"Stacked slices" build for complex shapes

openvsp.org/
www.iforce2d.net/sketches/stac...

[@JARC99_]

Your build technique actually helped a lot in my recent aircraft builds. If you are interested I wrote a Python script that uses the OpenVSP planar slice function to extract the aircraft cross sections and export them directly as .dxf file so that you can cut them with a laser cutter or router. I mostly do my slices along the x.axis, but the script can also handle slices in the y-direction. Thanks again for the great content :-)

[@tenlittleindians]

As much stuff as you pump out, you must never sleep!

[@PorscheMonster]

Excellent Video! Thanks for providing some of the aero technical detail as well!

[@markgreco1962]

Love the build vids, Keep teaching us !!

[@MichelPASTOR]

Very nice project. I will have to try this software. Looking forward to your next build videos and maiden :)

[@RobisonRacing68]

LOL! Awake and watching still! Okay watched the WHOLE vid. I didn't realize you were actually building the plane until you did. I love your projects Chris. I could never do them myself but it's fun watching you solve problems. I learn stuff :) - Lauren

[@AndrewNewton]

Brilliant Chris.

[@catallaxy]

Love your videos! Very inspirational.

[@GeorgeInAShed]

great idea! I might have to try it!

[@stofffpv3128]

Brill..your building skills getting better every plane..you obvs been quite busy on this one..looking forward to next episode

[@JakeBullit123]

Great video.

[@thenatedog]

Another thing i have done is taken an old scroll saw, removed the blade and put a hot wire into it. Its already a rigid piece of equipment made for that type of cutting and you can adjust how tight the wire is with adjustments already on the machine.

[@electronic7979]

Excellent project

[@didactylos4diddy474]

That's very interesting software. We used to create hull profiles for moulds using horizontal slices way back when, but that was done the hard way with plans,callipers fretsaws and a lots of planing and sanding. Never thought the slice system could be used to create a plane. :)

[@iforce2d]

Interesting what you can assemble from carefully made parts eh :) I think this video series probably influenced me somewhat: kzbin.info/www/bejne/omq4k6GAoc2lfqM

[@TomFYouTube]

Very interesting. Thanks for sharing!

[@ChristopherF_1971]

This is awesome

[@ardufpv4373]

Thanks Chris. I always wanted to build a solar glider. Now I know where to start at least.

[@mirko1998]

That is an interesting way to use the boolean modifier in Blender. Very clever^^

[@avejst]

Interesting project Thanks for sharing😀👍

[@mav9882]

great video and awsome looking plane. I love the look of the blended wing and it would be nice to have a go at that blend file.

[@iforce2d]

I added a link to some files in the description

[@mav9882]

@@iforce2d sweet thax hope the plane flies great

[@hoggif]

That's an interesting project like almost all your projects are. A huge amount of work in making a plane! Much more than simple multirotors that one can put togeather in an evening from commercial frame parts.

[@iforce2d]

Yeah, most of the work in making a multirotor fly is done in the firmware :)

[@gatisozols]

Just as I was about to start working Chris uploads a new video! Great :D Work will have to wait!

[@crabsodyinblue]

retirement should've started at 50...so much to learn,test out and enjoy... so little time. thanks chris :D

[@pauljs75]

I think the sweep would work, but you have to clamshell the top and bottom of the fuselage over it at the center to anchor it, the angle thing with the support rods would prevent it from sliding in from the sides. Angle drilling through the sections is tricky, but seems reasonable that it could be done with a jig. Given what was shown here already, it seems like it's possible with the skills you already have. I've done something similar with Blender and just messing about (idea more around 3D printing ribs rather than templates for full sections), but never did the aero sim programs or getting around to actual construction. (I wonder if there's some trick that would let you reverse some steps and go from Blender to those?) I think eyeballing reasonable-shaped airfoils would still work, but not as efficiently as something with more math behind it. Files from "SkyFry" at Thingiverse gives an idea of my oddball approach.

[@Mehmetcan93]

Thanks a lot

[@hilldaflyer4593]

Still watching... very interesting.

