thank you for the history chit chat time... very impressive... I've always thought it was a great name... thank you for your many years of amazing content... Stu and Lake
Under communism, the whole family wasn't allowed (most of the time) to leave at the same time, but individual members of the family were able to briefly go on holiday to a western country. Dad applied for permission to go to Sweden and then after he would return, then my mum, my sister and I would go on a holiday to Sweden separately. In order to travel you had to get permission from the bank (who would only sell you USD $12 per day per person), the army, your boss, the police etc. So mum filled in all her paperwork and got permission to travel on a certain date. Dad did the same with all the paperwork traveling on an earlier date but returning before mum left. He got all the permissions he needed, but had filled in his departure date with a pencil. When he went to the final verification office they yelled at him for writing it in pencil and told him to fill it in with a pen, and so he rubbed out the date, but wrote mum's departure date in pen instead. The clerk did not notice the change in date, but dad now had all the approvals and got the stamp he needed. In case that clerk would have noticed the change in date, dad was prepared to say, that he just made mistake and in that case my parents wouldn’t have been able to travel together. Mum (36) and dad (41) didn't tell my sister (13) or me (9) that we were escaping so we wouldn't accidentally tell anyone at school. They told us we were going on a holiday to Slovakia. No one else in the family knew either. We went to the border with West Germany, with only a couple of suitcases to make it look like a regular short holiday. Approaching the border our parents said: Surprise!!! We are going for a holiday to Sweden. That was so my sister and I wouldn’t blab something about Slovakia, which was in a completely different direction. The border guards searched the car, checked all the paperwork and even though mum and dad had matching departure dates all the paperwork was in order and we were let through. Dad pulled the car over at the first rest stop after the border. He then proceeded to remove the left rear tyre. He had taped down all of our important documents to the inside rim of the wheel. These included our birth certificates, professional and education papers, cash etc. that you weren't allowed to cross the border with. He also opened the hood and fished out a couple of $20 American gold coins out of the brake fluid reservoir that he put there to avoid detection when the car was inspected. We were going to need some money in Germany and Czech crowns were not worth anything. Dad hid a letter with the keys to our apartment at my uncle's home that explained everything to the rest of our family, and for them to take as much stuff from our apartment as they could because when the authorities would discover that we escaped they would have seized everything including the apartment my parents owned. We knew the phone lines from the west were bugged and so dad just called my uncle asking him for the name of some medicine, that he would find it in some paperwork and told him where the letter was. My uncle just read out the name of some random medicine, and that was the end of the call. We had friends in Germany that helped us to get in touch with the immigration and social departments and helped find some work for mum and dad. My sister and I ended up going to school in Germany and went to all the English classes we could. My parents received 2 letters. One from the Czech government, that they were sentenced to 18 months prison for kidnapping their own children. And a second one from the OSN that they were recognized as a political refugees. Mum and dad started the visa application process to come to Australia. 9 months later we got our visa and flew out to Sydney. The four of us never regretted escaping to beautiful Australia.
It looks like you have worked out a lot of tricks to make this a smoother process. And that history really explains your expertise with high pressures!
@@simonabunker Nope, that was the Mythbusters. :) I saw an episode they did on water rockets and I thought I have to give this a go, so I went over to dad's and we built our first launcher and a bottle with a nozzle based on instructions we found on-line.
Hi George Few queries if you can help answers with: 1. How many layers of glass did you go for for the main body tube / pressure chamber? 2. What thickness wall did you end up with? 3. Which epoxy / hardener you used for the main body tube? 4. Did you notice any flexing / bending of the tube during flight with J motor? Thanks
Hi, the pressure chamber was 6 wraps of 200gsm cloth followed by 1 fiberglass biaxial sleeve. I am not sure of the final wall thickness since we haven't cut it open to measure it. But it will be somewhere around 1.5mm or so. We used West Systems epoxy with the 206 slow hardener. From the on-board camera looking down the rocket during the boost, I did not see any bending. This is a fairly wide tube ~110mm so quite resistant to bending.
Your dad is so cool! The story is truly inspirational. It makes me want to go out there and do my best and sharing my creations with the world. About the construction technique, I keep wondering how many pieces you had to discard to achieve this level of expertise. Once I tried making a body tube out of fiberglass and it is still epoxied to the mandrel.
Thanks Dan. :) It's definitely been trial and error over the years to learn how to get the right results with the fiberglass, though we are still learning how to mate it properly to different materials. The important thing is to get everything prepped properly before starting. We spend at least double the time preparing everything for a lay up than actually doing it. A lot of the techniques in making tubes we borrowed from the pyro rocket community. We would eventually like to try winding on a winding machine and also vacuum bagging to get better strength to weight ratio.
