Need a knob - Page 1
Forum section: electronics / repair

author: artag
author_rank: Super Contributor
timestamp: August 11, 2025, 06:03:00 pm
content: I'm trying to find a replacement for the knob shown (it's from an Iwatsu DS-8812 oscilloscope). Exact match isn't necessary, I'm happy to replace all the knobs but they should be approximately this size (10mm tall above the panel, ~10-12 mm diameter) and most importantly should have the same fitting : it projects below the knob onto a recessed 6mm D shaft.I don't know what the projecting part is called, making searches difficult. Most of the knobs I've looked at don't have it and it's importantIdeally it would be grey, ribbed and have no marker.I see the term 'half shaft' and 'flower shaft' quite commonly. Flower shaft I think I know as a spline, as is sawtooth. I can't work out what half shaft is. It might be D but I think there's also a version of D where the cut is much closer to halfway whereas it's often used with a picture of a more conventional D (about 30%).I could possibly print it but it would be hard to match the ribbing and I'd likely have to print all 8. Something similar from stock would be simpler.I'm also interested to know how the optional FFT on that oscilloscope is provided. Might be different ROMs, some soft installation switch, a plug-in card (it has a memory card slot) or even enabled through the floppy drive.

author: Swake
author_rank: Frequent Contributor
timestamp: August 13, 2025, 11:49:53 am
content: Sounds like a 3d print job.

author: TexasAggie15
author_rank: Newbie
timestamp: August 13, 2025, 02:27:22 pm
content: I'd agree printing is likely your best method to get a tailor made knob. If you have your slicer dialed in right for the filament you're using, you should be able to get a snug fit. Measuring the rib size and location could be difficult, but you could measure the D shaft, add it in your CAD as construction lines, and design ribs around it.

author: Swake
author_rank: Frequent Contributor
timestamp: August 13, 2025, 09:06:58 pm
content: If you don't have a printer yourself you'll find one within your group of friends or an online service like pcbway

author: artag
author_rank: Super Contributor
timestamp: August 14, 2025, 08:31:47 pm
content: Yeah, the ribs are my biggest concern for printing.They're a rectangular section with rounded corners, and the rib comes up the side then bends across the top.It looks like I could model that in openscad by defining the rib cross-section then extruding that around a custom curved path.Might be doable but quite a lot of work, though perhaps a useful learning exercise.What might be easier is to push a knob into silicone or plasticine to make a mould, then fill it with ABS/solvent. Then print the shaft part and attach it to the moulded knob. Likely a lot harder than it sounds.A roughly similar knob would be a lot easier, if I can find one !The nearest I've found so far arehttps://www.aliexpress.com/item/1005008945008994.htmlbut they're a bit big, ugly, and have no ribs so will be harder to use than the original.

author: MAS3
author_rank: Regular Contributor
timestamp: August 14, 2025, 09:26:23 pm
content: Did you use a search for d-shaft knobs ?

author: artag
author_rank: Super Contributor
timestamp: August 14, 2025, 10:42:59 pm
content: Yes, but the search doesn't work that well. It did find that but mostly finds non D-shaft. And the D-shafts it does find rarely have that extension which may or not be called half-shaft (since many described as half-shaft don't have it). The most common type are hi-fi knobs with metallic skins, would be totally unsuitable even if they fitted, or have splines instead of D.I did order some of those (unfortunately they're slow and have rip-off postage but still pretty cheap) in case they're better than they look or to use for the shafts. But there may be neater ones out there. I've seen quite a few of those oscilloscopes for sale online and many have knobs missing so a fully printable model or off-the-shelf substitute would be nice.

author: MarkF
author_rank: Super Contributor
timestamp: August 14, 2025, 11:22:15 pm
content: The ribs won't be much of a problem.The bigger problem is printing that ring around the center.It will need supports and getting a smooth ring with be near impossible with a filament printer.Don't know what the result of a resin printer would be like.Getting a soft knob with TPU filament will also be challenging.As for actually drawing the knob, I had a long detailed discussion making a knob with indents.Making the ribs would be similar but probably easier.https://www.eevblog.com/forum/3d-printing/resize-a-stl-file-for-me/If you just want to skip ahead:https://www.eevblog.com/forum/3d-printing/resize-a-stl-file-for-me/msg5289604/#msg5289604and here:https://www.eevblog.com/forum/3d-printing/resize-a-stl-file-for-me/msg5557645/#msg5557645

