1 lb rocket question(s) from a new guy

[Guest no6]

no6, remember rule #3, if there is no video, it never happened.

 

Plus, you may want to have something to show the kids some day about how you made your first rocket.

 

Indeed. But money's a little tight at the moment. I will have to save for a video camera. Can you suggest a good inexpensive one that records color well? Can I hijack my own thread?

[dagabu]

Really, just record it on your phone or anything you have. We like to see any video, the better the quality the higher the praise but we want to see it all!!

 

NightHawkInLight bought a Sanyo VPC-CG20. Check with him and ask how it is performing.

[Guest no6]

Really, just record it on your phone or anything you have. We like to see any video, the better the quality the higher the praise but we want to see it all!!

 

NightHawkInLight bought a Sanyo VPC-CG20. Check with him and ask how it is performing.

 

I guess I need to catch up with all this fancy technology. My phone makes calls and that's about it.

 

So I just ordered the Sanyo.

[dagabu]

They make phones without cameras?

[Guest no6]

They make phones without cameras?

 

Oh it's got a camera. It's a second generation RAZR. I don't really use the camera much and didn't think anyone wanted to see my collection of CATO's. Though actually that would have been kind of cool to go through the whole process on video. But you guys got me sorted out after only one failure.

 

Looking forward to receiving the Sanyo. Didn't realize prices had come down so far. I'd been threatening to get one for over a year now.

[dagabu]

Set to Tchaikovsk's 1812 overture, CATOs can be a lot of fun to watch

[Guest no6]

Set to Tchaikovsk's 1812 overture, CATOs can be a lot of fun to watch

 

I think you're on to something there.

[Juiceh]

Did you ever fire off rocket #3? You should fire #3 and another screen mixed rocket back to back and film for comparison. How are you fusing your rockets? I don't use anything fancy, just 3mm waterproof visco, with 1cm at the end inserted into the nozzle bent back sorta like a hook. I can actually pickup a completed rocket, header, stick and all, just by the fuse and it wont come out, not that I'd recommend doing so as any sort of test to prove anything.. If I used a quick fuse my faster fueled rockets would probably CATO. Last time I did use quick fuse I had nothing but spectacular CATOs. Haven't used quickfuse with my 4 current fuels though.

[Guest no6]

Did you ever fire off rocket #3? You should fire #3 and another screen mixed rocket back to back and film for comparison. How are you fusing your rockets? I don't use anything fancy, just 3mm waterproof visco, with 1cm at the end inserted into the nozzle bent back sorta like a hook. I can actually pickup a completed rocket, header, stick and all, just by the fuse and it wont come out, not that I'd recommend doing so as any sort of test to prove anything.. If I used a quick fuse my faster fueled rockets would probably CATO. Last time I did use quick fuse I had nothing but spectacular CATOs. Haven't used quickfuse with my 4 current fuels though.

 

Hi Juiceh!

 

Rocket #3 was fired and it was a beautiful thing. This rocket took off a bit more slowly but flew very straight and went a good 50" higher than the screened mix. I'd have to say this rocket was the more refined of the two.

 

That said, I will be going with the screened mixture from now on. You can't beat it for ease of use and this mix gives a great roar and a great tail. And you can continue to experiment with the types and percentages of the charcoal used if you like.

 

EDIT: 50', not inches. Haha!

Edited January 26, 2011 by no6

[Guest no6]

Did you ever fire off rocket #3? You should fire #3 and another screen mixed rocket back to back and film for comparison. How are you fusing your rockets? I don't use anything fancy, just 3mm waterproof visco, with 1cm at the end inserted into the nozzle bent back sorta like a hook. I can actually pickup a completed rocket, header, stick and all, just by the fuse and it wont come out, not that I'd recommend doing so as any sort of test to prove anything.. If I used a quick fuse my faster fueled rockets would probably CATO. Last time I did use quick fuse I had nothing but spectacular CATOs. Haven't used quickfuse with my 4 current fuels though.

 

You should fire #3 and another screen mixed rocket back to back and film for comparison.

