大舜天成羽毛球馆:制作10英尺的风力发电机组（6）

It's nasty stuff. It smells bad, the fumes are toxic. Best to work outside or in a very well ventelated area. Use safety glasses (the hardener is especially dangerous if you get it in your eyes), rubber gloves, and a respirator.

It takes almost exactly 1 quart of resin to make 1 magnet rotor. (maybe a touch less) Usually a gallon of the resin comes with two tubes of hardener, each containing .77oz (22ml). When casting this stuff the resin tends to warm up and get hard much faster than it would in normal applicati** - especially if its warm outside and if the resin is warm to start with. We usually use about half the hardener that the instructi** call for. This lets it harden more slowly - I believe it helps it to be stronger, shrink less and make things less likely to crack. There have been times when we've used half the tube for 1 quart (what the instructi** call for) on warm days and the resin has become hard in 15 min or less! (it was hard before we could even pour it!) If it goes off too fast, there is also the risk of it catching fire. So be careful...
If you like, there are powders available to color the resin, or you can just use a little bit of acrylic enamel to give the resin a color. If you use enamel, I would use about 1 part paint to 50 parts resin.

Pour resin into the mold and over the tops of all the magnets. The mold needs to be level and it should be completely filled with resin.

Then we put the long end of the allthread through the backside of the wheel hub. Put on a lock washer, and another nut and finger tighten the allthread to the hub (no need to get things tight here - just finger tight is what we want). Do this with all 4 studs, and then run a nut onto the front of each stud so that about 1/4" of allthread is protruding. So, if we look at one stud here starting at the front (left to right in the picture) here is whats important: 1/4" of allthread, 1 nut, more allthread, a nut, a lock washer, the wheel hub, a nut, and then 7/8" allthread.

We take the back magnet rotor (the one with only 4 holes) and turn it so that the magnets face down on the bench. (be sure the bench is clean from metal bits)

Take the back of the hub and put it into the hole in the magnet rotor, such that the ends of the studs (the ends that are 7/8" long) are poking into the 4 holes. We do this to align things before we tighten anything.
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hog

论坛元老

58#
 发表于 2010-8-30 13:34 | 只看该作者

Then we use one of the steel blade hubs (the ones above that are painted black) and place it over the studs on the top and it should come to rest on the 4 nuts that we put up there. (thats why we put those nuts there with 1/4" of allthread sticking out). If we don't have these blade hubs, we could use the front magnet rotor, I would do it with the magnets facing up so that we can tighten things without worrying about magnets grabbing our wrenches. If we do it this way with something to align our studs both at the top, and the bottom - we are fairly assured that the studs are well aligned and everything will fit together nicely.

Now we can tighten the nuts on both sides of the wheel hub. We should get them very tight, and the goal is to move only the top nut (the one with the lock washer under it) and not the bottom one, so that we are sure to have 7/8" of allthread behind the back nut.

Then we can remove the hub from the top and the 4 nuts that held it there. We also remove the hub from the magnet rotor. Turn the hub upside down (so the back is facing up and we have 7/8" of allthread sticking up). If the studs were cut accurately and the nuts positioned properly, the hub should sit pretty flat on the ends of the studs as pictured.
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hog

论坛元老

59#
 发表于 2010-8-30 13:34 | 只看该作者

Carefully lower the back magnet rotor down onto the hub so that the studs go through the holes. The magnets should be facing down. Remember the hub is steel and the magnets will attract it strongly. If you bring it down right on center its fine, but if things are off center the rotor will grab the hub. Sometimes it's handy to have someone holding the hub down and helping to keep things positioned.

On the back side of the magnet rotor each stud gets 1 lock washer and 1 nut. We can tighten these a bit with a wrech now, but it's easier to really tighten these ones after the alternator is together.

Now we can grease our bearings. Press lots of grease into both bearings, work the rollers around for a while and be sure the bearing is well greased.
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hog

论坛元老

60#
 发表于 2010-8-30 13:34 | 只看该作者

The front and back bearings are identical for this wheel hub. Put one of the bearings on the wheel spindle and push it back all the way. It's probably a good time to mention... usually when you order a hub, it comes with a seal. We do not use the seal in a wind turbine, it creates too much friction and prevents easy startup. I believe if we grease the bearing well then they should be fine for quite a long time.

Carefully pick up the hub/back magnet rotor by the studs and place it onto the spindle, up against the back bearing.

Then insert the front bearing. Usually at this time I press a little more grease into the front of the bearing... can't hurt.