Velomobile design, engineering questions

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viznz2

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Questions about velomobile design

I'm chipping away at developing a velomobile design. Some understanding of applied aerodynamics for aircraft with near zero flow separation helps (sailplanes). Lack of skills and resources to formally model such separated flows with CFD, as applied to velomobiles...this held me back...maybe we can discuss on the Applied Aero... or CFD flow modeling for velo... threads.


For the other design/engineering issues I am a bit unfamiliar with bicycle design and there are no velomobiles available to interrogate/reverse engineer. So there are several questions, if anyone has thoughts.

1) Suspension/steering geometry.
- Camber
- Caster
- King pin inclination
- Toe in/out.

Are there common opinions about ideal geometry for velomobiles?

At looks like there are some similar values. The strut drawing that velomobeil.nl sent me, the axel looks to be angled up at 4deg. A lot of velo' photos show what looks like vertical struts and camber of -4deg.

If that strut is vertical, drawing a line from the top pivot down to the bottom pivot on the steering plate, looks like kingpin inclination is 5deg and caster is about 4deg.

The proximity to the wheel means that bottom pivot point can't shift much (dy) to increase kingpin inclination. The strut could be angled inwards at the top if the cost in cockpit width was acceptable. The castor does look it could be increased by shifting the pivot point forward, but I ignoring for now the kinematics of the system which includes the front linkage.

So are there opinions on ideal geometry? Caster and king pin inclination are much less than on a tadpole trike. Any opinions about that?

There are a couple of variations in strut design with different axel inclinations..that I know of. I assumed there might be more. Does anyone know what those variations are..? (length, axel position, axel angle, angle of steering plate mount area).

If we get past these ones we can look at Akerman angle and scrub angle....

A while ago I found a summary of the geometry ideas for velomobiles by an engineer at a symposium some years ago, but now cannot find it.....

2) Structural load cases for velomobiles...
Can anyone share a list of load cases and some ideas on the methodologies used? Applying loads to some of the complex composite shapes I can do, but I am starting from scratch on load cases.

I had a quick look and found some sources for references for bicycle load cases......

An Assessment of Bicycle Frame Behavior under Various Load Conditions Using Numerical Simulations
Derek Covilla,*, Philippe Allardb, Jean-Marc Drouetb, Nicholas Emerson
It's on ScienceDirect.com. Google the title, the link was huge, sorry.
One or two of their references may be useful.

INTERNATIONAL STANDARD ISO 4210-6
Cycles — Safety requirements for bicycles —
Part 6: Frame and fork test methods

One can also make/find a short list of critical load cases, rather than doing every single possible load case.

3) What are typical Q values in velomobiles?

4) Are velomobiles sensitive to pitch oscillations (squat/anti squat) from the pedal forces (pedal bob)? Do designers sometimes add an extra idler pulley to align the chain to the swingarm hinge point?

5) What are typical body shell GRP/CRP laminate stacks? The overall laminate, not at the locally reinforced areas.

6) Are velos with sandwich core quieter (urethane, klegecell/Devinicell/honeycomb)

7) What size rear wheel do most Evo-Rs have? How is it removed? I had a plan for the wheel to be removable to the front, which needed the swingarm to be morphed so the wheel fitted over it. But I'm thinking it might be easier to remove the swingarm with wheel.

8) Are there some long cage derailleurs that take up less space sideways ( Y axis)? Available space is limited for me and I do not have a flat floor running the length of the body. Maybe I can discuss the body in the applied aero thread.

More later...
Gregg
 
Hi Gregg, were do you live?
Maybe it’s best to by and drive a existing Velomobile to get some experience…
Is this a study-project?

Because my english is limited i tryed the deepL auto-Translation into german:
Fragen zum Design von Velomobilen

Ich bin dabei, einen Entwurf für ein Velomobil zu entwickeln. Ein gewisses Verständnis der angewandten Aerodynamik für Flugzeuge mit einer Strömungsablösung von nahezu Null ist hilfreich (Segelflugzeuge). Mangelnde Fähigkeiten und Ressourcen zur formalen Modellierung solcher getrennten Strömungen mit CFD, wie sie bei Velomobilen angewandt werden... das hält mich zurück... vielleicht können wir das in den Threads Applied Aero... oder CFD-Strömungsmodellierung für Velo... diskutieren.

Was die anderen Design-/Technikfragen angeht, bin ich mit dem Fahrraddesign nicht so vertraut und es gibt keine Velomobile, die ich befragen/umkehren könnte. Es gibt also mehrere Fragen, falls jemand eine Idee hat.