[@larrywatts4585]

Always Interesting to see the design considerations and tools as well as the actual construction with second thoughts! Looking forward to following the progress. Will she FLY??

[@iforce2d]

I think she will fly but with a higher wing loading than I wanted, so will have to be moving pretty fast, at least as fast as the mini talon I'm guessing. That's why I'm waiting on a motor for it, I only had 2212 size motors sitting around but I want something a bit more grunty (ordered 3536) that will also help put CG back a little more.

[@aeroakram]

This video certainly deserves a "like" from everyone. IMO a plane built like this also needs some form of covering. Weight only goes up even more. Nice video though, keep up the good work.

[@iforce2d]

Yes, true. I forgot to mention in the video but my plan was to cover with fiberglass skin. Having seen the weight of it already though, I might just put some along the lower wing surface, and around nose and tail.

[@aeroakram]

@@iforce2d glass fibre lamination would mean significant weight penalty tbh. However, if the point of covering the wing is to make it stiffer (both torsional and lateral), then I would strongly recommend covering both sides. From my experience, covering just one side doesn't give one much gain in that respect. Instead of using fibreglass and epoxy, why don't you cover it completely using a light lamination film?

[@StigBSivertsen]

Pretty cool but very complex

[@cyberspooky]

Chris would you get much weight saving by skeletonising each wing slice before gluing?

[@TalkieT]

Are either of the programs you mention suitable for modelling the performance of an airfoil hard mounted to a car? (A front wing?) I have one half built (CNCed foam with 2 layers of fibreglass waiting for final layer of CF) but being able to model the min and max AoA would give me good input for the mounting method...

[@iforce2d]

Yes I think XFLR5 would be. Assuming the wing would be a constant section the whole way along, you would only need the airfoil analysis part, not the full 'plane' simulation. This might be a good place to start: kzbin.info/www/bejne/i2jWkoKZpN-jn5o

[@holski77]

I can help you 3d print molds for the wing you made. You can use expanding foam to create the wing.

[@Reach41]

Amazing find: computational fluid dynamics in a can! Will it work for landing gear? 😃

[@iforce2d]

It's not full 3d CFD, that requires a ton more setup and CPU power, and usually money if you want a decent software for it. These two programs (OpenVSP and XFLR5) work by first calculating the pressure at each point around the airfoil surface, for a specific angle of attack and Reynolds number. Averaging those pressures gives an overall lift, drag, moment for that airfoil, in a particular situation. This is done for many cases so that you have a large sampling of calculated AoA and Reynolds cases to cover the whole flight envelope. Then you can interpolate between the nearest of these to get an approximation for any case in between. To determine the lift, drag and moment on the plane as a whole, I think it just adds up the forces from the individual airfoils. What I like about the XFLR5 is that it also gives you a real-world velocity (shown in bottom right).

[@Melw44]

I just found your channel. Could you tell me what kind of foam that is? I like the look of the plane.

[@iforce2d]

It's extruded polystyrene, Knauf brand here in NZ.

[@_KreeD_1116]

Hi How much did you increase the template?

[@jeffbluejets2626]

Have a damaged PC-21 wing here I'm trying to get rebuilt and have so far only tried reproducing the rib shapes using Fusion 360. Idea being I can access the two end formers (root and tip) and need to "average" the taper to give the resultant shape and size of the remainder. In your experience with the program you used here, do you think that might be possible with this OpenVSP?

[@iforce2d]

Actually I think it might. You can define the airfoil for the root/tip of each section. How you would get the result out of OpenVSP is another thing though...

[@jo2lovid]

Great looking design Chris. will the landing gear be strong enough? ;-D

[@iforce2d]

On this one I'm worrying more that the motor would be ripped out when landing if I don't use a folding prop :)

[@Migueldeservantes]

Incredibly interesting... I have seen some people outside of the us use this type of fabrication technique... and it is well know around the modeling circles... What I don't know is why didn't your hollowed more the wings! I mean you where perfectly capable to literally make them next to or equal to a monocoque construction style... that would have take a good 40% of all that weight.. The Skywalker use 4 spars... two on the leading edge of each wing and them as permitting one a cross about 20% from the leading edge and other about 60% making it somewhat capable to take some stress... "I usually just cover the entire leading edge with fg... and increase rigidity about an other 70% making the plane suitable to handle speeds of over 140 Kmh...