author: Psi
author_rank: Super Contributor
timestamp: August 15, 2025, 01:44:16 am
content: Quote from: artag on August 14, 2025, 08:31:47 pmI wonder if OP could make a mould out of polymorphic plastic and then coat it in oil as a mould release and push more polymorphic plastic into the mould. That stuff is pretty solid once at room temp and very pliable and workable hot.Would still have to figure out how to do the internal hole though.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 15, 2025, 04:28:03 am
content: You could make a mold with silicon mold compound, and then cast knobs in an appropriate resin. I know from experience that there is a fairly long learning curve to getting great results, and I have so far only reached the point of getting occasional good results. Watching the UTube videos on the subject indicates that setting up a vacuum jar to de-gas the various compounds is critical. This knob would require a two part mold raising the level of difficulty.Generating the model of the knob shouldn't be too hard with any of the major CAD programs. As you say the hard part is learning how to add the knowledge of the program to your toolbox. Unless the unseen top of the knob is very complex I would think this should be half an hour of work with a caliper getting all the appropriate dimensions, and depending on your CAD skills something between an hour and a day to do the model. In some ways most knobs are variants of just a few basic ideas so the time developing the skill won't be wasted.While I agree with MarkF that getting a polished look on the part of the knob below the center ring will be difficult on a filament printer, I'm not sure it matters. As I understand usage of the knob the "ugly" part won't be visible once installed. TPU is not too hard to print with a direct drive filament system at the harder Shore ratings, but it does get more challenging as you get to softer versions. Not sure how soft these knobs are. Shore 95 TPU has a little give to it, but is not what you would call rubbery.Resin printers give extraordinary surface finishes and detail, but the materials may or may not stand up to use as a knob. The inexpensive and common resins are brittle and hard. Don't know much about other UV curable resins but know that cost goes up rapidly.

author: Kean
author_rank: Unknown
timestamp: August 15, 2025, 04:54:58 am
content: If you design something for 3D printing, you can test it on a cheap 3D printer and then order high quality 3D prints from someone like JLC3DP.I was searching for similar parts with M4 thread for a client project. After trying lots of options from Essentra and AliExpress, I designed my own in Fusion 360 quite quickly. See attached pic.I've now bought hundreds of these and they are about $1 each plus shipping. I use a soldering iron to add M4 brass inserts, but you wouldn't need that.

author: artag
author_rank: Super Contributor
timestamp: August 15, 2025, 10:11:24 am
content: Loads of good suggestions there, thanks.I'd forgotten about polymorph, that indeed might make a good transfer mould.The knobs are not soft. I think they're ABS.I have both resin and filament printers available but they're older printers and not the best resolution. Approximating it and then sending it out is a good idea too.

author: MarkF
author_rank: Super Contributor
timestamp: August 15, 2025, 10:25:23 am
content: I would not be too afraid of older 3D printers.Most likely you will be able to produce an acceptable knob.Here's a photo of a knob I printed with my stock Creality CR-10 Mini:The diameter is approx 1" and printed in PLA at a 0.12mm layer height.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 15, 2025, 04:05:28 pm
content: I decided to practice and generated the following in FreeCAD. The shaft matching part is set to match a 6 mm D shaft, which is the most likely configuration. The rest of the sizes are eyeballed from web pictures of the scope. The attached zip file contains the model in FreeCAD format and you can adjust dimensions if these aren't close enough to suit. From the web pictures of the scope these knobs aren't much bigger than a BNC fitting, printing will take next to no time at all.The model is the work of a hobby user of CAD. My apologies to the pros who will have many objections to the approach. If you have trouble following or modifying I will be happy to explain where and how to make modifications.

author: abeyer
author_rank: Frequent Contributor
timestamp: August 15, 2025, 09:37:34 pm
content: Quote from: MarkF on August 14, 2025, 11:22:15 pmI'd do that as two parts with a press fit and/or glued assembly: print the knob and skirt as one piece, and a separate "shaft extension" that fits over the d-shaft and extends up into the knob. You should be able to design/orient them both for good quality printing without supports that way.Quote from: MarkF on August 14, 2025, 11:22:15 pmI would just stick with a hard knob if you're on a single head printer, with the ribs you'll have plenty of grippyness... but you can get pretty decent results if you have access to a multi-head one, by combining a less flexy TPU (you don't want the super soft stuff) outer skin over a PETG or other rigid filament body and printing them together in-place. I don't have one, but did some experiments on a prusa xl a while ago for exactly that and was able to get some decent results reminiscent of what you see commercially manufactured by injection molding soft grips over a harder plastic.

