Update to 10' Smoked, mods to genny

[mgtd]

As promised, here are some pictures of mod's made to various components of my homebuilt mill to allow more airflow over stator and rotors and hopefully make overheating less of an issue, once tail vane size and weight are changed for proper furling.  The following pictures detail the steps I've taken and each picture is captioned with what I'm attempting to show.  All work was done by myself in home workshop.

The front and rear rotors, blade supports have had their center holes enlarged to 3.00 inches to allow airflow around the hub (rear blade support hole enlarged to 3", front machined to 3". as the front was a flat plate). Performed on 14 1/2" Southbend lathe.

Thr Dexter trailer hub was trimmed and trued, removing a small amount of the bearing carrier diameter and in the process cleaning up the rough casting at these points. The flat area of the bub's carrier is down to 2.450", tapered to the end, as original.  Again to give more of an aperture for airflow. Performed on Southbend Lathe.

Next the flange of the hub was indexed at 30 degrees and .040 slots were milled approx. 1/4" deep around the hub. Performed on Barker Horizontal Mill.

At each slot, the rear side of the hub's flange was then milled to .200 thick to allow positioning of the blades without interference of the lug portion of the flange and to make blade fabrication easier, allowing a standard "nibbler" to be used to put the slot in the blade. Performed on Millrite Vertical Mill.

Then, 12 blades were cut from .042 mild steel. Blades are 1/2" by 1", with a centered .200" slot, 1/4" deep.  These were pressed into the hub's flange and then Mig welded in place, and the welds trimmed back to the flange's circumference. Blade slots made with "Nibbler" tool

Here are the blades in position.  Hopefully, creating a squirrel cage fan effect, forcing air inducted through the front of the blade and around the hub, over the stator and rotors.

Here is the completed hub with welded blades, sitting  in the rear rotor to check clearances.

Here is a straight on view of the blades and hub/rotor.

The jacking screws also needed modification (ends ground to tips) for clearance of blades during assembly.

Here is a trial assembly with both rotors with about .625 inch gap for stator, again checking for clearances.

Front view of trial assembly, showing approx. 1/4" gap for air induction.

Here is the back of the hub/rotor showing same 1/4" clearance.

Not shown is the blade assembly with it's 3" hole, nor the bearing cap that will be installed on final assembly.

Material in these mod's was nil, though it did take the better part of a full day to accomplish the machining and fabrication.

Parts are being painted now.

My wire order should be here on Tuesday from Otherpower--Ester Vinyl and ATH are already here.  A couple days to wind the coils and make a new stator and I'll be back in the air.

[Flux]

You have put a lot of effort into it and I have no doubt that it will help to some extent.

I am not sure that will make any spectacular difference but it would be nice to see a heat run with the 1/4" air vents open and closed to see the difference.

I suspect that the fan blades will do very little at such a small radius and low speed. More air flow will most likely be induced by the magnet rotors themselves but it can't hurt.

I can see how air is going to enter the back disc but unless you leave a hole in the prop hub I don't see how air will get in the front. If you are in a dry climate then having a hole at the centre of the prop hub may be ok.

At least it is a serious attempt to do something and if you could bench test it on load it would be a very useful bit of information.

If you can't bench test it then get the furling sorted out to a safe value and you can rest assured that you are in with a better chance than those without this modification.

Flux

[SparWeb]

Nice work, there.  It's especially fun to have a good lathe at one's disposal for these projects.  I have access to a Colchester lathe at work.  I've done some odd things with it, including chucking in a Dexter hub.  I used it for testing an axial flux alt that I built a couple years ago.

http://www.sparweb.ca/AXIAL_FLUX_Testing_V2.pdf

If your Southbend is big enough, you might try that, too, but your alternator looks sized right for a 10' prop anyway.

[ibeweagle]

like what you are doing but have a better way and design better than other powers and have servied 65mph winds and also 12 foot dim puting out over 1.2kw. first take out resin from rotors and magnets increase magnets to 16 also re wire coils to pie shape and also 4 coils per phase and 30 percent less turns use a magnet holder made from #14 gage metal glue on magnets with epoxie need more direction e mail me at ibeweagle@hotmail.com will help for mods cheers Mike

[Blewsage]

Hi Curt, it looks like you've done a lot of thinking about cooling. I applaud your efforts and your fine workmanship. The modifications you've made certainly can't hurt, and hopefully promote the success of us all in this journey to create a reliable wind alternator. I like how you've tried to promote airflow between the hub and disks.

I guess in my mind the approaches are:

1. Attempt to prevent the heat from occurring in the first place through proper design.
   
2. Being able to dissipate the heat if/when it occurs.
   
   

I guess the only other mod to the rotor I would suggest is to cut grooves in the resin between the magnets.

I love reading everyones ideas, and especially watching those who have the courage to go off the beaten path and try something different in hope of improvement. Bravo to you all for thinking.

Russ

[mgtd]

I've considered slotting the rotors between the magnets, however on my overheated rotors the resin has small heat cracks and think it not best to do that.  I think it is best to leave as much material there as I can.   If I ever have to re-cast rotors, I believe I will do that.  Thank for the compliments.

[Blewsage]

Hey Curt, What's going on? I'm dying to know how it turned out...

Russ

[mgtd]

Everything is back together and balanced.  May get it on the tower and back up today.  Been wanting to do some meaningful bench testing, but may have to forgo that and see how it does up and flying.

How is your project coming along?  How did your pour go?

Good luck,  Curt

[Blewsage]

Hi, good to hear! I'm looking forward to hearing how it runs. I'm curious on how it furls with the larger offset and decreased tail angle.

    The pour for the stator went ok; working with the Vinyl Ester was a learning experience. I'm thinking my next stator should go better. I spent the day welding up the bracket for the stator and making up the rotors. I used JB weld to attach the magnets to the plates, and I'm considering leaving them as they are for better cooling. I guess it'll be an experiment. I spent part of the day cutting out parts for another mill. I plan on having at least 3 mills running. I'm going 24 volt, and I'm wanting to see how this one runs prior to casting up another stator; I will probably end up adding or subtracting windings on the coils depending on how it runs. I'm setting up an inspeed anemometer so I can see what's really happening. I'll try and get some photos in a day or so.

Russ

[Blewsage]

Hey Curt, how goes the modifications?

[mgtd]

Hey, Russ.  Been back in the air for almost a week now.  Not a lot of wind so far.  Seems to cut in at about 7-8 MPH.  I've seen 12-14 amps into my 48 volt bank at about 20 MPH.  Haven't had enough wind to make it furl yet.  I guess there is no real way to make a determination if my cooling and other mods have had any effect unless I let er go in high wind and see whether furling or burn up occur first. Curt

[Blewsage]

Hey Curt, just saw your post. Great that your up and running! I'm anxious to see how it performs!

   I'm in the process of casting another stator; I was disappointed with the voltage out of the first one. 66 turns of 14 AWG and it was only showing 16-18 volts at 150 rpm. I wound this one with 80 turns. I'm using a 10.5' prop so I'm thinking my power band will be more on the low side. I guess I won't know until it's up and running. I also had some cogging from the stator bolts being too close to the rotor. I never even thought I would get cogging from there. Live and learn I hope. Anyway, thanks for the update; like I said I didn't see it until today.

Russ