber (i.e. when laminating sheets of plywood #7), and I used polyurethane when laminating any other material to the plywood, including the CF sheet #94, laminex altitude bearings #68, lamipanel azimuth bearings and base #7, the acrylic setting circles #36 and the glossy black ACP sheet #61.

 

I'm afraid a CNC mill is dream territory at present. :)  

 

 

I've ordered this...

http://3dtek.xyz/col...eoko-2-cnc-mill

 

Its an Australian upgraded version of the kit and in Australian dollars and without the international freight costs. Cost me a total of $1575 shipped along with the extras I needed, saving me about $500 had I imported.


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#56 brucesdad13

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Posted 16 June 2016 - 01:26 AM

Yeah, they're all very similar. The learning curve is not too steep if you don't dive right in trying to make complex things like I did. I wanted to make cellular blanks and designed this in BobCAD CAM only to realize I don't exactly know how to machine it yet. ;-o

 

12466090_10208642348722533_892794141715925745_o.jpg

 

You might want to bookmark something like Universal GCode Sender (UGS) if you'll be delving into third party software. Your vendor forums will have more info. https://github.com/w...l-G-Code-Sender I only mentioned all of this because I think it will really allow you some extra creativity. Sometimes you just cut the basics and use the drill press or table saw. Mix and match. I don't have a table saw so I use my CNC like one. Takes forever but while it's cutting I think about what next... ;-) Fancy CNC can even drill and tap or change their own bits. I figure most ATM just would like to cut precise shapes and 3-axis adds even more fun to mix. Next on my purchase wishlist is a 3D printer so I can try out what Chriske has posted.

 

 

 

Jonathan, seriously look at this unit I got in December. I bought the 1000mm x 1000mm package. It is probably less than what you've spent on a few eye pieces for Sterope. https://www.inventab...ologies/x-carve (full disclosure I have no connections with Inventables just a happy customer).

 

Hi BD with Merope I used PVA glue (external grade) when gluing timber to timber (i.e. when laminating sheets of plywood #7), and I used polyurethane when laminating any other material to the plywood, including the CF sheet #94, laminex altitude bearings #68, lamipanel azimuth bearings and base #7, the acrylic setting circles #36 and the glossy black ACP sheet #61.

 

I'm afraid a CNC mill is dream territory at present. :)  

 

 

I've ordered this...

http://3dtek.xyz/col...eoko-2-cnc-mill

 

Its an Australian upgraded version of the kit and in Australian dollars and without the international freight costs. Cost me a total of $1575 shipped along with the extras I needed, saving me about $500 had I imported.

 

 



#57 brucesdad13

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Posted 16 June 2016 - 01:28 AM

Did you get the 1000mm?

 

Edit: I noticed they have it all spelled out. Looks like Fusion 360 is the way to go. I might have to take a more serious look at it if you'll be using it could possible share woes trips & tricks. http://3dtek.xyz/blo...ftware-workflow


Edited by brucesdad13, 16 June 2016 - 01:34 AM.


#58 Oberon

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Posted 16 June 2016 - 02:08 AM

Yes the 1000mm. And it turns out Adobe Illustrator is fine for creating SVG files, so I'm all set, I just keep doing what I'm already doing and can use the Mac to drive it.


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#59 brucesdad13

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Posted 16 June 2016 - 02:18 AM

The guy in the video I posted mentioned that Easel (which it looks like you could use to get started) translates the grayscale into depth as a percentage of the thickness of the stock you specified. White he said doesn't cut at all... black cuts all the way through... so with the types of gradients you're already using to provide the illusion of depth you might experiment cutting out some of those recesses on some scrap wood or MDF.

 

Edit: I might install AI which I have from work... version CS6... and see what it's all about. I haven't used it since 1995 or such lol


Edited by brucesdad13, 16 June 2016 - 02:19 AM.


#60 Oberon

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Posted 16 June 2016 - 03:07 AM

Thank you. I watched the video. I liked what I saw.

