The Curta.org Bulletin Board

opensourcefan

I'm the new proud owner of a black type 2 and would like to keep it that way (black). It appears to be ever so slightly used so the knurling is still black.

For the time being I've wrapped one layer of clear tape on the inside circumference of the top can edge so it it's metal on tape vs metal on metal.

I had thought about 3d printing a protective sleeve to slip in there but there isn't a lot of room between the Curta and can edge.

Anyone have any other ideas on how to minimize in and out wear?

murff · Joined: 27 Oct 2009 Posts: 620

The metal canister is the perfect protection for the Curta... It is absolutely not necessary to additionally protect the Curta with a clear tape. In the past, the Curta was taken out of the canister and put back several times a day - without damaging the knurling.

Moreover, depending on the material of the clear tape, the medium-term damage can be greater than the supposed benefit.

opensourcefan · Posted: Fri Dec 29, 2023 4:12 pm

murff wrote:

The metal canister is the perfect protection for the Curta... It is absolutely not necessary to additionally protect the Curta with a clear tape. In the past, the Curta was taken out of the canister and put back several times a day - without damaging the knurling.

Moreover, depending on the material of the clear tape, the medium-term damage can be greater than the supposed benefit.

Well aware it'll protect the Curta however the coating on the knurls wears off doesn't it from frequent in and outs? Or does the coating come off in the hand from use?

opensourcefan · Posted: Fri Dec 29, 2023 4:17 pm

murff wrote:

Moreover, depending on the material of the clear tape, the medium-term damage can be greater than the supposed benefit.

You're actually thinking clear tape is going to damage the coating or the knurls?

murff · Joined: 27 Oct 2009 Posts: 620

It seems that you want to protect something that doesn't need protecting!
A frequently used Curta will have some wear and tear on the knurled areas and on the underside - this does not diminish its value or detract from its aesthetics.

Two Curtas with a history:

Imagine there was a time when Curtas were used for arithmetic! It was a tool and not a collector's item...

opensourcefan · Posted: Fri Dec 29, 2023 5:01 pm

murff wrote:

It seems that you want to protect something that doesn't need protecting!

A frequently used Curta will have some wear and tear on the knurled areas and on the underside - this does not diminish its value or detract from its aesthetics.

Imagine there was a time when Curtas were used for arithmetic! It was a tool and not a collector's item...

Oh knock off the nonsense murff!

I'll protect whatever I want to protect and I never mentioned anything about value. Detracting from aesthetics is a personal reaction, you can't make that decision for me.

We've all seen the photos of worn knurls, with coating worn off and even with enough wear to the point of their flattening. All I'm trying to do is prevent that.

If you don't have a solution then save your typing. You don't need to chime into everything, we all know you're passionate about Curtas and rule this board.

murff · Joined: 27 Oct 2009 Posts: 620

opensourcefan wrote:

murff wrote:

It seems that you want to protect something that doesn't need protecting!

A frequently used Curta will have some wear and tear on the knurled areas and on the underside - this does not diminish its value or detract from its aesthetics.

Imagine there was a time when Curtas were used for arithmetic! It was a tool and not a collector's item...

Oh knock off the nonsense murff!

I'll protect whatever I want to protect and I never mentioned anything about value. Detracting from aesthetics is a personal reaction, you can't make that decision for me.

We've all seen the photos of worn knurls, with coating worn off and even with enough wear to the point of their flattening. All I'm trying to do is prevent that.

If you don't have a solution then save your typing. You don't need to chime into everything, we all know you're passionate about Curtas and rule this board.

I apologize - in the future I will not bother you with nonsense or interfere in things I do not understand!

Uncle_Paul · Joined: 06 Feb 2024 Posts: 2

Sorry to hijack your thread. I've just acquired a Curta but it doesn't have any buffers top or bottom.

Can anyone steer me to suitable materials, type, sizes etc, and how to install them (particularly the top as I understand that the bottom one is just an interference fit).

Many Thanks,

Paul.

Kmcqueen · Joined: 14 Apr 2023 Posts: 38

I would recommend 1/4" white industrial felt! I got the idea from somewhere on this board and I believe Murff posted some pictures of his retrofitted cans. I found some at McMaster Carr. I had to double up for the small bumper in the top of the can.

https://www.mcmaster.com/products/felt/synthetic-felt-4/?s=white+felt

Graham Nash · Joined: 30 Sep 2011 Posts: 22

opensourcefan wrote:

I'm the new proud owner of a black type 2 and would like to keep it that way (black). It appears to be ever so slightly used so the knurling is still black.

For the time being I've wrapped one layer of clear tape on the inside circumference of the top can edge so it it's metal on tape vs metal on metal.

I had thought about 3d printing a protective sleeve to slip in there but there isn't a lot of room between the Curta and can edge.

Anyone have any other ideas on how to minimize in and out wear?

In response to the above, I agree Curta's will eventually show the effects of wear and tear from sliding in and out of the metal canister. Experience shows actual damage (i.e. chips) can occur on the ends of the pin sliders found on the early machines. What follows is a copy of a post of a solution to this problem made by me some time ago titled "Mushroom caps for the rest of us" ...

If you own an early type 1 pin slider type Curta you are probably aware of the little rubber "mushroom" caps that are sometimes seen on similar machines.
Aside from looking nifty, and offering slightly better grip, these caps actually protect the pins from damage as the Curta is slid in and out of its canister.

My type 1 No. 4440 is a beautiful and unblemished unit except for the ends of a couple of the pins. This is disappointing, especially as mushroom caps are so rare.
In the interests of actually protecting against further damage (rather than authenticity) I have come up with my own solution. Would you believe kite spar end caps ?

I used caps with a 1.5mm internal diameter, for a nice snug fit.

They look fantastically good, don't interfere with the function of the machine, and don't cause interference when sliding it in and out of the canister.

Total cost to protect all of my pin sliders was ..... wait for it ..... less than 80 cents !! .... all I had to do was trim them to length and put them on.

picture at following link (arrow points to slider without cap and same slide with cap)

https://www.instagram.com/p/C3Gr_sKvBKj/

The caps that worked so well for me came from http://www.skyshinekites.co.uk

If anyone has reason to believe this could somehow damage my Curta, please let me know.

Uncle_Paul · Joined: 06 Feb 2024 Posts: 2

Kmcqueen wrote:

I would recommend 1/4" white industrial felt! I got the idea from somewhere on this board and I believe Murff posted some pictures of his retrofitted cans. I found some at McMaster Carr. I had to double up for the small bumper in the top of the can.

https://www.mcmaster.com/products/felt/synthetic-felt-4/?s=white+felt

Many thanks,

I found some 3mm foam on Amazon (https://amzn.eu/d/grBX9R8) which I doubled up and it works perfectly.

Best regards,

Paul.