[@iforce2d]

yeah there are definitely some things that could be improved on next time

[@Migueldeservantes]

@@iforce2d Thanks for the prompt reply! best wishes!

[@ir0nm8n]

Wow, that's a really interesting project! Have you thought about creating 3d printed molds? (Could be printed in many parts that screw together :)) Edit: after seeing how large this thing turned out, this probably wouldn't be really feasible :)

[@iforce2d]

One day I would like to try proper molded fiberglass, 3d printing might be helpful for some part of the mold.

[@ehsanbaninajar5901]

So do you think it's possible to use 4cm thick xps foam for building this plane to get a total 2 meter wingspan? should the fuselage width and also changed? I may go with this design size with a 2820 motor, I would love to know your opinion on this, thanks

[@iforce2d]

Sure. The fuselage would no longer be cylindrical, but you could always trim it down however you like with sandpaper. I'm using a 3536 motor for mine, I think 2820 might be a bit small, especially if yours will be 33% bigger.

[@ehsanbaninajar5901]

@@iforce2d Thanks a lot for your reply Chris, I think I will make the fuselage a bit longer to be sure I wont have any problem with the CG. The motor I wanted to use is a sunnysky x2820 800kv which on paper has more power than the Turnigy D3536 910kv (is this make sense or you think it's just company advertisement?) so I think it should be ok. I hope for a long endurance plane. Thank you for the awesome stacked slices idea.

[@bobwebber8521]

Chris, what sort of foam are you using there to make the ribs? VERY complex program to learn i'm sure, way beyond me. Good luck.

[@iforce2d]

XPS building foam, here in NZ it's Knauf brand. www.knaufinsulation.co.nz/products/climafoam-extruded-polystrene-xps

[@shadetreehandyman]

I just discovered both Blender and OpenVSP... is there any chance you could elaborate on how you created the multiple planes in blender

[@iforce2d]

kzbin.info/www/bejne/f2OQimB4g9-AoNE

[@Sergiobd007]

It's funny because I've been thinking about doing this for a while, but I couldn't quite find a project that allowed me to do this. Thank you for your work kind sir :) EDIT: btw, could we get the stl file and perhaps the dxf too?

[@iforce2d]

I added a link to some files in the description

[@Sergiobd007]

@@iforce2d Thank you, you are doing god's work

[@iforce2d]

See also the comment I pinned when mentions how you can do the slicing in OpenVSP before exporting to .stl, it pre-merges objects that are in the same hierarchy too, so the first two steps are taken care of.

[@Smt_Glaive]

how long did it take you to learn the software and make the design that is shown in the vid?

[@iforce2d]

OpenVSP probably a day, QCad probably a day for basic use, XFLR5 a couple of days to fully understand what I was doing, Blender... a long time just to even scratch the surface :)

[@55Rumble]

Thanks for the video... I think I'll give vsp a go...BTW, Nice 'A-tail'! ;-) Lol...

[@icaruscomplex5588]

how did you export the out lines to dxf? I'm having trouble getting the export to work. Thank you very much for a great video!

[@christopherleveck6835]

Check out the highlighted comment it pointed me in the right direction.

[@icaruscomplex5588]

@@christopherleveck6835 Planar Slice is such a great tool, thanks Christopher, how do I go about printing out the Slices?

[@christopherleveck6835]

@@icaruscomplex5588 I'm not sure yet. I've been using open vsp for a little while. I use it to make wings so basically I can set the root cord and airfoil and then the tip Court in airfoil I can build in a little twist and then pretty much from there I will export that is an STL file and then I'll use something like tinkercad even just to cut the ends off so I get the the root in the wingtip airfoil and then I'll use those two to cut my wings that's as far as I've gotten.....

