P&G Fader knob 3D print

[ruffrecords]

@MidnightArrakis I have just been printing some samples of the P&G knobs from the STL file you provided.

The default orientation in the 3D drawing of the knob is on its side. I assumed this was perhaps something to do with making the 3D print work properly. However. the large overhang this creates where the fader tang is inserted sagged enough to create some very difficult to remove swarf.

The second print I did was therefore with the knob face down - the orientation it would be in on a fader. This avoids the long overhang and gave a much cleaner print expect the top surface is a little more granular. However the tang would not push into the slot.

Next I scaled the width by 5% to widen the slot for the tang. This printed OK and the tang would fit in to the slot but the slot was not quite long enough.

Lastly I increased the length of the knob by 5% to increase the length of the slot. This last print looked OK and the tang fits snugly.

I notice this design of knob has an arrow on the left and right sides and a line across the centre. The 'real' P&G fader knobs I have lines down the sides and one across the centre - not really an issue, there are probably many variants. As I printed in only one filament, none of these were reproduced. To create the central line I need to find the layer in which this is printed, pause the printer at that point, change filament colour, print the line, pause again, change the filament back to the original colour and complete the print. This many changes in such a simple part is a PITA. I might try printing the knob in the line colour up to and including the line and then change the filament to the base colour unless there is some other smarter way I can achieve this.Fortunatel the knob is small so even on my small printer and can print probably a dozen at a time.

You asked if the printer worked with plain and/or binary STL files. The answer is neither. Before printing, the STL file is sliced into layers for the 3D printer to print and then each layer is converted to gcode which is what the printer understands. So it is the slicer that needs to understand plain or binary STL files. Fortunately it seems happy with either (and a whole lot of other formats too).

Cheers

Ian

 

[MidnightArrakis]

That all sounds really good!!! I'm glad that you were able to get things all figured out.

>> I do hope that you understand that while I am more than happy to share with you all of these items that I happen to stumble across, since these STL files are all from various third-party sources, I have have absolutely no idea about anything concerning any of these files. Anything about how the STL file was created, its orientation, its dimensions, etc., etc., etc. are all beyond my control and certainly beyond my knowledge concerning this specific topic. I'm happy to share with you any audio equipment design items just because I also simply enjoy working with you on these types of projects. That's about it!!!

Going back to the fader knob.....from what I have seen on a few online fader knob catalogs, the various manufacturers of these fader knobs seem to offer like 12 different models of a single type of fader, just to accommodate all of the various dimensional variations as you described. Meaning, in other words.....before a specific fader knob can be selected for any type of linear-fader, you need to know the "tang" height, material thickness, length, etc. in order to correctly match a fader knob to a specific linear fader assembly.

So.....I suppose that if you were to provide me with those dimensions on the types of faders you use within your equipment designs, I could then keep my eyes peeled for any fader knobs that meet those criteria.

[As I printed in only one filament...To create the central line, I need to find the layer in which this is printed] -- Again, I don't know anything about how all of this 3D-printing stuff works, but.....since the P&G fader knob that I provided you also had 4 separate files, one of which was a "Line" file, isn't there some way for your printer to print that geometry separately while also using a separate filament and that separate filament would be "BLACK" instead? Actually, I was imagining you sitting at a brightly lit workbench with a box of freshly-printed fader knobs and you're sitting there holding a fader knob in one hand, while peering through a lighted magnifying-glass and holding a delicate teeny-tiny artist paintbrush with your other hand and ever so carefully painting in the black-stripe on each and every knob!!! HOW MUCH FUN WOULD THAT BE?!?!?!?!?!?.....

Whenever I import a -- STEP/STP -- file of an electronic component, I have noticed that their incoming orientation can be "all over the map"!!! As an example, the TAKACHI enclosure imports with its "rear-panel" as being on the bottom and the small "front-panel" as sticking up into the air. The NEUTRIK connectors import in as being oriented "every which way" but making any sense depending upon the model type!!! And, while I can rotate a component around to an orientation that "makes sense" visually, even when I save the file into my SolidWorks file format, the components' -- creation orientation -- still remains the same regardless of my new rotational orientation. And, I don't know if that is a changeable feature or not. So.....I can't help you out here in this department.....yet.

