Author Topic: The trials and tribulations of building...  (Read 10675 times)

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zap

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The trials and tribulations of building...
« on: March 19, 2010, 08:48:22 AM »
The title of this was going to be much shorter a few days ago... recent problems and setbacks changed that and I decided to show more of what I've gone through trying to get this project completed.


This all started with a bike training stand a friend gave me.  I already have a pedgen, described elsewhere on this site.  It looks like this:




It's not huge but it's not what I'd call portable... I figured one made using the training stand would be a little easier to move around.

The same friend called one day about a piece of electronic equipment a client of his wanted out of her attic.  He told me it had "Back UPS PRO" on the front... I said I'd take it.

The UPS had been sitting in the attic without power for at least 5 years but it still worked and the CSB 12ah battery even came around and seems to still hold close to the original 12ah.


With the trainer and UPS... I decided to build a complete system... with an eye toward selling it.


Here's the training stand, it's a Performance Travel Trac.  A magnetic resistance, friction drive affair.





I have a few "big" PM DC motors around here.  The first candidate was a motor from a handicap scooter.

I could never find any information on the motor.  It came out of an Ortho-Kinetics scooter and is marked "Redmond PV2R08R 24VDC".

The way it moved the scooter around, my guess is it is a 400-600 watt motor.


I first set it up as a friction drive using the trainer's roller and bearings.





All the gray blocks you see are pieces of Trex plastic decking.  I have a few pieces of scrap that I've used for a few different things over the years... they seem to make a good coupler but I went through that many trying to get a coupling that would run true.

Part of the problem was that the trainer's roller was a different size from the motor and was threaded.  Once I had a hole drilled all the way through the block and then threaded it onto the roller, the hole on the other side wouldn't be centered.

To solve this I ended up drilling a hole just long enough for the threaded part of the roller and then hooked up a drill to the roller and lathed a "true" hole on the other end.


The member that the motor sits on was part of a frame from a very old microwave oven.


The motor originally had a plastic cog drive for a cogged rubber belt and a flat side with a hole for a drive pin.  To keep the length of the unit down, I cut off some of the shaft and drilled another hole for a drive pin.

Here's a close up of that with a temporary pin made from copper wire.





I cut down a fan from a microwave oven, added some tabs to the mounting rail to hold the motor... and  had to make another coupler when the first one started running out of true!!!

I ended up using a through bolt for a drive pin and left the coupler square both for strength and for ease of removal using a wrench.




I melted and formed a cowling from a piece of Plexiglas from yet another microwave and added a diode and cigarette lighter socket to the motors wires.




This looked good and seemed to work OK although I wasn't too happy with the friction drive.

The output was fine at 3amp but trying to get anything above that resulted in extreme slippage.  The torque for the friction drive is supplied by a spring and I found that the triangle formed once you have the drive engaged (see the third picture above) was just about the right size to stuff a tennis ball into to increase the friction.  Unfortunately that also caused the roller to really distort the tire and it was losing a lot of efficiency.


I decided to try a chain drive to replace the friction drive.

I knew I was losing some rpm but I got lost trying to calculate how much so I went ahead and built up a chain drive setup.


Lathing more Trex decking and a using a small cog from a 5 speed gear cluster resulted in this:





End result... not enough rpm.


I jumped ship on the scooter motor and went to a treadmill motor.  It's flywheel has a built in fan and with the stock spring of the trainer I've seen around 100 watts from it.








The UPS is an APC BACK-UPS PRO 650.  Here's some of the guts and the face.





I ordered a couple Ghurd controllers and built one up soldering the LEDs in on the opposite side, added an 80 watt halogen light, a 12 muffin fan, a switch, and a male cigarette lighter plug.... drilled two holes for the LEDs and one for the halogen light... crammed it all in the front of the UPS and ended up with this:









Here's what the face looks like.





This is what I wanted to mark it up to look like.




This setup worked well enough and while I was working on the generator I'd hook this to the solar to control it's charge.

I made the mistake of wiring the + of the generator to the controller side of the switch.  I did this so there would be no voltage present at the cigarette lighter plug when the switch was off.  I fried something in the controller and needed to build the spare one up.

I moved the + of the generator to other side of the switch and added a diode to the  cigarette lighter plug and all was well.