[@christopherleveck6835]

@@icaruscomplex5588 I'll share a tip for cutting tape wings that works for me... It's hard to cut the airfoil into foam evenly because you need one side to cut faster than the other so you start at the leading edge and end up at the trailing edge at the same time.... So I draw the outline of the wing on the table and I extend the leading and trailing edge out until they meet. I screw a fishing swivel into the table at that point and attach one end of the wire to a line that I tie to the swivel. Now when you start cutting you only have to worry about the one end. As you guide the wire over the patterns you will enter and exit the foam on both ends at the same time.

[@icaruscomplex5588]

@@christopherleveck6835 thanks for the reply, I'm not sure how to use the STL file, I do not seem to know how to export over to QCAD, so I use the airfoil tool online and print out the airfoils on there, also I have not figured out how to cut foam properly either as you have, If we can do what he did here it would be so great. I hope he does a in depth tutorial one day

[@austntexan]

Since you've got it all cut, you might consider just using it as a mold and make it out of glass?

[@iforce2d]

One day I will try proper fiberglass molding, but not for this one. Maybe for that other flying wing design. But I need a lot of practice with the techniques first, will have to do some other smaller things to begin with.

[@buckstarchaser2376]

What kind of foam is this? It doesn't look like the standard insulation stuff.

[@iforce2d]

Extruded polystyrene. Here in NZ it's Knauf brand usually. www.knaufinsulation.co.nz/products/climafoam-extruded-polystrene-xps

[@Smt_Glaive]

man i tried delta wings a lot... they dont fly well unless something is done correctly...they are very sensitive.. i never got any design correct. the ones that did fly well flew so coz god knows why...

[@iforce2d]

Yeah I can imagine the plank style planes are very touchy in pitch. That's why it was not my first plan, and ultimately I suppose I'm better off going for the regular long-tail style.

[@erlconradgagni1623]

Hi what kind of foam is that?

[@iforce2d]

It's for building insulation, sold by Knauf brand here in NZ.

[@asteriondaedalus6859]

For your wing, you might want to build a cnc to make either a foam plug or mold. You might only need a dremel based thing, so you can build something on the cheap. Something like kzbin.info/www/bejne/f2jaoJ-ka9qljLs

[@iforce2d]

I made a little CNC a couple of years ago actually kzbin.info/www/bejne/fIqnoHeje7KBaNE I'd make a bigger one but I think the use I would make of it is not really worth the cost. The small one was enough to let me learn about how it all works which is the interesting part for me, the experience of building a big one would only differ in money and garage space.

[@landlifem5872]

I know it's probably not the style you're after, but canards may help out with your CG issue??

[@iforce2d]

I think once the tail goes on it will be ok. It should be easy enough to change the length of the tail to suit.

[@brooklyn_uav4589]

You can try 3D printing the tip of the wings.

[@markgreco1962]

He is not a fan of 3d printed parts. I have been trying for a year and a half now

[@iforce2d]

3d printing has its place but I don't think things that will take an impact, or aircraft parts that will be under bending or torsion, are it. If the part will only be compressed would be fine I think. Now when it comes to making a plug for a mold, 3d printing might be just the thing :)

[@stephengloor8451]

For a plank you need an airfoil with a low pitching moment commonly called reflexed. Martin Hepperle had a website which is still up devoted in part to tailless aircraft - www.mh-aerotools.de/airfoils/index.htm

[@iforce2d]

Yeah the airfoil I have is not ideal for plank, which is another reason I should probably just continue with making a regular tail. I think the reflex could be added with elevon trim, but with quite an efficiency hit.

[@stephengloor8451]

iforce2d Yep probably. However is the drag of reflexed elevons less or more than the drag of the tail? I don’t know. However I am pretty sure it will fly a lot better with a tail.

[@atheera349]

what is the name of the glue you are using?

[@iforce2d]

gorilla glue

[@atheera349]

@@iforce2d is it the one for all purposes? I appreciate it if you add a link to buy it.

