Your press

[Frozentech]

realy some nice stafe. I will make this weekend a press. why you all need a 20t jack (i think thats a lot of to much. i will make a 2 or 5t press, so what do you do with 20t :S.

 

20 Tons is actually more than needed for any reasonable pyro pressing, but... remember that the tons is in pounds per square inch. If you want to press a puck of BP for making corned powsder, your die may be a 3" diameter unit. Therefore just over 7 square inches of area to be pressed. When you divide the force applied by 7 you find you have much less on the actual BP than your press has on the ram.

 

I use 5 tons, 10,000 pounds per square inch on my BP pressing die, but actually only press the powder with 1428 pounds. A 2 ton press is only going to apply 571 pounds per square inch on a tool that size.

 

Another example, lets use a 1# rocket. The 'standard' accepted force to press a 1# BP core burner is 6,500 PSI. A 3/4" rammer has an area of approx. 1.77 square inches. A 2 ton press at full press will only apply 2260 pounds on your powder, or about 1/3 of what you need. A 6 ton jack at full press will just do the job. a 12 ton press costs almost no more than a smaller one, and is the same size, so why not do the job right ?

[Frozentech]

I'm going to make a press this weekend, I have already got a 20ton bottle jack and M16 threaded rod and can get some steel plate. I have some acrylic sheet at home it has bayar makrolon on it, I was wondering if I could use this because in my country its very hard to find lexan sheet or similar

50Caliber, I did a quick google search and found that Bayer Makrolon is a trademark name for polycarbonate, not acrylic. Lexan, Tuffak, etc are just other brand names for polycarbonate, so what you have is the *same* as Lexan.

[50caliber]

the reason I got the 20ton bottle jack is cause it was cheaper then all the others, i got it for 20$US. I'll try get more polycarbonate and make the blast shield about 25mm thick. my dad just got the sheet from work and he said it was plastic so i thought it was perspex or something. thanks for the help

[ewest]

I'm not trying to downplay the safety aspect of your shield, but 25mm is pretty thick, 1/2" (13mm) should be just fine. But if you're getting them for free, heck, why not go 25mm?

 

You can never be TOO safe in my opinion. Especially since when I press rockets they sit right at crotch level.......

[h0lx]

Is it so hard to use imageshack? 7 posts in a row is plain stupid in my eyes.

[h&k machineguns]

I think you will notice a difference, but I've heard people have trouble with CATO's running straight 70/30/1 Salycilate.

For the record 76/23/1 is the hottest whistle mix you can make,and ratio's like 70/30/1 and 64/32/1 are weaker wheather it's Sal or Benz for the 23,30,32 .

 

Here are some new links for new press idea's.Some are from the passfire board I have been hanging out on latley and others are from many hours of Googling. I plan on getting a power pack unit to mount on the first press in the links and run 12 volts deep cycle on a slow trickle charge.

 

I have to do some modifing to this guy

http://www.harborfreight.com/cpi/ctaf/disp...temnumber=44811

 

The power pack

http://www.surpluscenter.com/item.asp?UID=...=9-1480&catname

 

 

http://www.hobbyfireworks.com/Rocket.html

 

 

http://www.harborfreight.com/cpi/ctaf/disp...temnumber=93815

 

 

http://www.wichitabuggywhip.com/fireworks/powerpack.html

[ewest]

Thanks, I've been kicking this idea around for a while but I just can't seem to make it work financially. Plus I'm really not sure how to actually hook the pump to the press. I like the last link because it's actually got my same press on there, sweet.

 

The pump you have spec'd out is 24V DC which I like a LOT, I've been looking at electric ones that are a little cheaper but not as portable as a 24V DC.

 

Here's a couple hydraulic pumps I've been looking at. Notice the second two don't have a price listed, this usually means they're way out of your budget.

1HP 220V Harbor Freight Hydraulic Pump

 

Vektor Portable Electric Hydraulic Pump

 

Enerpac Portable Hydraulic Pump

This last one says you can set a working pressure on it. If that means I can set it to stop at say 2,000PSI and it actually does, that would make pressing the rockets much easier because you wouldn't overshoot the PSI and I think you'd get much more reliable and consistent results.

 

OH yes, on another note also related. I've looked into using an air compressor with the Air/Hydraulic bottle jacks. I even talked to Matt at Hobby Fireworks about it and he said that he though about building pure Hydraulic presses but opted to go with the air because it was much more affordable. I raised concerns about a hammering effect and he said he's never noticed one but that if I wasn't 100% happy he'd take the press back and refund my money for it. Heck, it's worth a shot I guess.

 

Plus another friend of mine was telling me that you can hook up an air compressor to an Air/Hydraulic bottle jack and if it does start to hammer on you that there is some sort of regulator or some way (don't know what he was talking about really) that you can control how much air it puts in at a time. And that by turning this down you can get a smooth operation from the bottle jack.

