katz MK3 Stager success

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liftoff
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katz MK3 Stager success

Post by liftoff »

Hi all

After about 2 weeks of heavy wind in South London UK and I decided to "throw caution to the wind" and have ago at launching some rockets. I had also just taken delivery of my new Joe Blow Sport Track Pump which works a charm so far. 2l rocket about 30 strokes to 100psi.

Launched the 2l rocket a couple of times to 100psi the 80psi. Then set up my newly spliced 6l rocket which launched nice and slow at 80psi. Very nice and slow take off, would make for great video (I didn’t pack the camcorder this time sorry)

I have had the MK3 Katz stager as wonderfully shown at aircommandrockets/mark_3_stager sitting in the shed for the last 3 weeks, it’s been mounted on my trusty 4l spliced rocket body for the 1st stage and the 2l rocket for the sustainer. I set the tomy timer on the sustainer with no recovery on the 1st stage and launched at 60psi....it all worked beautifully! a little spacer keeping the stager in locked position which got removed on launching. The first stage was nice and slow and went perfectly straight, the sustainer just shot up from what I guess must have been no more than 25-30 meters and away even at 60psi. Amazing how high it went with the initial "get off the ground" taken away and a little bit of momentum added. I was very pleased.

I’m hoping to get out again soon with the whole lot and the video camera this time.

Dieter
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Brian
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Re: katz MK3 Stager success

Post by Brian »

Good to here.
You'd get more altitude by using a larger nozzle on the booster, but I'm sure the small nozzle looks better!
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pudresful
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Re: katz MK3 Stager success

Post by pudresful »

I builded that too :D
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liftoff
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Re: katz MK3 Stager success

Post by liftoff »

I think this stages is relatively easy and cheap to build, every body should have one!!

Yes Brian I agree a larger nossle on the booster would work heaps better. I had a look at the 15mm i/d gardena nossle and female part but it just seems like to much hassle at this point in time, I was thinking of drilling out a 9mm standard nossle to as big as possible, perhaps 12mm or so. Quite keen to try drop away boosters, in my head I think you can make them relatively easy as-well (adapting the launcher-wise)

Any advice on drop away boosters welcome here

thanks

Dieter
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liftoff
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Re: katz MK3 Stager success

Post by liftoff »

o yea, I know that top section in the pic with the tomy-timer parachute unit in looks realy sad, it just doesnt want to die completely so I just let fly. I guess thats what it was built for :)
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Brian
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Re: katz MK3 Stager success

Post by Brian »

My first few recovery systems were Hot Melt Glue massacres but annoyingly they did die.
The booster mechanism is very simple and the launcher shouldn’t be too hard but strengthening the shaft that the boosters slide on and off is probably the main issue. If it is too hard then you could do a bottle cluster for the first stage then put your sustainer on top (similar to aircomands rockets).
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air.command
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Re: katz MK3 Stager success

Post by air.command »

Dieter, Happy to hear you had a good flight with the stager. One thing to watch out for is if you fly the booster without a recovery system then the booster is likely to land on the stager and damage it. A very easy recovery system for the booster is described here:
aircommandrockets/construction_5 You already have all the components for this at home.

- George
http://www.AirCommandRockets.com
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liftoff
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Re: katz MK3 Stager success

Post by liftoff »

Hi all

Here is a quick video of my rockets with the Katz MK3 Stager. 4litre booster and a 2litre sustainer at 65-70psi. It went well for three launches and then a fin broke on the booster.

Thanks for that link George, I fitted the recovery on the booster but I need to do some fine tuning on the stager because I think it releases a bit to early. I'm going to try and relax the springs in the stager and hopefully get another 5-7 meters out of it. I also found that the booster parachute struggle to open fully to recover it safely(hence the broken fin) and perhaps the extra bit of height would help.
Any other suggestions welcome.

I flew the 6 litre rocket also but the brand new shiny recovery unit with the tomy-timer fitted, it went up good enough but the shiny new recovery unit failed on the first launch and that was that. Brain, the mangled recovery unit in the photos above is still going strong on the 2 litre sustainer.

Enjoy the video

Thanks

Dieter

[youtube][/youtube]
air.command
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Re: katz MK3 Stager success

Post by air.command »

liftoff wrote:Hi all

Here is a quick video of my rockets with the Katz MK3 Stager. 4litre booster and a 2litre sustainer at 65-70psi. It went well for three launches and then a fin broke on the booster.

Thanks for that link George, I fitted the recovery on the booster but I need to do some fine tuning on the stager because I think it releases a bit to early. I'm going to try and relax the springs in the stager and hopefully get another 5-7 meters out of it. I also found that the booster parachute struggle to open fully to recover it safely(hence the broken fin) and perhaps the extra bit of height would help.
Any other suggestions welcome.

I flew the 6 litre rocket also but the brand new shiny recovery unit with the tomy-timer fitted, it went up good enough but the shiny new recovery unit failed on the first launch and that was that. Brain, the mangled recovery unit in the photos above is still going strong on the 2 litre sustainer.

Enjoy the video

Thanks

Dieter
The flight looked great! You'll find that the 65-70psi pressure is a little on the low side and probably why you're not getting a lot of altitude from the booster. Remember that the booster is having to also accelerate the weight of the sustainer with water as well as itself. If it's safe to do so I would try the same launch at 100psi - 110psi before trying to adjust the spring tension. Have you been able to measure how much force the spring provides? In the tutorial aircommandrockets/mark_3_stager scroll down to the "Measuring Spring Tension" section to work out how much force it provides. If it's significantly higher than the 800grams or so then the stager may be releasing early. Remember the booster will never go very high, it's there to provide speed for the sustainer, and on staging it gets forced backwards reducing it's coast time further. That's why it's important to start deploying the parachute just after staging. Also try to pack your chute on the booster so it opens faster. Fold it accordion style and only one or two wraps with the parachute line.

Good luck with the next flights.

- George
http://www.AirCommandRockets.com
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rockets-in-brighton
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Re: katz MK3 Stager success

Post by rockets-in-brighton »

Nice work, Dieter. I used to live in South London, which park is that? Looks a bit like Brockwell. I would love to have flown rockets in some of the parks nearby.
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liftoff
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Re: katz MK3 Stager success

Post by liftoff »

Hi All

Here is another quick video of my rockets with the Katz stager mk3. I still need to fine tune the booster, especially the recovery parachute, its still not opening quick enough to safely recovery the booster. Work in progress.

Steve, that's a park off Purley Way in Croydon. Its massive! which is good for my sometimes horizontally flying rockets :)

I am now starting to thing about building a new launcher to accommodate 3 boosters (drop away or cluster) and have a couple of ideas which I'll share when there's time.

I have also taken delivery of a Aerobird Swift rc plane, and launching rockets in between waiting for the batteries to charge is a good use of time.

Thanks all

Dieter

[youtube][/youtube]