Tilting Trikes Part 2 - Designing my streamlined, tilting, three-wheeled velomobile

[@wheeltherapy5433]

The front tilting design is interesting, as it avoids the oversteering tendency of delta trikes, but there is a major flaw regarding the weight distribution. Because your CG is approximately a few inches above your hip joint when you seat in a recumbent, the rear wheel will be loaded with 2/3 of your weight while the front wheels will each be loaded with only 1/6 of your weight in your current design. This will result in a 1:4 ratio of the slip angle between the front and rear tires. Except if you use front tires 4 times more sticky than the rear tires, it will understeer so badly you won't be able to carry any sort of speed in a turn, which defeat the purpose of a tilting trike. To avoid massive understeer, you need 1/3 of the load on each tire, i.e. 2/3 of the load on the front "axle". That's the reason why all tadpole trikes or velomobiles have the front axle around or behind your knees. It makes the implementation of a tilting mechanism more complex, as your legs are in the way, but it's better than having front wheels sliding every time you try to turn.

[@MetalMachineShop]

Hi, thanks for your comments. I am working on a prototype so will soon find out whether it works in practice!

[@ronkellis769]

Looking forward to seeing more. Consequences of cancer and general age related disintegration keep me off a regular bike now, am exploring options for making my own.

[@danielmaquinando8140]

I love this, I like velomobiles and I have always wanted to make my own velomobile, this helps me a lot and makes me want to start. Thanks for sharing. I look forward to the next video.

[@subhabrataroy2593]

Eagerly looking for your next video. Very much needed project. Respect 🙏

[@MetalMachineShop]

Thanks!

[@diversaurus]

The kingpin angle and rake geometry at the ends of the front end components is thoughtful. Could you rake the center frame pivots to achieve similar results? It might add some loading stability in that the chassis weight load would then be aiding in self-leveling or self-righting forces for better tracking. More or less like the rake added to the crown assembly of a conventional single front wheel trike or bike? Something to play with in 3D now. Nice cad work. I like the flexing suspension concept. 3D twisting provides some great compensating geometry and progressive response. Keeping all three on the ground is always best. Steering with tie rods is still simple with the tilting action if the wheel end steering pivots are on the same plane as the lower suspension pivots at the wheel ends and the center steering lever is integral to the lower suspension section keeping the entire steering apparatus in the same plane as the lower suspension section. Geometry can be created for the center steering lever to compensate for the natural understeering of the inside wheel.

[@roymacdonald6774]

Trikes don't usually have a rear brake because in real world riding they don't work very effectively and are more dangerous than helpful in stopping. (rear wheel skidding) They are normally only used as parking brakes. I don't use mine and have removed it as I kept forgetting to take it off and wondered why I felt so weak when I was peddling.

[@Snoddas457]

Awesome video, thanks! I really appreciate how you showed all the angles and offsets. Smart kingpin solution! Will be very interesting to see the ackerman solution with wires. A wire can only deliver pull, so to sync the front wheels perhaps a linkage is needed? Or if the handles instead of tilting would pivot underneath the rider (then steer by front/back movement) on a fulcrum the wires could connect to a plate, and the wire shells attachments in the correct place (for ackerman).. just dabbling here, will be interesting to see how you do it! Best regards from Sweden.

[@MetalMachineShop]

I’m still thinking it through and I will try to upload my solution before too long.

[@daniele_go]

@@MetalMachineShop hi, any update on your project after one year?

[@MetalMachineShop]

@@daniele_go Hi, yes my latest videos show progress on the prototype. It’s now almost at the ‘rolling chassis’ stage.

[@runcycleskixc]

It would be cool if you found a way to make a streamlined shell as a DIY, w/o it becoming a quest with styrofoam, epoxy, etc. Alleweder was a good shell concept, too bad it's not made anymore.

[@bjorngrauers]

I've been thinking about building a tilting tricycle for quite a while but stopped due to the difficulties solving all the engineering bits, since Im a designer myself. I love how detailed your describing every step of the process, very educational. Thank you very much, and eager to see the progress and result. keep it up!

[@MetalMachineShop]

Thanks! More to follow in due course.

[@frankie8762]

Well said

[@FACE-PROFILERZ]

I believe on Ayurvedic terminology that you are Vata Dosha personality. You may check online search engine. I could tell for you are creative, slim body, craves on sweet, etc. Loves the video and the CAD programs you'll use. Working on tilting trike FWD/RWD, no Ackerman steering for less weight. No CAD programs just sketchings.

