Print to Ride

[PonoBill]

Hopefully this makes the idea a bit more clear. The tube shown is a Rockwest 3K with a .375 (9.524mm) ID and .495 (12.57mm) OD. I used the tube as a tool to cut the shroud so it can slide in with both an internal ferrule and outside cover. This should make the joint very strong. We initially had a problem with ferrules breaking with Ke Nalu paddles. We solved it with an internal reinforcement strip of carbon perpendicular to the paddle blade that was embedded in the foam and went from the tip of the ferrule to the base of the blade. It was a pain in the ass, adding a step to the fabrication process.

The solution here would only be reasonable with a 3D-printed part.

The tube slides in to within about 1/2" of the mast. We'd probably print the whole part with 60 to 100% (solid) infill.

Where did you find a male-male carbon plug? I've researched a bit and can't find anything that isn't related to gay porn.

[PonoBill]

Raining like hell, no wind. So I'm screwing around.

[surfcowboy]

This is all looking really cool guys.

I think this wing/fuse/mast thing is really cool. What's the reason everyone puts the wing out in front of the mast anyway? I know ride engine/slingshot had a foil you could mount like this for Wind Foiling I think, right?

[PonoBill]

Actually, the Axis Advanced fuselage puts the mast in almost the same place.

[Admin]

This is all looking really cool guys.

I think this wing/fuse/mast thing is really cool. What's the reason everyone puts the wing out in front of the mast anyway? I know ride engine/slingshot had a foil you could mount like this for Wind Foiling I think, right?

There are some products that use partially wing-enclosed mast mounts.  One in kiting uses no tail wing and is a true mast integrated flying V.  Super interesting, but also very limiting and not for me.  The ones with stabilizers have alway been done with spade style wings (super low aspect) where the leading edge is super swept and the trailing edge flat to meet the mount.  These were commonly used as a two mast position, entry level / budget type wings that had very little faring, etc.

Have a look at this: https://www.ecalc.ch/wingdesigner.htm .  Change just the sweep from the default of 15 to 0 and see what happens to AC.  It moves forward dramatically.  This is what happens with higher aspect straighter wings (most current wings) This is why spade wings are not well suited for this design.  If the mast is one with the wing, that moves the whole wing towards the tail of the board (if nothing else is changed).  If you also have a spade style wing moving things further back, that is not great, especially for short tracks.  Now think of it from a current wing perspective.  As things have moved toward lower sweep, higher aspect forward AC/CL wings, we have also seen a rise of advance fuselages, etc. which pulls that back again. This is an extension of that.

They call it the "advance" fuselage because they are looking at it from the perspective that the mast advances closer to the front wing.  From my perspective it is the "retreat" fuselage.  If the mast stays in the same location in the tracks, the front wing moves back.

This design is selfish.  All about the Swim Missiles and soaring.  What would a complete kit look like if there were minimal power going in, low drag was critical and enough lift was available at swim-in , no-wave, minimal-pump, downwind-swell speeds?  How could we reduce vortices at these low speeds (where the are the most detrimental)?  How could we improve stall characteristics?  What could be done to exaggerate weaker arm/body pumping?  With my research so far, and borrowing plenty from the great products that we have all had access to,  this is my best guess.  It is still far from even V1 . This is simply what I have adjusted and made buildable since this: https://www.standupzone.com/forum/index.php/topic,38282.msg438284.html#msg438284

[Admin]

Bill, that is sweet.  We have so much more real estate with the front wing for support and locking that we have a ton of options.  It is shocking how stiff even a cheap 5 mm pulltruded carbon rod is, and we have room for much larger stuff here. The design I posted is an 1100 that fits between an Axis 1150 and ART 1099 in terms of both area and volume.  Obviously the area near the root has the majority of both.  That leaves us a lot of room for reinforcing the mast and making sure that the unwanted flex types are minimized.  I also left a vertical portion to the exposed mast well.  That is going to be used for horizontal hardware to completely secure any mast slop wit no shimming.  I have a model built which is really cool but needs tweaking.  I think there are a lot of baby gains that we can make that may add up when fully realized. 