I'm not sure that router steps could ever cut the gradients as smoothly as a sweeping blade, but...well, it might be good enough that the difference can be sorted out with sanding. I hope so.

 

What attracts me most about the CNC method is that my shapes are getting more complex. Look at the shapes proposed for my UTA for example in these posts here and here, and in particular the focuser detail in this...

gallery_217007_4999_71254.png

 

While each of those were generated with my present routing setup in mind, it was going to be VERY fiddly. Now it should be a doddle. And now I'll be able to generate and cut oval sections, not just circular sections.


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#61 brucesdad13

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Posted 16 June 2016 - 11:29 AM

The precision of the X-Carve, "properly tuned and calibrated machine should get to a resolution of ~0.075mm to 0.13mm." Which I think would be really sufficient. I definitely think with the shapes you're coming up with this will allow you to focus on the fun vs making crazy jigs for your router. ;-)

 

Thank you. I watched the video. I liked what I saw.

I'm not sure that router steps could ever cut the gradients as smoothly as a sweeping blade, but...well, it might be good enough that the difference can be sorted out with sanding. I hope so.

 

What attracts me most about the CNC method is that my shapes are getting more complex. Look at the shapes proposed for my UTA for example in these posts here and here, and in particular the focuser detail in this...

..

 

While each of those were generated with my present routing setup in mind, it was going to be VERY fiddly. Now it should be a doddle. And now I'll be able to generate and cut oval sections, not just circular sections.



#62 Chopin

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Posted 17 June 2016 - 09:06 AM

Thank you. I watched the video. I liked what I saw.

I'm not sure that router steps could ever cut the gradients as smoothly as a sweeping blade, but...well, it might be good enough that the difference can be sorted out with sanding. I hope so.

 

What attracts me most about the CNC method is that my shapes are getting more complex. Look at the shapes proposed for my UTA for example in these posts here and here, and in particular the focuser detail in this...

gallery_217007_4999_71254.png

 

While each of those were generated with my present routing setup in mind, it was going to be VERY fiddly. Now it should be a doddle. And now I'll be able to generate and cut oval sections, not just circular sections.

 

John, I love your UTA design! BTW, I think my wife is going to kill me. I just finished my 12" truss dob, and your thread is putting the nail in the coffin...inspiring me to jump to the next level and start my own binoscope. If my wife hunts you down after finishing me off I can only offer my deepest apologies. 


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#63 brucesdad13

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Posted 17 June 2016 - 10:00 PM

Good thing he lives down under!  :lol:

 

John, I love your UTA design! BTW, I think my wife is going to kill me. I just finished my 12" truss dob, and your thread is putting the nail in the coffin...inspiring me to jump to the next level and start my own binoscope. If my wife hunts you down after finishing me off I can only offer my deepest apologies. 

 


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#64 Chopin

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Posted 17 June 2016 - 10:21 PM

There is no place far enough!   :grin:


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#65 brucesdad13

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Posted 17 June 2016 - 10:25 PM

Yeah, he's given me the fever too.. might be some time though... well depending on the size I go for. Right now I need to finish the 8" and see about my homefused 20" blank. I wanna see if I can make a minimal string telescope capable of astrophotography now that Oberon has pointed out the difficulty with flexure. I'm stubborn ;)



#66 Oberon

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Posted 18 June 2016 - 12:00 AM

If I was going to play with string telescopes I would look very closely at using a carbon fibre tape for string. That would permit keeping forces to a minimum.


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#67 Oberon

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Posted 25 June 2016 - 08:38 AM

Another project. Another project to build a project...

gallery_217007_5817_14366.jpg


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#68 mark cowan

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Posted 25 June 2016 - 01:11 PM

Another project. Another project to build a project...

gallery_217007_5817_14366.jpg

:band:  :gotpopcorn:



#69 brucesdad13

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Posted 27 June 2016 - 03:25 PM

Yeah... I worked on mine for two days straight pounding coffee down my throat... lol... I was amazed that it all worked. At least you don't have to deal with self-tapping screws!