[@ronaldomartins8506]

Looking at your project, I figured it would be one of these with two seats. But not side by side, but one behind the other. It may not be possible to place rotating pedals but sliding ones with bars up to where the front crown would be and connected to it to such a bar that would be triggered to push the bar back and forth, allowing two people to activate the system at the same time. I don't know how to send figures around here or if it's possible. But if I knew a way, maybe we would exchange experiences.

[@MetalMachineShop]

I did seriously look at a linear pedal system but in the end decided that it was too complicated with no off the shelf components.

[@adamrahim6739]

Love your work mate ! Interested what basic what fork geometry you used. From my understand modern ideal is 73°head angle and 45mm rack. Tonight been brain storming an open recumbent based on a 80s Dutch Roulandt frame that I found today on road side chuck out. I believe 660mm width (legal cycle width in Australia) is achievable, considering it's to be an open design. I'm interested to liaise with you. I like your approach to design. I'd like to share some more of the ideas about the brief I've set for myself, particularly as you have been so open on the Web about basic geometry and what exactly you are building. I was just going to be doing a 2wheel recumbent but then contemplated tilting 3 wheeler geometry. Good on you for being so through about geometry variations and consideration there of. I've looked at a couple of utube clips. One of Harley Davidson bolt on kit and 2 of your videos. You've more less answered all my inquiries. Good on you. Inspired to practice on a 3D modelling program. Being a newb to it really I may just start with sketch up. Hmm how to correspond?? Here's my email:) [e-mail] Cheers

[@jarikinnunen1718]

Tip for practicality: Make lift function for better visibility in traffic. It is that bike class weak point. wormscrew and electrical motor is simple solution for it.

[@zico3239]

best videos to get practical with leaning suspentions

[@ramulaxmanpower96]

Nice designing and good development Ni engineering you work style....🚲🛴

[@daniele_go]

I am actually building a tilting velomobile as well...It is Front Wheel Drive and 2 rear wheels are Tilting with an elastomer suspension. Just busy completing the fairing...👍

[@MetalMachineShop]

Cool! I'd like to see some photos!

[@daniele_go]

@@MetalMachineShop Here is a recent video where you can see my tilting trike in action: kzbin.info/www/bejne/amfMgqqeYs59n80

[@AdrianvanWijk]

Looks great, if you're moving from the starting cam towards a drive-by-wire, could you overcome the offsetting limitations of the cam by using the wire to achieve similar geometry to a rack and pinion design? A personal consideration regarding the two chain guide pullies guiding the chain underneath the rider leading on and off the drive-chain-ring could be on the same axis just offset slightly so the chain would run in opposite directions parallel in the plan view rather than the typical parallel in the side view. as illustrated.

[@MetalMachineShop]

I did think about using wires for the steering instead of pushrods. Someone told me there might be problems with resonant frequencies, but I’m not sure about that; it seems to work ok for aeroplanes. In the end, the design got a bit complex need for return pulleys and so on. Good point about the chain idlers, I will look at that solution. Many thanks for your comment!

[@marcosrosa2743]

Seu projeto é fantástico, parabéns,vou continuar seguindo

[@kelleysimonds5945]

excellent planning. I'm very eager to see how this all comes out. I'm a new sub too.

[@MrSaemichlaus]

This series is extremely valuable! Could you arrange it in a playlist? I'd like to refer someone to it and the titles don't all show the part number. I learn't a lot of valuable things which I will likely apply in my starting carreer in engineering. Thanks a lot for sharing!

[@MetalMachineShop]

Hi, thanks. I will do that as soon as possible.

[@MetalMachineShop]

Hello, I've just added the playlist for this video series.

[@MrSaemichlaus]

@@MetalMachineShop Thanks a lot! Are you building a prototype of the velomobile?

[@MetalMachineShop]

@@MrSaemichlaus Yes, I am part way through making a basic prototype. It won't be pretty, but if it works, I will build a better one. I want to check if the tilting mechanism is successful before committing too much time and money!

[@myperspective5091]

I heard that tilting vehicles like this work really well on flat tracks , but I hear that tilting vehicles don’t work as well on streets because the crowns of the streets makes those vehicles lean towards or track towards the shoulders of the roads.

[@therealgerold]

Lovely design, very aerodynamic if only in the summer things could get rather warm, as there is little air ventilation inside. I had this idea, I don't know if you like it, but make something of a car grill(an awesome one with a logo in the middle lol)) in front so cool riding wind can pas through. Something with vertical blinds, that you can open and shut if the drag is too much.