[h&k machineguns]

Thanks, I've been kicking this idea around for a while but I just can't seem to make it work financially. Plus I'm really not sure how to actually hook the pump to the press. I like the last link because it's actually got my same press on there, sweet.

 

The pump you have spec'd out is 24V DC which I like a LOT, I've been looking at electric ones that are a little cheaper but not as portable as a 24V DC.

 

Here's a couple hydraulic pumps I've been looking at. Notice the second two don't have a price listed, this usually means they're way out of your budget.

1HP 220V Harbor Freight Hydraulic Pump

 

Vektor Portable Electric Hydraulic Pump

 

Enerpac Portable Hydraulic Pump

This last one says you can set a working pressure on it. If that means I can set it to stop at say 2,000PSI and it actually does, that would make pressing the rockets much easier because you wouldn't overshoot the PSI and I think you'd get much more reliable and consistent results.

 

OH yes, on another note also related. I've looked into using an air compressor with the Air/Hydraulic bottle jacks. I even talked to Matt at Hobby Fireworks about it and he said that he though about building pure Hydraulic presses but opted to go with the air because it was much more affordable. I raised concerns about a hammering effect and he said he's never noticed one but that if I wasn't 100% happy he'd take the press back and refund my money for it. Heck, it's worth a shot I guess.

 

Plus another friend of mine was telling me that you can hook up an air compressor to an Air/Hydraulic bottle jack and if it does start to hammer on you that there is some sort of regulator or some way (don't know what he was talking about really) that you can control how much air it puts in at a time. And that by turning this down you can get a smooth operation from the bottle jack.

Same goes here. I'm not stuck on that power pack. That's just what Dan sent me a link to when I went to him for advice.

 

I don't really care for Battery opererated power anyway.Since I have a 110 outlet 2 feet from the press,I would much rather get one that takes that voltage.

I also don't really know how to hook the power pack up to the press,but apparently the press I am going to be buying hopefully today , will take the pack with only a few fittings.

I'll buy the press and worry about hte power at a later time I suppose.

Just like everyone else I'd like to find the cheapest alternatives.

[cplmac]

Two things, first H&K I have to disagree with you on the hottest whistle mix. It has been my experience and nearly every other person I know who has put their hands on whistle mix that 70/30/1 is a hotter mix than 76/23/1. And 70/30/2 is hotter than either of the other two. ewest the hammering affect of the air over hydraulic press is not an issue. I've pressed about as sensitive a mix as you would ever want to press with mine (chlorate/salicylate) and never has it caused compression ignition. Honestly I was pretty worried about it too when I got my press and started pressing rockets with it, but I have come to realize that it is just as safe as a standard press.

[ewest]

Thanks. That's just more confirmation of what I've been discovering.

[FrankRizzo]

Two things, first H&K I have to disagree with you on the hottest whistle mix.  It has been my experience and nearly every other person I know who has put their hands on whistle mix that 70/30/1 is a hotter mix than 76/23/1. And 70/30/2 is hotter than either of the other two. ewest the hammering affect of the air over hydraulic press is not an issue. I've pressed about as sensitive a mix as you would ever want to press with mine (chlorate/salicylate) and never has it caused compression ignition. Honestly I was pretty worried about it too when I got my press and started pressing rockets with it, but I have come to realize that it is just as safe as a standard press.

Unfortunately, I think I'm the one who started that rumor. On my HF press, if you squeeze the valve open fully, it reciprocates quite fast and I was just leery of the compressions forces. If it's tested OK with a sensitive mix like chlorate/saly, I don't think we have to worry too much about it. :-)

 

Also, I still have that Haldex/Barnes 24V HPU for sale. If anyone is interested, send me a PM.

[h&k machineguns]

Two things, first H&K I have to disagree with you on the hottest whistle mix. It has been my experience and nearly every other person I know who has put their hands on whistle mix that 70/30/1 is a hotter mix than 76/23/1. And 70/30/2 is hotter than either of the other two. ewest the hammering affect of the air over hydraulic press is not an issue. I've pressed about as sensitive a mix as you would ever want to press with mine (chlorate/salicylate) and never has it caused compression ignition. Honestly I was pretty worried about it too when I got my press and started pressing rockets with it, but I have come to realize that it is just as safe as a standard press.

Talk to Steve LaDuke and Dan Themes,and Dan Creagan they will all tell you 76/23/1 is much faster than 70/30/1. I also can't go all the way to the top of my Long winded 1 pound spindle with 76 like I can with 70 without CATO. I can go all the way up the 4.25" long spindle with the 70. WIth the 76 I can only go 75% of the way up.

