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mtraven
06-21-2012, 12:44 AM
https://lh5.googleusercontent.com/-1-rLOh_A0Kc/T-KTp_GfiyI/AAAAAAAABEw/yOFal3zUuOo/s640/IMG501.jpg
I am currently making some sprinklers for my gardens. I will be making a batch of 10 initially & see how they work. I just finished the prototype & thought I throw it out there for critique before I start the first batch. prototype is alum (6061 I think) & used only because it was there. I am considering UHMW, PVC & aluminum to make the set from. UHMW is inexpensive & seems right for the job, but I have never turned it & people seem to have problems with it. What suggestions would you all make for material?

Also want to open up for general critique of the design, any suggestions for improvement would be great.
Here is the link to prototype pictures:
https://picasaweb.google.com/mtraven/Sprinkler?authuser=0&authkey=Gv1sRgCNXGofSC3desIA&feat=directlink


the assembly is a valve & rotating sprinkler designed to mount via 1/2"npt threaded "T" in a preexisting 1/2 pvc supply line. the lines are quite long, hence the need to valve each sprinkler to focus pressure to sections.

ed_h
06-21-2012, 02:39 AM
mtraven--

I'm afraid I don't have any answers for you--only questions, since I've been considering making some heads and nozzles, too. My sprinklers are for irregularly shaped garden areas, and I can't find commercial units with the right patterns.

Does the three-armed unit spin in reaction to the water? The water holes look like they are on the top of the arms.

How did you arrive at the size of the holes?

So you have a valve at each unit? I'm not getting how the valve works.

Thanks.

mtraven
06-21-2012, 03:04 AM
mtraven--

I'm afraid I don't have any answers for you--only questions, since I've been considering making some heads and nozzles, too. My sprinklers are for irregularly shaped garden areas, and I can't find commercial units with the right patterns.

Does the three-armed unit spin in reaction to the water? The water holes look like they are on the top of the arms.

How did you arrive at the size of the holes?

So you have a valve at each unit? I'm not getting how the valve works.

Thanks.

each arm has a rotational jet drilled at 90deg to the line of jets on the face, this causes them to spin, quite quickly I might add. those jets may not even be necessary as a slight angle in the lines of jets seems to accomplish the same task

re: hole size
really just a guess, grabbed the smallest bit in the case, 1/16" i think. might go a bit smaller with them in the future, some of it comes down to the material, which i have yet to decide on, although the alum. does work nicely. I planned to experiment with this variable, and I probably will, but its not just a start small & open up scenario, with the tiny drills I find a better resulting water stream from a single drill bit. I wont really know where I am at until I can gang a few together & see how many can be open at once.

re: valve

its a simple valve: two pieces connected via 1/2npt, off center holes through inside faces, threads bottom such that holes do not line up, open threads 90deg or so & flow is allowed. see https://picasaweb.google.com/mtraven/Sprinkler?authuser=0&authkey=Gv1sRgCNXGofSC3desIA&feat=directlink#5756325840254373586 for visual.

addition: also keep in mind this was made to spin vertically & is mounted @ h=7ft. that intent only shows up in the arms themselves which are threaded in & therefore exchangeable. I find commercial irrigation products to be rather restrictive and what the hell do I have a lathe for if I cant make a valve & sprinkler?

Duffy
06-21-2012, 10:50 AM
Just some thoughts. Aluminum is fine for prototyping, but in service you will have to anodize the finished parts or you WILL have corrosion problems at the orifices. For the arms, perhaps thin wall brass or copper tube?
Orifice size will be whatever. But water IS NOT CLEAN! It might be advisable to taper the orifice slightly. This will help eject any bits that try and jam the orifices. How to taper them-try a countersink or a taper drill.
If you jig a drill fixture for all the arms then, when they are installed in the rotor head, all at say 15 degrees or so off the vertical, the readction from the orifices should cause the spinning action. you might have to experiment with the angle.

ed_h
06-21-2012, 11:01 AM
Thanks for the reply. I hope you get some answers to your questions. I'm going to try a few things shortly.

Ed

mtraven
06-21-2012, 03:17 PM
Just some thoughts. Aluminum is fine for prototyping, but in service you will have to anodize the finished parts or you WILL have corrosion problems at the orifices. For the arms, perhaps thin wall brass or copper tube?
Orifice size will be whatever. But water IS NOT CLEAN! It might be advisable to taper the orifice slightly. This will help eject any bits that try and jam the orifices. How to taper them-try a countersink or a taper drill.
If you jig a drill fixture for all the arms then, when they are installed in the rotor head, all at say 15 degrees or so off the vertical, the readction from the orifices should cause the spinning action. you might have to experiment with the angle.


im pretty sure I am going to do these out of uhmw plastic. I wouldn't use thin brass tube because I run into the problem of attaching them to the head, which I cant do. my whole system has a few screens & filters on the supply lines to hopefully keep them cleanish, otherwise an overnight soaking in CLR has cleaned my commercial sprinklers well in the past.

mtraven
06-21-2012, 03:53 PM
hey duffy:

were you suggestion corrosion would only be a problem in the arms where there are tiny orifices and the valve body / sprinkler head would be ok in alum?

Duffy
06-22-2012, 12:33 AM
Depending on your water quality, corrosion could be a problem EVERYWHERE. That and so-called lime scale, if your water is hard and high in alkalinity. Anodized aluminum isnt much affected by corrosive water, but some alloys which, I think, includes 6061, are attacked. A lot of cheap commercial "watering stuff" looks pretty cruddy after a season. With your water, you might be fine.
By the way, no problem fastening brass tube to aluminum body-Locktite!:D

co_farmer
06-22-2012, 04:12 PM
If you intend to water the area immediately under the sprinkler, then the unit won't do it. It will spin the water spray outward. The old commercial sprinkler I have has one or two holes right in the top to solve that problem.

Paul

Rosco-P
06-22-2012, 06:21 PM
my whole system has a few screens & filters on the supply lines to hopefully keep them cleanish, otherwise an overnight soaking in CLR has cleaned my commercial sprinklers well in the past.

Irrigation systems usually rely on disc filters not screens to keep particles out of heads and nozzels: http://www.duralirrigation.com.au/onlinestore/index.cfm?NavigationID=15 Much greater capacity than a simple hose washer with a screen, cheaper than a filter housing with a string wound or pleated filter and easily cleaned, just remove, rinse and re-use.