ENJOY!!!

/

 

[grid_stopper]

i feel like this is the exact kind of task a resin printer would excel at. they are unfortunately a lot bigger PITA to use.

 

[Newmarket]

y separately while also using a separate filament and that separate filament would be "BLACK" instead? Actually, I was imagining you sitting at a brightly lit workbench with a box of freshly-printed fader knobs and you're sitting there holding a fader knob in one hand, while peering through a lighted magnifying-glass and holding a delicate teeny-tiny artist paintbrush with your other hand and ever so carefully painting in the black-stripe on each and every knob!!! HOW MUCH FUN WOULD THAT BE?!?!?!?!?!?.....

Not difficult tbh. Just use a suitable stencil to provide an accurate line. Question becomes what to use for the line - ink ; paint; Sharpie ? If the line is in a groove (I can't remember) then just "paint" and wipe to leave the line in the groove. This method been used on washing machine controls etc.

 

[13engrsapper]

@MidnightArrakis I have just been printing some samples of the P&G knobs from the STL file you provided.

The default orientation in the 3D drawing of the knob is on its side. I assumed this was perhaps something to do with making the 3D print work properly. However. the large overhang this creates where the fader tang is inserted sagged enough to create some very difficult to remove swarf.

The second print I did was therefore with the knob face down - the orientation it would be in on a fader. This avoids the long overhang and gave a much cleaner print expect the top surface is a little more granular. However the tang would not push into the slot.

Next I scaled the width by 5% to widen the slot for the tang. This printed OK and the tang would fit in to the slot but the slot was not quite long enough.

Lastly I increased the length of the knob by 5% to increase the length of the slot. This last print looked OK and the tang fits snugly.

I notice this design of knob has an arrow on the left and right sides and a line across the centre. The 'real' P&G fader knobs I have lines down the sides and one across the centre - not really an issue, there are probably many variants. As I printed in only one filament, none of these were reproduced. To create the central line I need to find the layer in which this is printed, pause the printer at that point, change filament colour, print the line, pause again, change the filament back to the original colour and complete the print. This many changes in such a simple part is a PITA. I might try printing the knob in the line colour up to and including the line and then change the filament to the base colour unless there is some other smarter way I can achieve this.Fortunatel the knob is small so even on my small printer and can print probably a dozen at a time.

You asked if the printer worked with plain and/or binary STL files. The answer is neither. Before printing, the STL file is sliced into layers for the 3D printer to print and then each layer is converted to gcode which is what the printer understands. So it is the slicer that needs to understand plain or binary STL files. Fortunately it seems happy with either (and a whole lot of other formats too).

Cheers

Ian

Sounds like you are ready for the Bambu AMS or AMS lite ;-)

 

[13engrsapper]

i feel like this is the exact kind of task a resin printer would excel at. they are unfortunately a lot bigger PITA to use.

The problem I had with the resin printer was it was not as accurate - required calibration and adjustment to hit and OD then often the ID would not be correct, and changing colors on the fly is impossible.

 

[grid_stopper]

The problem I had with the resin printer was it was not as accurate - required calibration and adjustment to hit and OD then often the ID would not be correct, and changing colors on the fly is impossible.

resin/sla has come a long way in recent years. there are a more than a few hobbiest printers that blow traditional fdm away in terms of dimensional accuracy. of course, the colour issue still remains.... but the few resin prints ive had done through JLCPCB have turned out excellently, and cost very little. this to me seems like the best option, resin is pretty nasty and taking the necessary precautions at home was far too much work for my likings

 

[bjosephs]

Resin printers still require supports in the gaps that result from print orientation so I don’t see resin achieving something here that FDM can’t besides improved resolution. It's true that great printers of both types can outdo lesser machines from either category (on accuracy) but people need to work with the tools they have. And even expensive CNC tools require some tuning for size/fit. We can do that on printers too. Even better is designing parts that are more forgiving of size variance.

