3d print?!?

[MagnetJuice]

[JW]

That would be easy to draw as an assembly model, it would be 3D, once I get my graphics card I could probably draw it in an hour or two.

 

[MagnetJuice]

Thanks JW

Good to know that you can draw that image. I still have a PC with Win98 and and another one with XP. I have some very useful and simple programs that don't work with newer Windows.

I wonder what is the maximum diameter that GreenTeam can print. Maybe we can help him build something nice.

Ed

[GreenTeam]

Santa came early for me!! \o/  <-- me waving my hands in the air , like I just don't care!!!
Geuss I wasn't bad this year because santa didn't leave me a piece of coal. He left me two 1/2 kg spools of specialty metal filaments meant for 3d printing. One is stainless steel and the second is Iron.
So first thing I did was a magnet test on the filaments. And I've already read that the performance can be increased if used wisely. Here is the iron pla filament, which is 80 percent iron/20 percent PLA.
Success!!  I would say for sure. So I wanted to see how strong the attraction can be. So I thought maybe add some weight. And this is a bit more weight , I think that this is about the maximum weight I can add. The string of magnets was barely just hanging on. Anymore and it would fall off.

I can't wait to work with the stuff, I see alot of potential here!!!!

[GreenTeam]

Thanks JW

Good to know that you can draw that image. I still have a PC with Win98 and and another one with XP. I have some very useful and simple programs that don't work with newer Windows.

I wonder what is the maximum diameter that GreenTeam can print. Maybe we can help him build something nice.

Ed

My maximum print size is 220x220x250 mm , and that would be very nice!

[MattM]

Spinning metal embedded filament has to abrade your nozzle.  I'm intrigued by CF Nylon and it's toughness being compared to aluminum.  But the trick with that stuff seems to be run metal tips at 15 degrees higher than what it calls for to allow flow without near as much abrasion.  I bet iron embedded filament works in a similar way.

[MagnetJuice]

OK, that is 220 mm (8.66 inches) maximum diameter for the stator. I think it can be done.

I am going to do some calculations to see if it would be possible to make a 9 coil stator. If not, we would have to do 6 coils for the stator.

I have to look at an old project that I started a few years ago. It is a small generator that can be built into a bike stand and powered by a regular bike. It could produce from 50 to 100 watts at 12 volts. It would power a USB module that would give 5 Volts to charge phones and other things like that.

My plan was to use the generator to charge a small battery. I was thinking of a 12 volts golf cart battery, they are good for about 35 AH. Or you can use a regular 12 volts car battery, but I would prefer a deep cycle battery. Maybe you can build the stator using the 3D printer.

Are you interested in something like this?

Here is a picture of what I have in mind.



Ed

[MattM]

Or he could simply build three or six interlocking segments to get a limit of a radius rather than a diameter.

[MagnetJuice]

Yes Matt, that is possible. You are thinking outside the box. 

[GreenTeam]

OK, that is 220 mm (8.66 inches) maximum diameter for the stator. I think it can be done.

I am going to do some calculations to see if it would be possible to make a 9 coil stator. If not, we would have to do 6 coils for the stator.

I have to look at an old project that I started a few years ago. It is a small generator that can be built into a bike stand and powered by a regular bike. It could produce from 50 to 100 watts at 12 volts. It would power a USB module that would give 5 Volts to charge phones and other things like that.

My plan was to use the generator to charge a small battery. I was thinking of a 12 volts golf cart battery, they are good for about 35 AH. Or you can use a regular 12 volts car battery, but I would prefer a deep cycle battery. Maybe you can build the stator using the 3D printer.

Are you interested in something like this?

Here is a picture of what I have in mind.

(Attachment Link)

Ed

Yes! I am very interested in this!
I will list off what mats I have to work with
magnets -  25x15x3.5mm LOTS of these, to many to keep track off
                25x10x3mm not so many left
wire  0.7mm approx 1 lb
         0.25mm approx 1 lb maybe more
         0.5mm approx  2-3 lb not certain. but lots
bearings 6202R2 about 20 or so ( still have to surgically extract them )
         6906z approx 10, but these are really large I think

I also dont have any metal for backplates on the rotors, but, I may be able to get some somehow

[GreenTeam]

Spinning metal embedded filament has to abrade your nozzle.  I'm intrigued by CF Nylon and it's toughness being compared to aluminum.  But the trick with that stuff seems to be run metal tips at 15 degrees higher than what it calls for to allow flow without near as much abrasion.  I bet iron embedded filament works in a similar way.