1) Aufhängung/Lenkungsgeometrie.
- Sturz
- Nachlauf
- Neigung der Achsschenkel
- Vorspur ein/aus.

Gibt es gemeinsame Ansichten über die ideale Geometrie für Velomobile?

Es sieht so aus, als gäbe es einige ähnliche Werte. Die Strebenzeichnung, die mir velomobiel.nl geschickt hat, zeigt, dass die Achse um 4 Grad nach oben geneigt ist. Viele Velo-Fotos zeigen so etwas wie vertikale Streben und einen Sturz von -4 Grad.

Wenn die Strebe senkrecht steht, sieht es so aus, als ob die Neigung des Achsschenkelbolzens 5° und der Nachlauf 4° beträgt, wenn man eine Linie vom oberen Drehpunkt zum unteren Drehpunkt auf der Lenkplatte zieht.

Die Nähe zum Rad bedeutet, dass sich der untere Drehpunkt nicht stark verschieben kann, um die Neigung des Achsschenkelbolzens zu erhöhen. Die Strebe könnte oben nach innen abgewinkelt werden, wenn die Kosten für die Cockpitbreite akzeptabel wären. Der Nachlauf könnte durch eine Verschiebung des Drehpunkts nach vorne erhöht werden, aber ich ignoriere vorerst die Kinematik des Systems, das den Frontkraftheber einschließt.

Gibt es also Meinungen zur idealen Geometrie? Nachlauf und Neigung des Achsschenkelbolzens sind viel geringer als bei einem Tadpole Trike. Gibt es dazu Meinungen?

Soweit ich weiß, gibt es eine Reihe von Variationen der Federbeinkonstruktion mit unterschiedlichen Achsneigungen. Ich habe angenommen, dass es noch mehr geben könnte. Weiß jemand, um welche Variationen es sich handelt...? (Länge, Achsenposition, Achswinkel, Winkel der Lenkplattenbefestigung).

Wenn wir über diese hinausgehen, können wir uns den Akerman-Winkel und den Scheuerwinkel ansehen....

Vor einiger Zeit fand ich eine Zusammenfassung der Geometrieideen für Velomobile von einem Ingenieur auf einem Symposium vor einigen Jahren, aber jetzt kann ich sie nicht mehr finden.....

2) Strukturelle Lastfälle für Velomobile...

Kann jemand eine Liste von Lastfällen und einige Ideen zu den verwendeten Methoden mitteilen? Die Anwendung von Lasten auf einige der komplexen Verbundwerkstoffformen kann ich durchführen, aber bei den Lastfällen fange ich bei Null an.

Ich habe einen kurzen Blick darauf geworfen und einige Quellen für Lastfälle für Fahrräder gefunden......

Eine Bewertung des Verhaltens von Fahrradrahmen unter verschiedenen Belastungsbedingungen mit Hilfe numerischer Simulationen

Derek Covilla,*, Philippe Allardb, Jean-Marc Drouetb, Nicholas Emerson

Der Artikel ist auf ScienceDirect.com zu finden. Googeln Sie den Titel, der Link war sehr umfangreich, sorry.

Ein oder zwei der Referenzen könnten nützlich sein.

INTERNATIONALE NORM ISO 4210-6
Fahrräder - Sicherheitsanforderungen für Fahrräder - Teil 6: Prüfverfahren für Rahmen und Gabeln

Man kann auch eine kurze Liste kritischer Belastungsfälle erstellen/finden, anstatt jeden einzelnen möglichen Belastungsfall zu prüfen.

3) Was sind typische Q-Werte bei Velomobilen?

4) Sind Velomobile empfindlich gegenüber Nickschwingungen (Squat/Anti-Squat) durch die Pedalkräfte (Pedal-Bob)? Fügen Konstrukteure manchmal eine zusätzliche Umlenkrolle hinzu, um die Kette auf den Gelenkpunkt der Schwinge auszurichten?

5) Was sind typische GFK/CFK-Laminatstapel für die Karosserie? Das Gesamtlaminat, nicht die lokal verstärkten Bereiche.

6) Sind Velos mit Sandwichkern leiser (Urethan, Klegecell/Devinicell/Wabe)

7) Welche Hinterradgröße haben die meisten Evo-Rs? Wie wird es ausgebaut? Ich hatte den Plan, dass das Rad nach vorne abnehmbar sein sollte, was voraussetzte, dass die Schwinge so umgestaltet werden musste, dass das Rad darüber passte. Aber ich denke, es könnte einfacher sein, die Schwinge mit Rad zu entfernen.

