MOD: 7747 Windmill Motorized

[mostlytechnic]

I want to add a windmill farm to the train layout we're planning to build in our basement. I've had the 7747 set for a while, but finally had some time to work on motorizing it to make things more interesting. (click the video or photos to go to the original full size ones)

First, a quick video. You can see that when you first turn it on, the motion is a little jerky. There's a fair bit of angular inertia to overcome, as well as backlash in the gearing and a long vertical axle to twist a bit. Once it's been running a few seconds, it smooths out and looks nice.

The hut hiding the motor and gears is just temporary and quickly thrown together. I'll eventually make something larger to hide the battery box in there as well.

One problem with the mod - it's much less stable than the original windmill. If you're not familiar with it, the stock windmill has a long 32 axle running up the center of the white column. Every couple sections of the column there's a blue round 2x2 brick with axlehole, which the long axle runs through. This provides a lot of strength to the structure. I removed the long axle and replaced it with several shorter ones with axle joiners - it's less springy that way. Obviously the bricks had to come out too to allow the axle to rotate, but now ONLY the column itself is providing structural strength. It's pretty easy to knock over. Definitely no longer kid-friendly :) It does keep the rotatability of the original model though, so I can turn the windmill to face whatever direction I want in the scene.

In the hut, there's a M motor with a 8 tooth gear, driving a 40 tooth. That cuts the speed a lot. Then it goes through a 16 to 20 reduction (the 20 is black, so hard to see in the photo). The net result is a 1:6.25 reduction, which gives something like 30-40 rpm as the final speed.

I want a small wind farm, so I ran an extra axle out each side of the hut. I'll hopefully end up with three windmills in the train layout, all running off the one motor in this one.

[frogstudio]

That's a nice MOD. It would be great if you could take more detailed pictures of all the gearing. Great work!!!

[lightningtiger]

Nice work 'mostlytechnic', the building housing the mechanics should be grey to look like a galv. iron or concrete build structure though ?

I too wouldn't mind seeing a break down of the gear train as well.

Brick On !

[LegoSjaak]

Oh yeah, that looks great! In My opinion, the 7747 is a really nice set, especially the windmill and the truck. (although the part of the truck where the rotorblades should be transported on is really shit) The tractor is outstanding!

But your mill is great!! Maybe you could change the color of the housing, like lightningtiger said....but that is just personally....

Succes with other MOD's!!!!

Great work!

Greetz, LegoSjaak

[mostlytechnic]

Yep, I'll definitely be changing the building. Probably a dark grey or something more industrial. This was just enclosing it to get an idea of size as-is - the final building will be bigger too to enclose the battery box as well. I just didn't want to dig through the larger part collection to find better building pieces, and I had the log bricks handy.

[arator]

Maybe a stupid question, but do i see 4 brown gears in a square? Why?

[mostlytechnic]

Maybe a stupid question, but do i see 4 brown gears in a square? Why?

Yes, you do. In that photo, the gear at the bottom is the drive coming into the square. The top gear is connected to the tower to power this windmill. The side two have shafts going out the sides of the hut to connect to two more windmills once I have my layout setup. You can see the shaft coming out the right side in that same picture.

[arator]

Yes, you do. In that photo, the gear at the bottom is the drive coming into the square. The top gear is connected to the tower to power this windmill. The side two have shafts going out the sides of the hut to connect to two more windmills once I have my layout setup. You can see the shaft coming out the right side in that same picture.

1 for the drive

2 for connecting the tower

3 for future connection (shaft)

4 ???? for the connection between 1 and 2, you can use 3. Or is the power from the driveshaft too strong?

[dr_spock]

Nice MOD. Great idea. Do you think you'll need to move up to an XL motor to power more windmills?

[LEGO Train 12 Volts]

Very well done!

It looks like a perfect copy of Vestas windmill (set 4999)!

Great MOD!

[mostlytechnic]

1 for the drive

2 for connecting the tower

3 for future connection (shaft)

4 ???? for the connection between 1 and 2, you can use 3. Or is the power from the driveshaft too strong?

The fourth is because I have "future connection" shafts going out both sides of the hut. I plan to have 3 windmills, and I'd put the powered one in the middle with shafts going out each side to the other ones.

[tongue60]

good some had already :http://www.brickpirate.net/forum/phpBB3/viewtopic.php?f=34&t=6436

[mostlytechnic]

good some had already :http://www.brickpirate.net/forum/phpBB3/viewtopic.php?f=34&t=6436

Yeah, I'd probably do it that way too if micromotors weren't $20 each for USED ones!

[Michael S]

Yeah, I'd probably do it that way too if micromotors weren't $20 each for USED ones!

I prefer the Power Functions. There is something very clean about building with one system involving parts that are currently available. It is neat how the expansion shafts allow connections to other windmills or whatever else he wants to power. It would be a problem not having the strengthening axle holding it all together - it would get knocked over way too much in my house. Still, I'd love to see a closeup shot of the gearbox, with the black parts swapped out for gray or tan gears and technic beams in any color other than black.