Quick Connects and Nozzles

[tcarnahan]

I have been using a Clark Cable launcher, but would like to move up to something that can take more pressure (i.e. metal quick connect / plastic nozzle). The only problem is that I have not had much luck finding a female brass quick connect that will mate with a plastic male quick connect to the point that they can take high pressure. Most of the suppliers I have investigated in the U.S. do not make the two so that they are compatible (i.e. metal with metal and plastic with plastic, but NOT metal with plastic)

Can anyone point to a supplier (preferably U.S. to keep shipping cost down) who has a metal female brass hose connector that will mate with a plastic male nozzle (they sell) that will hold pressure (~200 psi)?

Maybe it would help if you could specify manufacturer and model number ... everything I have tried doesn't even come close.

Thanks~

[WRA2]

I have been using a Clark Cable launcher, but would like to move up to something that can take more pressure (i.e. metal quick connect / plastic nozzle). The only problem is that I have not had much luck finding a female brass quick connect that will mate with a plastic male quick connect to the point that they can take high pressure. Most of the suppliers I have investigated in the U.S. do not make the two so that they are compatible (i.e. metal with metal and plastic with plastic, but NOT metal with plastic)

Can anyone point to a supplier (preferably U.S. to keep shipping cost down) who has a metal female brass hose connector that will mate with a plastic male nozzle (they sell) that will hold pressure (~200 psi)?

Maybe it would help if you could specify manufacturer and model number ... everything I have tried doesn't even come close.

Thanks~

Maybe what you need to do is buy the metal gardinia of your choice, install the "female" end on your launcher. Then take the male part and "copy it" in plastic using a lathe. The only problem you might have is the metal ball bearings in the quick connect female part may "pull through" the plastic. There was once a guy who made a high pressure "ball bearing" trigger but the plastic failed and the bearings made grooves in the softer plastic as is was weaker then the metal bearings.

I think it is going to be difficult to find a plastic/metal combination that will fit. Each manufacturer probably make the "pairs" in the same material.

You might have better luck with the "all plastic" ones and then isolate it from pressure using an internal launch tube. This keeps the pressure away from the plastic parts of the quick connect and make the launcher simpler. With an internal launch tube, you also do not need to build complex gantries or use guide rails making your launcher easier to setup and safer.

Another alternative is to just build a stronger cable tie launcher (do a search for "stainless steel cable ties" and see what you find). They are a little pricey but would also do the job.

Can you provide everyone with more information like the targeted pressure and nozzle size so that everyone has an idea of what to suggest. All of those would affect the choice of connector and materials it is constricted of.

[tcarnahan]

I was targeting 125 to 200 psi. I will have to go get a plastic nozzle and check the size. I don't have lathe or any prospects of gaining access to one.

Could you explain a little more about the internal launch tube concept and what you meant by it keeping the pressure away from the plastic parts of the quick connect? Currently, I am using an internal pvc pipe that I heated in the middle to get a seal on the bottle. The cable ties hold it against the "bump". Even though the schedule 40 pvc says it can handle the pressure, I am reluctant to put much pressure beyond 90 psi in it because of the potential for shrapnel if it bursts. Can you point to an example of what you meant (provide a URL)?

Thanks!

[thampson]

The Gardena metal and plastic male and female connectors are interchangeable. We use that very combination metal female and plastic male for the rocket itself. We also use Neta although In not sure if they are available in the US or not. Try looking for a genuine Gardena at a irrigation store.

I think the Gardena brand is owned by Nylex of that helps

Can you maybe outline a bit more what the issue is ? If the plastic is not clicking in properly you can modify the female part to enable it to fit. I think aircommand had a video on how to do this.

-todd-

[WRA2]

I was targeting 125 to 200 psi. I will have to go get a plastic nozzle and check the size. I don't have lathe or any prospects of gaining access to one.

Could you explain a little more about the internal launch tube concept and what you meant by it keeping the pressure away from the plastic parts of the quick connect? Currently, I am using an internal pvc pipe that I heated in the middle to get a seal on the bottle. The cable ties hold it against the "bump". Even though the schedule 40 pvc says it can handle the pressure, I am reluctant to put much pressure beyond 90 psi in it because of the potential for shrapnel if it bursts. Can you point to an example of what you meant (provide a URL)?

Thanks!

The bearing release launcher I spoke about was on a site that doesn't exist any more.

