My experience so far.

[JW]

https://www.fieldlines.com/index.php/topic,150505.msg1058557.html#msg1058557

[Astro]

 Well, my first attempt at stator building did not go well. I learned a few things though. I am going to continue building so I can spin it up and see how it does, but I am not real happy with the workmanship of the stator. There is much room for improvement and I will most likely build another before finishing and putting up the mill. But we will see what kind of numbers we get out of this one first.
 My wife is trying to be supportive by saying "it is not that bad" but she knows nothing about all this. I did feel a little better after doing a search for "messed up stator" and reading where some of you did not get the results you wanted first time building one either.

[SparWeb]

My first axial stator sucked, too.  It burned up within 6 months.

[Astro]

My first axial stator sucked, too.  It burned up within 6 months.

 I messed up the mix ratio on the epoxy. I also did not measure each coils thickness. I had a couple nuts on all thread to keep my winder at the right gap and they ended up moving, so some coils were thicker then others. Not enough to see, until you went to pour it and put the lid on the mold. But I weighed them all and ohmed them out.

[Astro]

Yeah, so beings it is going to be suspended sideways and more prone to flex from it's weight as opposed to being vertical where the forces are different. I had a small inner circle. And a larger outer circle. So there is a good 3/4 of an inch of epoxy all around the inner and outer circle of coils. maybe more like an inch. So I wanted to have my coils exact as I had no wall or edge to but them up to. I also put glass cloth on each side of the coils. Nice big mounting ears. I figure I can either work around them or trim them later if need be. My biggest worry is, I had this figured for a max of .75 inch gap space. Well a couple of coils are pushing all of that by a wind or two. It looked almost perfectly level in the mold. And I just barely covered some coils and some have a wind or two still exposed. Not dry mind you, they had epoxy on them, it just obviously just ran to the other side of the mold. So now since I poured a couple cups into it, maybe a 1/4 in thick, Because I had it exactly where I wanted the coils and wanted to hold it there before doing anything else like trying to pour it all and try and put the lid on. Also epoxy binds well with epoxy very well because of the heat it makes as it cures. So if you use cloth in each layer and make it sloppy so you end up with the cloth going from one layer or pour to the other, it also helps with strength. So I was not worried about that. But I screwed up the mixture really bad. I had 1/4 inch thick pour going and realize I stuck in like 8 drops of hardener for 8 ounces. SO now what? Get mad and scrap the whole thing and start over? Cant take them out and just dump the resin. So I added the hardener all around and mixed it best I could. It takes 8 drops per ounce.  SO it was not hardening at all. It has some pretty deep holes I need to fill, and a nice layer of candle wax in the very top layer. Could buff it out, but meh. It's got wax on it. I am ok with that. What is the worst that can happen it gets warm and spits wax all over? I am ok with that. coat those magnets and other stuff in wax, I mean that sounds like undercoating a car. Why not?
 So now my plan is to mix a little more and just try and brush it on with a sponge on a stick. Just want to make sure those coils top wind or two does not go anywhere and then fill in some of the bigger holes on the other side. Is it pretty? NO. Is it workmanship I am happy with? NO. But hopefully it works.

[SparWeb]

It's going to be pretty soft in places.  Let it cure for several days before you touch anything.
Another thing you can do, after the first curing cycle is to heat-treat it in an oven (if it fits) by keeping it at about 120-150F for an hour, not counting warm-up time.

Later, when you do get it out of the mold (and if it survives that) then you can put some glass cloth layers on the outer faces, at least two per side.  Wet them with epoxy using a brush and a roller, but don't use more epoxy than you need.  This thing will already have enough epoxy in it and just needs structural glass cloth.

This will not improve the thermal efficiency but with a bad epoxy mix you don't have a choice.  If the rescue goes well, try using this as your bench-top test machine, and plan another one for service out in the elements.

[Astro]

It's going to be pretty soft in places.  Let it cure for several days before you touch anything.
Another thing you can do, after the first curing cycle is to heat-treat it in an oven (if it fits) by keeping it at about 120-150F for an hour, not counting warm-up time.