[@MetalMachineShop]

Good idea! I was also thinking of removable side panels in the body which would probably not affect aerodynamics too much but would improve ventilation considerably.

[@frankie8762]

Brilliant Glad I found your channel

[@carliusanders]

Looking forward to the next video!

[@mohamednassar8407]

Great job, Thank you for the explanation. it would be great if you tell me the name of this design program.

[@MetalMachineShop]

Sorry for late reply, I missed the comment. Design program is Onshape.

[@LeesChannel]

Okay, so I am watching this in sequential order and I realize this is likely too late, but here it goes: Suspension is very important. Unlike an upright bike where your body can cushion the vibration, in a reclined position the bumps and vibrations go right into you. My fear is that the flexing, undampened suspension of the front would cause a lot of shock and vibration for the rider. Also, I'm worried about losing stability on washboard/cobblestone roads due to rapid flexing and tilting. I also feel that the rear wheel should be as large as possible. It will make for a smoother, more comfortable ride because it reduces the angle of attack and spans wider gaps. It will also reduce rolling resistance, and the tires will last longer because they have more material. Also, I didn't see it in the CAD render, but the rear suspension should be dampened so you're not bouncing, both for comfort and stability.

[@MetalMachineShop]

I did a design study with a bigger wheel, and while you are right about the advantages, it makes the trike a lot longer, a bit heavier, uses up the luggage space and makes for a tighter break over angle for the chain. Pros and cons, but for me smaller was better! Sorry for the delay replying and thanks for your comments.

[@difflocktwo]

Been thinking that an all electric drivetrain is more suitable for velos. Mechanical coupling and gearing required for these HPVs is really messy. You could even do all braking electrically.

[@SchemingGoldberg]

That's what the Podbike does. It will be interesting to see how well it performs in real tests.

[@difflocktwo]

@@SchemingGoldberg Doesn't really matter about performance. Supplement with a rechargable battery.

[@SchemingGoldberg]

@@difflocktwo Sure, most people won't care. But I personally care a lot about efficiency and raw speed. It's like a fetish.

[@difflocktwo]

@@SchemingGoldberg What I meant with my unclear comment was that you can get pretty much any level of performance you want with onboard batteries.

[@SchemingGoldberg]

@@difflocktwo Sure, but my (also unclear) comment was more about the efficiency side of things. A standard bike chain system is ~97% efficient, whereas generators + motors will be much less, 80% maximum. So there's a lot of wasted energy. That's a big deal if you run out of battery power and need to manually pedal it home.

[@paulneedham57]

Hi there Can I ask why the pedals are so high ? There is probably no room for a front dérailleur ? If the first pulley on the drive side taking the chain under the seat was a mid drive made from a IGH then you would not need a front mech and could also change gear whist stationary ? Keep up the good work , always a pleasure to see other peoples ideas take shape. I am old school and sit on a plank of wood with chopped up bike bits to see what goes where :-) regards Paul

[@MetalMachineShop]

The pedal height is dictated by two things; pedal/feet ground clearance at maximum tilt angle and the need to put the bottom bracket more or less in the centre of the velomobile body. Hopefully a front derailleur will fit but I haven’t looked at this in detail yet. I also want to add an e-drive unit somewhere.

[@paulneedham57]

@@MetalMachineShop I ride a Python trike where the front end pivots so effectively the front leans. I find I can get away with a BB height of 15" there is only a small amount of heal strike and that is always when stationary and leaning the front end over for a maximum turn. Obviously tilt angles vary between the Python and your velomobile , I have never measured the angle on the Python , I wonder if you can achieve maximum tilt when stationary without unexpected things happening ? regards Paul

[@victorrenevaldiviasoto9728]

Very good video, looking forward for more stuff! Following the ideas of the last video, what do you think about mixing your tilting mechanism with a Hossack suspension?, I've been theorizing about something similar

[@MetalMachineShop]

I think using the Hossack suspension as you describe would be a good solution. It would align the suspension travel with the body centreline (as described on another comment here). A minor problem when applied to my design would be that the central hinge of the upper wishbone arm would not be on the centre of the circular-section body under suspension compression, which would lead to clearance problems between the arms and the body at the point where the arms pass through the body.

[@aikabdroqib5191]

Yes Sir, i love it.. thanks

[@raynic1173]

I believe the term "fly by wire" has to do with 'electric or electronic" not metal cable wire as in there is not a "mechanical" push-pull involved. Mechanical would be rods, cables and even hydraulics.