I didn't want the UPS's beeper on constantly so started to work on silencing it.  I had already soldered in a temporary LED in parallel with the speaker in hopes I could have a "visual beep" to aid in cold starting the UPS and that worked.

The space is small where the beeper is situated and I wanted to try sticking a toothpick into it's output hole to try and silence it before I tried a more permanent fix.


I removed a few screws and was able to get the toothpick into the beeper but upon start up, I noticed a red LED on the UPS come on that usually didn't light up unless you had a low battery.

As I moved the UPS around to get a better view I shorted the PCB out on the metal frame of the UPS, saw a spark from somewhere on the PCB... DOH!

I removed the battery and hooked everything up again but when I pressed the start button all I got was a click from one of the relays.

I searched the PCB and found this:





It's a fuse that uses the board trace as a fuse.  Some of you have probably seen this before... I never had.

I found some small stranded wire that tested out at around 4 amp before it blew so I soldered one in for a repair.





I hooked the battery up and pushed the power button and got a steady scream from the beeper... not good.


That's pretty much where the projects stands now.

The PCB has two of those fuses, one appears to be good and two 40 amp automotive fuses that are soldered in and those appear to be good.

The circuits are too confusing for me to trace because the board has circuits on both sides.


Newegg.com has a 400 watt inverter that goes on sale often for $19.99 shipped.  I think I'll grab one of those and stick that, the Ghurd controller, and the battery in an old metal tool box I have.

« Last Edit: March 19, 2010, 08:48:22 AM by (unknown) »

Norm

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Re: The trials and tribulations of building...
« Reply #1 on: March 19, 2010, 11:26:01 AM »
Zap; on the treadmill motor where you got about

100 watts, what was the ratio to pedal speed?

« Last Edit: March 19, 2010, 11:26:01 AM by Norm »

fabricator

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Re: The trials and tribulations of building...
« Reply #2 on: March 19, 2010, 12:53:49 PM »
That first pic looks like it might be a little tricky to run, a unicycle pedgen. :)
« Last Edit: March 19, 2010, 12:53:49 PM by fabricator »
I aint skeerd of nuthin.......Holy Crap! What was that!!!!!
11 Miles east of Lake Michigan, Ottawa County, Robinson township, (home of the defacto residential wind ban) Michigan, USA.

zap

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Re: The trials and tribulations of building...
« Reply #3 on: March 19, 2010, 01:20:31 PM »
I can get some guesstimates for you Norm but it probably won't be until Monday.

Blizzard going on right now and the bike's outside.


I can tell you 100 watts with that setup was pedaling my legs off and I doubt I could keep it up over 10 minutes and maybe not even 5 minutes.

« Last Edit: March 19, 2010, 01:20:31 PM by zap »

zap

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Re: The trials and tribulations of building...
« Reply #4 on: March 19, 2010, 01:30:59 PM »
I have thick rubber platen from an old 24" printer that fits under the front of my couch and then sits on the pedgen's frame.  If you look close you can see where the paint's been rubbed off along the top of the frame on both sides of the vertical frame member.

That's usually good for 30 watts or so... pedaling any harder needs something in front of it to keep it from sliding forward.

« Last Edit: March 19, 2010, 01:30:59 PM by zap »

Jon Miller

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Re: The trials and tribulations of building...
« Reply #5 on: March 19, 2010, 01:49:20 PM »
Sorry to say the UPS is dead, grab another one of ebay, the 12 volt UPS will use 15 watts with no load on it and all the time you use it so some of your hard pedalling is going on keeping the UPS alive.  A cheap modified sine wave will use about half an amp maybe 0.3 so 3 watts to 6 watts, a lot less then the APC UPS.  


The pedal motor efforts look good.  When you sit on one for an hour one realises how much work it really takes to even delivery 100Whs.  


Regards

« Last Edit: March 19, 2010, 01:49:20 PM by Jon Miller »


Ungrounded Lightning Rod

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Re: The trials and tribulations of building...
« Reply #6 on: March 19, 2010, 06:57:22 PM »
When making a pedal generator you should arrange a small fan to blow air on your legs.  This ENORMOUSLY increases the power-time product you can produce before you tire out.