author: MarkF
author_rank: Super Contributor
timestamp: August 16, 2025, 10:05:17 am
content: @CatalinaWOW,Nice job replicating the knob.A small criticism if I may.Since the knob will not be injection molded, the lower half just below the ring will be susceptible to breaking. Its strength solely dependent on the print layer adhesion. To that end, I would have taken some liberties and made it stronger in that area.In other words, I would have made to lower half a cylinder with the D-slot cut in. Making the outer diameter as large as possible and still maintain enough clearance for proper operation. Maybe not even making the inside ridges to hold the knob on. Basically, trying to make the layer cross-section as large as possible for maximum strength on the lower half.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 16, 2025, 12:33:21 pm
content: Quote from: MarkF on August 16, 2025, 10:05:17 amAll valid observations. I don't have access to real dimensions so just threw sizes in that have worked for me. Anyone using this will have to make adjustments for their application and their judgement of how closely they want to match the original. Printing options will also matter. Layer height to nozzle size ratio. Number of wall layers. Best printed with a raft. And so on.One exception I take to your comments. The ridges on the inside of the slot serve a function. These knobs depend on a slight interference fit with the shaft for attachment. The ridges provide a degree of freedom for the base to bend to accommodate this interference. Without them stretching the material is the only thing that works. The ridges make the degree of fit less critical. In either case the design will have to be adjusted to get the desired balance between grip and force required to install. This demonstrating the benefit of 3D printing. Iterations are quick and cheap.

author: artag
author_rank: Super Contributor
timestamp: August 16, 2025, 02:30:50 pm
content: Quote from: CatalinaWOW on August 15, 2025, 04:05:28 pmThat's excellent, thank you very much for your work.I think it's a little too tall wrt width but I will try to get that closer, but in any case it might be desirable to reprint all the knobs.

author: artag
author_rank: Super Contributor
timestamp: August 17, 2025, 02:59:58 pm
content: Here's a print from @CatalinaWOW's drawing.The modelling is very good indeed but the dimensions (they were, after all, guessed!) are a bit off. I think the only missing feature is a radius on the upper corner of the flange. It's definitely good enough to be worth trying to get the dimensions right.Not sure I know where to start in correcting it. My knowledge of CAD is limited to OpenSCAD and KICAD, and FreeCAD is very different. I could simply scale it, but although the shaft size is also slightly big I think it would become much too small. My fastest approach would be to cut the stl in half at the flange and scale the two parts differently. A bit clumsy but workable.Here are actual dimensions. I'd welcome a description of how to alter it in FreeCAD but it might be much easier to change yourself than try to explain it. Would also be interesting to know if this is what you expected - it could be that my printer is not scaling correctly.@MarkF - I'm using resin so layer adhesion isn't an issue on this print. There isn't a whole lot of clearance in the panel hole so the outer of the D shaft is max. about 12mm but could be increased a little. However the D is unnecessarily applied to the outer shape so the shaft could be circular and the D only applied to the hole, which would increase the strength a little. It would also thicken the thin wall on the D flat.Code:actual printedHeight (under flange to above top ribs) 8.91mm/.351" 13.77mm/.542"Shaft tube length (under flange to end) 5.72/.225 10.16/.4Depth (full shaft tube) 13.67/.538 9.75/.384Depth (stopped shaft tube) 8.23/.324 16.41/.646Height (flange) 1.0/0.04 1.83/0.072Width (ribs) 0.97/0.038 1.3/0.051Diameter (flange) 11.96/.471 16.41/.646Diameter (largest ribs) 10.41/.41 13.97/.555Diameter (smallest ribs) 9.80/.386 18.18/.519Diameter (largest cone) 9.73/.383 12.98/.511Diameter (smallest cone) 9.09/.358 11.89/.468Diameter (clear circle in top) 5.92/.233 7.77/.306Diameter (shaft tube outer) 8.94/.352 9.73/.383Diameter (shaft tube inner) 7.32/.288 7.67/.302Diameter (shaft tube inside ribs) 6.02/.237 6.10/.240Diameter (shaft tube inside D chord) 5.54/.218 6.88/.271Diameter (shaft tube est. inside D chord ribs ) 4.45/.175 5.72/.225Diameter (D chord on actual shaft) 4.42/.174I've mislaid my metric calipers so measurements were taken in imperial to 0.001" and converted, 5/4 rounded to 0.01mm.The two dimensions for tube depth are because the hole actually goes almost to the top of the knob but has a bar across that's a little deeper than the flange position so becomes the maximum shaft length it can handle.'cone' and 'ribs' refer to measurements across the inner conical core of the knob and the slightly larger diameter of the knob on the ribs that follow that core's taper.The shaft fits reasonably well but is not tight, probably because of the D chord position.(change : added flange height and rib width)

