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		| adk_mechetech 
 
 
 Joined: 24 May 2020
 Posts: 4
 Location: 06076
 
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		| murff 
 
 
 Joined: 27 Oct 2009
 Posts: 599
 Location: Switzerland
 
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				|  Posted: Tue May 26, 2020 3:00 pm    Post subject: |   |  
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				| One first place I would mention the usability of a newly repaired Curta. For me the value of a Curta is given by the complete operational state and an overall nice and clean optic. The monetary value of a Curta will not influenced by replacing a broken part with a non-original duplicate.
 
 I think the clearing lever should be as close to the original as possible - it's not necessary to change the form.
 
 Also important is the fact that you need the fitting rivet (and rivet tool) - and more important, the skills to replace the clearing ring on your Curta!
 
 
 
   
 
 Good luck with this project...
 
 
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		| adk_mechetech 
 
 
 Joined: 24 May 2020
 Posts: 4
 Location: 06076
 
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				|  Posted: Tue May 26, 2020 3:23 pm    Post subject: |   |  
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				| Thank you for the input! 
 I agree, the value to me is in a fully functional Curta.  The only reason to change the design would be to make the ring more robust and avoid future breakage.  I believe the original part is aluminum, and I was going to see if there would be any problem using a different material.  If it can be done, the original design may be stronger.
 
 The rivets are not too complicated to make.  They are small, but very simple.
 
 I have been looking for information on the original assembly tools and have not found much.  There are a few ways it can be done without the original tools.
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		| murff 
 
 
 Joined: 27 Oct 2009
 Posts: 599
 Location: Switzerland
 
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				|  Posted: Wed May 27, 2020 3:04 pm    Post subject: |   |  
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				| The only related tool is the "Riveting tool 109.108": 
 
   
 A small spring-loaded tube helps to have the "10.033 - Flat spring" in position during the hit onto the rivet.
 
 
 
 
 
 
 
   
 Overvew of the four related parts
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		| adk_mechetech 
 
 
 Joined: 24 May 2020
 Posts: 4
 Location: 06076
 
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				|  Posted: Thu May 28, 2020 8:36 pm    Post subject: |   |  
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				|  	  | murff wrote: |  	  | The only related tool is the "Riveting tool 109.108": 
 
   
 A small spring-loaded tube helps to have the "10.033 - Flat spring" in position during the hit onto the rivet.
 
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 That looks about like what I imagined it would be.  The punch point for swage is probably 90 degrees or a hair over that I would guess based on the engineering drawings.
 
 Looking at picking a couple of suppliers to do a 2 piece sample run.  One will be investment cast, the other CNC machined.
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		| Pete 
 
 
 Joined: 04 Mar 2010
 Posts: 203
 Location: Great White North
 
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				|  Posted: Fri May 29, 2020 6:55 pm    Post subject: |   |  
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				| Excellent idea gents.  I agree these machines wouldn't be devalued by a fabricated replacement part, "resto-mod" is what we're going for rather than originality.  I wouldn't want a nonfunctional machine even if it was a rare one, #40579 lives on my desk and I use it frequently, as the maker intended, that's the charm of them for me too. _________________
 Cheers, Pete
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		| adk_mechetech 
 
 
 Joined: 24 May 2020
 Posts: 4
 Location: 06076
 
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				|  Posted: Fri May 29, 2020 11:21 pm    Post subject: |   |  
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				|  	  | Pete wrote: |  	  | Excellent idea gents.  I agree these machines wouldn't be devalued by a fabricated replacement part, "resto-mod" is what we're going for rather than originality.  I wouldn't want a nonfunctional machine even if it was a rare one, #40579 lives on my desk and I use it frequently, as the maker intended, that's the charm of them for me too. | 
 
 This is going to be a spare time project for me, but I fully intend to get some samples ordered in the next couple weeks.
 
 For material, I have chosen 17-4 as it is easy to machine, strong, inexpensive, and can be PVD coated to get the black color.  I have seen PVD coated 17-4 and a color and depth of finish can be attained that is very close to the original anodized aluminum.  Because of the material change I am also sticking with the original design/geometry since it will be significantly less prone to breaking.
 
 The second step is to get rivets made, however I am considering an alternative to the swage to attach it to the clearing ring.  I need to study the engineering drawings and consider the design before making a decision.  Regardless, the rivets are a fairly simple part and I can get them made too.
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