Print to Ride

[PonoBill]

Oh, and hey admin--did you get some special support interface material to print PA-CF? The temperature range of the Bambu Labs stuff is wrong for working with PA. I've ordered some stuff from Overture that's intended for use with PA12/6 that should work. Matter Hackers has some interesting support material called Ionic, which works both as a breakaway and soluble (in water). I've ordered some but it ain't cheap. $450 for 3KG. I bought a .75kg spool for $129 to try it. Max temp is 250C, which is a bit low for PA-CF, but might be OK.

You've probably figured out by now that getting the PA-CF filament as dry as possible is critical. I'm using the ability of the Bambu printer blate to bake filament since Diane banned me from the toaster oven. I have a filament dryer box on the way, the AMS just uses a desiccant to keep humidity low--it's not a viable substitute for pre-baking.

[Admin]

Oh, and hey admin--did you get some special support interface material to print PA-CF? The temperature range of the Bambu Labs stuff is wrong for working with PA. I've ordered some stuff from Overture that's intended for use with PA12/6 that should work. Matter Hackers has some interesting support material called Ionic, which works both as a breakaway and soluble (in water). I've ordered some but it ain't cheap. $450 for 3KG. I bought a .75kg spool for $129 to try it. Max temp is 250C, which is a bit low for PA-CF, but might be OK.

You've probably figured out by now that getting the PA-CF filament as dry as possible is critical. I'm using the ability of the Bambu printer blate to bake filament since Diane banned me from the toaster oven. I have a filament dryer box on the way, the AMS just uses a desiccant to keep humidity low--it's not a viable substitute for pre-baking.

Hiya Bill,

That is a cool direction!

I did get the green support filament  (actually kind of yellow) but I am not using it anymore.  Using the carbon for everything makes the prints go faster (a lot) and it comes off very cleanly.  I am finding it helpful to raft up 9-12 layers to get things away from the plate.  That was causing me some problems.  It is also helpful to trim a few mm of of the trailing edge in Fusion before printing.  I am sure you are on that already.  Were you getting blobs with undried filament or something else?

Working on some improved tools and a mast well right now. 

[PonoBill]

That is a cool direction!

I did get the green support filament  (actually kind of yellow) but I am not using it anymore.  Using the carbon for everything makes the prints go faster (a lot) and it comes off very cleanly.  I am finding it helpful to raft up 9-12 layers to get things away from the plate.  That was causing me some problems.  It is also helpful to trim a few mm of the trailing edge in Fusion before printing.  I am sure you are on that already.  Were you getting blobs with undried filament or something else?

Working on some improved tools and a mast well right now.

Actually, I realized I need to modify the trailing edge this morning. I'm going to thicken it to about the width of the walls, and round it off a bit. Sanding works also, but I want the parts to be finished as much as possible right off the printer.

Yeah, switching filaments slows things down, but I get a nice, clean break and any remaining bits of support wash off quickly since the fine points dissolve almost immediately

I get blobs and rough spots with undried filament.

[Admin]

It is a learning process for sure.  Once in place, though, it should only take an hour of work time to do a foil.  I keep seeing ways to improve each step.  V4 of my alignment tool is getting printed now.  It has two flat surfaces and some offset to combine dual sided alignment and a solid, abrasion free,  cut platform.  Not sure why that didn't occur all at once, but....

It is crazy dry in the house due to heat.  My desiccant packs are still new looking a month later.  Bora Bora has to be tough for that.  The name actually translates to "Moldy Balls".

[Admin]

With masts now available at 2.5 lbs, there is no reason we cant have complete foil systems at under 4 lbs (Mast, foil, fuse, tail and all hardware). 

[PonoBill]

What masts weigh 2.5 lbs??

[Admin]

What masts weigh 2.5 lbs??

