Hello everyone. Welcome back to the least updated blog EVER!

Just joking for the most part...

I've decided to start working yet again on P-Tug. The first thing I noticed looking back on all of this is that... my model sucked. I completely started working on P-Tug from the ground up, deciding to opt for a rigid frame and many other cool features.

I'm going to update more often, as I get time to work on P-Tug...

These moments might be few and far between, but at least feel confident that I'll be here.

As for the changes, aside from the rigid suspension I have a few other handy things planned, such as a winch connected to the pedals that you can engage and disengage, and possibly some type of light cable winch on the back with some type of A-frame. I'll elaborate more on that in the future.

Anyways, come back to this space and keep checking on the progress. Thanks for browsing and reading.

 

So I've been coming up to a dilemma. It's been a matter of time before I would have to deal with this one...

Now I'm having to deal with the idea of whether I want this contraption I'm making to have a freewheel or not.

For those that aren't savvy on this sorta lingo, a freewheel is just a gear or set of gears that ratchets, which allows you to stop pedaling, but allows the wheels to continue turning.

The reason this has been a while coming is because I wanted to implement some type of reversing ability of the vehicle. But, I've decided against it at this point. The reason I have is for this is because any direct sprocket to sprocket link is going to cause the issue of the flywheel still turning, causing large amounts of drag because eventually your legs WILL get tired and they won't want to pedal anymore, even if you want to continue.

So, the linkage from the pedals to the flywheel is where this will be placed. Freewheelin' away.

Also, the idea of using a mountain bike wheel, or other type of bike wheel thats very sturdy as a flywheel has been mentioned to me, and it makes perfect sense. What I'm considering is using a motorcycle wheel, and simply putting a freewheel set of gears on the outside of it, allowing it to freewheel. It would also be stronger, which would be great. Then, the other side will have a centrifugal clutch and a sprocket attached to it, which will go back to a smaller sprocket on the rear drive axle for better gearing to multiply the torque. Then, voila, I have my drivetrain figured out completely in my mind, and soon on paper and in metal. ;)

Thanks to Craig for really pointing this one out to me, as he's been a big help in discussing various ideas to make this work.

Thanks for reading people.

So I've been going on and on about flywheels with project P-Tug. Some people are probably wondering why.

At first I was considering the issue of why pedal powered vehicles haven't been capable of doing large amounts of work. After pondering it for a while, I realized that human legs simply aren't that strong. Even with the mechanical advantages given to use by good gear ratios, we still have issues maintaining powerful strokes over a decent amount of time. The average small engine on even a lawn mower has the capability of producing many times more power and torque than our own legs.

The first thing I did was to figure out how such low power engines that were made in the early 1900's were capable of producing power and doing sustainable amounts of work. Then I came across this video...

http://www.youtube.com/watch?v=ACmXLLqTnSs&feature=relmfu

What I realized is that through very minimal use of energy and resources, these engines could produce continuous power simply through centrifugal force harnessed in a large flywheel. These flywheels were basically big kinetic batteries.

So, why not use a proven technology to make human power feasible? It made sense to incorporate a flywheel to store a large amount of power that could be delivered when its needed. All the design concepts are based around this, which is to pedal the flywheel to the appropriate RPM, and then to let the flywheel expend its' stored energy.

The reason flywheels are so good at doing this, is because once a flywheel gains rotational momentum, it doesn't want to stop rotating at that speed. Otherwise, centrifugal force causes the flywheel to want to spin, even after the power source stops. So, a flywheel is perfect for creating mechanical force, in conjunction with a small engine.

The centrifugal clutch and the ratcheting system all lean towards this end. With the clutch not engaging until higher RPM, it ensures that the flywheel will have plenty of kinetic energy to impart and to push the cart forward before it is engaged. The ratcheting system simply keeps it from rolling backwards when the flywheel isn't pushing the cart forward.

I hope this brief explanation has helped clear up some people's understanding of why I'm diligent about using a flywheel system. Thanks for reading.

Hey folks.

