Hi folks. This is a great forum! With some "free plans" I had found elsewhere, I built a T-gun that didn't work so well as I was guessing about nozzles specs and psi, and then I found this forum. I've read all the introductory info here on T-guns, nozzles and SM4s. I converted my T-gun into an SM4. It's made from 3/8" galvanized piping.

Here in Raleigh NC the temps have dropped down to 27F (ambient thermometer) for 3 nights so far, but both T-gun and SM4 have not done so well with snow quality. The T-gun fed by 35-55 psi garden hose and 50 psi air basically coated the blades of grass with ice, and then last night with the SM4, it made very icey snow, again with the grass coated, but this time with white crystals and a very fine granular base. However, it was enough for my kids to slide on. I am hopeful that some of the experienced people on the forum can glance over the design and give me some more pointers. I'll try again tonight, as I found the wetbulb link on the main forum page and temps are dropping quickly.

Equipment:
Compressor - Craftsman 25 Gal 5hp (sealed oil/maintenance free), 7.1 CFM @ 90 psi, 9.1 CFM @ 40 psi. Regulator set to 40 psi. Connected to gun with 20 foot 3/8 air hose. Trying not to run the compressor continuously. 75% duty cycle is more like it.

Pressure Washer - Karcher with 5hp Honda gas motor, 2400 psi, 2.5 gal/minute. Fed with garden hose full-on. Engine throttle running full speed. I also tried to back off the speed a little, probaby 75% of max and it seemed to do about the same. If I close the water inlet valve on the gun slightly it causes my power washer to stop pumping, so I'm not sure how you regulate the incoming pressure to 400-500 psi.

Attached is a pic of my SM4 gun. What does SM4 stand for BTW?
I originally had 3 bulk water jets, but they were too big (0.45, 0.4 and 0.3 gpm) and too narrow (15 degree flat) These were what I bought before I did all the reading, so I'm in the market for better jets. Last night I ran only one bulk nozzle, a 0.32 gal/min 40 degree flat "General Pump" brand pressure washer jet, on the end of a 6 inch 1/4" nipple. The other two nozzles are currently blocked off. The water valve was fully turned on, the mix valve was just barely turned on so minimal water was mixing with the air and coming out of the nuc.

The nuc nozzle is a pipe cap with a 1/16th inch hole drilled through the center. The vertical distance between the nuc and the operating bulk jet is 12 inches.

The gun is tie wrapped to an A frame ladder, about 5 feet up. The jet steams shoot about 30 feet, with top of plume about 20 feet in the air, considering the sloping ground below.

What can I do to improve the gun I have now while we've got some cold temps?

My next plans up for comment would to be to buy a real nuc jet, probably 0.6 gpm 80 degree flat or cone, and then add another 0.3 gpm bulk jet, and a 0.2 gpm bulk jet, all 40 degree flat, so total bulks would be (0.3, 0.3, 0.2).

Thanks for any help on this.
Regards
JD

I'm another newcomer from Sanford, NC. I'd recommend that you keep trying and play around with your nozzle sizes. I'm making snow with a tee-gun, so I can't help too much with the SM4, but I think that you reduce pressure washer pressure by nearly shutting the inlet valve on your water. You could also try adjusting the distance from your bulk nozzle(s) to your nuc nozzle.

12" is too far between the bulk & nuc. Sounds like what's happening is you aren't mixing all of the P/W flow with the nuc, and you're freezing mist along with some snow. I would go with something around 4"-6".

As for adjusting the pressure, this is typically done with an unloader, which is a device that routes the output back into the input of the pump at a certain PSI. You have a gas pressure washer, so you may have one. Most cheap electrics aren't equipped with them ( and neither are a lot of the more expensive ones these days as well! ).

You need to figure out what pressure you're running, put a high-pressure water gauge on your gun at the top. My preference is to run 500+ PSI, but some here feel that produces too small of a water droplet size and is prone to evaporation and drift ( I run when it's not windy & the humidity is typically 60% plus and the evaporation is more minimal ).

80° might be a bit wide for a nuc, 65° would be a probably work out better.

I'd advise you to hold off on adding more bulks until you get a good run out of 1 bulk and nuc.

Take a look at how you have your nuc setup. As it is, the air and water come straight at each other, and then exit the nuc nozzle. You want the air to be going straight at the nozzle, meaning you have to change the position of that tee, so the air comes in the back and goes straight out the front of the gun (through the nuc nozzle). This will probably help you.

quote:

Originally posted by who8myrice:
Take a look at how you have your nuc setup. As it is, the air and water come straight at each other, and then exit the nuc nozzle. You want the air to be going straight at the nozzle, meaning you have to change the position of that tee, so the air comes in the back and goes straight out the front of the gun (through the nuc nozzle). This will probably help you.

Is it possible for you to get a picture of your gun running? Rice's advice may or may not be applicable for you, depending upon if you have any issues with your current nuc mixture.

