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teflon for bearing material

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#1 mtsaz

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Posted 08 March 2018 - 10:10 AM

HI- I am building a 12.5" full thickness mirror dob.  I have most of the major construction done- am working on a spider- and secondary holder- and ran into another issue.  What do you use for the "teflon" pads- on the bearing surfaces?  A sheet of 12x12- 1/8" thick from amazon is like 40$.   ---and I need like 1/4 that amount.  

 

What can you use and what thickness do you recommend?  I know I need two pads on the azimuth bearing surfaces, and like 3 of them on the ground board- all opposed by the (I forget name) black formica (stardust or something like that). 

 

I have some 1" thick delrin- I could cut with band saw into thin strips- 

 

Thank you for your help!!  



#2 Augustus

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Posted 08 March 2018 - 10:28 AM

I use this.

 

https://www.amazon.c...ds=teflon sheet

 

It works great.



#3 Pinbout

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Posted 08 March 2018 - 11:03 AM

this works just as well as Teflon

 

https://www.intersta...nhoCZGAQAvD_BwE


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#4 NiteGuy

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Posted 08 March 2018 - 11:04 AM

Go to ScopeStuff.com

 

You need Virgin Teflon (PTFE) thick enough so that, when grit builds up on it, you can just scrape it clean with a pocket knife. They also have center bearing kits, including center Teflon pads. You'll want to shim the center pad so that it's slightly higher than the pads on the base but then you probably knew that.

 

12"x3/4"x1/8" and other thicknesses - http://www.scopestuff.com/ss_ts31.htm

 

1/8" & 1/4" thick Teflon Pads, pre-drilled and countersunk, with screws - http://www.scopestuff.com/ss_tp41.htm



#5 Euclid's Brother

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Posted 08 March 2018 - 11:07 AM

I got this.

 

https://www.grainger...Orders_WillCall



#6 kfiscus

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Posted 08 March 2018 - 10:49 PM

I really like 1/4" stuff- it gives better clearance of exposed bolt heads underneath dob bases.  I've used and liked the cut and drilled blocks that ScopeStuff sells but would like to get some pieces bigger than he has.  If the OP ends up buying a large sheet of 1/4" Teflon, I'd buy the leftovers.


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#7 StevenYood

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Posted 09 March 2018 - 03:37 AM

I’ve gotten perfectly satisfactory sheets of Teflon on EBay and cut them to the desired size.



#8 Pinbout

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Posted 09 March 2018 - 06:01 AM

I really like 1/4" stuff- it gives better clearance of exposed bolt heads underneath dob bases.  I've used and liked the cut and drilled blocks that ScopeStuff sells but would like to get some pieces bigger than he has.  If the OP ends up buying a large sheet of 1/4" Teflon, I'd buy the leftovers.

You should really try the seaboard. A lot cheaper



#9 kfiscus

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Posted 09 March 2018 - 10:25 AM

Thank you, Danny.  I might try some.



#10 EAF

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Posted 09 March 2018 - 09:23 PM

What material are you using for the other surface, the bottom of the bearing and the bottom of the rocker box?  I have seen some references but still, I am stuck on what to use and where to get it.

 

Ed



#11 Augustus

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Posted 09 March 2018 - 09:35 PM

What material are you using for the other surface, the bottom of the bearing and the bottom of the rocker box?  I have seen some references but still, I am stuck on what to use and where to get it.

 

Ed

Formica.



#12 mtsaz

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Posted 11 March 2018 - 01:45 PM

It's the 909-42 from Lowe's right?



#13 tomykay12

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Posted 11 March 2018 - 01:57 PM

Second the Seaboard, also known as Starboard. I've never used it for telescope bearings, but have used it in  alot of  marine applications. Slippery stuff with a light pebbled texture.


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#14 airbleeder

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Posted 11 March 2018 - 03:59 PM

  You can order the Formica 909-42 from Lowes. Teflon 12" bars and sheets from McMaster-Carr.



#15 mac57

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Posted 11 March 2018 - 07:27 PM

So let me get this straight...  I use the Teflon pads on the upper hunk of wood, and put the sheet on the bottom, right?  I'm thinking of re-making my base and am kinda following along with this thread, especially because Danny is involved, as I have admired his knowledge and experience for years now.  I've never been happy with my stock Orion base, and with summer coming here in Florida, it's the time to take the scope apart and make some improvements.  I'm also toying with the idea of getting a 1/20 or so secondary.  Mark



#16 airbleeder

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Posted 11 March 2018 - 07:35 PM

   Teflon bottom hunk, sheet top hunk.



#17 mac57

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Posted 11 March 2018 - 07:38 PM

Thanks, bleeder




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