People are designed to jog all day to run down the furry things that overheat, so if you wear shorts and cool your legs you'll be able to get non-trivial power from a pedgen.


Some exercise bikes come with a small fan included and powered by a mechanical linkage.  (I've seen pix of one with a little squirrel-cage fan.)


Powering it mechanically saves a couple conversion inefficiencies compared to powering it electrically.  However the cube-law also applies to load vs. speed of the fan, so (like with your car's radiator) an electric fan that provides "enough" air circulation rather than proportional-to-speed airflow might leave you with more power in your battery.

« Last Edit: March 19, 2010, 06:57:22 PM by Ungrounded Lightning Rod »

Norm

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Re: The trials and tribulations of building...
« Reply #7 on: March 19, 2010, 07:37:07 PM »
I guess we can appreciate David Butcher pedaling

100 watt/hrs almost daily in an hour as a

regular routine ....on my machine I can do about

30 watt/hrs. going to hook up a more efficient

machine in the near future....
« Last Edit: March 19, 2010, 07:37:07 PM by Norm »

zap

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Re: The trials and tribulations of building...
« Reply #8 on: March 21, 2010, 05:15:20 AM »
I didn't take the time to check the idle current.

This wasn't going to be something you left on all the time so the idle current wasn't a big deal.

I have an old Philips 20" CRT TV that eats around 45-50 watts and the UPS ran it for an hour as I pedaled and the UPS barely got warm.


I have a feeling you're right about it being dead.  The city wide bulk trash pick up is a few weeks away and I've found a few UPS in years past.  If I can't get the current one running and don't find one in the "Trade Your Trash" event... I'll probably pick up an inverter.

« Last Edit: March 21, 2010, 05:15:20 AM by zap »

zap

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Re: The trials and tribulations of building...
« Reply #9 on: March 21, 2010, 05:34:56 AM »
You're right about a breeze but how much extra heat is produced depends greatly on how good a shape the engine is in.


At the time I built the first pedgen I was averaging about 500 miles a year on my bike and over the winter I could "pedal" the TV for 2 hours and hardly break a sweat.


Most of last summer's bike time was spent building the push trailer... I'm not sure I even rode 100 miles.  "Pedaling" the TV this winter has been a chore for a half an hour.  But I did benefit from being hot because I keep the house so cold to save money.  And also benefited by being in better shape for bike rides this summer.

We had a few nice days last week so I hopped on the bike on one of them and riding 10.5 miles was a breeze(pun intended).

« Last Edit: March 21, 2010, 05:34:56 AM by zap »

hiker

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Re: The trials and tribulations of building...
« Reply #10 on: March 21, 2010, 10:34:44 PM »
hey zap..

i converted a 300-480v ac motor awhile back-hooked all the phases in series..

hooked it up to a exersize bike.. wired in a extention cord for output..

works great for small tvs or stereos..[vid is a stereo and record player]

it can power a vcr and 45-65 watt tv--with hardly any effort--watched a 1 hour plus long tape with it..powered by ceramics-im going to change it over to neoes-just to see what it puts out..no need for batts or converters-straight ac out.....fun stuff..

http://s153.photobucket.com/albums/s208/hiker_07/?action=view&current=stereotestmotormill.flv

ps:with the coils rectified and wired in parelle i can get close to 300watts out of it.

3 100watt 110v bulbs..pedaling speed is all out of course!!

love bike riding also-the cross country skiers keep the trails packed up here...
« Last Edit: March 21, 2010, 10:34:44 PM by hiker »
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Re: The trials and tribulations of building...
« Reply #11 on: March 22, 2010, 05:33:13 AM »
It makes me appreciate 100W PVs a lot more!

G-

« Last Edit: March 22, 2010, 05:33:13 AM by ghurd »
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zap

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Re: The trials and tribulations of building...
« Reply #12 on: March 22, 2010, 08:30:28 AM »
I've got some numbers for you Norm.


My cadence(pedaling rpm)is right around 88rpm.


The drive train for the test was a mountain/comfort bike with a mostly tread free 26"(25 3/8" dia.) tire using the middle cog on front(38 teeth), high gear on the rear(13 teeth).


Pedal to motor flywheel ratio is close enough to call it 12 to 1... so 1056 rpm at the motor?


