Two "handle bar" positions

[bluesrocks]

I'm seeking suggestions for how to accomplish two handle bar positions.

I'm hoping to have two handle bars and seating positions available. I guess I could try for two seperate handle bars with twice as many cables as before, to control all the controls on the first handle bars, including throttle and digital readout. But I don't think that is very feasible.

I think I probably should have just one handle bar with custom made long enough cables and convertible cable routing for both positions. Then during transition from one seating mode to the other, just remove the handle bars and re-attach to the other position, while also making all the cables nice and neat. (No problem) :lol:

Suggestions

 

[fechter]

Just to be clear on your question; you want to be able to steer the bike from the rear seat? This would require a second head tube and some kind of linkage to the front.

 

[flat tire]

Be careful with the 3d printed mounts. The carbon doesn't add extra strength just stiffness (which can make it more brittle) and maybe some abrasion resistance.

 

[bluesrocks]

Yes,,,,,,,, I want to steer from the recumbent seat shown. ... ............. and optionally the upright seat too. Hence the two handle bar positions question for how to control it all from both positions.

That question is not, do I need more than one handle bars. Although that is part of it.

The question is, if I had two handle bars, how do I control everything, have two sets of cables for brakes and changing gears, and two sets of wires for the electronics?

How do you propose to control the brakes and shifting and motor (two controllers, two throttles, two shut off brake levers, two sets of power assist digital panel adjustment controls, two sets of sound alarms and displays!! one on the two handle bars???

That seems a bit mish mash and undoable.. Please clarify.

 

[bluesrocks]

Be careful with the 3d printed mounts. The carbon doesn't add extra strength just stiffness (which can make it more brittle) and maybe some abrasion resistance.

I saw serious tests showing top class strength in both the layer plane "and" 90 degrees against that plane, "both" planes of testing surpassed most other entries and demonstrated a strength and stiffness increase, not just stiffness like you claim..

Maybe if you don't use a proper printer you will only get more stiffness instead of strength, but unless I'm seriously mistaken, strength is most certainly increased by using infilled carbon fiber, not just stiffness. I think you might be generalizing a bit too much maybe. But Im very willing to learn I am mistaken. I'll go fetch the tests done. Do you not like 3D printers? Are you an engineer? hehe Just kidding friend. But I am curious why the rub against such a cool tech. I should admit I am a newbee in 3D printing tho, having done a fair amount of research.

 

[bluesrocks]

Here's a link to the video demonstrating increased strength by adding carbon fiber infused for 3D printing. Also, if you use mark forged I think they are called, they include a proprietary form of laying down a continuous thread of carbon fiber to add in the layer plane strength greatly.

I feel it's a bit outdated to simply assume that modern 3D printing is not well benefited (stronger more resilient parts) by adding carbon fiber to the mix. You must design properly, keep temp control tight, use good hardware, good settings, and focus on a good full and wide bead, getting better layer adhesion.

Im went with volcano eruption set, and upsized to 3mm with a nice dual gear driven extruder so both wheels are driving not one like most, and seemingly slightly larger wheels than most for better grip, better retraction and improved extrusion performance, probably except for flexible,,, but Im focusing presently on structural parts and jigs.

https://www.youtube.com/watch?v=m6i7oHQ8jks

 

[SlowCo]

.....Are you an engineer?.....

You clearly are not...
How do you propose to pedal in the recumbent position with the crank low down? Or do you also want to change that? And what's up with the two motors in your picture?

 

[bluesrocks]

.....Are you an engineer?.....

You clearly are not...
How do you propose to pedal in the recumbent position with the crank low down? Or do you also want to change that? And what's up with the two motors in your picture?

Degrading will get you,,, where you probably are, not as far as being more productive. The engineer question was to get at why be against 3D printers, not against engineers as a trade, and least of all against you as a personal comment. Please try remain topical and not to get me completely wrong. This used to be a friendly forum, so lets hope this is an exception.

I don't know what you are talking about with your first question. I'd say, using feet, but one may be insulted by that, so I don't think I understand your question very well. The photo describes everything. Please click on what you are arguably somewhat antagonistic against, yet you don't understand prior to judging.

The graphic is clear and descriptive, with the callouts explaining each highlighted part,,, the same one's you are asking about.

After you click on the pic, if it's still hard to read, click on it again and it should zoom in to really large letters for really easy viewing and reading. So there should be no problems understanding what I presented, from the first post.

As to ,,, "low down pedals"... There are no "high up" pedals as opposed to "low down pedals", so I don't know what you are talking about. There is just one set of pedals, the rear set was removed as shown and described in the first post.

 

[flat tire]

I should admit I am a newbee in 3D printing tho, having done a fair amount of research.

I've been 3d printing for years making prototypes for a unrelated business. A good rule of thumb is it's best not to 3d print anything structural where consequences of failure are meaningful. Seat anchors to hold your own person to a motorized recumbent are probably the last thing you want to 3d print.

