Eames EA117 (4-Star Base) missing parts?  

another picture

taken apart

from under the base

I am not sure where you are located but those castors do not belong to an EA117 (USA and other models worldwide).  The vintage examples have a standard issue black wheels and Herman Miller replaced those old wheels with the double wheel castors designed by Jorgen Rasmussen in 1965 and it is currently used on the current models.  You could also replace the wheels with a Herman Miller or Vitra (depending on where you are in the world) plastic glides if you don't want a rolling chair.  As for the wobble, you are probably missing a part that keeps it from wobbling and you can do your online research through the Herman Miller or Vitra websites.  Yo can also contact any aftermarket online parts sites to see if they have the fix you need.  (examples are Graham Mancha in the UK, Hume Modern in the USA, Design Restoration from somewhere).

or look through the Eames Office website, maybe they could help.

https://www.eamesoffice.com/the-work/eames-aluminum-group/

or check ebay, like where the image was from.

Thank you very much for your help and these infos on the castors! I will probably change the castors for glides, my soft wood floor will be very grateful. I'm not sure if the chair is from Vitra or Herman Miller or maybe even ICF or something similar because there is no label. The base says "Made in Norway". When I "found" the chair it was in a very bad state but after some elbow grease and removing of the arm rests (a lot of pitting), I thought this is a beauty.

I'm located in europe and I already had contact to Vitra but they said they don't have any spare parts for an 4-star base and had no information on the parts I need. I also contacted Design Restoration, they were very kind and asked for pictures. but after I provided some, I never heard from them again. So I think they also didn't know what parts are needed. I would love to get the chair back to life, but buying another EA117 to just take the base is not really in my budget.

Best regards,

jcalca

I can't see anything missing from the image of your base (maybe I'm just going blind), it looks just like the base of one of my chairs.

Thank you for your picture! I'm not sure but I think this is another base. I will clean my parts and make another photo, so it is better visible (my parts are full of remains of duct tape).

Best regards,

jcalca

I cleaned the parts and made some more pictures, I hope that gives a general idea of the problem

This is when the whole thread is in (slips just through, I think the thread inside of the "head" is worn off)

The brass (?) part is also very worn off and probably broken

This part looks fine to me

This is where I think the main problem is. I think there should be some part that can be threaded on to hold everything in place and center it. But I cant find any picture of it and Vitra also could not help me.

The construction of your chair base looks so different than the Vitra and Herman Miller examples I have encountered.  It looks like whoever produced this version in Norway used base fittings that is probably sourced there.  Your best bet is to find a similar chair that utilized the same base like what you have.  I don't know if your chair is a legit or authorized version, and the castors even if original deviated from the standard Herman Miller and Vitra examples.  Sorry if I can't be much of help to you.

Agree with mini that the entire seat stretcher/tilt assembly pictured is unlike those on any authorized editions I've ever seen. At first I thought maybe an early transitional iteration between the Bassick Flo-Tilt and torsion bar versions, though it does appear to use a torsion bar as well. Very strange. Graham Mancha would be the one to ask about this, I think.