Nelson Square Spray Sprinkler Ball Bearing Mod

Sprinkler Modding

A few weeks ago I bought some Nelson Square Spray sprinklers for the lawn, but they were terrible and I had this urge to mod and fix them. I replaced these with some better sprinklers for the yard, but the square spray sprinklers may come in handy at some point. They have a top spinner which, when spinning properly, distributes water fairly evenly from the sprinkler out over the lawn. The factory design of this sprinkler uses a rubber grommet in the center of the spinner, which spins around a metal pin. This lasted about 2 days before the rubber ring began binding on the post and the square spray wonder sprinkler quit working at all, it just blasted fixed streams of water into parts of the lawn.

I modified one of the sprinklers this evening with ball bearings. The bearings are well greased, but I’m sure they’ll eventually rust and seize up. The best type of bearing to use for this is a sealed bearing, but I had none handy, these only had metal shields on the sides. This should get some more time out of these sprinklers at any rate, most people probably would have just taken them back for a refund, because in the condition they were in, they were useless. Here’s the procedure I used to modify the Nelson Square Spray, the numbers relate to the photos in sequence.

1. Stock product
2. Disassembled product: Base, Spinner, Rubber Grommet, Washer, Nut
3. Resizing the hole for the new bearing
NOTE: I just used a bearing I had handy, any bearing which fits the post relatively close.
4. Grinding the hole carefully
5. The bearing inner inner race and outer race were roughened up to give the epoxy something to hold onto.
6. The spinner was roughened around the hole, on both sides.
7. 5 Minute epoxy works great for this kind of thing. It holds parts in position in about 5 minutes, is able to be handled in about 15, cured in 1 hour.
8. I epoxied the bearing into the spinner of the sprinkler, being careful not to get epoxy into the ball bearing races. Epoxy on both sides forming a fillet around the bearing.
9. I epoxied the sprinkler spinner and bearing assembly onto the sprinkler’s center post of the base since the inside of the bearing was slightly larger than the post and I was using what I had on hand.
10. The finished product. The spinner now spins very freely and doesn’t catch and drag. The new sprinkler works as the original was advertised.