Author Topic: Solar Trackers  (Read 9572 times)

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Offline rossw

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Solar Trackers
« on: January 13, 2012, 12:25:54 am »
Had small amounts of solar for a while, but couldn't really afford a lot more. Then the price of propane went up 30% in one hit, and the short term pain of solar didn't seem so bad. So I brought in a bunch. Commercial trackers were stupid expensive, so I figured I'd try my hand at making one myself.

One turned into several :)

The first one was a quicky, only seasonal adjustment. I'll make a separate thread for that one.
The next three were made from relatively inexpensive and easy to get materials.

I couldn't get thickwall U channel the size I wanted (a little larger ID than the square posts OD), so I got square RHS and cut one side off to make my own. (Had to make 3, just the first one done here)


The first one I welded end caps on, but the next two I did differently. The hole was a comfortable (loose) fit for the shaft material I'd chosen (3/4" steel)


Measured and marked the angles for maximum and minimum (summer/winter), and checking that the turnbuckle had the range required for adjustment.


Apart from the shaft, that worked out ok, but I wasn't entirely happy with the way it worked out.


Didn't have a die the size I needed, so cut threads in each end of each shaft in the lathe.


I machined up the "bearing blocks" from a chunk of 1214 steel. These are made 2-up. I cut each in half later.




When assembled, looks like this


Here's the first one with the frame attached. (Seasonal-only array in the background)


And fully populated, ready to start contributing power


A couple of things that were not quite so obvious along the way. It was going to be hard to hold the shaft without damaging it, while I did up the nyloc nuts. So I milled two flats on each shaft for an open-ended spanner to hold it.




Hadn't finished setting everything up square when I took the picture, but gives an overview.

Offline wilfor03

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Re: Solar Trackers
« Reply #1 on: January 13, 2012, 08:55:29 am »
Boy, RossW, that mount looks a lot better than the "store-boughten" ones! Seriously, damned fine machining there.

Makes my little C-band adapted mount look like a roller skate compared to your Cadillac!  :-[

My next "rack" will be more fashioned like yours if ya don't mind?

Got a quick question for ya? Do you run several mounts off of one Tracker Board PCB or do you run each on their own?

Great work, and really enjoyed the pictures........

Bill

Offline ChrisOlson

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Re: Solar Trackers
« Reply #2 on: January 13, 2012, 08:58:25 am »
Nice trackers.  Your homebrew ones are better than the store bought ones anyway.
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Offline Wolvenar

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Re: Solar Trackers
« Reply #3 on: January 13, 2012, 11:13:06 am »
Very nice Ross, I am seriously jealous
Trying to make power from alternative energy any which way I can.
Just to abuse what I make. (and run this site)

Offline rossw

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Re: Solar Trackers
« Reply #4 on: January 13, 2012, 01:49:05 pm »
Boy, RossW, that mount looks a lot better than the "store-boughten" ones! Seriously, damned fine machining there.

Makes my little C-band adapted mount look like a roller skate compared to your Cadillac!  :-[

My next "rack" will be more fashioned like yours if ya don't mind?

Got a quick question for ya? Do you run several mounts off of one Tracker Board PCB or do you run each on their own?

Great work, and really enjoyed the pictures........

Thanks for the kind words.

I don't have a mill, but I used my lathe to do it. I've got a bunch of extra photos showing how I fabricated the bits. If you want, I can post additional pictures?

It was my intention to build trackers for each. I built the first prototype (will write another thread on that too), and it worked, but then I got busy again and work stalled. Since my home is full of home-automation stuff (perhaps that's another project?), I simply set up two more outputs and drive all the arrays together. So far it has worked really well.
* Starting at sunrise, the panels drive west for a couple of seconds about every 15-20 mins, depends on the length of the day.
* Half an hour after sunset, the panels drive to a park position
* Half an hour before sunrise, the panels drive fully east ready for sunrise.

Offline rossw

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Re: Solar Trackers
« Reply #5 on: January 13, 2012, 01:50:39 pm »
Nice trackers.  Your homebrew ones are better than the store bought ones anyway.

Ta. I have one there that's a commercial tracker, but it's been a constant source of problems, so I guess you're right!

