Maybe use countersunk screws like those
Or is the head diameter of those screws wider than the ones you use?
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unfortunately no, this won’t work. m4 countersunk screw you showed has a 8mm diameter head while the cylandrical bolt head type has 7mm which is already too much
unless i find a cylandrical bolt head that has a small width head!
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maybe something like this?
my main issue isn’t clearence, but i assume that since there is less than 0.5mm that when the cnc cuts at that point it will just chip and break off, so if i do like this then there is no risk 
@Creavenger
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I just briefly skimmed over it. I’ll have a closer look later today. 
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That solution definitely looks better.
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Looks really good! you can also round the sharp corners with some fillets btw.
the small edges will be chamfered though, because this is easier to machine.
And the coupler will be a modiefied stock one?
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Great idea, I’ll add fillet to the corners as well.
What how many mm of fillet do you use? The stock had 0.40mm so that’s what I put but I have no realistic idea of what should be done.
I shared the files just two post above!
I modified them, yes.
I really do want to 3d print this to make sure it all fits 
soon! almost have the money for my ender 5 plus.
I don’t really know how to assemble all 3 objects. @Zwak helped me out but I didn’t try too much.
I believe you have to open a new f3d tab, insert the files from your f3d “recent projects” via the top left hand hand corner, and then add joints so they align.
I couldn’t work out how to add multiple joints and neither do I know how to do that expansion thingy where the you have a slider that separates the part and reassembles… Like an explosion effect. I’ll add you to our telegram f3d chat 
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I mostly use 0.5 mm chamfers for the edges, for the fillets on the bolt head cutout edges I used 2 mm in this case. You can use what looks good to you.
The coupler looks nice, wasnt sure if you wanted to machine them or they were a modified standard coupler, which is indeed the easiest.
Im still learning fusion too 
I just used basic joints. I am still used to the solidworks mating system which works slightly differently.
And thanks would love to be in the f3d chat 
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Finding a preexisting one that has a ~20mm diameter where the prongs don’t take up more than 10mm is very hard to find, In fact I haven’t found any. They already cost 80euro standard so I much prefer having them machined from scratch by you and paying a similar price 
I don’t expect this to be a cheap part of the project, already I have the chance to know you and have have the tools available is amazing 
Nice job. Keep in mind that the middle portion of the coupler which is referred to as the spider, is usually polyurethane. This provides for parallel misalignment of around .1mm and about 1 degree of angular.
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Thank you!
Could I possibly get away with making the spider in TPU @100% infill? That’ll what I was hoping for 
Unless someone can make a mold based of my file 
Print file, clean up the print, make a silicone mold, pour urethane
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Cool vid, definitely a quick and dirty mold method. TIL
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Just the way I like it.
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I remember you posting that a long time ago, such an easy way to do it
Do you need a vac for the urethane though? It to remove the trapped air bubbles but surely one or 2 bubbles wouldn’t matter?
If you want to get fancy with your castings yes ultimately you would mix your material then pour your cast and put it in a pressure pot while it cures. That compresses any bubbles so they are microscopic. But you can get away without that for a ton of stuff.
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Would you suggest the method Al linked above you better buy a 2 part silicone to make the mold? I see there are different shores for silicone, does this matter for the mold?
The technique Al posted is using silicone caulking. It cures by pulling moisture from the air, by adding water to it that speeds the setting. This process is going to be the cheapest route for you to go.
Looking at your model though there is a fair amount of details and counter sunk holes, I think a catalyzed silicone will capture those better then a caulk mold. Pushing rubber around a 2x4 is much easier then what you have.
As fair as shore hardness goes think of it like skate wheels you can get hard or soft duro. You get more support from a harder rubber but the demolding is tougher. In your case any silicone from 20-40 shore should be fine.
Making a simple (fully sealed box and doing a dump mold will still work for your model. Make sure whatever technique you use you properly affix your model to the board. You don’t want it moving or floating while putting on the silicone.
Vaseline or soap make for good release as opposed to splashing soapy water on it. If you go with straight soap let it dry first before putting on any silicone. You can use a hairdryer to speed it up if needed.
Hopefully this long rambling nerdy reply helps and isn’t confusing. But you’re in my wheelhouses now. Lol.
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That’s a decent vid showing more box mold how tos.
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dude this is super helpful! i just don’t quite understand how to make the mold with my weird shape… especially the knobs on top
it’s really small btw, only 8mm high, 22mm wide