 

Steve LaDuke has been doing Whistle rockets for over 20 years and has many video's and does siminars on the rockets.

[cplmac]

I would honestly be shocked if LaDuke says the 76 mix is stronger. I have a ton of respect for his experience and knowledge. I think this started with Creagan doing a "scientific" test of thrust and pitch on different whistle mixes and percentages. I kind of scoffed it off after he said benzoate was stronger than salicylate. I have several friends who have been doing the rockets for twenty years and I trust them. A good chunk of my info comes from them and this specifically. Ask the other two what they say about 2% iron. If they say it is not stronger I'm going to have to stick by my friends who I talk with often. When I switched from 76 to 70 I noticed a significant increase in thrust and sound.

[ewest]

a bit off topic for the thread, but....

 

I specifically don't use salicylate because it takes off too fast and I like the way benzoate sputters on takeoff. So for New Years I had about (10) 1lb rockets pressed with straight benzoate, but this time when I pressed them I went up higher than the normal 8800 lbs of force.

 

For a 1lb rockets at 8800lbs of force it should read 3872 PSI on my Wolter P2F gauge, but this time I ran it up to an even 4000 PSI on the P2F gauge which is 9090lbs of force.

 

These suckers took off like a bat out of hell, not like my normal benzoate rockets at all, they sounded a lot more like salicylate rockets to me. So I was just guessing (since I used the same method and chems as I always do) that this time the difference in speed and sound was due to the higher pressing force.

 

So it's not just the formula that determines speed, it's also using a consistent pressing pressure between each batch. You can take a weaker formula and speed it up by using more lbs of force to press it.

 

If I'm wrong someone please correct me.

[Boomer]

No idea really whether whistle gets hotter at hiher densities, since it has a different mechanism than just about any other comp. Some think the oscillations come from surface detonations that die, then re-start when the reflected sound from the nozzle hits it again.

 

Someone on a.e.e showed this is wrong via the hugoniot/raleigh line etc. (i.e. shock physics). They came to the conclusion it was a surface layer which, already partly decomposed and at lower density, went bang, and the process repeats when the next reflection from the nozzle hits the burning surface again, after some more stuff got 'ready'. It was shown that it was no det in the solid grain, as that would either die out and stay out (since the reflection is MUCH too weak to restart it), or consume the whole grain at 3-4 km/s (= BOOM at APAN level).

 

For everything else I ever heard off, lower density makes it hotter (faster) since heat spreads between the particles better. This is for deflagration mind you.

[cplmac]

I figured the density to have the same effect as you did Boomer, but ewest brings up a very good point. The pressure you press at has a noticeable effect on the finished product. I usually press my rockets at super high pressures to keep the CATO's down (15,000+) so I couldnt really say if lower density is faster or slower, but in my head I always imagined it would speed it up. ewest I'm gonna do a test on this this week. As for why it whistles I don't think it has anything to do with the nozzle. I say this because as most experienced whistle rocket folks willl tell you the loudest whistle you can get is off an endburn. In fact I know guys who have flattened out the top of their core spindle to get some more whistle out of the core burn. When I get my resupply of sally in, I will video a side by side test for you boomer of a core burn (closest to a nozzle with whistle) and an end burn. I have heard a lot of surprising things about whistles over the last couple of months, who knows maybe they do fly in the face of expectations.

[h&k machineguns]

It makes more sonce to me also that the less pressure you pack the whistle in the casing the faster it would be,but if you read all the posts on t he passfire board they will tell you that the harder or softer you pack the whistle in the rocket it doesn't change the temp or speed of the rocket. In fact if you press it harder PSI in the rocket means you can get more fuel in the rocket,and that means longer burn time.

 

As far as rockets and whistling go,I don't believe with all the rockets I have done it has anything to do with the tube,or how much you leave the tube empty on the end of the motor that effect the whistle noise.

 

The fact is I can completely cut open a whistle rocket that I have done that was ready to fire off,and break up the rocket into a few piece,and actually light them in that raw pressed form with no casing and they are still loud as hell,just like the rocket is when it takes off. Now if I take raw whistle powder(Non pressed) and light the same weight worth it just goes up in a fast flame with no noise whatsoever.

 

Again I am fairly new to this stuff,but I do know the facts of what I have personally experiance and have paid close attention to what the pro's are saying on passfire.

[h&k machineguns]

Here is a quote from Steve LaDuke from the passfire board.

 

76/23/1 is the fastest compaired to 70/30/1,and of course 64/32/1.

 

 

Anyway I can get more quotes from these guys,but this one stood out the most......

 

 

From: steve laduke

Date: 1/4/2007

Subject: Re: Whistle spindle (Steve L.)