8) Gibt es Schaltwerke mit langem Schaltkäfig, die seitlich weniger Platz einnehmen (Y-Achse)? Der verfügbare Platz ist bei mir begrenzt und ich habe keinen flachen Boden, der über die gesamte Länge des Gehäuses verläuft. Vielleicht kann ich die Karosserie im Thread über angewandte Aerodynamik diskutieren.
Später mehr...
 
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Kulle schrieb:
Hi Gregg, were you live?
Maybe it's best to by and drive an existing velomobile to get some experience…
Is this a study project?

Because my english is limited i tried the deepL auto-Translation into german:
Zum Vergrößern anklicken....

Hello Kulle,
I have never seen a velomobile in NZ except one home made hybrid one, traveling very fast in city traffic. So I am unlikely to have a chance to buy one. And I would only buy an Evo-R or an old Go-One :). I am thinking of getting a used tadpole trike. They are sometimes for sale here, but I never see any on the road.

I guess this is a study project in a sense, like engineering art.

For translation I right click and a translation option comes. German to English seems to work well. Do you get a "translate into German" option?

I noticed that you quoted my whole text in your reply. You can edit that, leaving just one or two phrases to indicate relevant ideas...

Gregg.
 
Many older velomobiles share the same strut, as develloped by Velomobiel.nl, with that 4 degr camber build in. The Quest, Strada, Milan, WAW, Evo models etc. The camber however is not only the result of that 4degr, but there is, may be, another unknown ammount of camber as the result of a slight outward angle of that strut. The lower mounts are further apart than the top ones. All those different velombiles do not have exactly the same dimensions on the front steering. However if u make a list of trackwidth, they are pretty close. 59-66cm. The distances between the inner parts of the wheelwells are also quite similar, often with velomobiles with a narrower track, having less space between the two upper strut mounts. Those dimensions are hard to find. Somewhere near 40-42cm.

Al velomobiles use a virtual pivot, wich is the result of the two seperately mounted links on the front suspension. The link coming from the front to the front hole on the strutplate, and the one mounted on the middle hole, just in front of the upright tube. This point can be easily found if u connect both links outward, beyond the plate, in the wheel.

Idealy the virtual pivot point should be within the tyre contactpatch. If u draw a line from the upper strut mount in the wheelwell to the virtual point then down to the ground, that should be within the tyre patch. Enter scrub radius. I get the idea u understand that.

This virtual pivot point, as a result of the two separate pivots for both links, might also answer some of your questions regarding Kingpin angle on the single pivot steering on trikes.

There are no general rules, but one can narrow the edges by looking at data from existing models. Take the widest, the narrowest. If u are in between both extremes, yours is likely to work to.

More later.
 
The struts are indeed mounted vertical, the second (sideways) link pivot hole is positioned just before the strut. about 18-25mm. This distance creates the kingpin inclination.

A major step is in the newer struts for the Alpha's and M versions. The main difference that is obvious to spot, without measuring is that the front end of the plate attached to the strut is longer. The lenght of this part plays a role, cause the diagonaly mounted front link attaches to it. If u mount that front link position forward, u also change the dimensions wich create the virtual pivot point for the steering. U must talk care that the scrub radius remains optimal.

There is no mechanical term i know of, but when experimenting with my homebuild Velomobile, i found that extending that front part forward does have positive effects on the steering behavior. My theory is that these arms ( 1 on each side) work on the self centering of the steering. Cause of the diagonal positioned links, the only position where the forces left and right are equal when steering, is in the centre position. When i moved the links 15mm forwards i also noticed that steering whilst braking at very slow manouvering (parking) pace, gets realy hard. U need significantly more force to divert the steering from a straight line. This is with all factors identical. Same weight, same tyres, same presure etc. It does alter the movements from the wheel also. Normaly cause of the virtual pivot it makes a J shaped motion, with longer plates the shape may stay the same, but the movements get bigger.

Steering stability is also related to the shape of the shell. Picture the Velomobile as a huge weathervane with ist vertical pivot point somewhere between the front and rear wheels. One can argue what is that pivot point. Is it where the centre of gravity sits? Is it where one could divid the shellside surface in two equal parts? If to much of that surface is forward, the velomobile will be pushed away from the wind. If the rear has more surface, it will help in going straight, pushing in to the wind. Most plains have a tailfin at the rear. The Snoek has a relativly rapid dropping headbulge. Adding a fin on top of that seems to help with its stability. The Milan and Bulk tails drop down way slower, they have a more rearward splitpoint for a 50-50 shell surface.