 

For you, I will do this. #4 & 5 are ready to go with the ball milled mixture. The only hold up is my technical dummetry on vidization. But the camera and the memory card are here. A friend will help.

 

How are you fusing your rockets?

 

I cut a 6 1/2" "Quick Fuse" taped to a 4" Chinese economy visco leader. Then inserted the quick fuse all the way into the rocket and taped the contraption on the stick to hold it in. Both are from cannonfuse.com. The quick fuse burns at 1/2 seconds per foot. So that's 1/4 seconds for 6". It seems to me that ideally you'd want to ignite the entire core of the rocket instantly. This comes pretty darn close. Try this for your 1 pounders. It seems this method would lessen the amount of CATO's rather than increase them. But what do I know? Still experimenting...

 

Yeah. You really must try the screened approach. I was impressed.

[dagabu]

Try this for your 1 pounders. It seems this method would lessen the amount of CATO's rather than increase them. But what do I know? Still experimenting...

 

Actually, its quite the opposite, running quickmatch or quick fuse all the way up will cause a higher initial pulse and has a greater likelihood to crack the grain. That said, if it works for you then go ahead and use it since it allows for mild fuel to be used to lift heavier objects. It also tells you that you are quite a ways from the red line.

[NightHawkInLight]

Thank you sir! Sticks going on now.

 

And my grog and paraffin wax are in the house so I'll be making a batch of nozzle mix and a batch of bulkhead mix next weekend. I'd like to see for myself both sides of that debate. I just used bentonite clay for these two rockets.

As a wise man once said(can't remember who): Why make a rocket only to have it push a clay bulkhead around?

 

Rather than ramming a clay bulkhead with a passfire, just ram a few increments of glitter comp or whatever your preference is over the fuel grain. It'll burn through just like a fuse, but with an added effect. Why waste the space and weight with clay for no visual gain?

[dagabu]

AMEN!

[WonderBoy]

I think it should be pointed out that the delay grain must be long/strong enough to contain the pressure from the core burn part of the flight, otherwise it will blow through the top(maybe not as much of an issue if you are pressing). Personally, I always use a clay bulkhead on my BP motors, even when pressed. It's cheap insurance that your header, if there is one, is not lit/ejected early. Edited January 27, 2011 by WonderBoy

[Guest no6]

Actually, its quite the opposite, running quickmatch or quick fuse all the way up will cause a higher initial pulse and has a greater likelihood to crack the grain. That said, if it works for you then go ahead and use it since it allows for mild fuel to be used to lift heavier objects. It also tells you that you are quite a ways from the red line.

 

How should it be fused? I'm open to suggestions.

 

As a wise man once said(can't remember who): Why make a rocket only to have it push a clay bulkhead around?

 

Rather than ramming a clay bulkhead with a passfire, just ram a few increments of glitter comp or whatever your preference is over the fuel grain. It'll burn through just like a fuse, but with an added effect. Why waste the space and weight with clay for no visual gain?

 

I will definitely look into this. Thanks.

[Guest no6]

I think it should be pointed out that the delay grain must be long/strong enough to contain the pressure from the core burn part of the flight, otherwise it will blow through the top(maybe not as much of an issue if you are pressing). Personally, I always use a clay bulkhead on my BP motors, even when pressed. It's cheap insurance that your header, if there is one, is not lit/ejected early.

 

I even put some hot glue on top of the clay bulkhead! Is that cheating?

 

I'll be happy to try some different approaches. That's the fun of it. Thanks for the all the advice.

[dagabu]

How should it be fused? I'm open to suggestions.

 

On all of my BP rockets including Hybrid fuel, I use the simple J-hook placed just inside the fuel and just past the nozzle clay with a short piece of tape holding the visco to the stick right below the nozzle. This way the fire from the visco sprays a pretty wide pattern ensuring ignition. Keep in mind that the ugly-cheapass-Chinese green visco spits fire like crazy and is by far the best visco for igniting rockets.

 

I am definitely not the only one that believes this either

[Guest no6]

Thanks!

