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6" Newtonian Primary Cell

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#1 AstroEdge

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Posted 14 February 2020 - 06:47 PM

I just recently bought a TPO 6" F/4 newt from a fellow CN member, but I don't like the primary cell because of the way you collimate it. I was looking all online and I can't seem to find a cell that would fit that scope.

 

If anyone knows of any suggestions for a 6" primary cell that would fit that scope, please let me know.

 

The diameter of the tube is 178mm wide.

 

Thank you,
Caleb



#2 Benach

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Posted 14 February 2020 - 07:10 PM

Just design a Kelvin clamp or Maxwell clamp and make one.



#3 AstroEdge

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Posted 14 February 2020 - 07:38 PM

I thought about designing one out of aluminum or any other strong material, but I wanted it to be precise. I guess a CNC machine would be pretty precise.

 

Thanks,
Caleb



#4 Benach

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Posted 14 February 2020 - 08:29 PM

First, can a Moderator move this topic to ATM?

 

It could be done with conventional machining. Precision can be obtained by using precision screws. Aluminium is fine for most telescope applications except a counterweight. But my comment about the Kelvin clamp/Maxwell clamp referred more to the method of collimation.



#5 Starman1

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Posted 15 February 2020 - 02:02 PM

Perhaps:

https://www.astrogoods.com/cells.shtml


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#6 coopman

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Posted 15 February 2020 - 04:27 PM

I bought a used Vixen 130 Newt recently & the primary cell is a cheaply made useless disaster. I can't even collimate it without doing some sort of modification of the cell.

#7 Jon Isaacs

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Posted 15 February 2020 - 04:31 PM

I just recently bought a TPO 6" F/4 newt from a fellow CN member, but I don't like the primary cell because of the way you collimate it. I was looking all online and I can't seem to find a cell that would fit that scope.

 

If anyone knows of any suggestions for a 6" primary cell that would fit that scope, please let me know.

 

The diameter of the tube is 178mm wide.

 

Thank you,
Caleb

 

What don't you like about It?  Can it be modified?  A 6 inch mirror is generally quite thick, the GSO 6 inch F/4 is 20mm thick so a simple cell is all that's necessary.

 

Jon



#8 AstroEdge

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Posted 17 February 2020 - 12:01 AM

What don't you like about It?  Can it be modified?  A 6 inch mirror is generally quite thick, the GSO 6 inch F/4 is 20mm thick so a simple cell is all that's necessary.

 

Jon

On my 8" newtonian the collimation is so much easier, but on this 6" it is just a pain to collimate, and the locking screws are between 2 adjustment screws, so it locks down 2 different axis at once.

 

Caleb



#9 Volvonium

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Posted 18 February 2020 - 03:39 PM

Why not just remove the locking screws altogether and perhaps install some stronger springs on the collimation knobs, so that it holds without needing locks?  I've never had an issue collimating GSO newts, even on older ones with weaker springs on the collimation bolts.  Removing the locking screws is one of the first things I usually do on a newt/dob, as I find they just get in the way.  


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#10 SteveG

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Posted 18 February 2020 - 06:23 PM

On my 8" newtonian the collimation is so much easier, but on this 6" it is just a pain to collimate, and the locking screws are between 2 adjustment screws, so it locks down 2 different axis at once.

 

Caleb

By that do you mean there are no springs, and it's a push-pull arrangement? Could you simply place springs behind the "pull" bolts, allowing you to eleminate the "push" bolts?

 

Does the back look like this?

 

TPO SCOPE.jpg



#11 Pinbout

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Posted 18 February 2020 - 08:37 PM

locking screws, who uses locking screws....

 

https://www.youtube....W8rBwA&index=33



#12 AstroEdge

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Posted 19 February 2020 - 03:16 PM

There are springs for the pull screws,but when i am twisting some of the bolts, they feel very tight when I have the locking screws loose, but the screws have a lot of travel left.

 

Thank you,
Caleb




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