[@MetalMachineShop]

Yes, you are right, I misappropriated the phrase! I am thinking of a closed loop pulley system, a bit like on an old aircraft or a glider.

[@edsondonascimento3412]

Belo projeto, boa explicação , ótimo vídeo , parabéns

[@beaconofwierd1883]

You might want to look into how ”Velotilt” is designed :) They use a ”lever” type mechanism which is probably more mass efficient.

[@MetalMachineShop]

Yes, it’s a cool design. Thought about using the velotilt mechanism on the front - it’s not impossible but would need to be adapted quite a bit.

[@beaconofwierd1883]

Metal Machine Shop Not sure if this is within your area, but do you know if it’s possible to build the hull out of a fiberglass cardboard sandwich composite? I’ve heard people do it to build a kayak. Would be a lot cheaper than any other core material if it’s strong enough.

[@MetalMachineShop]

In my experience, GRP is very strong but heavier than you might think. Single skin rather than sandwich would probably be sufficient with extra reinforcement only where needed.

[@asparx3748]

@MetalMachineShop Is your vehicle for urban use, possibly commuting? If so, do your urban environs include speed humps or pedestrian bridges with non-smooth entrances that are equivalent to speed humps for a velomobile? If so, a shorter wheel base may suit .

[@MetalMachineShop]

Hello again! It’s supposed to be for general use, including commuting, so I’m trying to make it as practical as possible by minimising turning circle and width and maximising ground clearance. However, ground clearance and length are a function of the basic design so with limited ability to change. I’m not sure a velomobile is ideal, or even very safe, for complex urban environments without excellent cycle facilities. A bike make be better for that.

[@asparx3748]

@@MetalMachineShop What ground clearance do you feel best? I have seen 4 inches and 6 inches. 4 Seems to provide less drag, while 6" should give fewer scraps on the bottom.

[@MetalMachineShop]

I would prioritise practicality over drag in this instances, but I would have though that 4in would be enough in most circumstances, but more would be better if possible.

[@Hotzenplotz1]

I haven't really understood what advantage the tilting wheels have. Could you explain in detail please? Thinking to develop my own one. But I'm not sure yet if to go with or without tilting wheels.

[@MetalMachineShop]

Hi, the advantages I think are: less risk of tipping over when cornering allowing a higher centre of gravity and/or a narrower vehicle; greater rider comfort and (maybe) enjoyment; less affected by bumps (I.e. the vehicle won’t tip to the side so much if one wheel hits a bump or a dip). The disadvantages are greater complexity and weight; ground clearance when tilting.

[@Hotzenplotz1]

@@MetalMachineShop Hi, have you seen this? Seems it could be built quite light and with minimal mechanisms. kzbin.info/www/bejne/qmLWhoKqjpmZj9U Still I'd go for an Quad....

[@noormanarief5814]

what design software that you use for it?

[@MetalMachineShop]

Hi, I use the free version of Onshape.

[@JohnR31415]

Don’t brake the back wheel in motion... if it loses traction there is a very good chance that it try to overtake you, and once you’re sideways and get traction back ... that’s no fun.

[@jpvv1220]

É possivel fazer um velomobile com direção inclinavel ?

[@MetalMachineShop]

I think it is possible but not easy.

[@simonbrooke4065]

Why not hydraulic rather than cable steering? Less maintenance and less risk of failure.

[@hermandurieux3247]

Nice job, what about stability at low speed? What if you accidentally lean to one site, are you not afraid not to able to get horizontal again?

[@MetalMachineShop]

It should handle like a bike at slow speed. There will be a tilt-lock for very slow speed or stopped, but you will have to remember to engage it. There will also be holes for the feet through the bottom of the shell for pushing backwards or as a last line of defence against falling over. If it does fall over, it will go right onto its side, which will be bad for the rider but very funny for everyone else.

[@calebsherman886]

I've been waiting for this video!

[@yannickpokam2069]

Hi Sir, I´m a German´s student in mechanical Engineering. As part of my Study´s project i have to design the front Achsis of a Velomobil. In my researchs i discorved your videos and i am in need of your help. Please Sir can you tell how i can proceed ? how can i calculate the physical dismensions of the Achsis ? We can also make a Zoom or skype meeting. I will be very proud to have your help. Thank you

[@MetalMachineShop]

Hi, you could send me an email on [e-mail]

[@karolkrzyzowski8814]

Is it possible to donate you? I am a cycle komooter and I think it’s a good alternative for cars.

[@lloyddotimas6302]

Friggin awesome!