I think you mispelled your title to be part 2 instead of 3. Other than that, your pressure chamber creation technique is perfected! I wish I could work with fiberglass like that haha
The rotisserie stops the epoxy from pooling on one side of the tube. If you use peel ply then you probably can do without it and still get a reasonable result.
Yes, I am worried that my eyes could get irritated, and that soreness in the throat could also occur. To my application that I want to work on, is to reinforce plastic so they will be able to withstand more pressure.
@@microbeMan So generally when you are working with fiberglass cloth you are fine in terms of handling it and cutting it. Where you can get irritation is if you are sanding it and the dust becomes airborne then you want to wear a respirator/mask. Sanding it with water helps cut down on airborne particles. You may also be sensitive to the resin before it hardens. This is much more rare but some people do have sensitivity to the resin/epoxy.
We use a simulator like this: www.aircommandrockets.com/sim/simulator.htm or cjh.polyplex.org/rockets/simulation/ to predict how long it takes to get to apogee. You don't have to be super accurate, usually within 1 second or so of apogee is close enough.
Thanks for sharing.
Looks like your dad owned Vaz 2101. My dad had Vaz 21013
Funny looking back at it now, how small it was. Didn't seem like it at the time.
Very nice family project and story. Now it is quite obvious why you have such a high performance and focus on details. It originates from your dad 😀
Wow what a interesting family history
Thanks for sharing the family history .
Cool history youve got there ;), greetings from the Czech Republic!
I love watching your videos George and think it’s absolutely wonderful this is something you continue to do with your Dad and family. All the best.
Thanks for the nice words Darren :)
thank you for the history chit chat time... very impressive... I've always thought it was a great name... thank you for your many years of amazing content... Stu and Lake
Thanks very much Stu & Lake! :)
I would love to hear more about your families escape and emigration.
Under communism, the whole family wasn't allowed (most of the time) to leave at the same time, but individual members of the family were able to briefly go on holiday to a western country. Dad applied for permission to go to Sweden and then after he would return, then my mum, my sister and I would go on a holiday to Sweden separately.
In order to travel you had to get permission from the bank (who would only sell you USD $12 per day per person), the army, your boss, the police etc. So mum filled in all her paperwork and got permission to travel on a certain date. Dad did the same with all the paperwork traveling on an earlier date but returning before mum left. He got all the permissions he needed, but had filled in his departure date with a pencil. When he went to the final verification office they yelled at him for writing it in pencil and told him to fill it in with a pen, and so he rubbed out the date, but wrote mum's departure date in pen instead. The clerk did not notice the change in date, but dad now had all the approvals and got the stamp he needed.
In case that clerk would have noticed the change in date, dad was prepared to say, that he just made mistake and in that case my parents wouldn’t have been able to travel together.
Mum (36) and dad (41) didn't tell my sister (13) or me (9) that we were escaping so we wouldn't accidentally tell anyone at school. They told us we were going on a holiday to Slovakia. No one else in the family knew either.
We went to the border with West Germany, with only a couple of suitcases to make it look like a regular short holiday. Approaching the border our parents said: Surprise!!! We are going for a holiday to Sweden. That was so my sister and I wouldn’t blab something about Slovakia, which was in a completely different direction.
The border guards searched the car, checked all the paperwork and even though mum and dad had matching departure dates all the paperwork was in order and we were let through.
Dad pulled the car over at the first rest stop after the border. He then proceeded to remove the left rear tyre. He had taped down all of our important documents to the inside rim of the wheel. These included our birth certificates, professional and education papers, cash etc. that you weren't allowed to cross the border with. He also opened the hood and fished out a couple of $20 American gold coins out of the brake fluid reservoir that he put there to avoid detection when the car was inspected. We were going to need some money in Germany and Czech crowns were not worth anything.
Dad hid a letter with the keys to our apartment at my uncle's home that explained everything to the rest of our family, and for them to take as much stuff from our apartment as they could because when the authorities would discover that we escaped they would have seized everything including the apartment my parents owned. We knew the phone lines from the west were bugged and so dad just called my uncle asking him for the name of some medicine, that he would find it in some paperwork and told him where the letter was. My uncle just read out the name of some random medicine, and that was the end of the call.
We had friends in Germany that helped us to get in touch with the immigration and social departments and helped find some work for mum and dad. My sister and I ended up going to school in Germany and went to all the English classes we could.
My parents received 2 letters. One from the Czech government, that they were sentenced to 18 months prison for kidnapping their own children. And a second one from the OSN that they were recognized as a political refugees.