[@iforce2d]

I buy it at the local hardware store, it's just called gorilla glue. www.mitre10.co.nz/shop/gorilla-glue-premium-3-hour-cure-500ml/p/370831

[@christopherleveck6835]

Do you ever use water when using gorilla glue? I keep a spray bottle with water and give it a light spray then put the pieces together exactly the same way you do.

[@iforce2d]

Not like that, but I do breathe on it sometimes if I want it to foam up - not sure that it really makes any difference though.

[@christopherleveck6835]

@@iforce2d I think it needs some moisture to cure completely but then again, i'm not using the same bottle you are......

[@benedictreimann1631]

Wow thats a complex build

[@iforce2d]

Yeah, I'm not totally sure it was worth it, but interesting to try once at least :)

[@noraajagger4239]

here is a different take on fuselage construction kzbin.info/www/bejne/nJqWdHSqpdt9gNU with a hot wire cutter

[@ftaliyfpv692]

I Try to repeat it with skywalker x8 ... It so hard

[@iforce2d]

yeah that would be pretty tough!

[@iforce2d]

I think you need a plane that is designed from the beginning to be built with this method.

[@thenatedog]

Awesome, cant wait to go watch the maiden, i see its live. I just maidened my hot wire cut 4kg f-100, slope soarer, check it out on my channel.

[@blancsteve4819]

A lot of that weight is glue ! Make a mould and fill it with home made foam.

[@iforce2d]

Yeah there is quite a bit of glue in there for sure. Although if you get it really thin it's not too bad I think. I actually bought some of the gap-filler foam in a can recently to fill gaps around my kitchen where crickets were coming in and driving me crazy. Is that what you mean? It's fairly light and easy to work with, but I think hard to ensure an even distribution.

[@blancsteve4819]

What is the best foam for modeling aircraft ? There must be hundreds of products...one of them might be perfect. Even some of the semi-industrial setups might be worthwhile. Polystyrene has been round for ages. How hard can it be to Do it yourself ? @@iforce2d

[@BigMeanyVids]

cool but i'm too lazy to do old school building like that. I'd just 3d print it. Not as durable but easier. :) Close to same weight also.

[@iforce2d]

Only good for one flight though eh.... :) I'd be surprised if you could make something anywhere near as durable at anywhere close to the same weight.

[@BigMeanyVids]

@@iforce2d I've been surprised that the weights can come close to balsa planes of similar size. Less durable for sure but should not matter much for experienced flyer such as yourself. Quicker to build since I don't count print time since I'm doing other things. It's got me excited about the hobby again anyways which is a feat after 15 years in it.

[@mr.sandman4782]

Is there a way you can make the hole slicing thing but take the slices and CNC cut foam pieces. Then glue the foam pieces together then lay carbon fiber (or fiber glass) over the whole foam plane (the one you actually wanted to build). When the carbon is set and sanded and finished drill a hole and pour acetone to dissolve the EPO foam. I have been thinking about doing this for a while and i thought you might like to hear it and maybe tell that it wont work or something. Thanks for the video learned a lot.

[@iforce2d]

As long as the CNC can cut angled holes (ie. not a plain old 3-axis machine) for positioning pins/spars and keep the edges nice and clean it would be ok. Although I would be inclined to just leave the foam inside and not dissolve it.

[@JyskMaker]

Use a CNC :-) machine

[@iforce2d]

no kidding... of course I would if I had one large enough

[@JyskMaker]

@@iforce2d Build one :-)

[@Reach41]

This has nothing to do with aerodynamics, but it might interest you on a different topic. Ignore all the minutiae, looking instead for basic concepts about composite construction using seemingly very weak core materials. www.sciencedirect.com/science/article/pii/S0264127519307506 If weight was a large enough driver, you might be able to switch from a high density foam to a hex core material, filled with something removable (wax?) to make it machinable on your router.

[@lucywucyyy]

you shouldve made alooooot more holes through the foam i think you couldve hollowed the whole thing out before gluing it together or maybe you need some less dense foam?