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Chris220220
Newbie

Joined: 17/02/2010
Location: Australia
Posts: 29

Posted: 06:02am 01 Mar 2010

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Afternoon all,

sorry but another newby question.
I have been playing with PVC blades and after getting little joy with anything on the F&P shaft with no magnetic back I grabbed the second unit I got with no plastic rotor(?), took the magnetic hub of the back and found it spins much more freely. The unit with the plastic bracket(hub?) is quite firm to start rotating by hand. There is no spin once you let it go.
I have not yet pulled it apart but was wondering how freely should it spin?

Will it just be the rubber seals on the hub causing the drag, or did I get a bad one?

The only issue with the one without the plastic hub is making up mountings. I have next to no workshop and I'm trying to get this together on the cheap.

(I have no welding gear, so nut n bolt and wood bits)

Hope some one can work out what I have desribed and may be able to assist.

Edited by Chris220220 2010-03-02

Regards
Chris

DTV004

Regular Member

Joined: 30/04/2009
Location: United States
Posts: 65

Posted: 07:28am 01 Mar 2010

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hi, cris220220 you might need to de cogg the stator the way i have my. is by i twist each coil a little bit. or you will need biger blades

Chris220220
Newbie

Joined: 17/02/2010
Location: Australia
Posts: 29

Posted: 07:38am 01 Mar 2010

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This is without the magnetic hub on. So there should be no cogging issues. That is what worries me

Regards
Chris

Downwind

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Joined: 09/09/2009
Location: Australia
Posts: 2333

Posted: 03:10pm 01 Mar 2010

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Hi Chris,

Sounds to me the black rubber seal is still in the bearing block, get a screwdriver and dig it out, as they cause a lot of drag on the shaft.

The seal i mean is in the end that went up towards the tub originally.

With that gone you should be able to feel how the bearings roll.
It is not uncommon the bearings are shot to, and if it was me i would replace them as a matter of course.
They are not that exspencive and are one of the hardest working items in the mill.

Pete.

Sometimes it just works

KarlJ

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Joined: 19/05/2008
Location: Australia
Posts: 1178

Posted: 04:29am 02 Mar 2010

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My tip is (stolen from Phillm)
pull the bearing out
remove the inner seals from front and back bearings, add oil in the middle (not too much) then loctite the shaft in
(loctite bearing mount)

This stops the oil coming out again and with the two seals removed (one from each bearing) the drag will be half.

Luck favours the well prepared

Chris220220
Newbie

Joined: 17/02/2010
Location: Australia
Posts: 29

Posted: 04:55am 02 Mar 2010

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Thanks guy's,

will get on to this tomorrow night and let you know how it goes.
thanks for the advice.

Edited by Chris220220 2010-03-03

Regards
Chris

Chris220220
Newbie

Joined: 17/02/2010
Location: Australia
Posts: 29

Posted: 10:58am 03 Mar 2010

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Evening all,

I got the block off the shaft and removed the rubber seal. That pretty well did the trick. After putting it back together it spins much more freely.
Thanks for the advice.

Now to get the blades worked out.
I have cut some from PVC storm water pipe and hope they will do the trick.

I'm hoping to get something I can take away camping.

I thought a VAWT set up may be a bit more portable and able to by run on the ground?Edited by Chris220220 2010-03-04

Regards
Chris

KarlJ

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Joined: 19/05/2008
Location: Australia
Posts: 1178

Posted: 11:57am 03 Mar 2010

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Nope a VAWT needs wind just like any other turbine.
start with a "normal" HAWT and go from there.
Needs to be at least a couple of meters off the ground and in some clear air.

RUle of thumb is 10m higher than anything within 100m.

This is a pretty tough ask for the best of us and usually site is the best we can do with what we have.

If you are in Melbourne I have a spare set of blades and other bits and pieces that can all go for peanuts PM me if you're interested
Karl

Luck favours the well prepared

Ghetto
Newbie

Joined: 01/09/2009
Location: Australia
Posts: 14

Posted: 04:34am 05 Mar 2010

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Handy thread for us beginners. Thanks heaps.

I had parked up my 60 series f&p thinking it was the cogging alone making it difficult to turn, seen this thread at work, got home, dragged out that stator and removed the black seal which i didn't even realise was there rubbing on the shaft.....Made a big difference...now i'm thinking of attempting to use it!

Is it hard to get the bearings out of the original bearing block in order to do what KarlJ mentioned? Is there any easy way?

Cheers,
Rob

Downwind

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Joined: 09/09/2009
Location: Australia
Posts: 2333

Posted: 05:27am 05 Mar 2010

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It is a piece of pie to remove the bearings i think.
You just need to knock them out from the inside.

Once the shaft is removed use a bit of rod or long screwdriver and place it through the hole in one bearing and down onto the other bearing.
There is a spacer sleeve between the two bearings that can be levered to one side slightly then tap the bottom bearing out from the inside.
Tap left and right to knock it out evenly.
Then the second one the other end is easy.
Try not to tap on the seal part as it will damage the bearing just use the inner race to tap on.

If it was me i would use a film of silicon or gasket cement when refitting the bearings rather than loctite as i know it might have to be me who needs to get them out again one day.

Pete.

Sometimes it just works

Tinker

Guru

Joined: 07/11/2007
Location: Australia
Posts: 1904

Posted: 02:41pm 05 Mar 2010

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Keep in mind that the shaft only comes out one way, by knocking from the nut end (after removing the nut, of course).
If the bearings are well used its a good idea to replace them anyway, then the removal method need not to worry about bearing seal damage. On reassembly I leave the spacer out, I see no reason for it being there as the bearings rest on shoulders and the shaft has a raised rim on one side and a nut on the other, making it impossible to slide about either way...

The second bearing, BTW,can be removed by cunningly re inserting the shaft and using the raised rim as a drift.

I dunno about using silicone to set the bearing as it requires a gap and there is (hopefully) none at a bearing seat

. There are loctites with less than superglue properties available, nutlock works for me on a cleaned surface.

Klaus

Chris220220
Newbie

Joined: 17/02/2010
Location: Australia
Posts: 29

Posted: 09:57pm 05 Mar 2010

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I struggled to get a grip on the big rear nut and ended up undoing the bolts from the rear and seperating the plastic bearing block from the stator. I could then slide the shaft and undo the nut.
The rubber seal has been forcibly removed and the rest put back together. Hopefully the same way it came apart.

Hopefully this weekend I'll do the rewiring job. I thought a staggered config for low wind cut in.

Keep you posted

Regards
Chris

KarlJ

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Joined: 19/05/2008
Location: Australia
Posts: 1178

Posted: 12:59am 06 Mar 2010

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Chris seems like a bit of work but....

CAPS CAPS CAPS!
you can pick up the required caps anything from 400-660uF
400-450V on ebay (you will need 12)
for about $30 or less.

Wire as you would but in Delta, cutin will then be lower than star of the equivalent re-wire AND
as a HUGE bonus you will get 1.7x the power output
AND as an additional bonus the F&P is more efficient in
delta.

Your cap setup will set you back $50 all up with the additional recs (no need to heatsink, keep all wires short to keep RFI down)

Personally Mine works un-believably well even with a 100S into 48V I have a cutin of 120rpm or less (about as fast as I can count!)
with the 80S cutin is down to 80-90rpm.
thus the delta re-wire with caps should cutin at 180rpm or so which for a single stator mill is fine.

Luck favours the well prepared

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