BIKEPGH MESSAGE BOARD ARCHIVE

You could go to Free Ride and fix it up.

There are a lot of cool things you could build though. Bike blender, maybe?

Bike blender--like "Will it blend?"

http://www.blendtec.com/willitblend/videos.aspx

I've been hoping someone would develop an attachment to a refrigerator that would let me run the compressor during a power outage. Whenever there's a huge storm or flood and the power goes out, people end up pitching all manner of food afterward. But that's only because the absence of electricity to run the motor. The compressor would be just fine.

So what would be needed is a hookup to the compressor that would let you attach a speedometer cable from a bike-wheel. Whether from a trainer or an exercise bike, doesn't matter. You could at least keep the food from spoiling.

Frankly, this is so obvious an idea to me, I don't know why it hasn't been standard household equipment since exercise bikes started becoming common 30 years ago. The difficulty now is finding speedometer cables.

I'm not too familiar with refrigeration technology, but I have a feeling a cable wouldn't be up for it, belt drive would probably be a better solution.

Better yet, why not just build a bicycle powered electric generator?

I was talking to a friend of mine about this, and he had a few thoughts I'm going to attempt to relay:

First, the fridge comes on pretty frequently throughout the day. If you wanted to pedal your bike to keep it powered in real time (assuming the power needs of a fridge can be met by what the cyclist can provide - not sure on that) you'd kind of need to be around all day, all night, until the power came back on, which doesn't seem practical.

He suggested (and wasn't sure how workable this would be, but was just thinking about how to possibly get around the above problem, and some other challenges with trying to integrate the belt drive into the compressor) getting a car battery to power the fridge during an outage (you'd need a power inverter with the right wattage to match the reqs of your fridge) and then using the bike to recharge the battery. That way you could pedal when it's convenient and store the power in the battery for when you need it. To get the power you generate on the bike into the battery, you could use an alternator (steal that from the car you took the battery from) and just replace the pulley that would normally be driven by the fan belt with a sprocket that could be driven by your bike chain.

There's also some additional electronics you'd need to power your battery with the alternator (like a voltage regulator) but that's stuff you can buy - they need it for cars so it's out there.

Problem is, you'd get hungry from all that pedaling, so you'd need to make yourself a sandwich, so you'd open the refrigerator, and all your hard work would go invisibly pouring out across your kitchen floor...

one piece cranks make nice toilet paper holders or coat hooks. just need an angle grinder to cut off the non-drive side crank and grind it down flat to the chainring. don't have pics.

also, you can make a cheap-o workstand with an old pair of drop bars.

I'm already on it.

My idea is similar to your friends. However, I am going to drive the alternator with a belt. I am going to use the rear wheel is a pulley. Driving the alternator with a chain from the crank wouldn't spin the alternator fast enough.

With a 50t chain ring, a 12t rear cog, a 27" (63cm) wheel, and a 5cm pulley on the alternator the alternator will spin 51 times. At a cadence of 100, the alternator will spin 5100 rpm. (if the 12 t cog was directly on the alternator, it would only spin at ~410rpm)

That's far less than the idle speed of the engine the alternator is coming out of. Plus, the ratio between the crank pulley on the engine and the alternator is about 2.3, so at at 750rpm, the alternator spins at ~1700rpm.

With the rider spinning at 100rpm, it is similar to a car at 2,200rpm, which is right in the area for average driving.

Plus, most modern alternators have voltage regulators built in. As far as wiring goes, I'll my design calls for positive and ground from the alternator to the battery (fused), and from the battery to the inverter--I'll just use the steel frame for a ground. I'll throw in a voltage gauge, but that's in the details.

The alternator I am going to use is a 90amp unit. I actually have a few of them laying around, so if this works, maybe I'll make more than one.

Now that I think about it, I cold just connect a belt from my training rollers to the alternator....

a direct drive might not work as well as making a fly-wheel. that's how many pedal powered machines work. think about how some of those old stationary bikes work. you pedal a really heavy wheel, that picks up a ton of momentum, that then powers whatever you want. it's hard to get started, but once it's going, it sustains power

That's a good point. With this design the wheel acts as a flywheels to a certain extent. A heavier one would be great, but with this design I pretty much have everything needed laying around, and I should be able to get it together in a few hours.

I was talking to robjdlc about machining a strip to bond to the inside of the rim to match the profile of the pulley on the alternator so the rim meshes to the belt correctly.

With a lb. or so added to the outside, it should change I (moment of inertia) significantly.

This video does a good job descibes some of the limitations of bike generators. I was looking into this after losing power during the big snow. I think Stu's idea of driving the compressor directly is probably much more efficient in the long run because there's a lot of heat energy lost every time you convert from mechanical to electrical and back again.

hmm.. from an alternate engergy standpoint, this might be neat if you already had something in your home like solar or wind where you already had the backend system to put the energy back on the grid. You could pedal your meter in the opposite direction.Just a guesstimate, if you could put out a consistent 200 watts during a workout, I would think you could probably convert have of that to usable electricity if not a bit more.

Would be neat to hook this to a television or something so you could only watch tv if you were on your bike.. would be pretty effective at remedying obesity imo.

@Marko82: (This also from my friend) Don't compressors have a specific rpm that they run at? So you'd need to really nail your cadence and be consistent. I think.

@ndromb: wow! cool. dude.

They have a laptop recharging bike at UC Davis in the student union building.

Article: http://www.dateline.ucdavis.edu/dl_detail.lasso?id=11269

YouTube video: http://youtube.com/watch?v=KB3NkahC8DQ

I've used it, but I felt like a big dork, as its in the middle of a busy hallway.