Your correct, pretty much anything harder than standard PLA will eat through a standard brass stock nozzle on all printers.
But, they are really cheap, like 8 dollars for a nozzle. So, the price is relational to the nozzle attributes.
And since I will be printing stainless steels, irons and possibly carbon fiber filled, or carbon fiber maybe nylons etc.
I upgraded my nozzle to a MK8 Tungsten Carbide nozzle, and it was prettty expensive. And for printing regular PLA, I noticed
an amazing increase in resolution, and I can speed up the printer remarkably fast.
And, I am hoping, than being pretty much the hardest metals known to peopleKind, I may not need to replace nozzles again!
Time shall tell

[MagnetJuice]

GreenTeam,

Here are the details that you need to build the bicycle generator as shown in the picture in the above post.

The following calculations are for using a bicycle with a 26-inch tire and a 6 1/2 inch rubber tire on the generator. If you use different sizes for the bike or the small tire, the number of turns in the coils need to be changed accordingly.

The calculations assume pedaling the bicycle at 45 RPM. With the average gear ratio of 2.33, the bicycle tire will rotate at 105 RPM. If the small tire on the alternator is 6 1/2 inches in diameter, the alternator will rotate at 450 RPM.

At 450 RPM, the alternator voltage will be about 14 volts DC. If you pedal faster than 45 RPM, the voltage and amperage will increase and the 12 volt battery will start charging. If you pedal fast, you can pump 5 amps or more, at close to 15 volts DC into the battery.

The coils need 90 turns of .91mm (19 Ga.) wire. To get .91mm you need to wind 3 strands of .5 mm (24 Ga.) wire in hand.

The alternator has 2 steel rotors but only one rotor has magnets. One rotor has 6 magnets and the other steel rotor has no magnets. For the metal rotors, you can use the standard 7 1/4 inch circular saw blades. I am sure you can find used blades. I would use 2 blades per rotor to increase the thickness to prevent saturation and get higher flux.

For the magnets, you need to stack 3 of those 25 x 15 x 3mm together, then glue another set of 3 next to it, as in the diagram. Each magnet will be composed of 6 little magnets. You will need 36 magnets total.



The best way to glue the magnets together is using epoxy. Make sure that you clean the magnets with isopropyl alcohol before gluing them.

For anybody else who wants to build this, the best magnet size to use is 1 x 1 x 1/2 inches.

For those that don't have a 3D printer, it would be even simpler to cast the stator in resin. The stator form can also be made from a 1/4 inch sheet of polyethylene.



This is a 3-phase alternator. Normally, for 9 coils you use 12 magnets. By using 6 magnets, you keep the cost low and still get about 80 watts. That is the average sustained power that a normal human can produce using a bike.

This little generator can be used during a power failure to charge phones, for LED lights and if you use the full 12 volts from the battery, you can run a laptop.

This is a USB module that can be used with this. They cost about $6 US.



A few years ago, my power went out for 18 hours. I had a bike generator similar to this one. Using a bike and a cheap 12 volts 400-watt inverter, I was able to keep the food in my refrigerator and a small chest freezer from spoiling. My wife and I took turns pedaling. It was cold outside, so the pedaling helped to keep us warm. 

We also heated cans of soup using a small microwave oven that we keep for emergencies.

Anybody that wants to build something like this and has questions, just ask.

Ed

[GreenTeam]

Thank you! I never even thought about stacking magnets beside each other.

[GreenTeam]

What should I use for an axle? And how do I mount the bearings? Are the bearings mounted to the rotor or the stator? Or does it matter?

[Adriaan Kragten]

GreenTeam,

Here are the details that you need to build the bicycle generator as shown in the picture in the above post.



Ed

This generator picture looks very strange to me. If you have nine coils in the stator, the armature should have twelve poles and not six. For twelve poles, a north pole is passing the left leg of a coil at about the same time when a south pole is passing the right leg of a coil. So in this case, the voltage generated in the left leg is in phase to the voltage generated in the right leg and this results in the maximal total voltage. If you have only six poles, the situation is far from optimal and the total voltage which is generated will be very much lower than for twelve poles.   

[MattM]

With his magnets front-back like that does he want stators on both sides?

[MagnetJuice]

Yes Adriaan, that alternator design looks "strange" but it works.

It looks strange because it is not a conventional design. Most people are familiar with the ratio of 3-coils to 4-magnets. For example, 12 coils with 16 magnets, 9 coils with 12 magnets, 6 coils with 8 magnets. Those are the most popular configurations.

However, there are times when it is necessary to take a conventional design and change the number of coils or magnets to fit a particular design.

