Introduction: Laminar Flow Water Jet for Under $25.
This instructable is for everyone who has ever wanted to build a Laminar Flow Water jet, it sounds complex but it is actually very simple. You will need some PVC pipe, some brass pipe, about 300 straws, 4 test plugs, and some sponges. So lets get started!!!!
Here is a link to my second instructable that shows how to add lights to the water jet.
If you have any questions or comments feel free to leave a comment, I don't mind if it is negative, you can always improve something when it is wrong but one its right there is no improvement.
Step 1: Supplies
1) A foot long piece of 3 inch pvc pipe.
2) A 3 inch pipe cap.
3) A 6 inch piece of 1 inch pvc pipe.
4) A strong water proof epoxy or similar glue. (i.e. Marinetex)
5) A 6 inch long 3/8 inch brass (or copper) pipe with somewhat thick walls.
6) 200+ straws (if they are the bendy ones it doesn't matter)
7) 4, 3 inch test plugs.
8) Some 5 x 3.5 x .25 sponge/scrubbing pads. (if they are wider then that is fine, you want them to be thin though.)
9) A razor blade or even better a small bandsaw.
A small razor or exacto knife,
Sand Paper (light and heavy grit)
Drill bit that will fit snug into the 1 inch pipe.
A band saw.
3 inch hole cutting bit(helps to round the 1 inch pipe)
Glue mixing supplies ie. Mixing board, stirring stick, applicator.
Various size brass pipe (for making different nozzles)
Extra 3 inch PVC Caps(these are a little expensive so i just used one.
Step 2: The Nozzel.
Chosing a nozzel can be difficult, but for a 3" PVC pipe a 3/8" brass pipe works very well.
To start you will want to start with a somewhat thick 6" piece of 3/8"brass pipe, first if you have an electric drill it goes much faster, you want to clamp one end into the drill and let the other end move freely. Now the important part get some heavy gritt sandpaper (80 gritt) and roll it into a cone shape with the gritt facing out, now run the drill and slowly push the sandpaper into the end of the pipe the goal is to create an inside taper, once a fine edge is created you need some very very light gritt sandpaper, like finishing paper, (400 gritt) then roll it into a cone and do the same thing so the inside is very smooth.
(Optional but you can also taper the outside of the pipe in the same way just reverse the sandpaper)
Step 3: Nozzle Cont.
Now you want to cut the nozzle off about .5 inch from the tapered end. (the excess pipe can be used to make more or new nozzles) a metal pipe cutting wheel works best for cutting it. Now you want to remove the excess pipe from the drill and put the nozzl into it with the tapered end facing inward, now you have to do the same thing to this side only you just want to remove the ragged edge, you don't have to completely taper it. Once that is done take the nozzle out and roll a piece of fine sandpaper into a tube that will fit into the nozzle, now take the nozzle and slide it up and down over the sandpaper tube but DON"T TWIST IT!!!! You want the sandpaper marks to be stright in the nozzle. (see picture)
Step 4: Inserting the Nozzle
Now take your Cap and drill a 3/8 inch hole and insert the nozzle with the fine tapered end on the inside of the cap as in the picture. Then use some super glue to secure it. (remember it is going to be pressurized)
Step 5: Main Body Part 1
First you will need a drill bit that fits well inside the 1 inch pipe, then use it to drill an offcenter hole in the bottom side of the 3 inch tube as pictured. Then use a piece of heavy gritt sandpaper to round one end of the small pipe so it fits on like in the picture. It helps to cut one end of the small tube to the appropriate angle that way you don't have to sand as much. Now you need the the epoxy to attach the pipe as in the first picture, i used Marine-tex to attach it but quick drying glue would be nice.
Step 6: Main Body Part 2
Now for the inside you need to punch out the test plug so you have the side and lip left, then use a razor or saw to carefully cut the top lip off the plug so you make a platic ring with the side of the plug. Now cut one side of the ring so you can shrink it, you then want to cut out a small protion of the ring so there is a gap in it then when you put the ring in the tube by its self it doesn't overlap but instead the the edges of the ring should push together and hold it tightly, you then want to take a sponge and cut it so there is a 1/2inch overlap on the sides of the tube then place it on the tube and then put the ring in it and press the ring and sponge down about an inch past the water intake opening on the bottom of the pipe with the sponge sticking out the sides of the ring as shown. you want it to be as tight as possible in the pipe because the sponge has to hold the straws in place and resist the water pressure.
Step 7: Main Body Part 3
Now place as many straws as will fit comfortably in the 3 inch pipe (inserting the bendy part down if you have it.) Press them down to the bottom sponge (a spraypaint can works well for this) make sure they are all about the same level in the pipe then cut out another sponge and plug and repeat the previous step 6, only push the sponge from the top of the tube so the straws are in between the two sponges, but be careful you don't force the other sponge out the bottom!!!!!
*You can also cut a small piece out of the ring so the sides don't overlap so instead the edges push together, you can also super glue the ends of the ring together just make sure it fits snug in the 3 inch pipe.
Step 8: Main Body Part 4
Finally if every thing is dry push a test plug into the bottom of the 3 inch pipe and secure it but DON'T GLUE IT!! Just press fit it or tape it if you have to. Now the last part fit the top cap with the nozzle and press it on very tightly!!!!
Step 9: Finally
Now with everything secure insert a hose into the 1 inch pipe (conveniently fits) and slowly open the water till you can just hear it flowing and slowly wait for it to fill up and if everything is done right you should have a very nice laminar flow water jet, but wait theres more!!!!!
Step 10: Before Cranking Up the Pressure.
If it works good at low pressure then remove the top cap(if its stuck then sit the pipe on its base, turn the water on so there is a1 inch fountain and cover the hole until it pops off don't worry about it spraying it won't, but be sure the bottom one doesn't come off first if that happens then you need to just try to pull the top off yourself) now take either superglue or epoxy and put a few drops on the plug rings to attach them to the pipe(do this on both sides, top and bottom, otherwise the water pressure will force the sponges and straws up then blow the top off and then continue out onto the ground, which isn't fun) Once the glue is secure you can reassemble, gluing the test plug on with super glue and then just press fit the nozzle plug, very tightly!! and your ready for some serious water jets!!!
You don't want to glue the nozzle plug on in case you need to open it later.
Step 11: Troubleshooting
If you don't get a laminar flow and it looks like the stream isn't perfectly round then you have an obstruction in the nozzle (it may be too small to see) but just take your light gritt sandpaper and give it a final good sanding and that should solve it.
If the stream is laminar then goes to a jet like stream then reduce the pressure and if it doesn't stop then you need to check the inside and make sure the straws and sponges haven't moved. If they are still in place then replce the top and try again, also if you touch the nozzle while its on it can make it do that, just either run over it again or shut the water off and let it sit for a few seconds then turn the water back on (this clears the nozzle of the air bubbles)
If the stream is laminar but it varies in height and kinds wobbles up and down then that is just a pressure problem (gonna try to find a cheap fix for that).
Step 12: Optional
I plan to add a bigger nozzle to hopefully stop the stream breaking up quickly, then i want to add a light system and a cutter which i will try to document better.
Also for info on how it works i will explain:
Water enters the bottom swirls around and finally goes through the sponge which slows the water, then the straws remove the swirling and you get one continuous coloumn of water, then the second sponge slows it again then it fills the space to the nozzle and it settles in the space, then it is forced through a (usually precision cut nozzle) and you have a laminar water stream!!!!
As mentioned in the Supplies section extra PVC caps can be used to create other nozzles and you can use various size brass nozzles if you have extra caps, just remember to follow the same technique when ever making a new nozzle.