Here is what the web archive has on it:

http://replay.web.archive.org/200903090 ... lease.html

When he pressurized it to 600PSI the ball bearings cut grooves into the plastic nozzle and it let go. (there used to be a page on that site which showed pictures of the aftermath but apparently were not archived (too bad).

At less then 200 PSI you should not have any issues with cable ties (even standard plastic ones) breaking or pulling off How many ties were you using (I had to ask as people have made launchers using only 3 ties and then wondering why it does not hold).

Todd had a good suggestion that a plastic "nozzle" ma be easily modified to fit inside a metal "female" connector.




The Gardenia connectors can be found in the US

http://www.acehardwareoutlet.com/produc ... KU=7034648

http://www.acehardwareoutlet.com/produc ... KU=7039084

http://www.amazon.com/Gardena-36004-Gar ... B00004SDY5

I think these are the plastic ones but maybe a trip to the local hardware store may find the metal ones.

[SaskAlex]

Personally, I'd much rather go with a full bore nozzle for your desired pressure range. Cable tie launchers are plenty capable of withstanding 200 psi. If you're worried about using pvc at that pressure, you can use metal pipe.

As for PVC turning into shrapnel, I've seen it happen (at only 140 psi). If your launcher explodes, I honestly think the possibility of a horizontally flying rocket is much more dangerous than the PVC itself. Not that that really makes much difference.

Alex

[Spaceman Spiff]

Personally, I'd much rather go with a full bore nozzle for your desired pressure range. Cable tie launchers are plenty capable of withstanding 200 psi. If you're worried about using pvc at that pressure, you can use metal pipe.

As for PVC turning into shrapnel, I've seen it happen (at only 140 psi). If your launcher explodes, I honestly think the possibility of a horizontally flying rocket is much more dangerous than the PVC itself. Not that that really makes much difference.

Alex

We had a PVC pipe let go at work a while back. It was in a low pressure air line that was 10 years old. It was on the wall by the windows and U.V. changed the PVC and made it brittle. It exploded one day and we never found all the pieces. Some of them were stuck in the sheetrock!

[tcarnahan]

I haven't had any problems finding plastic quick connects. The problem I have is that the plastic male QC does not fit any of the metal fems ale QC's. I don't think modifying a store-bought plastic male QC will work because they fit too loosely in the female without modification. I have yet to find any metal QC's that fit plastic QCs.

I have seen a good number of launchers that use metal female QC's, but I have yet to find any here in the US that mate properly with a plastic one (that would attache to the rocket). A number of them I have seen have been in Australia ... I wonder if they have a different standard than here.

[thampson]

Im not sure if we have a different standard in Australia ... maybe ;)

I can send you a brass one, but it will take a few weeks to get there and will be a pain every time you need one to have to wait so long. I have found the irrigation stores here are great, they usually go out of their way to help and even crawl through the product catalogues to find what I need and order it in specially. Try a few around your area, I would think that if you stay with the same brand, the plastic and metal ones should be interchangable.

I did lookup the Gardena product catalogue in Canada, (closest I could find to US) and it only really has plastic quick connects not metal ones, so maybe thats the problem. Here gardena is like a defacto standard and the other manufacturers make their quick connects to fit gardenas as well so you can swap any plastic or brass fittings and they will usually fit.

If you need me to send a brass one, let me know

-todd-

[Spaceman Spiff]

Im not sure if we have a different standard in Australia ... maybe ;)

I can send you a brass one, but it will take a few weeks to get there and will be a pain every time you need one to have to wait so long. I have found the irrigation stores here are great, they usually go out of their way to help and even crawl through the product catalogues to find what I need and order it in specially. Try a few around your area, I would think that if you stay with the same brand, the plastic and metal ones should be interchangable.

I did lookup the Gardena product catalogue in Canada, (closest I could find to US) and it only really has plastic quick connects not metal ones, so maybe thats the problem. Here gardena is like a defacto standard and the other manufacturers make their quick connects to fit gardenas as well so you can swap any plastic or brass fittings and they will usually fit.

If you need me to send a brass one, let me know

-todd-

I found plastic and metal ones on the shelf at the Home Depot and they were incompatible.

Does anyone make them for other types of plumbing other than garden hose? Maybe some other type of connector would have more suitable thread spacing?

[U.S. Water Rockets1]

I found plastic and metal ones on the shelf at the Home Depot and they were incompatible.

Does anyone make them for other types of plumbing other than garden hose? Maybe some other type of connector would have more suitable thread spacing?