[dagabu]

I think it should be pointed out that the delay grain must be long/strong enough to contain the pressure from the core burn part of the flight, otherwise it will blow through the top(maybe not as much of an issue if you are pressing). Personally, I always use a clay bulkhead on my BP motors, even when pressed. It's cheap insurance that your header, if there is one, is not lit/ejected early.

 

Only with rammed rockets do I say that the bulkhead is necessary. I have completely abandoned bulkheads and have had zero bulkhead blowouts since I stopped using them. I also press to 9000 psi and use no less then 2 increments of delay.

 

This way, the shell fusing becomes easy as pie since the amount of fire that is present above the end of the delay is intense and rather long lived, giving plenty of time to pass fire to the heading fuse or blackmatch.

 

I even put some hot glue on top of the clay bulkhead! Is that cheating?

 

Smarty-Pants

[WonderBoy]

That is what I figured about pressed rockets. Also, I only press bp rockets to 5000 psi otc, just never had the need for higher, and I press whistles around 7000-7500 psi otc. Also, for the passfire, for a 1lb'er I hand twist a 1/8th" drill bit through the clay almost touching the tube wall, just touching the fuel. Then I use the back of the drill bit to hand press whistle fuel into the hole, filling it completely. Then, just for extra insurance, I put a small scoop of whistle in and hand press it firmly on top of the clay using the solid rammer. This throws plenty of fire to ignite the header.

 

I will also vouch for the upside-down j-hook with chinese visco method. But when I used to use a slower fuel, I would sprinkle some riced BP or riced rocket fuel into the core, then insert the j-hooked fuse, then ball up a small piece of paper towel and press it into the nozzle very firmly. This effectively lit the entire core at once.

[Guest no6]

That is what I figured about pressed rockets. Also, I only press bp rockets to 5000 psi otc, just never had the need for higher, and I press whistles around 7000-7500 psi otc. Also, for the passfire, for a 1lb'er I hand twist a 1/8th" drill bit through the clay almost touching the tube wall, just touching the fuel. Then I use the back of the drill bit to hand press whistle fuel into the hole, filling it completely. Then, just for extra insurance, I put a small scoop of whistle in and hand press it firmly on top of the clay using the solid rammer. This throws plenty of fire to ignite the header.

 

I will also vouch for the upside-down j-hook with chinese visco method. But when I used to use a slower fuel, I would sprinkle some riced BP or riced rocket fuel into the core, then insert the j-hooked fuse, then ball up a small piece of paper towel and press it into the nozzle very firmly. This effectively lit the entire core at once.

 

Do you find fault with my method of fusing then? It seems similar to but less violent than the BP I would think.

[WonderBoy]

If it isn't broke, don't fix it. I was just giving you another method that I have found to work, and may or may not improve the performance of your motor. I've never used the fast visco before, so I can't really comment much on it.

 

Out of curiosity, does the motor eject any of the fuse before it burns its entire length? In my mind I am picturing the fuse touching the fuel grain, then being ejected out of the motor mostly un-burned. Does this happen? Or does it burn fast enough to jet fire up the whole length of the core?

 

Another method somewhat similar to yours, but more "traditional" is written about in Skylighter newsletter #65 where black match is piped into the core.

[Guest no6]

If it isn't broke, don't fix it. I was just giving you another method that I have found to work, and may or may not improve the performance of your motor. I've never used the fast visco before, so I can't really comment much on it.

 

Out of curiosity, does the motor eject any of the fuse before it burns its entire length? In my mind I am picturing the fuse touching the fuel grain, then being ejected out of the motor mostly un-burned. Does this happen? Or does it burn fast enough to jet fire up the whole length of the core?

 

Another method somewhat similar to yours, but more "traditional" is written about in Skylighter newsletter #65 where black match is piped into the core.

 

No. I am using quick fuse. As it burns it pushes upwards. And the entire firing event is over in less than 1/4 of a second.