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 17, 2025, 11:06:09 pm
content: Here is a resized FreeCad file with my best effort at interpreting your measurements. Use of customary units is fine, it is what I use and for much the same reason. I have a metric micrometer, and more than a dozen micrometers, calipers and other instruments in customary.The model was a quick and dirty effort. This time I spent a little more time on naming elements and constraints to make it easier for you to refine. I also added shaft clearance inside the cone. In addition to the bulk resizing, I reduced the contact dimensions of the shaft by 0.002 to get a tighter fit. This is an area where tweaking is always required. All in all it should be much closer to your original, but I am sure it is still not perfect.Some general instructions for using FreeCAD to modify further if it is needed. Go to the Part Workbench which is where I generally work (Sorry experts).1. To adjust shaft fit go to Sketch001 and double click on appropriate dimensions and modify as desired. If the cutout for the shaft inside the knob needs to be modified close this sketch and go the the Cone Dimensions sketch. The depth of the hole is dimensioned and is changed with a double click. The radius is unconstrained and can be changed by dragging with the mouse. Length is adjusted by modifying the Lengthfwd parameter in the data table for the shaft element. If length is adjusted the element will have to be moved to line up with the Cone using the transform feature. Select shaft and right click, then select transform on the menu.2. Cone dimensions are changed on the Cone Dimension sketch.3. If cone dimensions are changed, you will have to modify the ribs to match. Small changes will probably only require moving the base rib (select rib, right click and select Transform and move as needed). To do this easily hide the Fusion (select and press spacebar to toggle visibility), show the Cone (select and toggle visibility). Larger changes will require adjusting the basic rib size (look in the data table with Base Rib selected) and possibly the size of the fllets used to round the end of the rib and soften the edges. (Select the appropriate fillet and right click then select edit fillet.) After doing this you will have to refresh the Full Set of Ribs. In the data table for this element you will find a table element named Base, and it will have Fillet001 (Rounded Edge Fillet... as a data entry. Click on the three dots to the right and a window will come up, with the Rounded Edge Rib selected. Click on Clear and then re-select the Rounded Edge Rib. Clicking OK will then create the newly modified set of ribs.

author: MarkF
author_rank: Super Contributor
timestamp: August 17, 2025, 11:45:03 pm
content: @CatalinaWOW,I don't believe the OP has any experience with FreeCAD.If true, this series of videos will help to get started.At least the first two; installation, setup, and navigation.https://www.youtube.com/playlist?list=PLWuyJLVUNtc0UszswD0oD5q4VeWTrK7JCFor use on my laptop, the 'Touchpad' input mode works best for me.- Rotation by holding the ALT key and any mouse movement (touch movement on the pad)- Panning by holding the SHIFT key and any mouse movement (touch movement on the pad)For units, you can select metric or imperial.You can also input either just by entering the units after the value.Else no units will use the current default setting.That should at least get him started.Oh, I believe CatalinaWOW and I are both using version 0.21.2.For myself, that is the last version to support Win 7.Old versions of FreeCAD

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 18, 2025, 12:47:39 am
content: Actually, am using 1.0.1There are good and bad features about this first "Official" release. The bads that bother me are that the Combo pane has disappeared, and the task windows that pop open keep moving off the screen display. I have to reposition them continually. But the goods, and the fact that the older versions will be left behind fairly rapidly.The OP is completely unfamiliar. I am optimistic that this modified model is close enough that he won't need to modify it. But things like the shaft fit always need tweaking in my experience. Which is why I was so explicit in the instructions. I am aware that even that level of detail will still leave a beginner floundering, but hopefully after a couple of days of FAFO and watching videos it should be enough.You can select units, but there are traps here.FreeCAD is inherently metric, and does on the fly conversion for the screen displays when you use traditional units. But if you use named parameters in a spreadsheet and do arithmetic on them you must do the conversions. For example if you set dimension ShaftOD to 1.000 inch, Dimension ShaftID to 0.5 inch and then compute ShaftThickness = (ShaftOD-ShaftID)/2, the answer will come out 6.35 Why? because internally the two dimensions are 25.4 and 12.7 and it does no conversion.These situations don't strike right away, but can really confuse you when you are unsure of what you are doing in the software.