Offline ChrisOlson

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Re: Solar Trackers
« Reply #6 on: January 13, 2012, 02:30:10 pm »
I don't have a mill, but I used my lathe to do it.

Ross, I do the same thing.  I got a Bridgeport vertical mill.  But when it comes to cutting blind or open end slots on shafts, and other small projects, I'll typically chuck a four flute endmill in the lathe, clamp my work piece in a mill vice mounted on the crossfeed and use the lathe to do it.  Way less setup time than the Bridgeport for small stuff.
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Offline wilfor03

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Re: Solar Trackers
« Reply #7 on: January 13, 2012, 06:18:55 pm »

[/quote]
I don't have a mill, but I used my lathe to do it. I've got a bunch of extra photos showing how I fabricated the bits. If you want, I can post additional pictures?
[/quote]

You bet, I'd sure like to see the other pictures. Worth a thousand words each, eh? Again, super job

Offline rossw

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Re: Solar Trackers
« Reply #8 on: January 13, 2012, 06:56:25 pm »
You bet, I'd sure like to see the other pictures. Worth a thousand words each, eh? Again, super job

lol. Your wish is my command!

In no particular order then....

The pin that the head tilts on (seasonal adjustment) was also made of 1214 steel. I machined a groove in each end to take a circlip so it couldn't work its way out, and a small bevel one end to help line it up and get it through the holes.


We don't get the frozen ground (frost heave?) that some of you far northern folk get, so my posts were holes 3 feet deep and a foot diameter, with the 4" galvanised steel post dropped in, then filled with concrete. Here's one with the head on, just waiting for the concrete to cure before I continued. The frame around it was just to hold it square while the concrete went off.


I started with a length of 40mm solid 1214 bar stock, cut to length. Drilled a hole through it, then bored it to comfortable fit for the 3/4" shaft, leaving clearance for grease and so it would turn.


Grease nipples added so I can keep the things turning. I figure half a turn a day just wasn't worth the extra complexity of bearings, and this would be plenty strong.


The threads came up pretty well for a non-mechanical guy. I chose a half-nut to lock the inside, and a nyloc for the end. They won't shake off.


Took some time with a calculator to work out the geometry of the mounting bracket so I would get maximum east/west tilt with the actuators I got. This pic also shows the orientation of the panels. Half one way, half the other. This keeps the connections as close as possible, so induction loops are minimised. (for lightning protection. Does this need more explanation?)


Closeup of one "bearing block" (bearing as in "load bearing"). The bolts that hold these on are high-tensile and go ALMOST the whole depth of the block.


There's an O ring on the back to help keep the grease in and moisture out.


The turnbuckle eyes were just rough cast and slightly different sizes from one to another. I machined them out to a clean, constant size so they could be attached so they would swivel, but not slop.




I turned up some threaded "slugs" to hold the cross pieces in place. They press firmly up the centre of some gal pipe.




The cross-piece (shown here not mounted) serves several purposes. It helps keep the U channel rigid, and it forms the attachment point for the turnbuckle (for seasonal adjustment)



"Milling" the slots for the spanner, as mentioned earlier. I only used a 2-flute slot-drill here, but the result was quite satisfactory. Hardest part was getting the two sides exactly parallel.




This shot was a setup, using a long bolt to show the mounting to the post. The inner sleeve isn't visible when a shorter bolt is used and it's all done up.

Offline philb

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Re: Solar Trackers
« Reply #9 on: January 13, 2012, 07:35:47 pm »
Beautiful! rossw.
After seeing yours, I think I can build my own. I doubt it would look that good. lol

How are you controlling the trackers daily travel? Is it off the shelf stuff?

Offline rossw

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Re: Solar Trackers
« Reply #10 on: January 13, 2012, 10:44:22 pm »
Beautiful! rossw.
After seeing yours, I think I can build my own. I doubt it would look that good. lol

The story continues. Before you build your own, be sure to check the next part! or you might suffer the same problems!

Offline wilfor03

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Re: Solar Trackers
« Reply #11 on: January 14, 2012, 10:05:58 am »
RossW....
Thank you for posting more of your "build" pix. It's always good to share (and see) how people do certain things on their builds.

I still am thinking about building "ANOTHER" solar mount and you've cleaned up some mental cobwebs I've had on how could I

build it better next time.

Thank you for sharing, bud.....

Bill