Tips & Tricks 27

Index
Making easy windmill sails.
Making fancy windmill sails.
Adding an electric motor.

These instructions will tell you how to make the sails for the windmill. Instructions for building the windmill are on the Windmill Building Instructions page.

The windmill uses mold #76 which needs to be cast 20 times in order to have enough blocks to make it.

Making Easy Windmill Sails
1. You'll need four 7" long kabob skewers or dowel rods. These should be 1/8" diameter. You will also need one 4.5" dowel rod, which should be 1/4" diameter.

The easiest way to cut the dowel rods is to roll a hobby knife over them until you can break them cleanly.

2. Next we'll glue the center hub together.

The 1/4" fender washer is optional. I'm using it to help the dowel rod stick out the front slightly.

Place glue on the flat "U" shape area of each hub block. Be sure to use a very small amount of glue. If you use too much, dried excess glue will block the channel openings.

3. Put a small amount of glue on the end of the 1/4" dowel rod. Place all 4 hub pieces on top of the washer, put the dowel rod in the center and put the 4 hub pieces around the dowel rod.

The washer helps the dowel stick out the front slightly but this is optional. Remove any excess glue from the holes.

4. Print out the sails on a color printer. You can find them on our Printed Plans page labeled as "Windmill Plans".

Under the windmill plans are direct links to the original JPEG files which are higher quality. Cut them out using a pair of scissors and fold them in half.

5. I'm using a glue stick and covering the center and one side with glue.

Then I'll place the kabob skewer in the crease and fold the sail together.

6. Press together and flatten the sail halves smoothly.

The kabob skewer in the crease will form a lump. Try to get the lump to show up on the back of the sail instead of the front. The back of the sail has the gridwork of beams on it.

7. You will have a little excess white paper showing where the sail edges didn't meet exactly.

Trim these edges off with a pair of scissors.

8. Test fit the sails into the hub. Do not force them or you will break the hub blocks!

If they are too tight, gently trim the kabob skewers using a hobby knife.

9. Glue the sails into the hub. Do not push them all the way in or they will block the holes for the other sails.

Once all the sails are inserted, then push them all the way in. Twist the sails until they are all flat and straight.

Once dry, paint the wooden parts brown.

10. To insert the sails, lift off the top of the windmill. Place the end of the sail dowel rod into the hole in the back of the windmill.

Let the front of the dowel rest in the half-circle on the front. Place the roof back on the windmill.

Instructions for building the windmill are on the Windmill Building Plans page.

Making Fancy Windmill Sails
1. I'm going to make the sail frames out of 1/8" square basswood. You can find this at most large craft stores or model railroad supply stores. Balsa wood will also work but it's much softer and will break easier.

You will need six - 24" sticks of this wood to make the 4 sail frames.

2. Lay the sticks down directly on the plan. Use a hobby knife or straight edge razor to cut the wood strips to the proper length. You can find the plans on our Printed Plans page.

If you don't want to end up cutting the plan paper, push the knife down on the wood where you want to cut it, then move the wood strip off the plan when you push the knife down the rest of the way to cut through it.

3. After you cut the 3 long strips, set them aside and cut the short cross pieces.

You do not have to angle the ends of the cross pieces, but be sure the cross pieces reach all the way to the outside edges of the sail.

4. The best way to assemble the sail is to lay the cross pieces down on the plan first.

Then lay down one of the long pieces beside it and place dots of glue where every cross piece will be.

5. Flip the long piece over and press the glue side down onto the cross pieces. While you're holding this piece down, you can adjust the cross pieces and push them back into position if they had moved.
6. Continue this method until you have glued all 3 long pieces on top of the cross bars.

If you're careful, you will not have glued anything down to the plan paper and can immediately start on the next sail frame.

7. Paint the frames using brown paint. You can give a nice weathered look if you dry brush the frames with light brown paint afterwards.

At this point you do not have to add paper to the sails if you like the way it looks on the photo on the right. Instead you can skip down to step 19 and assemble the frames to the hub.

If you were doing a ruined version of a windmill, you might cut or break several of the wooden spars, paint the wood a more grayish color and leave them without adding paper to the sails.

8. For the paper covering of the sail, I'm going to use brown paper napkins. I got these from my local Taco Bell restaurant. Try to find some without decorations or texture for the best result.

I also tried several other materials. Thin drawing paper or tracing paper was too thick and gave the appearance of a solid sheet of steel. White napkins worked well for texture, but it was difficult to figure out how to color them. Facial tissue was just too soft and dissolved too easily in the glue/water mixture and was also difficult to find the right coloring. The brown napkin gives it almost the appearance of leather, which is more what I wanted.