Toe is slightly inward, with a very strong feeling that turns to zero when all the play in all the links is pushed away under riding force. Doing rollout tests is in my mind the only way to know for sure if toe is set optimaly. All other methods just result in 1 value. Rolling out relates two values. The toe setting and the resistance it causes. Least resistance is best.

Track width is related to having the wheelwells open or closed. With closed wells, u need a narrow track to have equal movement when steering out or in. Track is narrower than vehice width. With open wells, the wheel needs to sit flush with the shell, and the track is often the widest point.
The upper strut mounts can't be to close together, or your knees won't fit between them. Some velomobiles are designed for short people, for average, and some for tall people. All are designed for people on the skinny side.

I am no engeneer, so i worked with very simple things whilst designing mine. It has about 25.000 km on the clock and nothing structural failed so i must have done something right. With about 35 KG it is on the heavy side.

There are several different load scenario's that the velomobile must endure.

1 the Rider and its luggage in the Velomobile, and the rider leaning on the edges of the entry hole while getting in and out. I took simple real weight for that. There are two beechwood sticks in the side of the hole, that can support my weight while extended over that span. 20x20mm beech is enough. The seat should not sag when the rider sits on it. Simple static load scenario's.
2 The vehicle moving along with that weight and hitting something. I shared the weight of rider, load and vehicle equaly over 3 wheels and then multiplied that with 3g. as example 120kg total, 40 per wheel x 3 = 120 kg per wheel. So i build for example the strut support in the top of the well so i trust it to support 120 kg. U can add a safetyfactor to that, just to make sure. One may ride on two wheels and hit a bump.
I do not have the skillset to calculate, but used experience from building 3 carbon recumbents, and i cheated*. The dynamic moving scenario.
3 The rider pedals the vehicle and puts a huge force on the pedal, while pushing the pedal forward, he also pushes the seat backwards. Stretching the shell. This can be seen/felt in some velomobiles. It is also a reason behind the reinforcements on top of the wheelwells in the DF. And Milans, and the Bülk. Because the chain attaches about half way of the crankarm, there is a roughly 1:2 lever ratio there. The rider pushing his bodyweight with 1 leg is realistic, double that with the lever ratio. This force pulls the rear hub towards the chainring, but also acts on the rear swingarm, on the idlers, diverting the chain from its straight line, and on the mounting points of those idlers. If u look at the evolutions on several models or newer models from the same designer, many improvements are there to make the velomobile stiffer for these forces. Rider power scenario's.
4 Torsion. Besides these there is also torsion. Torsion from the pedal wich is excentrical to the boom. Torsion on the shell when cornering on 2 wheels at 40 km/h. Torsion cause the swingarm is mounted single sided, torsion on the rear wheel while cornering.

q factor is not as important as the pedalbox, the smallest posible box in wich u can pedal. Using a narrower crank, wil make it narrower. Using a shorter crank saves space above and below the BB axle. Using a 1 cm shorter crank, results in shaving 2 cm of the hight of the frontal surface of the nose. Because of the roughly teardrop top view, the narrow bit matters with the crank forward, further back the shell is wider anyway. It also matters with the crank upright, there the nose should also be as narrow as possible. But without a real life example this is a nearly unsolvable 3d puzzle. U got no idea where your feet forward position is in relation to the rear axle(yet).

I am no carbon expert. So i did the same cheating there. A very vitaly important insight was that not only strengt is important, shape also helps a lot. Using the same material, just giving it a different shape, can make it stronger. A sheet of a4 paper on its side can't support a pair of scissors. But if u make a roll of it, it can. Undulating a shape adds thickness wich makes it stronger. The nose of a velomobile is stiff cause of its shape, the bulges on the nose of a Milan or Bulk are stable cause of their shape. Shape is very important, as are smooth transitions in strenght between parts, sections. U can make a strong swingarm, but if that is mounted on a flimsy shell, it wont help. A to sharp transition is in German called a Sollbruchstelle a thing sometimes used to build in a wanted point of failure. If 1 part is very flexible, and its neighbour is ridgid, it will break near the transition between both.