[@walterretlaw4051]

What was these cad software used in this video..? Anyone..?

[@MetalMachineShop]

It's Onshape.

[@walterretlaw4051]

@@MetalMachineShop Oh..!!! 👍Thank you very much...!!!!!! Greetings from Argentine.

[@ironman8257]

Very interested in your project. By the way you have the same intro music as Saukki(velomobiles amateur) What about a electric motor to help you on uphils?

[@MetalMachineShop]

Yes it’s from the free KZbin audio library! Definitely planning an electric assist.

[@ironman8257]

@@MetalMachineShop NOICE, *Saukki

[@CharlesNewkirk-lb6uh]

What has happened with new videos?

[@MetalMachineShop]

Been a bit busy with other stuff for a while but I am hoping to build a new, improved version of the trike in due course.

[@maxsainty9816]

Love your design ideas . I am wanting to build something along the same lines as this thinking all carbon fiber. Would you have any objection to me borrowing some of the ideas that you have shown here ?

[@MetalMachineShop]

Feel free, most of my ideas are inspired by other designs anyway!

[@activedrive8310]

Wow! Cool!

[@safugpac2691]

Will it be built in UK or passed to Velomobile factory in Romania? Let me know if you need help as I speak Romanian.

[@MetalMachineShop]

Intended to be a UK home build. Thank you for the offer!

[@safugpac2691]

@@MetalMachineShop That's great. Do you have final specifications including the weight? Also will there be a version without electric motor? Will be available for purchase this year or next? Expected price? Thank you very much. Looks beautiful.

[@raynic1173]

Does "counter steering" come into play with this three wheel designs?

[@MetalMachineShop]

It should do, just like any bike. Low centre of gravity may make it a bit wobbly though.

[@asparx3748]

@@MetalMachineShop Wobbly is not good! I thought the lower the centre of gravity the better.?

[@raynic1173]

@@MetalMachineShop I'm not sure you know what I mean by countersteering. When at speed a conventional two wheeled device turns left by turning the handle bars right. From what I have observed by watching other reverse trike leaning designs, countersteering is not a component because the tires are manipulated on to their side mechanically. A two wheeler is subject to gyroscopic forces which requires the countersteering principle.

[@model4002]

что за программа скинь

[@MetalMachineShop]

CAD software is Onshape.

[@mikefranz1056]

What software for 3D CAD do you use?

[@MetalMachineShop]

It’s Onshape.

[@DrXupetin]

🙏👏👍

[@creativehuman3d383]

What is your email to show you the tricycle that I made but it is different

[@MetalMachineShop]

Hi you can get me on [e-mail], cheers!

[@19Brenni75]

springs is often used to keep these machines upright

[@danieldragota2985]

Un tinar inginer roman desena astea acum 30 de ani..tu esti?

[@MetalMachineShop]

I didn’t know that!

[@danieldragota2985]

@@MetalMachineShop ok,.....very elaborate wat you do,thank you.

[@barryrodgers2067]

How do I get one

[@MetalMachineShop]

Not yet commercially available unfortunately!

[@philcmoa6080]

very good video

[@patrickmckowen2999]

Excellent Cheers

[@saburovanatoly2197]

Дайте привод на переднее колесо!

[@autotuningkmv]

Спасибо за урок!)))

[@Traderhood]

Great videos. A lot of useful info. Just a suggestion, you can go a little higher on sound volume in your videos.

[@melizagonzalez2520]

No entiendo por fabor mandamelo en español

[@lucasmorton2862]

Very cool! I'm not sure what this is called, but I saw this design where the shocks are connected indirectly to the frame through this triangular plate: kzbin.info/www/bejne/qaG9pYSBaJyrgdk . It looks like it provides some stability against tilting too much.

[@raynic1173]

Do you realise how bad for your neck that low seating posture is?

[@MetalMachineShop]

Do you think so? Seems like a fairly natural posture, possibly better for your neck than a normal bike. I’ll just have to try it I guess.

[@raynic1173]

@@MetalMachineShop no it's really bad for you, as someone who has neck issues I can attest. The position is actually, with the chin closer to your chest reducing the curve in your neck and strengthening the muscles on the front, anterior side, of your neck. Try reading a book in bed or on your couch in similar position with your head unsupported. The hypoextenion position is not recommended in any form and worst when unsupported. I guess you got to do what you got to do for progress. But that position is unsustainable in the long run.

[@hellopsp180]

activate your windows man :D

[@MetalMachineShop]

Ha! Yes it’s done now!