Halloween Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #1
I'm a fledgling prop maker embarking on the use of pneumatics. I'm seeing inexpensive solenoids, etc on eBay from china. Can anyone weigh in on some pros and cons?

Many thanks!

PS to anyone living in the Los Angeles area - do you know of any shops or stores that sell pneumatic supplies?
 

·
What Hump?
Joined
·
1,107 Posts
I'm in the same boat and recently asked the same questions here.
Make sure that you are aware of the fitting types that your solenoids have (BSPT vs. NPT).
Buy the correct fitting type.
I've not bought them yet, but the $9.00 solenoids that you are seeing on Ebay appear to be legit, as long as you are aware that they are BSPT and not NPT.
 

·
Registered
Joined
·
204 Posts
I use the low price solenoids from China extensively, without issue. We run more than 30 pneumatic props in our yard for the entire month of October and they fire thousands of times during the month. Keep in mind, the more expensive solenoids are probably made in China as well.

As Abunai stated, the low price solenoids usually have BSP threads and not NPT, but BSP fitting can easily be found at a low cost on ebay as well.
 

·
Soccer and Lacrosse Dad
Joined
·
1,761 Posts
2013 was my first venture into pneumatics and I purchased three 12VDC solenoids and they worked great. I used 500mA 12VDC power supplies to power them. It took about 3 weeks for my order to arrive in Canada. I used them with scubaspooks 4 button prop controller.

I will order them again.
 

·
Registered
Joined
·
401 Posts
I agree with the other posters in that the China sourced solenoids worked just fine for me as well. Biggest issue was with the fittings. Coast Pneumatics in North Orange County was simply over the top in terms of helping me out and passing along knowledge. I went in there knowing only what I'd read online and with an SMC cylinder in one hand and a China sourced solenoid in the other. As others pointed out, the fittings were all wonky, but SMC has what they call universal fittings that'll fit both NPT and BSPT. They worked just fine for my application, although I had to put some teflon tape on them for good measure.

I too feared the solenoids would die at the worst time and considered buying backup units and even went so far as to make all of my electrical connections with bullet connectors in case I had to change something out Halloween night on the fly. It never happened.

I'll say though that if using dual acting cylinders you'll want to wire the air such that the solenoid is in an unpowered state most of the time. I once had the air ports reversed and noticed while testing that the configuration I had required the solenoid to be activated so that the prop would not be extended and when the solenoid was turned off the prop would then actuate and extend. This meant that while the prop was just sitting there ready to be triggered the solenoid was actually open and had current applied to it, and as a result it was very hot to the touch. So swapping the air on the cylinder changed the process so that the prop was at the ready with no power applied to the solenoid (as it should've been) and once power was applied to the solenoid relay it would then swap air ports and activate the prop.
 

·
Registered
Joined
·
21 Posts
I have been using pneumatic products from automation direct in industrial applications for many years now. They are quality products at a very affordable price.
I have also used there PLC range, again with no problems.
 

·
BAD INFLUENCE
Joined
·
11,413 Posts
Evil Eye, could you please post a link to the SMC fittiings that you refered to. I searched the website and could not find what you are describing. Thanks
 

·
Registered
Joined
·
401 Posts
Here's one of the solenoids with the fittings I was talking about. The guy at Coast Pneumatics said they were universal and would fit either pipe thread. You're right though in that I google'd for 10 min and couldn't seem to find anything. I know these will slightly leak air in some cases so I had to put tape on all of them and they were just fine after that.

solenoid.jpg
 

·
Registered
Joined
·
10 Posts
Discussion Starter #12

·
Registered
Joined
·
401 Posts
Lawnzombies, that's likely to be them. When screwing them in, I noticed they have some slight play in the threads as I could wiggle them a little. But even if you cinch them down and fully seat them I noticed sometimes you could hear a little bit of air escaping. So after that I'd just teflon them all by default. They all worked just fine on my solenoids and cylinders.

edit: btw, that's a killer price. I think I got nailed for a couple bucks each so it quickly added up for 3 solenoids and 3 dual actuating cylinders.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #15
Lawnzombies, that's likely to be them. When screwing them in, I noticed they have some slight play in the threads as I could wiggle them a little. But even if you cinch them down and fully seat them I noticed sometimes you could hear a little bit of air escaping. So after that I'd just teflon them all by default. They all worked just fine on my solenoids and cylinders.

edit: btw, that's a killer price. I think I got nailed for a couple bucks each so it quickly added up for 3 solenoids and 3 dual actuating cylinders.
Thanks for the info. I also found some BSPT fittings and mufflers on eBay. Everything pretty much from China. It's crazy how inexpensive they are and shipping is free as well. The pessimist is me keeps asking, "what's the catch?" So far as I can tell, there isn't one. That said, I understand it's gonna take a few weeks to arrive but I have plenty of time.

The only worry I have now is how to wire the solenoids. I'm sure to be back here asking advice soon enough.
 

·
BAD INFLUENCE
Joined
·
11,413 Posts
Here's one of the solenoids with the fittings I was talking about. The guy at Coast Pneumatics said they were universal and would fit either pipe thread. You're right though in that I google'd for 10 min and couldn't seem to find anything. I know these will slightly leak air in some cases so I had to put tape on all of them and they were just fine after that.

View attachment 187787
The reason I'm asking is I'm thinking that there are some sizes that are real close to each other and that's why they fit. I've worked as an Industrial Mechanic for over 20 years and not heard of this. I'm not saying it can't be done, just whenever we needed solenoids ,cylinders, fittings ,etc. we always made sure we matched the threads for correct fit. I have heard of people wrapping about 4-6 turns of teflon tape to get them to seal ,but that's not the way it should be done . You only should use at most 2 wraps of tape otherwise you may have a bad part .The tape is judt a seal not to fill gaps. I'm going to researcg this some more for my own curiousity. Thanks for the info.
 

·
Registered
Joined
·
401 Posts
Lawnzombies- the way I tell when wiring the solenoids is to look at the LED's polarity when connecting the +/- leads for power as they weren't marked on mine. There is a small LED connected where the power leads are that shows when the solenoid is activated.

bfjou812- I agree as I asked a few times how these universal type fittings could work and the shop iterated a few times that they'd just got them in and that as he put it, were capable of fitting both threads. FWIW, I can tell you that I only put one pass of tape on them though.
 

·
Registered
Joined
·
135 Posts
I use hundreds of the SMC uni-fit fittings on industrial machinery. They will fit NPT, BSP, and G (straight german pipe thread). They seal on the face of the valve or cylinder using a flanged sealing ring vs sealing on the threads.
 
1 - 18 of 18 Posts
About this Discussion
17 Replies
11 Participants
gadget-evilusions
Halloween Forum
Halloween forum - Keeping the Halloween spirit alive 365 days a year. Discuss decorations, costumes and more!
Full Forum Listing
Top