9. I'm going to use 2 plies of paper for the right thickness. In other words, unfold the napkin until you only have one thin sheet of paper. Now fold it back one time so there are 2 sheets of napkin paper.

Lay this over your sail frame and cut a piece slightly larger than the frame. Leave an extra 1/4" all around.

10. I'm going to paint the napkins with a mixture of 1/2 white glue to 1/2 water. Be sure to mix these together well.

I've found that the more glue you use, the more translucent the paper becomes when it dries. You may want to do a test first to see how it comes out dry.

Lay down a piece of plastic on the table top. I just cut a piece of trash bag to lay down.

11. Lay the napkin on the plastic and soak it with the glue mixture. It's almost not a matter of brushing it on as it is just gently pouring it on.

Lift up the paper to make sure it has soaked through to the back side. You should see some of the glue mixture on the plastic underneath.

12. Place the soaked paper over the frame. Lift up an edge of the paper and pull it to one side to form a wrinkle in a couple of places. Push down on the wrinkle with your finger to secure it.

Push down the paper in the gaps between the long bars using your fingers or the brush. This will give the paper the impression that wind is blowing on it. When the paper dries it will stretch slightly so you may have to push it a little deeper than it will end up being.

Alternate doing these two things until you get the sail the way you want it to look. If the paper tears or falls apart because it took too long, simply throw it away and try again.

13. After it dries, flip the sail over and trim off the excess paper using a hobby knife.

Be careful not to cut the wood accidentally or you'll have to touch it up with paint. When you remove the excess paper from the small end of the sail, you'll probably lift off some of the paint and need to touch it up there.

14. When it dries, you'll notice that the paper stretches slightly and becomes a little more translucent than it was originally.
15. To add a bit more realism, I'm going to weather the sails. I'm using Doc O'Brien's weathering powders. For more information on this, take a look at our Weathering Powders article. Weathering powder is simply a finely ground pigment in different colors.

I'll start with the dark grayish brown. Dip a soft brush into the powder and knock the excess off into the lid.

16. Then gently sweep the brush into the cracks and recesses that you want to darken.

The powder goes on much softer and more even than paint or ink and gives a much more natural weathered look.

17. Next I'll use a light tannish yellow. I will brush this color over the entire surface to lighten the whole thing up. It also gives it a more dusty and faded look.
18. To finish the sails, I'm using a permanent black marker to add rivets.

Also you can add tears and holes in the paper with a hobby knife which also adds age to the sails.

19. Glue a hub block on the end of each sail frame. Be sure you glue it the direction shown in the last photo.

If the block is too tight, do not force it. Instead gently trim the end of the stick down until it fits.

20. The axle of the sails will be made from a 1/4" diameter dowel rod. Cut this dowel down to 4.5" long by rolling a hobby knife over it until you make a really deep groove all the way around, then breaking it.

The fender washer is optional. I'll use it to help the dowel stick out of the sail hub.

21. Place the sails around in a circle wooden grid side up.

Glue the hub ends together around the dowel rod. You'll need to hold them in place until the glue dries. I've placed a 1/4" fender washer under the hub so the dowel will stick out of the front slightly.

If you want to leave the sails to dry completely, you may have to prop something up under the sails to hold them up off the table. I used some of the 1/4" thick flat blocks to do this.

22. Paint the hub and dowel rod brown.

To insert the sails, lift off the top of the windmill. Place the end of the sail dowel rod into the hole in the back of the windmill.

Let the front of the dowel rest in the half-circle on the front. Place the roof back on the windmill.

Your fancy sails are now finished! Instructions for building the windmill are on the Windmill Building Instructions page.

Adding an Electric Motor
Adding a motor to make the windmill turn is fairly complicated. The instructions show here are basic and do not go into great detail. Also, many of the items I use may not be available to you, so your plan may need to change depending on what materials you can find.

I do not recommend that you try to motorize your windmill unless you have a good deal of hobby skill and a fair variety of tools. These tools may include drill bits, cutting tools, pliers and other hobby related tools.

1. The electric motor I'm using is from www.micromark.com. The motor costs about $16 plus shipping.

This motor is item #82090, "Animation Gearmotor" and the description is as follows:

"The motor is 2" diameter x 1" long lifetime-lubricated, high-torque 110v AC gearmotor that has a 7mm diameter x 16mm long shaft that turns clockwise at a constant 2.5 rpm."

