Predicta Volume Knob dimensions

[rickfray]

I am trying to make a Predicta Holiday Volume/on/off knob out of wood as a prototype for making some reproductions on a 3-D printer (and to use on mine until I find something better). Since I don't have one, I'm having to guess at some of the dimensions and scale based on a few pictures I've seen on the internet. To confirm what I'm found/figured out so far, can someone who has one of these please provide the following measurements in inches and millimeters if possible?

1. length of the shaft up to the bottom of the wide "disc" that has the metal disc embedded in it? 1/2"?
2. diameter of the shaft? 7/16"?
3. diameter of the disk at the end (outside of the plastic)? 1/2"?
4. diameter of the metal disk embedded in the end? 7/16"?
5. Exact or approximate amount of "Teeth" or grooves etched into the edge of the plastic disc on the end? 80?
6. How much of a gap is there (if any) between the bottom of the shaft and the edge of the contrast knob that sticks out the farthest? In other words if you look down from above, directly over the two knobs, how much of a gap is there in their normal positions?

I'm working with a friend who is building a 3-D printer and thought this would be a good first project to test it out and maybe provide a product at a much more reasonable price than the real ones that rarely come up on ebay.

I'm working on how to assemble it the easiest way and how to incorporate the brass colored disc on the front. I have a method for the "blade" that goes in the split shaft that works well on my wood prototype.

Once I get the dimensions, I will model it with some software that will generate the file needed to run on the 3-D printer.

What other colors does this knob come in? I've only seen brown and black?

Are there Predicta models other than the Holiday that use the same size knob?

Pictures are of the prototype I think is close pending getting final measurements.

Thanks

Rick

[bandersen]

The knobs came in ivory, brown and black. The Holiday, Tandem, Princess, Debutante and Siesta models all use them. Probably the Continental and Barber Pole too.

1. length of the shaft up to the bottom of the wide "disc" that has the metal disc embedded in it? 1/2"?

Yes.

2. diameter of the shaft? 7/16"?

O.D. = 13/32", 3/8" would be close enough I think.
I.D. = 3/16"

3. diameter of the disk at the end (outside of the plastic)? 1/2"?

15/32", 1/2" would be close enough

4. diameter of the metal disk embedded in the end? 7/16"?

3/8"

5. Exact or approximate amount of "Teeth" or grooves etched into the edge of the plastic disc on the end? 80?

60

6. How much of a gap is there (if any) between the bottom of the shaft and the edge of the contrast knob that sticks out the farthest? In other words if you look down from above, directly over the two knobs, how much of a gap is there in their normal positions?

I'm not sure what you're asking here

[Jon F]

If you guys need some modeling work I can create models from physical pieces and provide STL files for 3D printing. I do this at work often.

[rickfray]

Thanks very much Bob, that's a big help. What I mean on my last question is, if you install the knobs on the vol/contrast pot, I don't think the volume knob is normally as far in as when they are just nested like in your photo. If the hole for the volume shaft is not deep enough there may be a visible gap between the end of the volume knob and the upper lip (highest point) of the contrast knob. If you can take a picture with them both installed, from the top down, directly above the knobs, that'll answer my question with the other dimensions answering the rest. Thanks

Rick

[QUOTE=bandersen;3095995]
6. How much of a gap is there (if any) between the bottom of the shaft and the edge of the contrast knob that sticks out the farthest? In other words if you look down from above, directly over the two knobs, how much of a gap is there in their normal positions?

I'm not sure what you're asking here

QUOTE]

[rickfray]

Originally Posted by Jon F

If you guys need some modeling work I can create models from physical pieces and provide STL files for 3D printing. I do this at work often.

Thanks Jon, that's what I'm trying to learn to do. A chance to learn a new skill and have some fun.

[bandersen]

Originally Posted by rickfray

Thanks very much Bob, that's a big help. What I mean on my last question is, if you install the knobs on the vol/contrast pot, I don't think the volume knob is normally as far in as when they are just nested like in your photo. If the hole for the volume shaft is not deep enough there may be a visible gap between the end of the volume knob and the upper lip (highest point) of the contrast knob. If you can take a picture with them both installed, from the top down, directly above the knobs, that'll answer my question with the other dimensions answering the rest. Thanks

Rick

It's recessed about 1/16"

[rickfray]

awesome, thanks