NoLimitz.  I am doing the Takuma adapter next. 

https://www.nolimitz.com/foilmasts

[PonoBill]

Some refinements on the original fuselage ideas. Narrower, a little more refined shape, and the trailing edges of the airfoils are rounded. Can you tell I'm still struggling with fucking lofts and splines? I suspect the culprit might be the dat-to-spline tool. If I don't get it hammered down soon I'll probably start tracing the airfoils, and wouldn't that just suck. Anyway, the mast-to-fuselage tube connection is bomber and I can't twist it even with just hot glue. The trick is the little divot on the male part of the plug. It creates a wedge of glue that resists twisting--same thing we did with Kenalu paddles. Only this shaft winds up being glued both inside and outside since it inserts into the female socket up to the mast. If I really wanted to get crazy I could V-notch the end of the tube and use the mast as a key. All this stuff reads like a porn script. The mast cutout for an axis aluminum mast fits tightly but well. A little persuasion with a mallet and Bob's yer uncle. I haven't figured out how to do a countersink on a curved surface yet. It's obvious that the hole tool understands the issue, I just haven't figured out what it's asking for.

[PonoBill]

bottom. The live piece is even prettier--or it was until I broke it. If I jump up and down on my goofy test jig you can indeed break one. It was 20% infill and a 3-layer wall so that's not too surprising.

[PonoBill]

The NoLimitz masts have always been tempting. No adapter is necessary if we go with my fuselage approach. Why add a bag on the box. Bare nekkid.

[Admin]

bottom. The live piece is even prettier--or it was until I broke it. If I jump up and down on my goofy test jig you can indeed break one. It was 20% infill and a 3-layer wall so that's not too surprising.

Hiya Bill.  Are you still printing in Blue PLA?  If so switch to solid carbon (PA-CF) for the center section with zero infill and test again.  Nothing will break, even press fit/no glue.  That is also important because the materials retract differently and you will need to redo your tolerances when you switch.  You will need some kind of fuse key on both ends to get/keep the rear wing angle perfect.  glue notches or perf holes are a great idea.  I want the root component ready to accept anything we throw at it.  Any mast head, adaptor or bare mast should fit with a simple extrusion.  Mast attachments (and bare masts) are all really basic shapes with very little dimension variation and once the universal head block is done we can use any or all.

[PonoBill]

Yeah, I think you're right. This one is PA-CF. The cutaway for the mast is too tight. I couldn't get it inserted even with the BBFH (big, big fucking hammer).

I'll probably take the layer height down to .16mm to get a better surface finish. Easy enough to sand it smooth, but I'd like it to be smoother right out of the printer. If I were using a single filament I'd probably do adaptive layering, but I like the yellow support filament.

[Admin]

Yeah, I think you're right. This one is PA-CF. The cutaway for the mast is too tight. I couldn't get it inserted even with the BBFH (big, big fucking hammer).

I'll probably take the layer height down to .16mm to get a better surface finish. Easy enough to sand it smooth, but I'd like it to be smoother right out of the printer. If I were using a single filament I'd probably do adaptive layering, but I like the yellow support filament.

Looks cool!  I have been doing a bunch of smaller mast well models and I finished the (uncut or rodded) Alien wing this morning.  Lots of stuff to test, break and adjust.

How much material below the base of the mast well base will be needed?  I matched Axis at 6.5 mm for now.

How much non tapered thickness surrounding the exposed areas of well?  I went with 6.5 mm again and mostly that rolls off into more substance.

How deep does the fuse plug (even if molded) need to penetrate into the wing.  I went with 60 mm. 

There are a million choices, and I can be an eternal editor.  At some point I gotta bring it in for a landing. 

[PonoBill]

I have questions:

Where did you get the carbon mast tube? I can't find 19mm OD, 15 ID anywhere. The 19mm sounds suspicious. Some kind of sports thingy?

This PA-CF shrinks dimensionally quite a bit. Have you settled on a percentage? I increased the size of the mast cutout by offsetting the outer edge of the mast cutting tool by 1mm and decreasing the size of the inner plug by 1mm. It's not quite enough. I'd like a tight fit but I still can't hammer it into place.

I also went too far on scaling down the chord where the mast attaches. I want the front of the shroud to start at about 33 to 50% of the chord. The latest version is more like 75%. I guess that's not really a question.

This is though: Fusion 360 continues to seem random. Actions that worked an hour ago suddenly don't work. I thought perhaps I needed to be more careful selecting what construction plane I'm working on, but nope. Any words of wisdom?

You said you aren't using breakaway support material anymore. I have a tough enough time removing supports with the breakaway stuff. How are you making that work?