2.
My plan that didn't work
My first idea for a motorized windmill was to put the motor down between the upper and lower windows. I wanted it positioned there just in case I wanted to add lights later on (and the motor wouldn't block the back window).

Since the tower slopes, I had to put a 1/8" piece of basswood (the same used on the sails) behind the motor to tilt it straight.

I used 1" diameter nylon pulleys (for patio doors) and put one on the motor and one on the sail axle. I used a rubber band as the belt so I could easily pull the belt off if I wanted to remove the sails from the windmill.

However, when I turned on the motor there was a very noticeable problem. The sails would move, then stop, then move, then stop. The jerking motion was very unrealistic.

The reason it didn't work is because the least amount of friction would stop the sails. As the motor turns, the rubber band would stretch until it built up enough force to turn the sails. When it had enough force built up, the sails would suddenly break free and spin a little, relieving all of the pressure in the belt. Then the sails would stop again until enough pressure built up to send it moving another few inches.

It was clear to me that what I needed was either a direct gear drive or a belt that did not stretch. Since an unstretchable belt would make removing the sail difficult, I decided to go with meshing gears instead.

3. To get the windmill to turn correctly, there are a few items I had to buy first. You can find most of these items at a large hardware store.

Two nylon bushings, each with a 1/4" dia. hole, 1/2" outside dia. and 1/2" long.

A cotter pin that can fit around a 1/4" shaft (the axle of the sails).

Two Lego gears. I "borrowed" these from my son's Technic Lego set. They have a 1" outside diameter.

And of course, the motor shown in step 1 above.

4. The first thing I had to do was to remove the back hole block, and replace it with a nylon bushing.

Since I had used "tacky glue", I was able to wet the blocks around until it softened up enough to come out. Then I used pliers to pull it out.

This would have been a whole lot easier if I had not glued the blocks in there in the first place. So If you're planning on motorizing yours, don't glue the hole blocks in there.

5. You may want to remove the front hole block. I liked the stone texture, so I just sanded mine thin and glued it back into place.

Place the 2 bushings on the sail axle and glue the back bushing to the back of the windmill.

Do not glue the axle or the front bushing.

6. I think the most difficult part of this whole process was to put a 1/4" hole in both of the gears. I used a dremel tool, some drill bits and some cutting tools to grind the hole out.

The motor takes a slightly larger hole than 1/4", but it's pretty close. Try to get the center hole as close to center as you can. Once you do that, go ahead and glue a gear onto the motor shaft. I used 5 minute epoxy for this and it worked very well.

7. What we need to do is find out where to glue the gear onto the axle. The only way to do this is to temporarily hold the motor in place. The easiest way to do this is to lay the tower down on its back.

At this point you will notice the motor is tilted (because the tower slopes). To straighten it up, place a strip of 1/8" square bass wood under the lower bottom like on the diagram on step 3 above.

8. Now with the dowel rod fully inserted into the back bushing (well, don't push it in quite all the way - you don't want it to bind up), you should now be able to tell where to glue the gear on the top shaft.

Mark its position with a pencil or something, then remove the top shaft and glue the gear into place.

The front nylon bushing will now be trapped between the sails and the gear. You should be able to slide the front bushing but not remove it from the axle.

9. Next we have to glue the motor in position using 5 minute epoxy. First, lay the tower down on its back and prop it up with a few blocks.

Then glue the 1/8" basswood onto the back of the motor with 5 minute epoxy. Insert the sails into the windmill tower.

Place 5 minute epoxy on the top and bottom of the motor and place it in the tower. Make sure the gears mesh properly and wait for the glue to set up.

Once dry, you should be able to plug in the motor and test the windmill. You should also be able to remove the sails from the windmill when you need to.

10. The last thing we need to do is install a cotter pin behind the front bushing.

This will keep the sail from sliding forward when the motor is running.

To install the cotter pin, you will have to drill a hole in the shaft right behind the front bushing. It should pop into place fairly easily.

11.
Inserting the sails.
1. Slide the front bushing towards the gear. Place the end of the sail axle into the back bushing on the windmill.

2. Lay the axle down flat so the gears mesh and slide the front bushing away from the gear as far as it will go.

12. 3. Stick the cotter pin in the axle behind the front bushing. This will keep the axle from sliding forward.

Place the roof back on and your motorized windmill should be finished. You many notice that the motor will cover the back window, so you may have to paint there.

Also, if the top roof doesn't fit back on, you may have to trim the hole block attached to the roof in order for it to clear the front bushing below.

Your motorized windmill is finished! Instructions for building the windmill are on the Windmill Building Instructions page.

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