• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Reproduction Fisher Knobs

I did get the clock-spring today and it still looks promising as a source for knob spring-clips. Still a few more hurdles to jump before I'll know whether this project is doable.
 
]5.jpg

The clock-spring seems to be a good source for home-made knob spring-clips. I cut a couple and roughly fashioned them with a Dremel. It's easy to make a small bend in the repo clip with a couple of pliers, and with a bit of coaxing, it fits the three types of Fisher receiver knobs that use spring-clips. The original spring-clip is on the left.

At this point, I'm going to wait and see how the other repo knob types from my son turn out, and how they look with the brass brass caps and rings I have lying around.
 
Last edited:
It has surprised me nobody has attempted to 3D print these and then I finally stumbled upon this post after another dead end search for originals. I was going to try something similar myself. Definitely staying tuned to see how this turns out!
 
I have a couple units I saved from being totally parted out. Luckily, they just need tubes and knobs. Would love a source for repro knobs. :lurk:
 
I’m hoping my son will be able to model and test print the other knob types in the next week or two. At that point we’ll see how well they work with stock brass caps rings. It they look good enough, the next step would be how to fabricate the brass bits. Since nobody is selling the brass rings, we’ll have make or have them made. And if we’re doing that, might as well do the caps too. Looking at possibly getting a mini metal lathe and fabricate the caps from solid brass rod and the rings from brass pipe. Anyways, still a ways to go on this project.
 
ncwalz said:
I’m hoping my son will be able to model and test print the other knob types in the next week or two. At that point we’ll see how well they work with stock brass caps rings. It they look good enough, the next step would be how to fabricate the brass bits. Since nobody is selling the brass rings, we’ll have make or have them made. And if we’re doing that, might as well do the caps too. Looking at possibly getting a mini metal lathe and fabricate the caps from solid brass rod and the rings from brass pipe. Anyways, still a ways to go on this project.
Click to expand...
Someone said that it might be possible to print the rings in place using a brass color change. At any rate, looking forward to the end result.
 
Hey Steve. I did pass on the colour change idea to my son when you posted it a couple of weeks ago in your Facebook group. His response was that he didn't think it would be possible to do this with the printer and resin type he and I would be using.
 
I agree on the paint followed up with a clear acrylic. The knob might have to re-printed to provide a surface to accept the paint however. And on the brights if I may make a suggestion: look into Marshall amp knobs. They come with a bright that is extremely passable. They sit a little proud of the knob so I cut them down to size. The filed edge is buried in the knob so you can’t tell it was modified. And the bonus: very cheap!!

Exciting!!
 
Thanks for the suggestions, guys. I see the Marshall knobs are available on Amazon. I’ll check them out.
 
Small update:

Both my son and I have been busy with some other projects, but today he was able to model and reproduce the lower Fisher knob.

1.jpg
The left is the reproduction prototype in black plastic.

2.jpg
The prototype is close enough that a stock Fisher brass ring snaps in place.

So the next step is reproduction of the brass rings. The original stock rings appear to have been stamped from brass washers and have a flange that allows them to be snapped into the plastic knob. My son informs me that at least to start with, we should try to fashion the rings from brass pipe using a metal lathe. They should look correct from the front but won't have a flange, so we may have to modify the plastic knob slightly to accommodate the reproduction ring.

Next step is procuring a mini metal lathe and brass pipe.
 
Last edited:
ncwalz said:
Small update:

Both my son and I have been busy with some other projects, but today he was able to model and reproduce the lower Fisher knob.

View attachment 3787798
The left is the reproduction prototype in black plastic.

View attachment 3787799
The prototype is close enough that a stock Fisher brass ring snaps in place.

So the next step is reproduction of the brass rings. The original stock rings appear to have been stamped from brass washers and have a flange that allows them to be snapped into the plastic knob. My son informs me that at least to start with, we should try to fashion the rings from brass pipe using a metal lathe. They should look correct from the front but won't have a flange, so we may have to modify the plastic knob slightly to accommodate the reproduction ring.

Next step is procuring a mini metal lathe and brass pipe.
Click to expand...
Very nice, I'm certainly in need of knobs and will be keeping up with your progress.
 
IMG_3486.jpg

Small update: Slowly mastering the use of the small, basically kinda okay, Chinese metal lathe.

I'm able to fabricate the metal rings now from brass pipe. I'll use a Dremel with a polishing tool from now on to polish the front bevel while the brass pipe is still in the chuck and then part the ring from the pipe.

Parting has been the biggest challenge with this small lathe. But now that fabricating the brass ring of the knob is doable, I think I can move forward since the rings were not previously available anywhere else.

Fabricating the brass caps with this lathe may or may not be possible; we'll see, but since the these caps are still available, or can be fabricated by other means, this is not a deal-breaker.
 
Last edited:
01.jpg02.jpg


A bit of polishing on the chuck and a bit of steel wool after parting the ring. Not perfect, but maybe close enough.

I really only have to measure the inner and outer diameter of ring. My son ground a high speed steel cutting tool that has the correct angle of the bevel.

One pleasant discovery: If I'm careful about correctly reproducing the inner diameter of the ring, the parting tool leaves a flange on my reproduction ring that is very close to the flange of the original stock ring and fits nicely into the groove of the plastic knob. It's not a friction fit like the original, but three tiny dabs of glue to the holes in the plastic underneath should hold it in place.
 
Last edited:
I think it gets easier with some experience and practice. I can machine a length of brass pipe to the correct outer and inner diameter sufficient for about five rings. Then it's just two tool changes: first to bevel and second to part the ring from the pipe: about five or six minutes at present.

Next step is obtaining an Anycubic Photon Mono 4 3D printer of my own. My son has made the reproduction plastic prototypes with his printer up to this point.

Should be able to print a complete set of receiver knobs at one go, so they should all match exactly in colour.
 
You must log in or register to reply here.
Back
Top Bottom