Here are my answers to your questions though, or at least what I'm doing right now:

q: How much material below the base of the mast well base will be needed?  I matched Axis at 6.5 mm for now.

a: I'm at 14mm.

q: How much non-tapered thickness surrounds the exposed areas of well?  I went with 6.5 mm again and mostly that rolls off into more substance.

a: Mine varies from 10mm at the back to 5mm at the front.

q: How deep does the fuse plug (even if molded) need to penetrate into the wing.  I went with 60 mm. 

a: What? my part is only 32mm deep. I'm at 14mm deep in the back and 12mm in the front except at the tip of the leading edge where it's just 7mm.

The breakaway stuff is very sensitive to the interior temperature. I've had it print perfectly, but last night I forgot to close the door and got this:

[Admin]

I have questions:

Where did you get the carbon mast tube? I can't find 19mm OD, 15 ID anywhere. The 19mm sounds suspicious. Some kind of sports thingy?

This PA-CF shrinks dimensionally quite a bit. Have you settled on a percentage? I increased the size of the mast cutout by offsetting the outer edge of the mast cutting tool by 1mm and decreasing the size of the inner plug by 1mm. It's not quite enough. I'd like a tight fit but I still can't hammer it into place.

I also went too far on scaling down the chord where the mast attaches. I want the front of the shroud to start at about 33 to 50% of the chord. The latest version is more like 75%. I guess that's not really a question.

This is though: Fusion 360 continues to seem random. Actions that worked an hour ago suddenly don't work. I thought perhaps I needed to be more careful selecting what construction plane I'm working on, but nope. Any words of wisdom?

You said you aren't using breakaway support material anymore. I have a tough enough time removing supports with the breakaway stuff. How are you making that work?

Here are my answers to your questions though, or at least what I'm doing right now:

q: How much material below the base of the mast well base will be needed?  I matched Axis at 6.5 mm for now.

a: I'm at 14mm.

q: How much non-tapered thickness surrounds the exposed areas of well?  I went with 6.5 mm again and mostly that rolls off into more substance.

a: Mine varies from 10mm at the back to 5mm at the front.

q: How deep does the fuse plug (even if molded) need to penetrate into the wing.  I went with 60 mm. 

a: What? my part is only 32mm deep. I'm at 14mm deep in the back and 12mm in the front except at the tip of the leading edge where it's just 7mm.

The breakaway stuff is very sensitive to the interior temperature. I've had it print perfectly, but last night I forgot to close the door and got this:

This is the best tube.  I ordered a few types including from the premium vendors and its not even close.  It is actually one of the nicest finished carbon products I have seen.  https://www.amazon.com/dp/B08J8FYJ7T?smid=ARU89Z0RN1J44&ref_=chk_typ_imgToDp&th=1.  I have two tubes here and just ordered two more.  My caliper picks up zero variation in ID or OD on either tube, either end, or at my cuts and it is super accurate and calibrated.  One of the "premium" ones was as consistent as a zucchini.

I don't think it is just shrinkage on the PA-CF.  I think a part of it is high nozzle temp and gravity in that instance before cooling.  The same tube horizontally will have the tiniest bit of sag while the vertical version is 100% true to spec.  It also depends on if you are using support inside the holes and drilling.  That is not a bad way to go although skipping it is nice.  There is a hole adjust feature in Bambu studio that allows you to adjust there.  I would avoid that.  It is hard to control and its a major time suck.  My 4 mm holes are 4.12 in Fusion and that works great at my print angles.  I did a test block for hole sizes and then realized that a modified version  would also make a great rod cutting tool.  I have that set up so I can straight cut 5 rods to length at once with the Dremel and the cuts are square.

Fusion is F'in amazing but quirky as hell.  Mostly because fiddly AI interference.  It tries to assume contextually what you want from a step.  Hate it and you cant entirely disable it, I asked.  The big one is selection.  If you select from your whole project (everything visible) and for instance use the move tool, it may auto populate "bodies" when you need "sketch", even though the sketched item is selected, and it wont let you move your sketch.  Easy to fix if you see it but until you do...  If you ever are having real trouble make only the part you are working on visible, select that and then move on.  Also, zooming way in is critical when making attachments. 

The carbon supports break right off.  Raft it up 10-12 layers to get away from the heat of the plate.  That helps everything a lot.