Mum and dad started the visa application process to come to Australia. 9 months later we got our visa and flew out to Sydney. The four of us never regretted escaping to beautiful Australia.
@@AirCommandRockets Jesus christ 😮
@@AirCommandRockets Wow, I can't imagine how nervewracking and stressful that must have been for your parents. Thanks for sharing the story.
Hi George
Once again, I admire your wonderful work! You really are the king of fiberglass!
Cheers François :)
Nekünk is voltak rokonaink cseszlovàkiàban . Üdvözlet Frank from Hungary Bànfalva 🎉
That was a cool story about your dad. Czechoslovakia's loss is Australia's gain!
A great video of the process and thanks for the explanation about the names. It makes sense now )
It looks like you have worked out a lot of tricks to make this a smoother process. And that history really explains your expertise with high pressures!
Definitely, I leave all the high pressure stuff to dad, that stuff is scary. :)
@@AirCommandRockets so was it you or him that came up with the idea of bottle rockets? Or did it just seem like a natural progression?
@@simonabunker Nope, that was the Mythbusters. :) I saw an episode they did on water rockets and I thought I have to give this a go, so I went over to dad's and we built our first launcher and a bottle with a nozzle based on instructions we found on-line.
Hi George
Few queries if you can help answers with:
1. How many layers of glass did you go for for the main body tube / pressure chamber?
2. What thickness wall did you end up with?
3. Which epoxy / hardener you used for the main body tube?
4. Did you notice any flexing / bending of the tube during flight with J motor?
Thanks
Hi, the pressure chamber was 6 wraps of 200gsm cloth followed by 1 fiberglass biaxial sleeve. I am not sure of the final wall thickness since we haven't cut it open to measure it. But it will be somewhere around 1.5mm or so. We used West Systems epoxy with the 206 slow hardener. From the on-board camera looking down the rocket during the boost, I did not see any bending. This is a fairly wide tube ~110mm so quite resistant to bending.
Your dad is so cool! The story is truly inspirational. It makes me want to go out there and do my best and sharing my creations with the world.
About the construction technique, I keep wondering how many pieces you had to discard to achieve this level of expertise. Once I tried making a body tube out of fiberglass and it is still epoxied to the mandrel.
Thanks Dan. :) It's definitely been trial and error over the years to learn how to get the right results with the fiberglass, though we are still learning how to mate it properly to different materials. The important thing is to get everything prepped properly before starting. We spend at least double the time preparing everything for a lay up than actually doing it. A lot of the techniques in making tubes we borrowed from the pyro rocket community. We would eventually like to try winding on a winding machine and also vacuum bagging to get better strength to weight ratio.
thanks
Cool story about your dad and his work on regulators!
I think you mispelled your title to be part 2 instead of 3. Other than that, your pressure chamber creation technique is perfected! I wish I could work with fiberglass like that haha
Ahh good catch, thanks. I've fixed that now.
Can I cure the fibre glass without having the process of the rotisserie? will it make the body tube too bad for flying?
The rotisserie stops the epoxy from pooling on one side of the tube. If you use peel ply then you probably can do without it and still get a reasonable result.
A lot of fiberglass sure gets everywhere. How do you remove it? Just use a vacuum or somethings else?
Yes, just the shop vac from the sanding. We're normally quite careful about picking up all the small fibers and throwing them away.
What is the gsm of the fiber glass fabric that you used??
It's plain weave 200gsm fiberglass cloth.
Question: are there any good cheap alternatives to fibreglass?
I have heard that it can be dangerous
Depends on the application. In terms of dangerous, is there a specific aspect you are worried about?
Yes, I am worried that my eyes could get irritated, and that soreness in the throat could also occur. To my application that I want to work on, is to reinforce plastic so they will be able to withstand more pressure.
@@microbeMan So generally when you are working with fiberglass cloth you are fine in terms of handling it and cutting it. Where you can get irritation is if you are sanding it and the dust becomes airborne then you want to wear a respirator/mask. Sanding it with water helps cut down on airborne particles. You may also be sensitive to the resin before it hardens. This is much more rare but some people do have sensitivity to the resin/epoxy.
where to buy this cylindrical fiber?
We buy the sleeves from Soller Composites in the US. sollercompositesllc.com/
So a water pressure rocket but no carbon?
The answer is here 0:45
Can you give me the specifications of the fiberglass for the rocket body?
hey George, how do you make calculations for the parachute timer? how do i ensure it deploys on time?
We use a simulator like this: www.aircommandrockets.com/sim/simulator.htm or cjh.polyplex.org/rockets/simulation/ to predict how long it takes to get to apogee. You don't have to be super accurate, usually within 1 second or so of apogee is close enough.
@@AirCommandRockets thanks!