* how did i cheat? I can't do the math, don't fully understand the matter. But i can look realy good at what other people do. I know a 60x3mm alu tube is enough as main boom for an alu recumbent. Many where build with that. I know optimal carbon can be 4 times stronger than alu. I know that if i double the diameter of a tube, it gets 4 times as strong. I know a carbon guru who build recumbent frames with 1 layer of a specific very thick carbon sock. Records where set on them. So if i make my carbon frame with 2 layers of that same sock, and do not go under 60mm in lightly loaded area's and significantly bigger, where high loads are expected i probably get away with it. ( and so far that worked)

My homebuild one is heavier than the M2 Milan. My two inch carbon boom and its support structure is significantly stiffer than the 40x40x1,5(2?) mm boom on the Milan. When on 2 wheels, the shell of the milan is way better, stiffer than mine. It is significantly faster also.

So most of my engeneering is done by getting near enough, with a sizable saftey margin in stead of being exactly spot on.
 
tieflieger schrieb:
Many older velomobiles share the same strut, as developed by Velomobiel.nl, with that 4 degr camber build in. .....

Al velomobiles use a virtual pivot,...

Ideally the virtual pivot point should be within the tire contact patch..... draw a line from the upper strut mount... to the virtual point then down to the ground, that should be within the tire patch. Enter scrub radius......

This virtual pivot point, as a result of the two separate pivots for both links, might also answer some of your questions regarding Kingpin angle on the single pivot steering on trikes.
Zum Vergrößern anklicken....

Thank you low flyer. That was a great read. I'll sift through it.
The kingpin axis, if drawn simply from top pivot to the ball joint on the steering plate....I cant see a scenario where this can project onto the contact patch. Changing the axel angle and inclining the strut, the steering plate soon hits the spokes.... I agree that looking at the virtual pivot point (caused by the role of the front strut) may give some insights.

For the structural load cases....I think I will scout for likely critical load cases. I have expertise in an old FEA code that is very good with composite shell elements, stacked layers, fiber orientations. I'm gradually learning some surface modeling in Rhino, so will model and make meshes for the FEA with that.

Re the aero....I reactivated my expertise with 3D panel code PSW and modeled flow over the body without wheel wells. It is easy to include a ground plane effect. I tried some yawed cases to see the directional properties of the shape. The shape is similar to the Evo-R, but there is more contraction approaching the trailing edge (TE), so pressure recovery happens before leaving the TE, so less tendency to separation before the TE.

For the directional stability....I normally take moments about the center of gravity (CG) to think about directional stability of flying bodies. It's a new thing to have the force contribution from the tire contact points. It is maybe useful to make comparisons between different versions or types of bodies, as you are doing.

Thinking just of the sideways component of pressure distribution over the body, the forepart is less effective than the tail. But the CG is well back in aero terms. I'm thinking that most velomobiles need the tire contact to be directionally stable.

But the wheel wells, cutouts, spinning wheels are too important. CFD is the only way I can see for simulating those. We'll see.

Gegg.


Gregg.
 
anotherkiwi schrieb:
Of course you could always buy a plan and work things out from there... ;)
Zum Vergrößern anklicken....

At first I thought this was a funny wind up. Now I get it. I could be very useful. What plans are available? I need Evo-R, Evolution, Milan, Bulk, Quest. Surveying a spread of the interesting designs. But I don't think I will get them.

Are you an expat?
Gregg.
 
There are no plans for the factory built Velomobiles. The design concepts behind those and layup schedules are pretty closely guarded secrets.
 
viznz2 schrieb:
At first I thought this was a funny wind up. Now I get it. I could be very useful. What plans are available?
Zum Vergrößern anklicken....
There are plans for the Sitko Agilo available on ebay. A wooden plywood velomobile, and @anotherkiwi is building his second Sitko. The price is rather reasonable.

Also you might check the building thread from @Schrau-Bär , he documented his building process of his (two) wooden velomobile quite extensively.
 
@anotherkiwi has build an Agilo. https://www.sitko-velo.de/infos/agilo/ There are plans for that.

As Ben said there are no plans for commercial build velomobiles or detailed build info's available.

I suggest Daniel Fenn's channel. https://www.youtube.com/@LausbubDaniel . lots of good info to be found there. He has a laminating video where he builds a wheelwell. And this one visualizing the virtual pivoting.

This is my tread about my plywood velomobile. https://www.velomobilforum.de/forum/index.php?threads/mein-holzvelomobil.43038/

I started with the trackwidth, from that i decided on the wheelbase. Wheelbase is the result of your forward seatposition, then the rear end of it, and then the size of the rear wheelwell has it's conflict with seat. Then work out the interaction between both.
 
