Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 01:37am 18 Mar 2010
Copy link to clipboard
Print this post
karl
1)Stacking plates, for the middle rotor plate can you have magnets on both sides of one steel plate or does it need separate plates ?
2) can you have a inter and outer ring of magnets? (basically a circle inside a circle to produce higher magnet field) and if so does the stator coils have to be separate for each circle of magnets
naill1,
After some internet searching I have seen several company's offering noe magnets with precast holes but have only found one company with pie shaped magnets and they don't offer the holes
there are allot of amazing adhesive glue type products out there now days that probably would work without fail but gluing something with out securing just makes me nervous personally Edited by goldhunter_2 2010-03-19
niall1 Senior Member Joined: 20/11/2008 Location: IrelandPosts: 331
Posted: 01:39am 18 Mar 2010
Copy link to clipboard
Print this post
hi Karlj
i dont doubt the adhesives you mention are extremely strong and i,m sure they would bond very well to the nickle coating on neos but heres my concern...
the coating itself has at best a very tentative grip on the neo material beneath and its microns thick , i dont think its purpose is for mechanical strength ....but thats just a personal opinion
if the coating is compromised in any way due to corrosion , bad handling or even a scrape it can blister and can be easily peeled off...try it with an old neo its very easy...
once the coating is damaged you'll peel lumps of it off with your finger nail in a second or two
the adhesive properties of nickle to the magnet beneath
are similar to a banana skin and the fruit beneath
this is just some off my experience with them ... all be it the bad ones...maybe i,ve been unlucky but i,ve seen a fair few nickle coated ones fail this way in open axial machines
heres a worst case scenario ..the nickle coating is in freefall , its only a matter off time ,
not pretty... but in some cases that can be the level of protection and strength nickle gives , the rotor above came out of a working machine with no signs off rubbing the stator yet the coating still failed , why it happened is anyones guess
its not all bad ...and i really dont want to be negative but neos can be a pain in the ass sometimes ....theres nothing new here , magnet problems on rotors seem to crop up and frustrate people ..me included , how to minimize the problem is the big question
ps ...climate seems to be a major factor... here its perfect for corrosion , maybe that colours my thinking ...
pps ..sorry for the edits i,m at the bottom of a bottle of red ...its paddys day after all.. Edited by niall1 2010-03-19niall
KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178
Posted: 09:58am 19 Mar 2010
Copy link to clipboard
Print this post
i'm out of my depth here, personally i cant see any problems with running magnets on both sides of a disc,
BUT i think it would be better to use the magnets both sides so perhaps something that grabs them down their sides?
Bury the whole things in epoxy, should solve all these corrosion issues (and fly away magnets)
Tules has suffered some neo cancer recently too!Luck favours the well prepared
niall1 Senior Member Joined: 20/11/2008 Location: IrelandPosts: 331
Posted: 12:07pm 19 Mar 2010
Copy link to clipboard
Print this post
out of depth here as well....
using epoxy/vinyl ester with epoxy coated mags seems nice but the cost goes up
i think this is another thread in itself niall
Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333
Posted: 12:25pm 19 Mar 2010
Copy link to clipboard
Print this post
Epoxy wont stop fly aways as it has little strength except on face to face surface contact.
It has been said many times that several coats of epoxy paint over the magnets for enviromental protection is required, and i think Oz has stated this many times to.
I see no reason back to back magnets can not be used as long as the poles were reversed either side of the plate.
The folks in the real know of this design have butted out of the thread from what i understand as the whole expectations are unrealistic to achieve on many fronts, from battery capacity, to required cable size required, Etc,etc.
Karl we have followed your project to make 400+ watts average, and we are now talking 20 times that.
It just aint practical in 1 VAWT....Simple!!!!
For all those who think it is worth while i would like you to start a thread on the "otherpower" site asking their thoughts as there is many people there that have built big mills and have gone through the process of the failures to know what works and what is realistic to be acheieved.
Pete.