The nuc nozzle is a pipe cap with a 1/16th inch hole drilled through the center. JD[/QUOTE]

Correction: My nuc nozzle is currently a pipe cap with a 7/64" hole drilled through the center. I can see the throw pattern is too narrow to cover the 40 degree bulk jet. -JD

Great advice folks. Thank you. I made some more snow last night, enough to sled on - 15' x 100', about 1/2" depth in 4 hours. My nuc spray pattern (7/64" pipecap) is definitely too narrow, looks like 30 degrees. I'll make those other recommended adjustments. I found a pressure gauge at Tractor Supply (TSC), but it only went up to 400 psi, and I think this isn't enough. I may try Agri-supply next. I haven't been able to find the right nozzles I need locally, checked TSC and Northern Tool, so I'll be mail ordering some. Last night my nuc valve required adjustment every 5 minutes, seems the water going to it would gradually be reduced over time, so I had to compensate for it. Here's a photo of the gun running, I'll get some better ones during the next cold night.

the reason you are having to readjust the nuc is because its a ball valve
try switching to a gate or needle vale they are more precise and hold their position well

Northern DOES have nozzles that will work, they're just numbered differently. They have 1/4" NPT pressure washer nozzles of varying sizes. For several years I used a 2530, which is a 25°, nozzle that I believe is .3 GPM ( @ 40 PSI ).

But, I checked your forecast and you're in the same warm weather boat I am for the next two weeks, so go ahead and order them ( mcmaster has everything you need ).

I recommend a pressure gauge that goes to 1000 PSI.

hmm, What might help the adjustment of the nozzle is the nut behind the arm on the ball valve for adjusting it. Take off the screw that the arm is for the ball valve, take off the arm, then there should be a hex nut there, very small one, get the wrench out and tighen that up, then out the arm back on. Don't tighten it too tight because that nut secures the ball in the socket so that it doesn't move. I've had to tighten this nut up on all my valves. It keeps the valve where it is all the time. I go 8 hours without adjusting a ball valve. I personally like ball valves better than gate valves because on a gate valve you have to first open the valve, and nothing will come out, then as you know you turned it too much and there should be a ton of water coming out, as you turn it off all the water then starts coming out, so its kinda difficult to get that adjusted right, alot easier to spend a minute longer moving the ball valve 1mm to get the right adjustment and not have to touch it all night... hmm weird. I've herd of people having that problem but personally haven't encountered that problem except only on a gate valve...

Sounds like you had a loose/broken gate valve. There's also a nut on most gate valves to tighten it up. If the valve is loose and doesn't line up correctly, when you open it up it'll move to one side of the chamber ( and possibly blocking flow ), and then when you close it, it'll be pushed to the other side of the chamber ( and possibly stop blocking flow ). If it's lined up correctly, it will only open one direction, and close the other, in a smooth fashion.

he isnt using a gate valve he is using a ball valve

I'm talking about Matt.........

Its maybe too tight, I can barely turn the knob...

Jono,

Your bulk nozzles are toooo far away from eachother. Whats going to happen if your gun is on a 5' tower is the bulk won't mix quick enough and by the time the droplets are already falling down they'll just be then mixxing with already nuc'ed bulk. Maybe change the nipples between the water in T and the first upper bulk to a close nipple, then change the nipple after the T to the washjet to a 2" nipple.
What will also help is higher air pressure, 40psi is prettymuch the minimum for any snowmaking, a sm4 typically will require more PSI to get the nuc nice and dry before it mixxes with the bulk spray. I would set your regular at at least 60psi. Do that cloth test, read my Sm4 guide.

You also want to change out the 3/8" air hose and quick connects for garden hose and use garden hose swivel adapters. The quick connects, will freeze, which im sure you already know by now. Same goes for the check valve. If you want the check valve, put it right after your compressor outlet.

The 80* nuc will actually be just fine for 40* bulk nozzles. I'm actually discovering when I'm using my low pressure sm4 that its actually kinda good to have a tad wider nuc nozzle than your bulks, that way if theres any wind from the side, the nuc still reaches the bulk, plus if you get a strong gust from behind, the nuc will want to flatten into a smaller spray angle if theres wind from the back, which if its a tad wider than the bulk it should still be fine. So give the nucjet a try. That should help snow quality as its a flat fan nuc...

Looks good!

Great info. You guys rock. Just checked Mcmaster, man they have a lot of nozzle categories. Wasn't able to find what I think I need, rated at 40 psi...
0.2 gpm 40 degree flat bulks
0.3 gpm 40 degree flat bulks
0.8 gpm 65 or 80 degree nuc
Is it best to do a flat nuc or a full cone nuc?

Ideally in 1/4" or 3/8" NPT.
Am I looking in the wrong place? Looked in flat fan spray nozzles, high pressure spray nozzles, misting nozzles, pressure washer spray nozzles... The flow rates are either too high, the angles too wide. I'll look at the other mail order places tomorrow. What was that place I read about in one of our lists that had real cheap shipping?

Thanks, JD

i use pressure parts for nozzles sometimes. they have all the nozzles u need. 4002 would be the 40 degree .2gpm and so on. and most use flat nuc.

Jono, the teejeet nozzles are the ones that start with 3234K. They're on Page 2034 of their current catalog, and McMaster calls them 'Standard High-Pressure Spray Nozzles'. McMaster doesn't call them teejet nozzles because they frequently change manufacturers for certain items, and they want that to be transparent to the consumer. I highly doubt they will switch from spraying systems anytime soon, but there's the possibility that if you order 5 years from now, you'll get a completely different nozzle.

You have to specify what degree you want. If you order a 40° 3234K1, you'll end up with a 4002 TeeJet nozzle.

I personally prefer looking at the mcmaster flow charts for what nozzle, since they show 300+ PSI flow rates, which is what you'll be using in practice.