On reading, it is clear that I need to improve my wing/fuse fillets but I painted myself into a little corner there in Fusion.  I need to correct that.

[PonoBill]

Yeah, I tried to add fillets at the wing/shroud and shroud/mast junction but Fusion gave me errors with impenetrable reasons. Popping the tip up in the dialog just said "try a different fillet" more or less--not much help. I'm a little concerned about a filet around the mast anyway. A very tin fillet lip would be prone to breaking.

Bambu says my new printer is on the way. This being outer Rangoon in Bora Bora I may see the printer in time to ship it to Hood River. The Prusa I have here is suffering from extreme blobbing. I'll fix it, but this is the kind of crap that Bambu has solved by going to an integrated hot end/nozzle that a lot of printing dweebs are whining about. 15 bucks for a solution that slips in with 2 minutes of fiddling and works every time vs. 5 bucks for a nozzle that might take you four hours to repair after applying too much torque shifts the hot end in the extruder body and the blazing hot nozzle (the only way to get them off once melted plastic has flowed through them) burns you a few times. Then again, economics is rarely a strong suit for geeks.

[PonoBill]

I'm going to print this as soon as my printer shows up or the new parts for my Prusa arrive. I think it has potential and I want to see what kind of dimensional accuracy I can hold. Might have to loosen things up. I'm working on a wing for this, basically a 999 clone. It will have to be printed in four sections plus the root section unless I farm it out to a shop with bigger equipment.

[Admin]

Here is one of the prints I did yesterday (I keep seeing little things that I want to improve).  I am really happy with this direction.  I can get two 4 mm bars in with no problem.  The tolerances are very good for solids, but cavities do retract a fraction, even when supported fully.  It is easily adjusted for, but may require a few test prints.  The result is very exciting.  This is going to work.  The fuse attachment is super strong and stiff.  The prints are clean even without sanding (although, I will sand) and it just screams "ride me".  Bambu tech support has been very patient with me and has coached me through a lot of settings and tweaks, many of which I would have never suspected.  The issue there is that the setting name and description often does not match what the setting does (or what real value it offers).  They also essentially advised to unlearn what you know about printing with other materials.  I am forcing myself to take the time to get each part right, but that is made easier by a frozen Gorge. 

[Admin]

In also added collar guides on both sides that can mate to small fuse notches.

[PonoBill]

I'm pulling my hair out trying to get splines to work as guide rails with the airfoils generated with Dat to Foil. I'm getting the error that the rails are not connected to the foil profile even tough they're snapped to the ends. I tried adding a construction line through the middle of the foil to be certain I have a snap to connection but no dice. WTF.

[Admin]

First press fit today.  No glue or sanding yet.  I learned a ton from this and I (again) see a lot of ways to make this better.  I figured out how to get my 4mm carbon rods (which are a bit over) into my cavities (which are shrinking to a bit under) with a super snug fit.  I was concerned about placing the rods too close together, which I thought might compromise strength. but no more.  I see now that I can get can get four 4mm bars in each side with great coverage.   Stoked on that!  I also need to clean up the trailing edge in my file.  It is still to thin for the printer to manage well.  Next up I need to figure out how best to glue and finish.  I am wide open to suggestions on super durable adhesives, etc. 

[LaPerouseBay]

I am wide open to suggestions on super durable adhesives, etc. 

https://www.sika.com/en/brands/sikaflex.html

[tarquin]

Epoxy. Sika is good for some things for sure. But very messy and hard to clean up. It's quite thick and not great for tight tolerances.
 Is this to glue the sections of wing together?
 Great progress

[Admin]

Hi Guys,

Yes, this will be for the rod holes and joining the gaps.  Also interested in some leveling if need to smooth the seams and possibly a light surface sealant.

Thanks