Under those conditions:


Open voltage is 21vdc


Powering a 12v automotive headlight:

9.3vdc

6.15amp

for 57.2 watts


Powering a 12v headlight and 12v halogen in series for a 24vdc load:

17vdc

3amp

for 51 watts


Hooked up to a fairly flat 12v 5.2ah NiCd pack

13.9vdc

5.3amp

for 73.7 watts


To save your knees... gear it for higher pedaling rpm.  I'm usually up around 100 on my cadence by the end of the summer.

« Last Edit: March 22, 2010, 08:30:28 AM by zap »

zap

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Re: The trials and tribulations of building...
« Reply #13 on: March 22, 2010, 08:48:15 AM »
I remember that video hiker... impressive power.  That was a motor from an airplane or something aviation?

All the conversions I've done have seen the stator over saturated by adding better magnets.


I'm a fair weather rider but the ski trails sound interesting.

« Last Edit: March 22, 2010, 08:48:15 AM by zap »

zap

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Re: The trials and tribulations of building...
« Reply #14 on: March 22, 2010, 09:02:47 AM »
But you still have parts waiting around for building a pedgen right? :)


Do the Amish curse pedgens?  As far as I know they use bikes so...

Maybe this could be the next phase in your dozen-aire status.

« Last Edit: March 22, 2010, 09:02:47 AM by zap »

ghurd

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Re: The trials and tribulations of building...
« Reply #15 on: March 22, 2010, 09:56:38 AM »
Yup!  Lots of dust collecting parts still waiting for some kind of use.


Amish are hard to explain, except to say they don't use bikes in this region at all.

Typical old order around here.  Nothing to either extreme of the wild stories.

Kick scooters were only semi-recently accepted, for children only.  I mean really, would you be caught going to work on one of those?  LOL

Red, pink, etc, would be not-a-good-color-choice for them, around here, and those are made mostly for resale to people like me & you.

(mostly BS site with a reasonable pic)

http://www.amishshop.com/hazel-doc/imagesnewamish2006/scootergreen.jpg


Exercise bikes are OK, though not common.

Hang one of those $250 ebay Ameteks on a $250 exercise bike, sell it for $524, and I'd be all set!

G-

« Last Edit: March 22, 2010, 09:56:38 AM by ghurd »
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Norm

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Re: The trials and tribulations of building...
« Reply #16 on: March 24, 2010, 05:27:13 PM »
Thanks for the data Zap. Little bit better than

Ametek with 1:18 ratio its easier to charge 24

volt than 12 volt and 6volt requires way too much

torque.....it's easier to pedal fast to get higher

voltage and less amps the watts stay the same

 but like you say ....it's easier on the knees.
« Last Edit: March 24, 2010, 05:27:13 PM by Norm »

zap

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Re: The trials and tribulations of building...
« Reply #17 on: March 25, 2010, 05:50:53 AM »
You're welcome Norm.

I guess I did type the ratio backwards... oops.


I'm surprised this motor would do better than an Ametek.  The treadmill it came off of did seem like a good one.

I used the treadmill's deck for the pulley/flywheel in the first picture on this page.  That pedgen uses the motor off of a corded electric mower and it's ratio is 1:7.

« Last Edit: March 25, 2010, 05:50:53 AM by zap »

Norm

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Re: The trials and tribulations of building...
« Reply #18 on: March 26, 2010, 02:53:06 PM »
Yep....I'll have to try a treadmill motor next

then the ECM.....My first one was a small DC

motor that turned 1:40 and charged 12 volt

batteries at 1.5 to 2 amps which wasn't bad and

thinking of using it again for hand cranking

great for the shoulders!

Pedgens are ever bit as satisfying as  generating with ....free? wind.

.....my opinion of course.
« Last Edit: March 26, 2010, 02:53:06 PM by Norm »

hiker

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Re: The trials and tribulations of building...
« Reply #19 on: March 26, 2010, 11:39:52 PM »
hey norm..

if you want a treadmill motor i have a few laying around collecting dust..

for the cost of shipping..

no idea what the shipping cost would be?

drop a e mail if interested...
« Last Edit: March 26, 2010, 11:39:52 PM by hiker »
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REdiculous

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Re: The trials and tribulations of building...
« Reply #20 on: March 27, 2010, 07:52:03 AM »
Is that an offer you might extend to others? Or something close to that?