author: MarkF
author_rank: Super Contributor
timestamp: August 18, 2025, 11:04:08 am
content: Yes, I've been on the struggle bus with units in spreadsheets and named parameters.For spreadsheets, the value and math works out as one would expect if you embed thethe unit with the value entry. FreeCAD does the conversion properly when used inexpressions.I run in 'Imperial units' the majority of the time because I don't have any metric calibers.Old school mechanical dial calibers only.I'll be staying with version 0.21.2, at least for the near future, because my only Win10laptop has been dedicated to running the model railroad. Mostly because the touchpadbuttons don't work very well and it's easy to use the touchscreen for changing turnoutsand switching lights On & Off.

author: artag
author_rank: Super Contributor
timestamp: August 18, 2025, 09:32:34 pm
content: Thank you @CatalinaWOW for all your work. This is very close indeed, certainly good enough to replace all the knobs with printed ones. The difficulty of colour-matching the original - especially as they've yellowed a little - makes replacement a more sensible route than trying to replace just the missing two. I'm after an attractive result rather than just something usable and I think that's achievable.There's a small problem with space for the shaft - it narrows at the end so the knob doesn't go fully onto the shaft. I may have mis-measured the depth. More of a problem is that the resin I'm printing with is quite brittle in the fine details and so the spurs that line the shaft crush too easily and stay crushed, making a loose fit whereas the original ABS holds reasonably tightly. I should try a resin with more 'give' ,such as the tough ABS-like resins and that would likely also be grey. However it might also be sufficient to paint the knobs or coat them in ABS/solvent and perhaps glue them to the shaft (I don't want the replacements to get lost too!).In the picture, far left is CatalinaWOW's second version, middle is the earlier version with quite a lot of fettling in OpenSCAD (several iterations to get that close) and right is obviously the original. The features on the prints would be a little more pronounced in a darker colour.@MarkF - Thank you for the tutorial pointer. I'll go through those and may be able to further tune it using CatalinaWow's instructions, Overall a very pleasing result and as you said, quite possible without the latest printing tech. I used a Nova3d Elfin3 Mini with the default Novastan 8k resin. My other printer is a CR10 Max which is a bit coarse but a friend has a Bambu Lab A1 Mini that I know can achieve about the same resolution as the Elfin and I'll try that, too.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 18, 2025, 09:55:42 pm
content: Glad to see this is helping you. I am not familiar with resin printing so can't give you any suggestions on how to handle the shaft attachment. OEM knobs use several approaches. I believe that a lot of accumulated knowledge or test runs were required to get the solid plastic ones to work. There other approaches I have seen which may appeal to you. One is a D shaped spring that fits the D of the shaft well, with just the right amount of tension. The D has an opening either opposite the D or at one side of the flat. The spring is glued on the flat side to the knob, or sometimes has a flap which is pressed into a slot. Such springs may be available for sale, I haven't searched. Another is a single curved leaf spring whose ends are captured in the knob, and whose raised middle portion presses against the flat of the D. Such a spring can be fabricated from thin steel stock or perhaps salvaged from automotive clip nuts.

author: artag
author_rank: Super Contributor
timestamp: August 18, 2025, 10:59:36 pm
content: The originals allow just enough deformation to fit but are not as tight as I'd like. I may be able to do that but glue is probably safer. I'm familiar with the springs you describe though - that could be worth looking at.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 21, 2025, 11:05:13 pm
content: I've am posting a parameterized model of the knob in the replacement knobs thread.https://www.eevblog.com/forum/testgear/replacement-knobs-feet-and-fittings-for-test-equipment/This model will allow you to change dimensions on the knob by simply editing data in the spreadsheet (one of the entries under model tree. All of the measurements/parameters in the spreadsheet are things that are easily and directly measurable with a caliper. The only things that aren't adjustable in the spreadsheet are the degree of rounding on the various edges. Those can be changed but require diving a little deeper into the FreeCAD model.The fact that the teeth in the shaft are crushing before the shell breaks suggests to me that you are printing a really thin shell and possibly also a very sparse fill. I haven't done resin printing yet, but assume it is similar in some respects to FDM printing where wall thickness and fill factor are parameters set in the slicer. But it is also possible that something is being lost when exporting the model from FreeCAD into your desired program for fettling. In any case I would look into this before further adjusting dimensions.