The alternator above is a design to fit a particular situation and solve a particular problem.

The problem is this, how can you produce 80 watts from a rotor with a diameter of 6 inches (175 mm)?

I am sure that there are other ways to solve that problem. I chose to do it that way to keep it simple and because the alternator will run between 400 and 900 RPM.

I could have used 12 magnets, but because there must be separation between the magnets to avoid flux leakage from one magnet to the adjacent magnet, I opted to use 6 larger magnets. The 6 large magnets have a magnet area equivalent to 12 smaller magnets.

By using only 6 magnets, I can have adequate separation between the magnets and avoid the flux leakage.
There are many other combinations besides the conventional ones. Which configuration to use depends on the application.

Here are two other examples. One is 3-phases and the other 5-phases. 3-phases is more efficient than 5. I just want to show what is possible.



Those 2 configurations are good for when you have powerful magnets and want to use smaller rotors. A higher RPM can compensate for the small decrease in voltage caused by having a smaller number of magnets than a conventional configuration.

Ed

[MagnetJuice]

What should I use for an axle? And how do I mount the bearings? Are the bearings mounted to the rotor or the stator? Or does it matter?

The easiest way would be to use one of these hubs. They are used on the front axle of Go-Karts. The blue one sells for about $25 ca. The other one sells for less.



They have removable bearings with 1/2 or 5/8 inch hole.

For the shaft, you can use a piece of cold rolled steel. A piece of all-thread rod will work too. Home Depot and many other places sell that.

Ed

[GreenTeam]

What are these hubs called if I were to search it out?
Part of my issues is that Vancouver isnt really anything like Alberta for shopping,
unless your shopping for weed stores, starbucks and beatnik foods

[bigrockcandymountain]

Part of my issues is that Vancouver isnt really anything like Alberta for shopping,
unless your shopping for weed stores, starbucks and beatnik foods

Ha ha made my day. 

[MagnetJuice]

I agree, shopping in Canada for parts is very difficult.

I live close to the US border, so I normally order from the US and cross the border to pick it up, but now it looks like the border will be closed until May for 'non-essential' travel.

And if the US bussiness ships to Canada, they charge $35 shipping for a $10 part. That is obscene. 

GreenTeam, since you live close to me, I will see if I can mail you some of the parts.

If you want me to mail you some parts, PM me your mailing address.

Ed

[Mary B]

I agree, shopping in Canada for parts is very difficult.

I live close to the US border, so I normally order from the US and cross the border to pick it up, but now it looks like the border will be closed until May for 'non-essential' travel.

And if the US bussiness ships to Canada, they charge $35 shipping for a $10 part. That is obscene. 

GreenTeam, since you live close to me, I will see if I can mail you some of the parts.

If you want me to mail you some parts, PM me your mailing address.

Ed

I used to make some astronomy related electronics(portable lithium power supplies with on board charging and solar controller. Guys would setup that morning to let it charge all day then have full power for the night), shipped quite a few to Canada until about 6 years ago when rates quadrupled making it not cost effective to buy from me... some ham radio operators bought them also. Biggest was a 50 amp hour. Most around 10 amp hour to run the tripod and camera if they did astrophotography. I used some voltage stabilizing electronics so they had a clean and solid power supply to keep noise out of the delicate electronics.Went from $20 shipping to $80!!!!

[MagnetJuice]

GreenTeam, I can send you the axle, metal rotors, wheel hub with bearings and mounting hardware.

I also have extra magnets, so I can mount the magnets on the rotor before I send them to you.

I have plenty of 19 Ga. wire, so I can make the coils also.

I had to change the design to make it 12 Magnets and 9 coils because the magnets that I have are smaller, but they are strong and have a mounting hole.

I will use 12 of these magnets:



This is the new stator form. After I wind the coils, I will know the exact dimensions.



You would need to 3D print the form for the stator and set the coils in it using epoxy.

If you don’t have a bike, you can find one at a second hand store.

I was planning to do this bicycle generator project for the Forum, but Covid has affected all my plans. And homeschooling 3 children takes a lot of my time.

I don’t have a 3D printer but I noticed that there are a lot of people that would like to use a 3D printer to build an alternator. So having this on the Forum would help many of the users.

So far, I have not seen any alternator built using a 3D printer. There is a lot a talk on the WEB and some have built something, but they are not complete systems and they look like toys.

So, because you are so enthusiastic about it, I want to help you and I hope that you will be the first to build and assemble a useful and complete battery charging system using a 3D printer.

Email me so we can coordinate this.