Explain why you want the carbon and I'll tell you why you're mistaken. And of course I'm an engineer, although anyone could say that. The advice is what matters, not some credential.

 

[SlowCo]

Hahaha, I never commented on the 3D printing (in plastic on a domestic printer) but flat tire (who did) is spot on about that.
It seems you have no clue on how to build this contraption you've dreamed up. The recumbent seat position with the seat in that spot and the crank down below will result in a very "interesting" posture while trying to pedal. And how will you steer from that seat?
I think your design needs more than a little extra thought... :wink:

 

[amberwolf]

If you look at my early CrazyBike2 posts either in it's thread or on the http://electricle.blogspot.com, you may find some useful info on how to create the rear-position steering mount and linkage.

Justin_LE also did something similar for his Cross-Canada Trip bike, in a different way that would probably require less modification.


The pedal problem being referred to is that with a seat as laid back as that one, the pedals will need to be up higher, perhaps as high as the front seattube/toptube junction height, but more forward, for you to be able to pedal from that position. Otherwise your legs will be at an unnatural and probably extremely uncomfortable angle.

If you ahve a reclining chair at home, you can try laying back in it at the angle the seat will be, then put your feet and legs out at the angle/distance necessary to reach a spot equivalent to where the pedals are. This will show you if you can even reach that position, much less pedal from it, before you build the bike. Then you can use this technique to figure out where you will need to add a second set of pedals to, to be able to reach and use them realistically.


Without understanding why you want two independent seating/control positions, I couldn't say whether it would be better to make one or two control sets.

However, the reach requirements and clearances are very different for the two seating positions, so you will likely have to use two different handlebar shapes. If so, it's probably going to be much simpler to design and build two separate handlebar / control setups that are permanently installed in their respective positions. Most things you can just "parallel" the cables and wiring for, but LCD-to-Controller connections may not work properly done like that. You might have to use a switch to toggle between one LCD or the other, for it's serial I/O pins, and possibly power/keyswitch lines from the LCD to the controller).


YOu can also look up the various tandems that have both a 'bent and an upright seat, and see how they designed their positions, pedal locations, chainlines, etc. I don't recall any that had steering available from both positions (the tandems I've seen just have a grip bar for the stoker) but there certainly could be some. If so, you can copy some of that stuff, too.

 

[bluesrocks]

No, it's a tiltable seat, so you can be at any incline. The second set of pedals are yet future possibility. I first want to just figure out how to deal with two different handle bar positions. In other words, how do I deal with two sets of breaks, throttles, displays, controls for the display, etc?

 

[bluesrocks]

I posted that I "might" want both seating positions and thus both handle bar positions IF that can be reasonably done. But how would I replicate the motor and display controls??? Would I need a seperate controller too? Im more than willing to have only one seating and handle bars position is it's not feasible to do both handle bar positions with all it's controls. Or maybe I just need to move the one handle bar to both positions when I change seating mode. So this issue is NOT A PROBLEM.

The following is for all except amberwolf who is being helpful and constructive.

Im not here to debate the value of a 3D printer. I showed evidence you are all wrong and none of you responded to it because evidently you are too afraid of the reality demonstrated. And i don't need lectured about having a strong enough part, if it needs injection molded, I'll do that, if it needs to be made thicker, I'll do that, if it needs using other materials in the mission critical part, I will do that and just use 3D printed parts appropriately, but the last thing I need to be told is, but the part needs to be strong enough. YES I KNOW THAT, OK!!!!!!!!!!!!!!!!!!!!!! So drop it, Im still going to use the crap out of my 3D printer for my many projects.

But if you are going to avoid clear evidence shown in order to continue to act like you are cogent and responsive, that's just a joke, so please stop patronizing me and actually respond cogently. Otherwise I don't want to hear another bs thing about 3D printing, you all sound like 10 years ago or my grandpa or something.

I dented or defeated most of all your points about 3D printers and you just can't deal with it. So whatever. And if this is how this forum is run, maybe it's not such a friendly and helpful place after all. Some of you sound like serious malcontents and no one appreciates being given a hard time for no good reason.

If you want to be helpful, RESPOND TO MY VIDEO EVIDENCE RICHLY PROVIDED OR SHUT UP PRETENDING YOU ARE COGENT OR RELEVANT, no you are just an old fart unwilling to update your mind.

More of this malcontent negativity and I'll gladly leave you all to your own sad crappy selves.

 

[bluesrocks]

And before anyone continues down the, but you are seating up too high for such low pedals to have a comfortable riding position path,,, it's roughly the same design as the infamous long wheelbase design that started the modern recumbent movement back in the 70's represented by the gold rush and tour easy models. My design is nearly the same, just the seat is a bit higher for better balance controls, so I highly doubt it's such a bad design as has been,,, variously suggested. Instead it's based off of still in production designs and they still provide top of the line performance and ride comfort.

