Category Archives: Blog

All posts (most recent first): a mix of latest news, progress, disasters, rants and raves, mileage, power produced… along with other DIY off-grid, sustainable projects that might be of interest. To isolate posts on a specific subject (e.g. ‘chain’ or ‘design’ or ‘others’) click that Post Category in the “Categories” menu to your right.

The Unstealable Bike

A lock for your bike can be awkward to carry and use. It also adds weight. But worst of all is completely forgetting to bring it with you! But concerns like this could soon be a thing of the past – if your bike IS the lock!

True, with an angle grinder or blow torch a thief could still take it (so ‘unstealable’ is little more than a catchy name for the concept). But wrecking a bike while stealing it is will put off a lot of serious thieves. Because considerable repair will be needed before reusing or selling on. Which is going to reduce the rate of theft worldwide.

Well done “The Yerka Project” at UnstealableBike.com. Good thinking!

The Pedal Powered Prime Mover

Ever since the notion of pedaling my own power struck me, David Butcher’s Pedal Powered Prime Mover has always appealed.

The PPPM has many advantages over the Turbike. Namely:

  • comparatively small footprint: the Turbike takes up two pallets worth of floor-space; the PPPM might consume (based on a visual guess) slightly under one pallets worth.
  • easier to make: you won’t need to… weld… wind coils of copper… attach dangerously-jumpy, powerful magnets to rotors… use clever engineering tricks to prevent the two rotors permanently sticking together as you align and space them on either side of the stator… mix and pour fibreglass… align the turbine frame with the bike stand… I could go on and on…
  • cheaper to make: magnets… steel discs (2 x 10mm thick, laser-cut into perfect circles)… 2-3m of angle iron… 2-3m box iron… welding rods… bike chain… bike training stand… and you’re suddenly well over €500 (whereas the PPPM plans cost $50 and materials maybe $250).
  • flexibility: the PPPM’s design allows it be more readily adjusted to mechanically power drills, saws, hammers… and perhaps more. Adapting the Turbike to do the same would be far more complex.

So, about the only way in which the Turbike might trump the PPPM is in power output – and clearly, given the time and money costs involved in constructing it, the Turbike would need to put out a LOT more power than the PPPM to make it worth the finances and time invested.

The Turbike’s power output potential is something I hope to share here once I’m sufficiently recovered from Follicular Lymphoma to get things up and running again. However this make take me several months. So, if you’re eager to get pedaling your own power, I suggest you consider David’s PPPM in the meantime.

 

How to tension a chain

Would have liked to wait for the right bike to show up at the recycling centre, but time was slipping by. So I bought a lighter chain wheel to replace the one used to test the concept.

Might be placebo, the power of suggestion, or perhaps I’m getting fitter… but I was able to pedal so hard that the alternator generated 17.9 volts. A new personal best! 🙂

If you want the details, this pic shows the chain wheel specs.

The Breathing Bike

Trying to find a way of coping with the polluted Beijing air, Matt Hope has come up with ‘The Breathing Bike’. The notion that his setup produces 5,000v makes me green with envy! The video was produced by the “Cool-Sparks” team of Xiao Li Tan & O Zhang – whose aim is to “profile cool people doing inspiring work”.

Chain tensioning

Spotting my chain problems, one kind visitor took the trouble to make contact and give me this tip. It’s made a big difference to my confidence while pedaling. So I’m sharing it in case it helps others.

The chainwheel inserted here is from a kid’s bike dumped at the local authority recycling yard. It is a bit heavy and you can see the effect on the chain. Mountain bikes and racers would have lighter pedal sprockets. So I’ll be checking the recycling centre often. Sure, I could probably buy one. But I prefer the idea of rescuing / re-using parts from bikes others think are only worth throwing out.

Meanwhile I can relax while pedalling and make electricity in comfort 🙂

Two more turbikes

The mobile phone was busy taking video and pics. The frame was viewed from all angles. The bike was pedalled up to 20kph. Twice. The tyres were metaphorically kicked… and so the ideas emerged gently into the nurturing silences between the three of us.

Two local lads, each with their own, quite different electrical needs, came to visit. Both were keen to try pedaling – and were pleasantly surprised at how easy it was to overcome the inertia and resistance. It was nice to see their reassurance.

Also nice to realise our chat has saved them time, energy and frustration by helping them steer clear of some pitfalls.

Like making sure your alternator frame design makes it easy to align the turbine with the bike chain. Or exactly centering the sprockets on the front of the alternator hub (because the 5mm off-centre alignment I have is causing immense chain-wobble and vibration at higher speeds).

Thanks to their different needs it looks like they make two very different turbikes. Both intend taking plenty of photos and I hope to visit them often during their work. So both their projects will be documented here in time. Check back here. Or like this Facebook page to stay up to date.

Meanwhile here’s a well-written piece reviewing various pedal power strategies: Pedal powered farms and factories: the forgotten future of the stationary bicycle

Pedalling… to save a battery?

A few weeks back it looked like my battery was kaput – no longer able to hold a charge. For instance that 10.20v charge of mid Sept dropped way back to 9.6 within two days. Not a good sign.

