Water Rocket Forum

I've got my supply figured out for the air, and so I'm really close to being able to launch.

Now I only have to figure out the remote launch trigger. Maybe my gardena isn't the smoothest out there, but it seems to be very hard to pull it down with the cord. I have a pulley underneath, and there is a straddle wire connected to two sides of the gardena. The cord goes up from the pulley to the straddle wire that pulls the mechanism from both sides. I'm using a plastic Gardena, so maybe the trick is using a metal one. Any Ideas?

Jtrops wrote:I've got my supply figured out for the air, and so I'm really close to being able to launch.

Now I only have to figure out the remote launch trigger. Maybe my gardena isn't the smoothest out there, but it seems to be very hard to pull it down with the cord. I have a pulley underneath, and there is a straddle wire connected to two sides of the gardena. The cord goes up from the pulley to the straddle wire that pulls the mechanism from both sides. I'm using a plastic Gardena, so maybe the trick is using a metal one. Any Ideas?

I have heard that plastic gardena on the launcher is less reliable, that it tends to stick or leak. I recently built a plastic one for experiments but haven't put it through its paces yet.

Try a bellcrank. Do a google image search.

You pivot on the corner of the L shape.

The short end of the L, you tie the gardena

The long end you tie your launch rope.

The force multiplication is (length of long end) divided by (length of short end)

Rocket_Scientist wrote:Try a bellcrank. Do a google image search.

You pivot on the corner of the L shape.

The short end of the L, you tie the gardena

The long end you tie your launch rope.

The force multiplication is (length of long end) divided by (length of short end)

A bell crank would work, but it would be more complicated to rig than a pulley system. In my current setup I have it as a 1:1. If I add a pulley at the straddle cable and anchor the end of the cord at the first pulley I will have 2:1. I could put one more pulley in for 3:1, or 4:1 depending on where I anchor the cord. I hadn't thought of using a multiplier, so thanks for the suggestion. I'll look to see if someone has come up with a simple bell crank that I could add to my rig without much hassle. I have pulleys, and the space to use them.

Did you modify the gardena when you made the launcher? I took the springs out of mine and it makes it much easier to pull down. The only "problem" is that you have to slide it up to engage it.

If you would rather not risk ruining your gardena, you could do a pulley or bellcrank. Of the two I would choose bellcrank just because it is simpler to setup, and you can make it yourself, no need to go buy something.

AirCommand uses a metal quick release in his design. I assume that the metal quick release works with a plastic nozzle, but I am not sure. Also, his launch abort valve at the bottom of the page is a good idea too. Much safer way of releasing the pressure.

I tried to take the plastic Gardena apart, and it just didn't budge. I honestly thought that if I continued I would just break it. So, I bought an actual "Gardena Premium Quick Connect" starter set. I have to say that this thing is so much smoother in every way than the cheap plastic one I was using. I haven't got it all rigged up yet, but already it is practically effortless to pull the straddle cable. I imagine my original setup will work fine with this fitting. We'll see tomorrow!

Jtrops wrote:I tried to take the plastic Gardena apart, and it just didn't budge. I honestly thought that if I continued I would just break it. So, I bought an actual "Gardena Premium Quick Connect" starter set. I have to say that this thing is so much smoother in every way than the cheap plastic one I was using. I haven't got it all rigged up yet, but already it is practically effortless to pull the straddle cable. I imagine my original setup will work fine with this fitting. We'll see tomorrow!

Good to know thanks! I won't spend too much time fidgeting with mine if it has issues.

I don't recommend plastic although I have used it. Where can I get metal? Does home depot sell them.

Water Rocket Expert wrote:I don't recommend plastic although I have used it. Where can I get metal? Does home depot sell them.

I tried Home Depot with no luck. The only metal ones they have use a different connector, and aren't compatible with Gardena nozzles. So, I ordered from Amazon. $20 for the set including two quick connects, and a few adapters. That's only $5 more than getting the connector alone.

I ended up using a bellcrank made from part of an old broken front derailleur. It works perfectly. We did a dry, just air, launch this evening with low psi (40) to see if it would release. and the rocket (without fins) went 50'. I had to bail on the milk crate base and completely redesign my rig, but it was worth it. I'm using the tripod base from my black powder launch pad. If I can figure out how to put up photo's I'll add a couple.

Here are some pix if it works!

Jtrops wrote:

Water Rocket Expert wrote:I don't recommend plastic although I have used it. Where can I get metal? Does home depot sell them.

I tried Home Depot with no luck. The only metal ones they have use a different connector, and aren't compatible with Gardena nozzles. So, I ordered from Amazon. $20 for the set including two quick connects, and a few adapters. That's only $5 more than getting the connector alone.

I ended up using a bellcrank made from part of an old broken front derailleur. It works perfectly. We did a dry, just air, launch this evening with low psi (40) to see if it would release. and the rocket (without fins) went 50'. I had to bail on the milk crate base and completely redesign my rig, but it was worth it. I'm using the tripod base from my black powder launch pad. If I can figure out how to put up photo's I'll add a couple.

Does anyone in the USA have a source for the large Gardena style hose connectors? They sold them at Home Depot a few years ago, but they no longer have them in stock.

Glad to see the pictures!
Lowes sells a Bosch branded nozzle called Gardena.
Go to their website and search "quick connect"

Jtrops wrote:Here are some pix if it works!

image.jpg

image.jpg

Nice looking launcher!
I sacrificed my tripod to make adjustable legs for a solar telecope because the thumb latch broke. Is that thumb latch plastic like mine was?

bugwubber wrote:

Jtrops wrote:Here are some pix if it works!

image.jpg

image.jpg

Nice looking launcher!
I sacrificed my tripod to make adjustable legs for a solar telecope because the thumb latch broke. Is that thumb latch plastic like mine was?

It's an old tripod that I modified to use for my solid fuel rockets. I cut the center column short, and epoxied the brackets for the brace higher up so the legs spread wider. I also ditched the extra leg extensions. The lock for the quick release plate is plastic. If it fails I'll just drill a hole through the plate and secure it with a bolt.

Repurposing old stuff is one of the best things about water rockets.

Jtrops wrote:

bugwubber wrote:

Jtrops wrote:Here are some pix if it works!

image.jpg

image.jpg

Nice looking launcher!
I sacrificed my tripod to make adjustable legs for a solar telecope because the thumb latch broke. Is that thumb latch plastic like mine was?

It's an old tripod that I modified to use for my solid fuel rockets. I cut the center column short, and epoxied the brackets for the brace higher up so the legs spread wider. I also ditched the extra leg extensions. The lock for the quick release plate is plastic. If it fails I'll just drill a hole through the plate and secure it with a bolt.

Repurposing old stuff is one of the best things about water rockets.

We have a launcher under construction that is made from some discarded shelving brackets. It's not quite as nice as our Instant Launcher design, but it is easier for people to replicate. We'll be posting plans shortly showing how we did it. Once we have it finished and tested.