Pillow Bearings

jasonhc73

Cat herder, and dog toy tosser.
Joined
Oct 1, 2019
Messages
1,729
Location
Wichita, Kansas
I am making a single-axis tracker now...

My main spar is 1 7/8 inch pipe (aka 2 inch rigid metal conduit, https://www.homedepot.com/p/2-in-x-10-ft-Rigid-Metal-Conduit-0544310000/202068054)

Do I get a 2 inch pillow bearing and use 1/16 shims to squish into the bearing between the conduit, or just go with 1 7/8 pillow bearings?

This is a little unusual single-axis tracker, the spar will align E/W to basically be seasonal tilt (but it will still adjust automatically), not N/S for daily tracking.
 

Alphacarina

Solar Enthusiast
Joined
Feb 22, 2021
Messages
214
I would check the diameter of your pipe with a caliper or micrometer and see what size it actually is, then buy the appropriate sized bearing. I kinda doubt you would be able to fit the pipe into a 1 7/8ths bearing . . . . but you won't know until you accurately measure the pipe

Don
 

MarkSolar

Solar Enthusiast
Joined
Mar 3, 2021
Messages
222
The finish of conduit/pipe is so rough that it might take a good bit of finishing to get it to fit properly into the inner race. You could oversize the inner race and use the set screws to take up the slop, but if you're going to do that there's no need for the precision and expense of bearings. Given the slow speed and limited travel, you might just use a pillow block without the bearing if you can find one that's close to the size of the conduit. That would give you a grease fitting and a solid mount. You could also make something yourself out of a piece of steel, drill a hole the size of the conduit and put your own grease fitting on it. If you weld it would be easy to fabricate something.
 

jasonhc73

Cat herder, and dog toy tosser.
Joined
Oct 1, 2019
Messages
1,729
Location
Wichita, Kansas
2 inch pillow bearings are HHYYYYUUUUUUGE!

20210623_224021.jpg 20210623_223919.jpg
This is the "2-inch" metal pipe (actual dimension is 1 7/8) The two set screws are all I plan to use to secure the pipe.
20210623_223753.jpg

Some more goodies:
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400 feet of 8AWG PV wire.

I'm adding two strings of Santan Solar, Canadian Solar 340W - "NEW" panels to my 2 LV6548's. This will put my 6548's at 6.9 kWp, off-grid.
I am presently able to stay about 80% off-grid with the 3.5 kWp PV and 57 kWh of battery I have now. It's just not able to recharge the batteries enough to remain off-grid during the hot summer using the nice cool air conditioner at 78°F.

I expect (hope) that after adding this 3.4 kWp, and making it a single axis tracker, I won't need to recharge from the grid ever again.

What I am doing now during the amplest solar month of June in the USA, is disconnecting my house from my off-grid setup and running on my grid-tied setup. My grid-tied setup is 6.2 kWp on a 5kW SolarEdge. At the end of the day, I switch to off-grid again and run batteries all evening and night. About 8:00 am there is enough sun to switch everything back, stay solar, and not use any grid, and recharge the batteries from the off-grid array.

Screenshot_20210623-230728_mySolarEdge.jpg
 
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