The trick is finding fittings with the same threads as a bottle. The bottles are the problem in these cases. The threads are not standard with any common plumbing, so you have to modify gardena connectors to fit the bottle. There's a lot of ways you can adapt the threads by slobbering epoxy in them and letting it cure and form new threads.

[tcarnahan]

Im not sure if we have a different standard in Australia ... maybe ;)

I can send you a brass one, but it will take a few weeks to get there and will be a pain every time you need one to have to wait so long. I have found the irrigation stores here are great, they usually go out of their way to help and even crawl through the product catalogues to find what I need and order it in specially. Try a few around your area, I would think that if you stay with the same brand, the plastic and metal ones should be interchangable.

I did lookup the Gardena product catalogue in Canada, (closest I could find to US) and it only really has plastic quick connects not metal ones, so maybe thats the problem. Here gardena is like a defacto standard and the other manufacturers make their quick connects to fit gardenas as well so you can swap any plastic or brass fittings and they will usually fit.

If you need me to send a brass one, let me know

-todd-

Todd,

I appreciate your kind offer to send a QCs.

I don't think I am at the stage to take you up on the offer yet, but maybe later. Perhaps I could swap you QCs for PL Premium which we can get easily here in the USA. I would have to check to see what was involved ... the postal people are somewhat skittish about people moving semi-liquids through their system since 9/11.

For info, we can get QC's from Gardena, Orbit, Gilmour, and a few more that I cannot remember at the moment. We have a lot of manufacturers in the USA that moved their operations to suppliers overseas and now only distribute the parts. That may be part of the problem. I have corresponded with a few of the companies and when I tell them I want a metal female and plastic male that will hold pressure, they have several reactions. 1) Outright say, "Our connectors are not designed to do that" or, 2) get quizzical and ask "Why would you want to do that?". The only positive reply I have received was from a supplier in the UK who said his products would fit the requirement. My concern is that a supplier can say anything and after ordering and receiving the parts, if they don't fit, I am out a lot of time and money. I would prefer to find one in a local store that works before ordering a number of them. So far, I have found nothing.

I think before I ask you to send QCs, I am going to try something I read in "Wired" magazine. They had an article about a number of small companies that will produce 3D articles (in plastic, metal, etc) from CAD (computer aided design) files that one can design on a computer. I may be able to design a nozzle that will fit both the metal female QC's I can get and the threads of a a 2-liter bottle (maybe, maybe not ... threads are difficult) ... but at least a shape on the non-QC end that would work with the cap of a 2-liter bottle.

I don't have a lot of free time, so you may or may not hear back from me soon on this idea.

Thanks again for the offer! I will keep it in mind.

-- Tom

[tcarnahan]

The trick is finding fittings with the same threads as a bottle. The bottles are the problem in these cases. The threads are not standard with any common plumbing, so you have to modify gardena connectors to fit the bottle. There's a lot of ways you can adapt the threads by slobbering epoxy in them and letting it cure and form new threads.

Lisa,

I am aware of the problem of mating the QC to the rocket. I remember George Katz has a nice video describing how to address that problem. My problem is on the other end (i.e. Launcher to male plastic QC)

What type of launcher does U.S. Water Rockets use? I would imagine USWR has graduated into high pressure rockets. Do you use quick connects or some other method? (forgive me, I didn't have time to search the archives of this site to see if the answer is already there).

Tom

[air.command]

I have been using a Clark Cable launcher, but would like to move up to something that can take more pressure (i.e. metal quick connect / plastic nozzle). The only problem is that I have not had much luck finding a female brass quick connect that will mate with a plastic male quick connect to the point that they can take high pressure. Most of the suppliers I have investigated in the U.S. do not make the two so that they are compatible (i.e. metal with metal and plastic with plastic, but NOT metal with plastic)

Hi Tom, Why not make the nozzle out of the brass quick connector that matches the female QC? You can cut off the metal thread and just use a plastic cap as normal. The weight increase is only minor, and with higher pressures rockets it's almost insignificant. The nozzle also won't get damaged by the ball bearings in the quick connector. (If your QC is the ball bearing type). We machine our nozzles out of aluminium, but have used brass ones in the past. In the event of an explosion on the pad, it's the only component that is held down and protected by the QC, so is unlikely to go flying anywhere at high speed. You can use the brass one in the interim while you search for a plastic nozzle that matches your brass release mechanism.

- George

[tcarnahan]

That is an interesting idea I had not considered ... you are a Treasure Trove of ideas, George! Thanks!