I pulled the caps off of my Alps faders and copied the geometry they have. The extra gaps to the sides of the main slot do three things: They provide some give to the walls that grip the fader slide, they keep wall thickness more uniform which improves injection molding quality, and they help reduce material consumption. There are also some keying features that accommodate the upsets in the sheetmetal tab. My first print with these dimensions fit beautifully. An STL is attached though it is disguised as a .PDF

 

[bjosephs]

Some thoughts on print quality:

Due to the slot(s) fit being critical I don't see a good way to print on the side. You will also get a different surface finish on both sides this way. Even if your printer can make decent supports the slots are bit narrow to pull it out after. Some printers use caustic or even water-soluble support but those are very much an exception right now. Avoiding supports is generally good practice.

If you print flat on the bed the main challenges are overhangs, bridging, and radii that are not normal to the bed (Like the finger shaped arc most caps have). Some printers may struggle with a clean sharp upper edge too. Keeping overhang angles greater than 45 degrees can make unsupported angles achievable on most printers (though some can do much shallower angles with well tuned speed and cooling). A radius further removes overhang scenarios. A radius on top or even just a small flat might be nice option if your printer struggles with a sharp upper edge. Technically we are bridging anywhere material is printed above the slots but the distance is so short I think most printers will handle this well. The finger arc is the most troublesome. With a .2mm step height you get some free "texture" for grip but it doesn't look that great. My printer supports .08mm step heights and that can be accessed either by setting to that height always (slower) or activating "adaptive" layer heights and letting the slicer adjust. It looks a bit better.

 

[13engrsapper]

resin/sla has come a long way in recent years. there are a more than a few hobbiest printers that blow traditional fdm away in terms of dimensional accuracy. of course, the colour issue still remains.... but the few resin prints ive had done through JLCPCB have turned out excellently, and cost very little. this to me seems like the best option, resin is pretty nasty and taking the necessary precautions at home was far too much work for my likings

Ya, having resin prints done elsewhere is defiantly the route I would go.

I was impressed enough with the progress in all of this to jump finally. I literally just returned a Elegooo Saturn Ultra, it made beautiful prints. I ran it for about 90% of its first film life before deciding to return it. I am not sure how many kilos of resin I used, maybe 15, I still have about 17 kilos of various resins left here if you decide to try. I did not try any of the water washable types. Others have commented on the smell/mess and consumables used in the process too. I ignored that, of course, and they were right. Best I could manage was about 6 ounces of 99% isopropyl alcohol, and two pair of nitrile gloves per print.

I made some awesome vintage knob replicas, but the threads needed to be chased/cut with a tap. I could nail an OD, or an ID, but not both. There is compensation in the slicing software for that, but the wide temp swings in that shop (it is only humidity controlled) meant you still had to calibrate almost every print. That is not the printers fault, and higher end ones have heated reservoir areas etc. Also, the resins I used, even the ones they called "flexible or tough" were much harder than the filaments I have used so far, but man did they feel good. Kinda like bakelite.

I have a keen interest in the powder fusion process with a laser - but I am spent out for the next couple years and we will just be using these for mounting brackets etc most likely - so no need to go nuts... so far. Plus I wanted something my grandkids could use with supervision - after the first few prints and waiting for cleanup in another room, plus not really being allowed in the print area etc, they lost interest lol.

The filament printer now runs about 50% of the time they are here, I am starting to teach them basic CAD skills, and soldering etc. Fun stuff.

 

[paulcheeba]

I seriously need EAB fader caps as they are a size and style all of their own.

 

[ruffrecords]

I seriously need EAB fader caps as they are a size and style all of their own.

Do you have a link to a drawing of them?

Cheers

Ian