Anker RZ revisited
 

Old post, this, but I came across it recently in my own quest for Anker info. I got this RZ in very good condition. I also have a few other machines from the era (Singer, Pfaff, Elna, Necchi, Husqvarna and Bernina) and could try different bobbin cases in the Anker if you still haven't found a solution.
The reason I haven't already is that the Anker and the Necchi are in our mountain cabin, and the rest are at home.

Stein

I don't even know if Claus still follows this forum, but I guess there's no harm. I tried the Necchi Supernova bobbin case in the Anker RZ, as both the cases and the bobbins look the same. Sewed the basic stitches, straight, ZZ, you know...I couldn't detect any difference in stitching at all, they seem completely interchangeable.
There may not be an abundance of vintage Necchis around, but they are easier to find than the Ankers. For all I know they still use the same case.
Stein

First off, From me personally, Welcome to this end of the Asylum.

You must have done some homework to find this info and thank you for letting us know what you were able to find out, and confirm it. You are right. Finding a Necchi part is MUCH easier than finding a part for an Anker.
I have had two Anker machines. So Precise. A real joy to use. Both of mine were the plain-ish black ones and one was badged Free Westinghouse. Yours looks beautiful. Much prettier than either of mine. And I LOVE the two upper tension knobs!
~Grant~

This is very exciting news! Now you have me wondering if there was a European standard bobbin after WWII and we Americans never learned about it in time before sewing machine production moved out of Europe mostly.

Now this was fun - a warm welcome, and actually being able to contribute. I thought this would only be useful to Claus with the Anker, but I can see possible wider implications. A word of caution: The parts look and act interchangeable to me, but this has not been verified by anyone "official" or really in the know. I don't want people to ruin their precious machines if there are small differences that cause harm over time. Please be careful.
Later today I'll try to post a photo or two of the Necchi and Anker systems, they're the only ones I have here. When I get back home I'll take a closer look at the other Europeans.
Stein

Check the slot in the bobbincase closely to see if it matches width, and position of the hole in the case. Some are identical except for the hole. Some SS (straight stitch) machines bobbin cases may fit and work perfectly, but for SS only and will break the needle if you try to do a ZZ (zig zag) stitch with it.
~G~

Beautiful machine and I love the twin tension dials. Give me gadgets any day.
Welcome! and thanks for sharing the picture.
Rodney

As you can see there are differences.
I now have tested both machines with the other's bobbin system. Carefully, hand wheel only at first, then gradually to full speed ss, all lengths. Back to hand wheel, same procedure for zz. I ran them as hard as I could, changing direction and width at full speed. I did some specials, including the satin stitch, full width, full speed. No mechanical misgivings that I could detect. No visual damage to needles, bobbins, cases or needle plates.
Comparing stitch quality in all these modes was not part of this test, to many parameters, but they both sewed without glitches.
Are there other tests you want me to do?

To Rodney: Yeah, gadgetry is grossly underrated.

Stein

I have no idea about the Anker, but Necchis are standard 15 class. The older Italian machines just had their bobbins and cases made for them instead of using a Japanese standard one. I've never had an issue using a standard bobbin case/bobbin in a Necchi machine.

Cari

Welcome to the board Stein. You fit right in. Great photos.
HelenAnn