I plan on possibly moving the seat a little further up and adding a set of pedal cranks up near the front handle bar area but out of the way of the top of the forks to avoid heal strike. But that is next year's project, presently I just want a recumbent ride, so I will be sitting as low as I can go to enhance a better recumbent position.

 

[bluesrocks]

Flat Tire, it may be a metal pipe clamp that secures the seating frame to the seat posts, and 3D printed parts connects/integrates the clamp to the seat mount body. I would use 3D printing more for integration than mission critical load bearing whenever possible. The general idea about 3D printers is more about flexible adaptability than 3D printed parts are structurally preferable over other technology, no that is not my ignorant or mistaken perspective.

I am a wannabe inventor, having numerous other mostly alternative energy projects, so prototyping is very interesting to me. You can insert metal strapping or a metal threaded nut into a plastic printing part before the part is done printing so the plastic can act more like an integration mount to the more structural component. There are probably dozens of ways of augmenting 3D printing plastics to perform more like metals for structural parts, but I'm sure you already know that..................

Anyway, it bothers met to see so many negative presumptions as mostly presented by others about a process or technology BEFORE knowing if one is going to use inferior processes or quality control or material choices, or combination parts, or other design improvements, etc. I am a positive force for good, and in life, we all want things to go easier and smoother and not go more difficult and with a struggle. I greatly appreciate tips for prototyping. Im a rookie so I have much to learn.

 

[fechter]

Try not to let the negative comments get to you. Just kind of goes with the territory around here. You can filter out what makes sense to you.

As far as dual controls go, all the electronic stuff (throttle, display, brake switches, etc.) can be duplicated and switched. Some things like the brake switches can be active on both sets at the same time. The throttle and display lines could be switched for front or rear position.

A more difficult issue is the brakes and gear shifters. It would be possible to make a brake line combiner that would take two cables in and have a single cable out so either lever would activate the brakes. If using hydraulic brakes it would be much more difficult.

Your idea of having all the controls on one handlebar and being able to swap the handlebars between front and rear would solve many issues but you'd have to figure out a way to route all the cables so both positions work and have a very secure but easily removable mount for the bars. In this case, hydraulic brakes might be better since the lines can be fairly long and not affect operation much and you have more flexibility in routing.

 

[bluesrocks]

Right on, thanks, will do. I've never done hydraulics before. I was concerned about probably one foot longer cables, maybe 9" but the added length, over time, is not a benefit. Hydraulics might be better, I'm happy to learn more about that. I youtube a lot. Thanks for the tips and helping clarify what can be duplicated.

I much prefer having just one changeable handle bars and just have a cable routing struggle, but Im ok with that challenge.

...

Here's an interesting video showing strength of the stronger plastics for 3D printing. I can print polycarbonate too, but felt the superior layer adhesion of nylonx to be highly desirable as shown by the previous video. I want the parts to full strong in all planes not just mostly in the layer plane as most are, except for nylonx, that one has exceptional layer adhesion, coupled with extraordinary strength, in that plane, the hardest plane for 3D printers to do well at, so THAT, is the filament, I chose, and for good reasons.

Fortunately there are nice options for improved polycarbonate filaments which are easier to print, less stinky, better layer adhesion, etc. Arguably, polycarbonate is the hardest filament to print. Maybe I should have focused more on polycarbonates, but the testing I've seen was pretty convincing for nylon infused with carbon fiber.

You should see my large filament role for that one!!! hehe I got a discount this holidays and so I bought the 3kg instead of the half kg!!! It's one big mamma jamma, Im telling you!!! hehe

The following does not make plastic stronger than metal, nor printed plastic stronger than injection molded and other modern processes. However standard sheets of plastic can not normally be formed into comlex and organic curves like a 3D printer can. So stock plastic, plastic injection molding, and 3D printing all have their niches they do well at. There simply is no need to dish against 3D printed parts, just because many have strength problems, yes, Im sure they do, but I suspect my luck will be a bit better than most.

https://www.youtube.com/watch?v=n0GdrC21qWw

 

[Smoke]

If you're relying on luck for structural integrity, you're doing it wrong.

Real fiber reinforced composites can have tensile strength up around 450 ksi which is at least 1.5 orders of magnitude better than the best 3D printed plastic, carbon fiber reinforced or not.

The keys to high performance composite materials are the orientation of the fiber reinforcement and the ratio of reinforcing fibers to plastic matrix in the part. 3D prints can't do well on either of those counts.

This is the type of stuff taught in very introductory ME courses.

Better to learn it here than with a seat tube stuck in your spine.

 

[Chalo]

Hobbyist 3D printing isn't suitable for bicycle structural components. It's as if you're making seat mounts from wood, or yarn, or Lego, or bread dough, just because you're familiar with the process.

In the real world, such things are welded, machined from solid metal, or forged.