author: artag
author_rank: Super Contributor
timestamp: August 21, 2025, 11:27:58 pm
content: Thanks for the parameterised versionResin shapes generally have to be 100% filled, as enclosed spaces can't drain unless you add drain holes manually. And they don't set undser final cure so just trap liquid resin indefinitely. So there's no fill pattern or wall thickness, at least on my slicer (I believe it's a badged version of chitubox, possibly with some features removed).The D shaft side is where I have had the most trouble. On the one I fettled the top edge broke away and this could well be a wall thickness issue. On your second version the wall didn't break (though I think it isn't solid right to the outer circle) but the ribs on it crushed. The resin is quite brittle, though - more so than typical filament.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 21, 2025, 11:34:35 pm
content: The ribs crushing is what doesn't make sense to me mechanically if the knob is 100% filled, and hence homogeneous strength. The brittle nature of the resin should lead to cracking in the shaft wall before crushing the ribs. It does seem possible that if the rib width is significantly smaller than the shaft wall thickness it would crush before the wall cracked. A test with wider ribs would verify this.

author: artag
author_rank: Super Contributor
timestamp: August 22, 2025, 12:38:06 pm
content: I did make the ribs on the D flat wider on the version I made, and that's where the wall broke. The wall wasn't reinforced by filling back to the circular outer wall. So making them wider with a stronger wall might well work.When the ribs crush they actually crumble rather than crack. Or maybe they get shaved down to a thinner level, but I find them smaller and powdery residue there. That's why I think I need to use a resin that deforms, as ABS does, rather than breaks up.

author: kwass
author_rank: Frequent Contributor
timestamp: August 22, 2025, 01:20:19 pm
content: What about something like this:https://www.etsy.com/listing/1151705812/through-panel-extension-volume-control?variation1=2546957116&variation0=2428050736

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 22, 2025, 03:35:37 pm
content: Changing resin is a possibility. Or changing fit. Thousandths of an inch matter here, and that level of error can creep in on both the measurement side and in the printer. I usually have to go through a few iterations to get it right. Fortunately, once you get it set up on a given printer it tends to be very repeatable.

author: artag
author_rank: Super Contributor
timestamp: August 26, 2025, 08:59:44 am
content: All the controls are encoders rather tan pots so the pointers aren't ideal.But thanks, possibly best fit so far. The ones I got from aliexpress were no good.

author: kwass
author_rank: Frequent Contributor
timestamp: August 26, 2025, 11:43:13 am
content: Another option is to look for car radio knobs. Something like this:https://www.amazon.com/XTPTFABS-Radio-control-Compatible-Cooper/dp/B0DRNJYXWM

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 26, 2025, 01:45:17 pm
content: Quote from: artag on August 26, 2025, 08:59:44 amPointers are only built when the number of ribs is set less than 12 on the parameters page. Fit is adjusted there also

author: BILLPOD
author_rank: Frequent Contributor
timestamp: August 26, 2025, 07:21:15 pm
content: Just as I suspected...'Knobs.com' is a website, but not the type of knobs required here

author: artag
author_rank: Super Contributor
timestamp: August 26, 2025, 08:46:47 pm
content: Quote from: kwass on August 26, 2025, 11:43:13 amInteresting. But $18 each !

author: artag
author_rank: Super Contributor
timestamp: August 26, 2025, 08:51:25 pm
content: Quote from: CatalinaWOW on August 26, 2025, 01:45:17 pmNice ! Yes, I think your design is still the best option. Need to get some more resin.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 26, 2025, 09:43:58 pm
content: Quote from: artag on August 26, 2025, 08:51:25 pmBe thoughtful when making adjustments. The parameters were selected to be easy to measure, which makes it a bit confusing to adjust sizes. For example to change the effective inside diameter of the shaft you adjust either the tooth height or the outside diameter. The inside diameter is the outside diameter minus twice the tooth height.