@viznz2 I'd contact @Velomobileworld and the other manufacturers if they have customers in NZ and could make a contact to other Kiwi velomobile riders. Inquiring about velomobiles over the internet and seeing/riding one or two in person is a completely different matter.

Maybe there is even one for sale in NZ and you could get some hands-on experience. That would most likely change some of your design requirements.
 
viznz2 schrieb:
At first I thought this was a funny wind up. Now I get it. I could be very useful. What plans are available? I need Evo-R, Evolution, Milan, Bulk, Quest. Surveying a spread of the interesting designs. But I don't think I will get them.
Zum Vergrößern anklicken....

The Sitko plans use the Quest front end so similar geometry to all of those you list. The rear end is a 2 sided swing arm from the Leiba XStream.

viznz2 schrieb:
Are you an expat?
Zum Vergrößern anklicken....

I suppose I am, 48 years in the EU in August :giggle:
 
viznz2 schrieb:
I found a summary of the geometry ideas for velomobiles by an engineer at a symposium some years ago
Zum Vergrößern anklicken....
Suche mal nach "Velomobil-Seminar", da gab es einige (ursprünglich initiiert von Carl Georg Rasmussen, Erbauer der Leitra.dk).
In den Seminaren gibt es einige grundsätzliche Vorträge zu Velomobil-Design.

Weil sich Patente im Nischenmarkt Velomobile nicht lohnen, gibt es einige Entwickler, die nicht gerne ihr Knowhow rausgeben wie z. B. Gelegepläne zum Laminieren.

Vielleicht sichst Du auch ein bißchen nach den diversen Fäden zum GoOne 3 und Evo-R. Die Optik der Kanzel ist Geschmackssache, die Nachteile erfordern teilweise aufwändige Lösungen.

Spannendes Projekt, und, wie ich finde, eine sehr gute Herangehensweise von Dir.
 
wolfson schrieb:
Search for “velomobile seminar”, there were a few (originally initiated by Carl Georg Rasmussen, builder of Leitra.dk).
The seminars include some basic lectures on velomobile design.

Because patents are not worthwhile in the velomobile niche market, there are some developers who do not like to give out their know-how, such as: B. Lamination plans for laminating.

Maybe you'll also look up the various threads about the GoOne 3 and Evo-R. The look of the pulpit is a matter of taste, the disadvantages sometimes require complex solutions.

Exciting project and, in my opinion, a very good approach from you.
Zum Vergrößern anklicken....

Thanks for the encouragement, and the pointer to the seminars....

Velomobile Seminars online – resources available for download

Velomobile Seminars online - resources available for download.
velomobileseminars.online

I was thinking of the 8th seminar (2015)....
"Chassis engineering of three wheeled human powered vehicles"
by Martin Wöllner.

I haven't sifted through yet, but noticed...
1st seminar (1993) p50, A paper by Andreas Fuchs on dynamic stability of velomobiles which should have some idea on the static yaw derivatives.

Some thoughts on the issue of proprietary vs shared knowledge/data...

I had a couple of good European students working on my sailplane development a few years ago as part of their Diplom practicum. One was a key figure at Akaflieg Braunschweig and many ideas were shared. The Akafliegs have been an open source for data about composites and composite design for aircraft. Also it seemed that Germany had a busy culture of hobbyist designers/builders of one off aircraft. Each aircraft was designed/engineered as if for certification, or so it seemed.

The design methodologies and the load cases employed were common knowledge and shared.
I see no reason why a similar freedom could not exist in the velomobile home builders community.

This is not to say that commercial designers/developers/builders of velomobiles should give away their data. No. But some information is generic or common anyway. Other data, like new test results for materials, or new methods may best be shared.

Re the detailed laminate schedule for a commercially developed velo. I don't assume this would be given, except to those making repairs. For design, it would be useful background reading, but one can't simply copy or paraphrase it. Composite stiffness and strength has to be designed, tailored to the loads and requirements.

Looking at photos of a well designed composite part, one can sense the design rational, and those factors and similar features may be very likely if designing ones own part.

I was previously wondering about the overall laminate on the velo production body shells. This would be a useful reference. What is it that sizes that laminate...? If it was a sailplane there were some example laminates and opinions about that.

Gregg
 
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The maximum efficiency of the Tadpole trike in terms of aerodynamics and drive is achieved with front-wheel drive and rear-wheel steering.An example is Wim Schermer's Different or you can look also for rear wheel sterring to the Velayo.
These are completely different to most current bikes, but it works also in Velomiles.
 
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