A few updates to project P-Tug... I've decided that as far as the seating position goes, I'm going to have it be a nice happy medium between recumbent and upright. Think partially leaning back, sitting mostly upright, regular seat from possibly a lawnmower thats reclined slightly. Of course, I want it to be adjustable... I'm thinking maybe the rack from an actual car.

Also, due to some motivation from a friend, I've made a lot of progress on my 3-D model. Here it is!

I've put the flywheel on, and put all the sprockets on as I see necessary. I need to facilitate a centrifugal clutch, which I'll put between the flywheel and the sprocket attached on the nearest side. The project keeps looking, at least in concept, very realistic.

My friend J.D. and I are going to be looking at the ATV frame soon, to determine how to really work with it to make the drivetrain fit in properly. It'll be a nice starting point for a physical proof of concept.

And lastly... as the 3-d model would suggest, I've decided to use a loped flywheel. With the assistance of gravity, it should give you more power during certain parts of the cycle. Should increase maximum power during a cycle, which will be very ideal considering the strain of the tasks this will need to perform.

Thanks for reading. Guys, COMMENT AND LIKE so I know you're reading.

So I haven't messed with project P-Tug a ton lately, because I've been involved in other things. Mostly things relating to life.

But, I have gotten a few minutes here and there to put some detail into making the sprockets look better, and I've been considering positioning for the flywheel, and making the sprockets align.

I've also reclined the seat back some, which actually brings me to a question...

Should project P-Tug be recumbent or upright? I think that recumbent makes comfort better, but upright seems to be capable of generating more power. I would like to hear your feedback on which you think would work better. I'm also going to release a comparison post on other common pedal powered vehicles and their drawbacks Thursday evening.

Thanks for reading. :)

Hello interested readers (I hope you are at least. :D )

I've come back with a first shot of the 3-D model I've been making. I'm thinking its about 60% done so far. Chassis = mostly done. Rear end with a swing arm and tires = check. Front sprocket = finished!

It's a long and involved process, this 3d modelling. You have to be ever so conscious of placement of parts so they don't obstruct other parts, plus you'll have to consider the stresses involved and what points might be weak. Anyways, here is the picture.

I'll be posting again soon comparing the concept of my drivetrain as compared to other common pedal-powered drivetrains on the market and why I think mine will outperform those. I'll be showing video examples as well. I'll also be posting updated pictures of the model as I slowly work towards finishing it. Thanks for the read.

Also, if anybody looks at the model and notices anything that seems to be a glaring issue, feel free to let me know.

Hi all. Wanted to update with a new post concerning the current direction, and additional ideas that have been given to me.

First, I want to say that I will be attempting to write up the blueprints and do a 3-d model of a prototype. The prototype is going to be an offroad vehicle, which will serve as a proof of concept for the drivetrain assembly I'm attempting to make.

I can't think of many people that have thought of using flywheels with centrifugal clutches, or ratcheting systems, so I'm not quite sure how it will all work out. I think that it will work well, but I won't know til I make something physical. I am choosing to make a single-person offroad vehicle because they often undergo the same stresses as vehicles pulling large loads. They also tend to need bursts of power when climbing over obstacles, which will seemingly be well delivered by the flywheel drivetrain I'm hoping to make.

I've been exploring ideas for the pedal-to-flywheel part of the drivetrain. I think you can use gearing for that part to make spinning the flywheel up easier. I was wondering if you couldn't set up some sort of automatic hub that changes gears centrifugally? I think higher-end bikes have contained hubs that do just this, but I'll need to do more research on the subject. I've heard that they are also very, very expensive.

I'll be using the program Google Sketchup (Now Trimble Sketchup) to try and make a 3-D model. I'm also going to try and draw up some blueprints, and attempt to make them as standard as possible amongst the industry. I'll try to have these posted within the next couple of weeks.

The last thing I want to talk about is an idea given to me by a friend named J.D., who's suggestion it was to consider using an electric assist motor on this vehicle. His idea of using the flywheel to also generate electricity via magnets was great, and I truly appreciate his input. Also, he has agreed to donate some ATV frames to the cause, with which I'll be attempting to make the prototype when the time arises. Again, sincerest thanks J.D. :)

Thanks for the read, and look forward to the blueprints and the 3-D models coming soon. :)