Sometimes it just works
goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 01:38pm 19 Mar 2010
Copy link to clipboard
Print this post
naill1,
yep that's what worry's me about the adhesives
I have contact some of the magnet company's asking for custom shape magnets with countersunk bolt holes so now I'll wait to see what they can offer
Don't worry about the editing I have a habit of editing my post for one reason or the other to
Downwind ,
I listened about the voltage and found a company who sells a 48V controller 440 Amp! -- 10,000 watt!! - Diversion (Charge) Regulator
With High contrast LED Battery Voltage Meter
Works directly with 12, 24 and 48 volt systems
I have looked at otherpower before but find it harder to navigate so I don't go there often
yes it is a shame that other persons exclude them self as they probably had plenty of knowledge to offer, but this thread has become more productive in answering questions since they left then it was when they where here.
Karl,
Thanks
Edited by goldhunter_2 2010-03-20
birdhouse Regular Member Joined: 27/01/2009 Location: United StatesPosts: 63
Posted: 06:15am 23 Mar 2010
Copy link to clipboard
Print this post
gold hunter-
1st point. gizmo, one of the guys to leave this thread is the person running this forum. you ought to be nice.
2nd- you are only interested in the pma for your purpose. generally here we talk about all the ins and outs of a full system. just how it goes. no one cares about a 10 kw alt. unless they know the whole scoop.
3rd- you talk of multiple porshe's in the garage. most of us have not that luxury. you may have the deep pockets to pull of such a feet. are you an engineer? one will be needed to complete your project.
4th- just level with us. who are you and why and how do you plan to pull off such an amazing feat?
5th- vawts are WAY WAY WAY less efficient than HAWTS!
6th- you talk of gearing... there is only so much power in the wind for a given swept area. gearing has losses, so the geared machines should actually produce less power than the direct drive options.
7th- as stated before if two turbines have the same swept area and one is claiming 6X the output, they are lying!
8th- you are the one starting to sound like the commercial interests are in your court!
birdhouse. Edited by birdhouse 2010-03-24i pee more than once before flushing, and don't have to flush at all up at the ranch!
goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 05:04am 24 Mar 2010
Copy link to clipboard
Print this post
oh well so much for this thread starting to be productive I see where back at this again
first off I don't see where I have ever spoken with Gizmo privately or on this public thread. 2nd I treat people the same as they treat me
again as I have said a few times already by talking about a whole system you get disagreements in opinions causing the thread to stray away form the intended subject just as this thread has thus clouding any real information that was offered or attempted to be offered
here is something else I have implied before but lets repeat it. there are NO two people that have the exact same resources at there disposal thus trying to compare one person reasons to another is a useless waste of time another words you mite have access to things I do not and vise versa so again comparing complete mills for the propose of this question was useless
I am just someone who has a interest(I would have expected a warmer welcome but hey that's life some groups are friendly to outsiders others threat you well..) I have seen guys pull a almost prefect grade with a piece of heavy equipment and seen others that can't even use a shovel so I guess what mite seem "amazing" to you (as you keep putting it) may not seem like a big deal to someone else
yes yes yes you keep saying that and I keep saying but guess you somehow missed it I don't want a HAWT system if you want it that is fine but I do not.
Again another reason to avoid speaking about complete systems , went though this a few years back wen we started gearing other stuff gear just multiples the torque produces thus making it more efficient. if you don't believe it or like the gearing then don't use it on yours this was never part of the question asked to begin with
Buts ok lets compare..... say you have two incidental VAWT 35' towers, turbines(blades), generators with the exception one is geared 6 to 1 ratio the other is direct drive or 1 to 1 ratio sitting side by side in a field
1:1 turbine spins at 100rpm generator spins at 100rpm x1hr
1:6 turbine spins at 100rpm generator spins at 600rpm x1hr
Both have the same wind turning the identical turbines at the same Rpm with same KW size generator so witch one produces more power in that 1hr time frame?