Mark, I think my design has some features that help over come the problems his design has.

First, I am using an alternator instead of a generator and I am utilizing a few hundred Ah of batteries. The load resistance should be a lot lower. The electric appliance isn't getting power directly from the alternator, it is getting power from the batteries.

Also, having the wheel acting as a flywheel is should over come some of the resistance.

Most important, I have a significally better hair-do than that guy.

But, I guess we will just have to see when it's done. Hopefully I can get the frame started tomorrow. I am quickly running out of cheap bikes to chop up.

I have a foundling bike I've been wanting to make into a penny fakething.

Just googled "penny fakething"... There is another project I need to make!

That's awesome! I was thinking about doing one of these for my son, when he's a little older...

I got it!!! Just buy food in cans that don't need to be refridgerated! Oh wait, I forgot about BEER...

Penny Fakething: "All the danger and none of the historical authenticity."

Actually, I think they are safer in that the standard ordinary traps your legs underneath the handlebars. Whey the wheel stops there is nothing to hold you back from taking a header. Whereas, in the penny fakethings, the handlebars are typically under your seat so, should you go over, you lead with your feet and may be able to hit the ground running.

Proper beer you can serve at cellar temperature.. so just keep it in your basement.

ok - I'm looking in to making a bike blender and maybe a bike fan... Anybody have any DIY bike blender step by step instructions (or link to one) that produces a non-frustrating, functional result? We tend to use the blender more days than we don't, and at least twice a week it could be very useful to have a fan-assisted laundry rack setup.

I'm open to ideas that both use a bike permanently and those that are temporary add ons to a bicycle that can remain independent. I'm just looking for something easy/cheap to set up and that will work without mess/fuss.

help?

Nick,

I like the idea of charging batteries with a bike but as far as attaching the belt from the wheel to the alternator you have to remember that when you increase the revolutions you decrease the torque and a generator is not the easiest thing to turn. if you try to increase the rpm by a factor of 51 you reduce the torque by a factor of 51

Total power output does not change at any point in the drivetrain. The only thing that changes is how the power is used.

Please forgive me if I am coming off condescending. it is not my wish. I have simply spent to many years in engineering

dbacklover: Back when this was first posted, I shared with nick something I had built:

Ejwe: all of my plans for bike blenders involve bevel gears and welding, sorry, haha.

I haven't spent much time on this since I started it...

Edit: I wrote a long reply and lost it trying to edit it.

ej, I think the best way to build a bike blender is as a standalone machine. If you Google it, there are some step-by-step instructions available, but I cannot vouch for the end product.

I've had a stand along blender on my project list for a while, but it is a long list....

Ok, I've got a friend who is more mechanically experienced than I am, and my ideas entertain him, who has offered to help. I also found some links online:

http://www.magnificentrevolution.org/2010/02/the-return-of-bicycle-blender/ (looks sleek, but they don't include directions)

http://www.instructables.com/id/How-to-create-a-human-powered-bike-blender-for-les/ (haven't read the whole thing, but there seem to be enough comments that people have tried it and posted modifications, should be able to figure something out).

I've just discovered a way this week of driving (ICK) to work in about an hour (independent of time of day, no traffic, no tolls) but will still need to get in my hour of sweating to maintain my sanity - ergo incorporate bicycle blending, fanning, laundry, additional rotory machinery, into my life may help for days when I dont' want to spend an extra 3 hours commuting.

I'll post results here.

Rob

That picture is my kind of prOn!! hard to tell from the pic, what is the green cylinder, a flywheel?

I swear I get twitchy just getting near a machine shop.

dback - I don't think we ever figured out what it was originally for, but its basically a 6 inch rubber wheel with set screws holding it onto the shaft. The original design had it planted against a treadmill, but it basically works for any wheeled application.

Not pictured: top left, tig welder and sandblasting booth, top right, metalite wheel, grinding wheels, plasma table, vertical and horizontal bandsaws, right, plate bender, lathe, bridgeport, direct left, mig, air tools, pipe bender, assorted other goodies.

Feelin' twitchy yet? haha.

Thats it Rob, talk dirty to me.

what really kills me is I have designed machines for years and years but if I ever tried to use any of the machines you just mentioned there is a good 75% chance I would end up in the hospital.

oh dback, it's easy. I worked as a machinist through college, and had about as much training as "this is aluminum, run it at this speed, use this oil, these are your measuring devices, make this drawing - go."

Best. Job. Ever. Highlight of college experience. Been trying to figure out how to get a job as a machinist (preferably in a small interesting shop, not ass'y line) without being a 17 year old apprentice first ever since. Turns out engineers are wanted with machinist experience. Machinists are wanted pure and untainted by Cubeland. You can never go back...

"what really kills me is I have designed machines for years and years but if I ever tried to use any of the machines you just mentioned there is a good 75% chance I would end up in the hospital."

...that's an engineer for ya....

Nick,

That's pretty much it.

I know, my dad is an engineer, and I spent the majority of my time at Pitt in the engineering school. It so happens, that is also the reason I left the engineering school.

I have made some revisions to my design (simplified it immensely), and maybe some day before I die I will finish building it.

Hey dback, if you like machinist pr0n, check out the Gingery "Build a metalworking shop from scrap" books. They start out teaching you to make a charcoal-fired furnace for melting small quantities of scrap aluminum, and you end up making drill presses and horizontal mills and stuff.

I have the series...every couple of months, I re-read 'em and pretend I'll actually start the projects.

Dan

I saw them on MAKE: I know what you mean.

If you like metal work and bikes, check out Jeff Tiedeken's Blog Monkey Likes Shiny