Eirbyte suggested taking the battery to a garage and have them charge it for a few days. Because maybe some high amp input might help. So I figured well why not see if I can produce a few high amp bursts myself and see what happens (and if it didn’t then I’d take it to the garage)?

So in recent weeks I’ve found a few spare half hours and done a few 5km spins.*

The first one was the easiest – thanks to the resistance being low. During it I managed to hit a peak of 17.5 volts while pedalling 23-25km/h (for maybe 10-15 seconds). The end of that run saw the battery charged up to 11.2v before gradually dropping back to 10.7 over a week.

Another 5km cycle ten days ago (during which I managed a couple of 16.5v bursts – 17.5 was just not possible) topped it up to 11.75 – and the perhaps reassuring news is that this morning the voltmeter shows the battery still have 11.15v in it. That seems better.

Of course I may be engaging in some futile cycling here. This might not work. But at least I’m getting a bit fitter while learning what sort of voltage can be put out at a given speed.

I’ll give it a few more 5km cycles and see if the charge can be brought back up to – and stays – anywhere near the original 12.3v it had when I bought it. If not, then I’ll try the garage.

But two things I’ve learned from this.

  1. Don’t drain the battery down to levels that make the inverter alarm go off.
  2. Don’t leave a battery at a low-charge level for any length of time.

Oh… and now that I’m getting into the numbers… it’d be handy to have the gadgets to measure my amp / watt output. So I can compare my pedaling with that David Butcher (interesting project and, yes, I’ll probably build one of them too!).

* Before you pour ridicule on that rate of pedaling, bear in mind that a) I am dreadfully unfit and b) there is amazing resistance in this yoke! Getting anywhere near 25km/h is quite a feat. Far more realistic to keep around 12-13km/h and work up to short sprints every so often to hit those higher voltages.
 

Chasing numbers…

… can begin in earnest soon!

Finally fitted nice snap-on/off battery terminal clips. Also rigged up wires to run from the terminals forwards toward the front of the bike. So I can attach and read my voltmeter as I pedal – a major motivator when it comes to putting in the time pedaling.

But another motivator is the classic “fear of loss”.

Had a dose of that this evening when I noticed the battery voltage was down at 9.41v. Given my considerable neglect over the summer, it may have been like that for up to two months – and leaving batteries like this so undercharged for extended periods is not a good idea.

Time, and some pedaling, will tell if that inattention will cost a battery. But this evening’s not-too-fast, not-muscle-burning 8km spin brought the volts up to 11.72 (with peaks of 15v while pedaling). Of course, the voltage will ‘settle’ overnight. So dawn will be revelatory.

But, potential battery problems aside, I am now happy (genuinely!) to find that I can soon begin to engage in a bit of pursuit cycling: chasing numbers!

More on that later…

Update 22/09/2012: with no more pedaling or drawing of power since this post, the battery seems to have settled @ 10.20v.

TG4 Wind Turbine friend spot + FAQs

My friend Miriam Sheerin of BuildYourOwnWindTurbine.com is scheduled to feature on the TG4 programme “Garraí Glás” at 8pm tonight. If you’re at all interested in a project like the turbike (or even a normal ‘turbine’) then I’d highly recommend going on a course with either Miriam & Jimmy or Hugh Piggott himself.

Garraí Glás filming Miriam Sheerin

Also want to let you know I plan to put up a FAQ page soon on this site. So drop me your questions to the ‘[email protected]’ address and I’ll try and work them in.

 

Bike and Turbine pretty solid now. Chain next…

As you’ll see in the vid below, I’ve overcome the two biggest, and inter-related, problems:

  1. the turbine occasionally tilting forward toward the bike and
  2. the bike stand sometimes being pulled upwards and back toward the turbine.

Building a frame and using clamps to help keep the bike stand in place, and bolting and bracing the turbine into that frame, seem to have resolved those two project-killing issues. So finally I can produce electricity in relative comfort!

(Note: motion sensitive people should watch with caution – hand-turning a pedal to get over 12.5 volts is hard work, so my camera arm wobbles a lot!).

Next challenge…

The last (hopefully!) major issue left is that of the chain skipping / jumping a cog or two when pedaling at 13.4 / 13.5 volts. Probably at least two contributing factors here.

  1. the wobble in the face of the turbine means the cogs aren’t keeping to one plane while they rotate (although how to address that without stripping the whole thing down and shaving off some of the rotor’s steel face beats me!).
  2. I’ve not quite managed to get the face of the turbine parallel with the chain going to the bike. Fixing that might mean altering the new frame and bracing arrangement <sigh>.

Of course in the video you might notice the chain appears very slack – and wonder why I don’t tighten it. The simple answer is that, with two links already taken out, tightening it any more will make it too rigid by far. Even moving it onto a bigger cog to take up some slack makes it far too tense. It wouldn’t last long given the forces at work here.

Of course the real answer is to start all over again and build a frame that allows for micro-adjustment of the distances and angles between bike and turbine… but affording the raw materials and time to do that would take a decent lotto win!

So I have to hope that I can resolve the chain problem another way.