I think your referring to the geared vs no geared turbine systems early in this post . I can see two incidental units causing question but that wasn't the case . again if you can't comprehend that gear multiples your torque well just don't use it in your system
Like I said before I have no commercial interest I just want what will work for me
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 05:53am 24 Mar 2010
Copy link to clipboard
Print this post
Hi Goldie
I have read some of this thread so will add my comment on what you want to do.
Many years ago I set up a 60 volt 220 amp VAWM using a Lincon welding generator that are a high speed generator 2800 3000 rpm Problem was the gear up ratio of 30 to 1
I used a truck differential 5 to 1 and a belt drives using tooth belts, primary 3 to 1 secondary 2 to 1 tooth belts have a very low transmission loss.
The generator is a bit to noisy for residential use unless you make a sound proof room.
This was set up on a 12 ft dia 20 ft high mill with a central governing vane to limit rpm to 130 to avoid self destruct with six aerofoil blades. It would have worked the genney at half that size so plenty of reserve power.
Still see the lincon on ebay from time to time
All the best
BobFoolin Around
goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 11:04pm 24 Mar 2010
Copy link to clipboard
Print this post
VK4AYQ,
interesting using both belt an gear in one application I have build a few belt drives for small props and several gear drives but never combined the two in one application
thanks for the input
Robert
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 12:08am 25 Mar 2010
Copy link to clipboard
Print this post
Hi Goldie
The advantage of using the old differential housing is that you can get from scrap and use the wheel bearing assembly to carry the weight of the rotor and the brake drum as a stop rotor device, older truck diff ratio usually over 5 to 1 so makes a good step up gearbox when the planetary gears are locked up.
All the best
BobFoolin Around
turnymf Regular Member Joined: 04/10/2008 Location: AustraliaPosts: 84
Posted: 01:04am 25 Mar 2010
Copy link to clipboard
Print this post
"1:1 turbine spins at 100rpm generator spins at 100rpm x1hr
1:6 turbine spins at 100rpm generator spins at 600rpm x1hr"
How can this be?
I would be surprised if a mill with a different gear ratio can produce 6x power or am I missing something?
goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 01:30am 25 Mar 2010
Copy link to clipboard
Print this post
turnymf
The numbers where just theoretical round numbers to make the point. gearing is simple one side reduces rpm the other increase rpm. The actual proper ratio would be determined by the specific application as to high or lower would hinder its usefulness. even a belt on a alternator for example is a geared ratio with two different size pulleys so its been around for awhile
niall1 Senior Member Joined: 20/11/2008 Location: IrelandPosts: 331
Posted: 01:43am 25 Mar 2010
Copy link to clipboard
Print this post
now i,m getting confused about the benefits of increased rpm
i remember testing a 12v alt in star into a regular car headlight ....it took a certain amount of force spinning it by hand to light it up fully...
in delta the physical energy seemed easier ...but the speed needed was much greater....
so did i just use up the same amount of energy by needing to increase the rpm ....
edit ...thinking a bit about this ...i,m not sure if theres a free lunch in there Edited by niall1 2010-03-26niall
turnymf Regular Member Joined: 04/10/2008 Location: AustraliaPosts: 84
Posted: 02:19am 25 Mar 2010
Copy link to clipboard
Print this post
"The numbers where just theoretical round numbers to make the point. gearing is simple one side reduces rpm the other increase rpm. The actual proper ratio would be determined by the specific application as to high or lower would hinder its usefulness. even a belt on a alternator for example is a geared ratio with two different size pulleys so its been around for awhile"
Sorry but I don't understand what you are trying to say
I understand what gears/belts do, every bicycle has them
You only get out what you put in
"Both have the same wind turning the identical turbines at the same Rpm with same KW size generator so witch one produces more power in that 1hr time frame? "
The one with direct drive
goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 03:02am 25 Mar 2010
Copy link to clipboard
Print this post
VK4AYQ
yep that is a good idea . scarp yards always a great place to get stuff for experiments I had good success using a VW bus gears and bear house before to make a box swinging a 74" 12" wide airboat prop before and that was back when they said the same thing you can't do that
turnymf
seeing is always believing try this some time take a small elec motor that turns at a set RPM mount it to the work bench with a pulley then make a shaft mount that you can connect a tachometer first put the same size pull on it as the motor has and write down the RPMs now leave the motor pulley alone but change the pulley on the other shaft so it is twice the size (2:1) now run the motor again and compare that RPM reading to the first one. you still applied the same amount of force from the motor but your RPM readings will be different
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 03:49am 25 Mar 2010
Copy link to clipboard
Print this post
Hi Goldie
The gearing situation under discussion is best summed up as an effort to do work in our terms horsepower. the relationship of the power in remains the same when going faster or slower by gearing the device with transmission losses ignored in this example.