Ed

[GreenTeam]

Okies, will do!

[GreenTeam]

Okies, will do!

[kitestrings]

I had to change the design to make it 12 Magnets and 9 coils because the magnets that I have are smaller, but they are strong and have a mounting hole.

One minor advantage of a 12-pole alt is that if you can easily measure the frequency of the AC sinewave output, you can easily convert to rpm.  I believe frequency (Hz) = pn/2 (where p = # of poles, n = rps).  So, if you measure 20 Hz, your turbine is doing 200 rpm.

[GreenTeam]

What would the advantage be of having a sinusoidal wave pattern on the electrical wave forms? Its not like it is directly powering up a Power 9 quad server with SAS RAID 10 or sumthin...
Would the battery bank really care what the wave form is that much? And, also, when the power comes out of the battery, would it not be repped into the nicer waveforms?

[JW]

What would the advantage be of having a sinusoidal wave pattern on the electrical wave forms?

For one a SCR would not operate without it. Also read this.

Link- https://www.electronics-tutorials.ws/accircuits/ac-inductance.html



Link- https://www.energy.gov/articles/war-currents-ac-vs-dc-power

Starting in the late 1880s, Thomas Edison and Nikola Tesla were embroiled in a battle now known as the War of the Currents.

Edison developed direct current -- current that runs continually in a single direction, like in a battery or a fuel cell. During the early years of electricity, direct current (shorthanded as DC) was the standard in the U.S.

But there was one problem. Direct current is not easily converted to higher or lower voltages.

Tesla believed that alternating current (or AC) was the solution to this problem. Alternating current reverses direction a certain number of times per second -- 60 in the U.S. -- and can be converted to different voltages relatively easily using a transformer.

Edison, not wanting to lose the royalties he was earning from his direct current patents, began a campaign to discredit alternating current. He spread misinformation saying that alternating current was more dangerous, even going so far as to publicly electrocute stray animals using alternating current to prove his point.

The Chicago World’s Fair -- also known as the World’s Columbian Exposition -- took place in 1893, at the height of the Current War.

General Electric bid to electrify the fair using Edison’s direct current for $554,000, but lost to George Westinghouse, who said he could power the fair for only $399,000 using Tesla’s alternating current.

That same year, the Niagara Falls Power Company decided to award Westinghouse -- who had licensed Tesla’s polyphase AC induction motor patent -- the contract to generate power from Niagara Falls. Although some doubted that the falls could power all of Buffalo, New York, Tesla was convinced it could power not only Buffalo, but also the entire Eastern United States.

Would the battery bank really care what the wave form is that much? And, also, when the power comes out of the battery, would it not be repped into the nicer waveforms?

But there was one problem. Direct current is not easily converted to higher or lower voltages.

[SparWeb]

What would the advantage be of having a sinusoidal wave pattern on the electrical wave forms? Its not like it is directly powering up a Power 9 quad server with SAS RAID 10 or sumthin...

When working in strictly AC systems (example: AC power supply -> AC motor -> mechanical load) then the clean AC means you get the best power transmission through the system.

Would the battery bank really care what the wave form is that much?

No, it doesn't.  It can't get a clean AC in the first place because the AC circuit doing the work (wind turbine) is having its load switched on and off every cycle (rectifiers).  The battery clamps the voltage to a certain value, which chops the top of the sine wave.  It's a total mess.


There's nothing sinusoidal about that one.

It can get worse:



This one has the clipping, and it also has harmonics in the AC (3rd and 6th and probably more) all as a result of the rectifiers switching off-on-off-on every cycle and resonance in the AC circuit.  At 98 RPM the resonance was damped out but at 176 RPM the resonant frequencies are banging around more strongly.

And, also, when the power comes out of the battery, would it not be repped into the nicer waveforms?

Yes, that's generated by your inverter, which can and should be independent of the wind turbine's AC.

[JW]

What would the advantage be of having a sinusoidal wave pattern on the electrical wave forms?

Link-  https://www.electronics-tutorials.ws/accircuits/sinusoidal-waveform.html

Atleast he is using the properly terminology...

Steve I disagree with your oscilloscope waveforms     

[JW]

sinusoidal wave

[SparWeb]

Steve I disagree with your oscilloscope waveforms 

Do you object in a technical way, or just morally opposed to such horrible distortions!?   
I was blown away by this when I first saw this.

[kitestrings]

I think the point that may be, being missed is that the turbine is producing AC, albeit b@$terdized wild AC with variable frequency.  Or, I could have misunderstood, which is entirely possible too.