I almost tore apart my current project so I could make a pedgen instead. The treadmill motor I've got cost me like $35...you probably know the motor; the Argord that surpluscenter had for a bit. A few days ago I found the exact same model on ebay w/ a starting bid of $70.


I can justify $50 but not much more than that, yaknow. tia

« Last Edit: March 27, 2010, 07:52:03 AM by REdiculous »
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Norm

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Re: The trials and tribulations of building...
« Reply #21 on: March 28, 2010, 08:18:34 AM »
Yes hiker I could use one for the pedgen as I'm

using the other one for another project namely...

an electric assisted conventional bicycle. If it

has a flywheel ....that heavy cast iron thing...

you could keep that!

I wish I could have got one of those when they

were selling for $10....remember?  

....that was the big drawback back then the heavy flywheel...hiked the cost of shipping

 let me know how much for

shipping please E-mail me and I'll give you my address?

and thanks Hiker!

   
« Last Edit: March 28, 2010, 08:18:34 AM by Norm »

zap

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Power box update
« Reply #22 on: April 28, 2010, 10:26:07 AM »
UPDATE

When I last reported on this project, I had managed to zap the electronics of the APC UPS and the project was dead in the water.

I had my eye on an inverter on newegg.com.  It seemed to go on sale every few weeks and as luck would have it, a few weeks after I zapped the UPS, the inverter went on sale at the lowest price I've seen yet, $18 shipped.
See my review of the inverter here.
It's a 400 watt Rosewill RCP511F and if you read the reviews on newegg you'll see most people like the inverter and the only real problem they report is the loud fan.

The fan is loud and sitting in standby the unit pulls 220 ma.
I found a circuit years ago on a ham radio site that's pretty simple.


Here are the parts ready to be installed in the inverter.


And here they are installed.


It's not sophisticated but it works and now the fan and circuit pulls around 130 ma in standby and fan RPM will rise with temperature.

I had a couple of old metal tool boxes sitting around.


 
I painted one...



...and stuck the inverter in one along with 15.6ah of Bruce NiCds, a Ghurd controller, and a cheap HF meter.



I cut a slot on the right for the cigar plug cord and and a rectangle on the left for the cords for whatever will be powered by the inverter then placed rubber sheeting over the opening and sliced them so the cords can go through.



I cut out the foam in the lid and used Velcro to fasten the meter.  I bent the blades off an old plug and drilled two holes in it for a socket for the meter probes and hot glued it above the hinge.


I'm still using an 80 watt halogen bulb for a load.




It weighs around 22 lbs and so far has worked well.  I did an endurance test using a 19 Philips crt TV(45-50 watts avg.) and at around 2 hrs and 10 minutes it started emitting a low voltage buzz.  Voltage at that point was 10.2v... the NiCds should do fine.
« Last Edit: April 28, 2010, 11:19:59 AM by zap »

DamonHD

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Re: The trials and tribulations of building...
« Reply #23 on: April 28, 2010, 11:12:19 AM »
Don't try taking that anywhere near airport security!  B^>

Rgds

Damon

zap

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Re: The trials and tribulations of building...
« Reply #24 on: April 28, 2010, 11:21:17 AM »
heh... yeah... do doubt it might raise some eyebrows!

ghurd

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Re: The trials and tribulations of building...
« Reply #25 on: April 28, 2010, 03:06:13 PM »
That fet is operating linearly by design.
Should be OK with the low power fan, but I'd suggest a heat sink on it anyway.

The IRF246 was a TO-3 package, meaning by default it weighed about "a lot" and had some heat sink area built in by default for that kind of power.
The TO-220 package is exponentially harder to keep cool.

Sad when something has airport issues... just because of hot glue.   :'(
G-
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zap

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Re: The trials and tribulations of building...
« Reply #26 on: April 28, 2010, 04:03:27 PM »
Don't ask me why but I figured the 'linear' part was being taken care of by the thermistor.  I ran it for quite a while on the breadboard and never noticed anything getting hot.

You or anyone else is welcome to tweak the circuit.


I saw a 555 based PWM motor circuit the other day that I might try for thermal fan operation but it won't be nearly as small.


HOT GLUE! ;D