The horsepower required to do a job is
torque required times rpm required divided by math constant 5252
Example 100 ftlb X 1000 rpm = 100000 divided by 5252
= 19.04 hp
1000 ftlb X 100 rpm also = 100000 divided by 5252
= 19.04 hp
150 X 3000 = 450000 / 5252 = 85.68 hp
10 kw = 14.28 hp that's how much power it will take to drive your proposed generator plus transmission losses ad 10% to be on the safe side.
Horsepower is a product of speed rpm and torque ftlb and the only factor to add to that is transmission losses
On the star and delta difference in an alternator the globe will light at a slower speed in star because the windings are in series so producing nearly twice the voltage as in delta where the windings are in 120 degree out of phase parallel, its like your car in top gear or low gear one is faster and the other pulls more.
Hope I havn't confused you to much,
All the best''
BobFoolin Around
turnymf Regular Member Joined: 04/10/2008 Location: AustraliaPosts: 84
Posted: 04:27am 25 Mar 2010
Copy link to clipboard
Print this post
"seeing is always believing try this some time take a small elec motor that turns at a set RPM mount it to the work bench with a pulley then make a shaft mount that you can connect a tachometer first put the same size pull on it as the motor has and write down the RPMs now leave the motor pulley alone but change the pulley on the other shaft so it is twice the size (2:1) now run the motor again and compare that RPM reading to the first one. you still applied the same amount of force from the motor but your RPM readings will be different "
Yes I can see that
If I put a load on the second shaft, surely the motor would strugle at 2:1 compared with 1:1 using the same power
Gearing, I would think, would only be used to match alternator rpm requirements to mill rpm ability
Perry Senior Member Joined: 19/11/2009 Location: Posts: 190
Posted: 07:38am 25 Mar 2010
Copy link to clipboard
Print this post
A gearbox won't increase 'power'. You always get less out than you put in. Power is torque times rpm. Yes the rpm will go up but the torques will go down. The net will always be less due to friction losses. Physics 101.
High-rpm generators are easier and cheaper to build. That's the only reason you would ever want one, especially with the low rpm's of a VAWT.
It's really important to understand the differences between power, rpm, voltage, current, etc, etc before undertaking this project.
Perry
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 11:08am 25 Mar 2010
Copy link to clipboard
Print this post
Hi Goldie
I have built a slow speed direct drive generator if you are interested in doing it contact me through messenger and I will try to guide you through the process. will cost about $1000 to build and you will need access to a lathe and milling machine.
Not to harp on the point as most have done in this thread a VAWT is better in low wind as survivability is a problem in high wind areas so will need to be built very strong to survive over 40 ms.
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
Print this post
I had good success using a VW bus gears and bear house before to make a box swinging a 74" 12" wide airboat prop before and that was back when they said the same thing you can't do that 
try this some time take a small elec motor that turns at a set RPM mount it to the work bench with a pulley then make a shaft mount that you can connect a tachometer first put the same size pull on it as the motor has and write down the RPMs now leave the motor pulley alone but change the pulley on the other shaft so it is twice the size (2:1) now run the motor again and compare that RPM reading to the first one. you still applied the same amount of force from the motor but your RPM readings will be different 