Source of copper tipped sprung contact fingers?

[PippinParticipant @phillspowart84010]

That’s the route I’m going down now, but thankyou to everyone for suggestions. Good point on the BeCu, for anyone wondering what it is it’s Beryllium copper.

I’ve worked with BeCu before, I made new fingers for the green controller in the first post. (That one is off a 1940’s electric factory truck.)

Drawn up and made 3D printed prototypes of the controller internals today. Everything seems to fit and function mechanically, now to make it for real and see if it works.

[Robert Atkinson 2Participant @robertatkinson2]

Hi Phil,

Sorry for the late response, I couldn’t find the parts I was looking for. I have some medium size relays that have moving contacts about the size you are looking for.
The are springy copper with double sided button contacts at one end and a hole at the other. They are 4.5mm wide and about 30mm from center of button to center of the hole.
If they sound useful I can post a photo.

Robert.

[PippinParticipant @phillspowart84010]

Evening, thanks for the offer. I think relay contacts are going to be too hard on the tips, they’ll need to be copper. Thankyou anyway. Am waiting for material to arrive now so I can start making the real parts, then see if it works.

[rjenkinsgbParticipant @rjenkinsgb]

Are these any use? It’s a scrap emergency stop module with three relays, each with eight sets of contacts; 24 sets in total.

The contact arms are around 40mm from contact centre to the end of the solder tail and look to be around 5mm wide. The contact buttons are silver tin oxide alloy, which is apparently very wear resistant. Rating is 10A per contact.

I don’t want anything for it, it’s just in my junk box. (I can see one burned contact, which is why it was scrapped).

 

[PippinParticipant @phillspowart84010]

Thankyou for the offer, but I don’t think that’ll do. The tips need to be copper, as they rub against the barrel segments, which are also copper. If they are hard, they’ll wear the barrel.

Other problem is that I hope to have the design published, so I’d need a source I could point other people to-along the lines of “Go on RS components and buy 10 of these”. I thought it worth asking before I designed the controller, rather than finding a suitable part after.

What has helped is I’ve found you can get D shape copper bar is small sizes, which makes the finger tips much easier. Material is in the post, so hopefully soon I’ll get to see if it works.

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