Later, when you do get it out of the mold (and if it survives that) then you can put some glass cloth layers on the outer faces, at least two per side.  Wet them with epoxy using a brush and a roller, but don't use more epoxy than you need.  This thing will already have enough epoxy in it and just needs structural glass cloth.

This will not improve the thermal efficiency but with a bad epoxy mix you don't have a choice.  If the rescue goes well, try using this as your bench-top test machine, and plan another one for service out in the elements.

 Oh it is pit of the mold. I poured about 1/4 of the mold first (with cloth. A couple hours later I thought oh no I think I mixed it wrong. It was not even trying to harden. So I took the right amount of hardener and mixed it in while in the mold with the coils. Problem was I could not get under some spots where I made connections. But I mixed it really well on the insides and outside of the coils and even in the middle of them. I ended up with about 3 or 4 spots where it just did not dry. They are maybe 1/8 in deep and vary in size from small to about a couple inches around. Otherwise that side is perfect. So I will fill them in. The stator mold is 20 inches across, so you have an idea how big it is compared to the spots I need to fill. Also why I made it with a good inch of epoxy on both the inner and outsides of the coil (make it stronger because it is so big and will be laying flat for a vawt). On the other side, like I said I made some coils slightly thicker and some slightly bigger round because I adjusted the nuts holding the winding plates apart. Same winds though.  So some coils are covered a just barely and some have a wind or two sticking above the epoxy. So I thought I would just brush a little more epoxy over them just to make sure that top wind is good and stuck down.
 The whole thing is not horrible, it just is not something I am proud to put my name on. I could have done better. I should have done better. I am sure it will work and all, but meh, not picture worthy or even a hey buddy check this thing out I built worthy. Glad it goes inside of the mill and up in the air type of thing.

[SparWeb]

Hmmm.  I get so much c**p from people telling me to STOP being a perfectionist at work. 
It's nice to work on something until my inner perfectionist is happy. 
I'm just saying I'd do it again until I was sure I had it right.
And don't you want the machine you can show off to your buddies?
Awright enough nagging from me.  Keep having fun, eh?

[Mary B]

Hmmm.  I get so much c**p from people telling me to STOP being a perfectionist at work. 
It's nice to work on something until my inner perfectionist is happy. 
I'm just saying I'd do it again until I was sure I had it right.
And don't you want the machine you can show off to your buddies?
Awright enough nagging from me.  Keep having fun, eh?

I went around with my last boss at work. He wanted me to do a half a**ed job and splice a ratty old connector with a pigtail of 28AWG wires onto a new harness I made from 16AWG wire. I told him no, order the dang crimper we need to do this the right way. That old ratty pigtail was going to have the exact same problems the old one I was replacing had because the wires were to thin to stand up to the abuse it gets. That was when my back sidelined me from working, he went ahead and spliced it and it failed within 3 weeks. He called me to come in and show him the right crimper, I told him I charge $100 an hour form the time I leave my front door until I get back to my office, they had laid me off over the injury, I wasn't going to give him free labor!

He sputtered and said he would do it himself. 3days later the casino manager calls me and I tell him the same, he said we will pay it, not out of line for any other specialist we bring in. I got the tool ordered from home and brought it in with me and billed them for it after adding on 20%, spent 3 hours undoing the mess my old boss made of the harness and put on a brand new connector with wire that was 4 times thicker so it would stand up better. Since that repair they have called me in a dozen times to either repair something or design a project and order the parts so the flunkies could do it.

I am stubborn, do it right or don't do it at all!

[Astro]

Hmmm.  I get so much c**p from people telling me to STOP being a perfectionist at work. 
It's nice to work on something until my inner perfectionist is happy. 
I'm just saying I'd do it again until I was sure I had it right.
And don't you want the machine you can show off to your buddies?
Awright enough nagging from me.  Keep having fun, eh?

 My friends would not have the slightest idea what they were looking at anyway. Lol