:gotpopcorn:
 

Another project. Another project to build a project...



#70 Oberon

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Posted 30 June 2016 - 03:52 AM

They shall beat their ploughshares into binoscopes...

gallery_217007_4999_70853.jpg

 

gallery_217007_4999_31010.jpg

 

gallery_217007_4999_27037.png

 

Happily the curve is very close to where I expect to land for my altitude bearing, allowing both my feet and the mirrors to snug the ground, keeping the eyepieces low and my feet on the ground.

 

Not shown are ventilation and proper support plans. This is just a concept. The real thing will be reinforced on edges and have an aperture for the fan etc. 

 

But I expect it to be stiff, kinda like a meniscus mirror works.


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#71 brucesdad13

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Posted 30 June 2016 - 07:41 PM

Interestin'  :gotpopcorn:



#72 Oberon

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Posted 17 August 2016 - 06:49 AM

Here is exploded view of my proposed mirror cell. No screws or bolts, no sliding parts, basically the foam keeps everything located while permitting tip tilt and a little translation for expansion. The rockers and triangles roll on either 6mm or 10mm ball bearings, which are also held in place with the foam sheets. The whole thing snuggles down into the plough disc which enables the mirrors to stay as close as possible to the ground, making the eyepieces accessible without a step.

As the rockers and triangles roll on the bearings, not slide, I'm expecting virtually zero stiction. And because the balls can roll just a very little (despite being held firmly in place), then no stress should build up on the back of the mirror due to expansion, and teflon pads won't be required.

 

Not shown are the hardened surfaces that make contact with the ball bearings; these will probably be snap off knife blades glued in place. Alternatively I may recess hardened 10 x 2.5mm valve shims into the contact points.

The hole in the centre is for the fan. All the air is forced to flow directly under the mirror and out up past the sides.

See also this thread for discussions where some early aspects of this design were developed.

 

gallery_217007_4999_71454.png



 


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#73 prfesser

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Posted 17 August 2016 - 09:40 AM

I like this idea very much!  There may be some uncertainty in the location of the bearings, because the foam is not totally rigid, but I doubt that that will be an issue.  I may just do this for my 14.75" when (if?) I finish the mirror.

 

Thanks! -- Terry


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#74 brucesdad13

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Posted 17 August 2016 - 03:12 PM

Looks good, Jonathan :D How does one collimate a binoscope? Will you adjust the disc ploughs or is it all done with the trusses like Merope?

 

Here is exploded view of my proposed mirror cell. No screws or bolts, no sliding parts, basically the foam keeps everything located while permitting tip tilt and a little translation for expansion. The rockers and triangles roll on either 6mm or 10mm ball bearings, which are also held in place with the foam sheets. The whole thing snuggles down into the plough disc which enables the mirrors to stay as close as possible to the ground, making the eyepieces accessible without a step.

As the rockers and triangles roll on the bearings, not slide, I'm expecting virtually zero stiction. And because the balls can roll just a very little (despite being held firmly in place), then no stress should build up on the back of the mirror due to expansion, and teflon pads won't be required.
 
Not shown are the hardened surfaces that make contact with the ball bearings; these will probably be snap off knife blades glued in place. Alternatively I may recess hardened 10 x 2.5mm valve shims into the contact points.

The hole in the centre is for the fan. All the air is forced to flow directly under the mirror and out up past the sides.

See also this thread for discussions where some early aspects of this design were developed.



#75 brucesdad13

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Posted 17 August 2016 - 03:14 PM

I'm thinking you could affix a soldering iron to your new CNC and figure out the cut speed that wouldn't catch the house on fire... if this foam will melt... could use it to cut nice shapes sort of like poor man's EDM. Or maybe an engraving bit...

 

Edit: And... looks like people have done this ;) https://www.youtube....h?v=TUa4VkFSzLk


Edited by brucesdad13, 17 August 2016 - 03:15 PM.



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