[billofca]

Hi guys, its been a while since I've been on this site. I've spent the last 2 months on Passfire learning a great deal and catching up on my reading. I have also been making and shooting many rockets. I now have tooling for 3#, 1# and 4 oz. rockets.

 

I have been reading this thread tonight from the start and I have learned a few things in the last 2 months of intense learning and doing, that might help sort out some of the confusion. There is definitely a major difference on how to build rockets depending on whether they are pounded with a mallet, or pressed hydraulically. For example, a rocket with a certain hot fuel that is pounded for consolidation may CATO, but the same rocket may work fine if hydraulically pressed at much higher pressures. I see tips being given that I can ID with hydraulic pressing while Pyromaniac is pounding his rockets.

 

Another influence on performance is one's tooling. Narrow spindles will develop more thrust than thicker ones; therefore higher chamber pressures. Rich Wolter's tools are pretty much a standard many of us use, so any advice will be universally applicable to others using Wolter rocket tools.

 

If a rocket CATOs one solution is to cool it down with more charcoal. The type of Charcoal will influence whether the motor CATOs or not. A mix of hardwood air float charcoal with coarser mesh charcoal for tail sparks works well and you folks have covered that nicely. I think the willow charcoal is great for making shell lift BP, but is a bit too hot for core burning rockets.

 

Hot fuel advice for hard pressed end burners should not be mixed in and confused with advice for core burners.

 

Ball milling fuel is another topic that needs further explanation. Ball milling may likely cause a CATO with rockets that are pounded, while not happening to motors that are hydraulically pressed. This presumes that both methods are using the proper increment charges. On my 3# rockets (standard BP tool by Wolter), I use 60-30-10 fuel that's been milled for 3 hours. The charcoal is air float, and my tail is produced by the delay. Before mixing and milling the fuels, I previously mill the KNO3 for 3 hours by itself until it is like talc dust. I rice this fuel and then press the increments at 7000 pounds on the rammer for the 3# rockets. They take off with a tremendous roar! No CATOs yet. I did have a blow through once when I used QM to fuse the core. I went back to using visco just above the clay nozzle.

 

On my 1# rockets, I use a 70-20-10-10 mix of PN, air float C, 80 Mesh C, Sulfur in that order. I ball mill without the 80 mesh C for 3 hours and then screen in the 80 mesh after milling. I rice this too, and press with 9000 pounds on the rammer. No CATOs yet. My tooling is the universal hybrid (Steve Laduke's design) but purchased from Wolter. These motor fly fast with great thrust. Steve Laduke gave me the formula to use with the UH tool.

 

Now here is an interesting give away about the importance of dialing in your fuel to match your tooling. Master rocket maker Tom R. makes his 1# rocket fuel using 57 KNO3, 34 C - all 80 mesh, and 9 sulfur. He does NOT ball mill but simply screen mixes and rices. His KNO3 is pre-milled to dust. He presses pneumatically with 3850 pounds on the rammer (1700 on the conversion gauge). He told me that if he ignites the fuel just after the clay nozzle his motors take off too slow every time. He instead ignites with QM at the top of the core and gets no blow through but very fast take offs. That is just the opposite of my experience with my tools and my fuel. I think the reason is he is not hydraulically pressing or ball milling. I should mention that he made his rocket tooling himself (he is a retired tool & die maker) and his spindle is rather long compared to Wolter's 1# tools. Tom loads increments of fuel until the spindle is covered, and then switches to his delay comp which is a modified silver wave formula using 60 mesh spherical Ti. His delay is 5/8 of an inch above the spindle. His header typically weigh 400 to 500 grams .

I've been friends with Tom for 30 years and I talk with him on the phone regularly.

 

Bill O.

[dagabu]

Another influence on performance is one's tooling. Narrow spindles will develop more thrust than thicker ones; therefore higher chamber pressures.

In nozzled motors that is true, in nozzleless motors that is not true, in fact with the nozzleless motor, the larger spindle will have more off the line thrust. It is the choke or nozzle that creates the pressure, not the spindle.

Edited January 28, 2011 by dagabu