 

Dan:

Your information is from the hand out I supplied for my mini whistle rocket seminar. If you note, all the spindles were the same length, except the 1/2'' rocket. What I did was to show the difference of power and sound, using the two fuels, sodium banzoate and sodium salicylate and compared them to each other. I also demenstrated the lifting capacity or take off speed by varing the diameter of each spindle. All these rockets are demoed on a video that AFN sells. The hand out also shows the different mixes I used in all the rockets fired. Once the spindle is made longer than what was used on the handout, the danger of catoing becomes greater. All these rocket motors were pressed using an arbor press. Once you make the spindle longer than 1-3/4''- 2'', then pressing on a hydraulic press is recomended. To insure that my rockets don't cato, I use a sleeve on all of them and press in a hyd. press. I also didn't use a sleeve on any on the rockets demoed except 1 of them, if you get the video. One of the rockets was pressed to 4500 psi. and one was pressed to 8666 psi. using a sleeve on both and the one using 4500 psi. catoed and the one using the higher psi. flew like a bullet. This was to deminstrate how important using the right psi. when pressing rockets.

If a rocket catoes, it means two things are wrong. The spindle is to long or the fuel burns to fast for that size spindle and to fix the problem, you can do one of two things. Shorten the spindle or slow the fuel down. I would do this in increments of 5. For example, the fastest whistle mix is 76-23-1-1.5: perk, salicylate, iron oxide, vasoline respectively. They're are two different length spindles for whistle rockets, the mini spindle and the full length spindle. As shown on my hand out, I used the mini spindle where you don't need a sleeve on the rockets when pressed. For the full length spindle, you have to use a sleeve and high loading pressure. When making the rocket using the full length spindle, the 76-23 salicylate mix is to fast burning and you have to slow it down by making a mix using a ratio of 70-30-1-4. For a slower mix progressively, decrease the amount of oxidier by one and increase the salicylate by one. And to each of these mixes, by increasing the amount of vaseline by one, you slow down the mix by one notch until you have added 5 parts of vaseline. You can add more vaseline than five parts but the mix starts to get squishy so I don't use more than five parts.

So if you start with 76-23-1-2.5 and your rocket catos, use a slower mix. Or, you can use the LWS loading method and use a slower mix in the upper portion of your rocket by using a mix of 64-32-1-5 benzoate mix or salicylate mix. If your spindle is 3 inches long, press two inches of salicylate mix, then press the rest of the way up using the ben. mix at a ratio of 64-32-1-5. Make sure you press up above the spindle at least 1/4'' using the ben. mix before you add anything else. You may finish the rocket with sal. mix to change the sound. Make sure you have enough bulkhead pressed above the spindle, say, 3/4-1'' of sal. mix altogether. If you use the ben. mix 1'' above the spindle, the delay will be much longer.

I could talk a few hours on this subject. I hope this isn't to long winded.

SLD

[FrankRizzo]

You really can't take one specific ratio of fuel:oxidizer, use it with different types of fuels that may have differing oxygen requirements, and then make a claim that one fuel is superior to another. With all the testing the Creagan's did, they never tested the "usual" ratio for sodium benzoate-based fuel which is 70/30. Both 70/30 and one that is very close to 76/23 are listed in Hardt for benzoate and salicylate respectively.

[h&k machineguns]

http://f1.grp.yahoofs.com/v1/8FitRa8J1YJgp...VA3/WHISTLE.JPG

[cplmac]

You are right about whistle whistling regardless of the tube or core design. But the length of the tube will affect the pitch of the whistle. If you listen to a whistle as it burns down the tube you will notice the sound of the whistle getting deeper. You're right about the whistle grains not whistling when unpressed. I made a batch of whistle substituting chlorate for the perchlorate, and a small pile of the unconfined grains chirped VERY loudly.

 

Unconfined whistle grains

[oriansbelt]

I finnally got my press built, it's not all that pretty but maybe I could atleast press some desent rockets with it.

 

 

http://www.apcforum.net/files/DSC00287nMediumn.JPG

 

http://www.apcforum.net/files/DSC00286nMediumn.JPG

 

http://www.apcforum.net/files/DSC00285nMediumn.JPG

[ewest]

What are you talking about? It looks fine to me, just like the press on passfire (the wooden one).

 

The press doesn't need to look pretty, just the rocket when it goes off

[h&k machineguns]

http://youtube.com/watch?v=Cn7DwauQV1w

 

Harbor frieght press $172 after tax

Power pack $329 shipped

Deep cycle battery $48 after tax

2 battery cables 6 gage from WalMart $5.98 after tax total with ends(Goes from battery to power pack.

6' of Parker hose with 3/8'' ends $42 total

2 sheets of 3/8'' lexan $40 total

Metal for brackets $5.00 total

Labor to weld bracks $15 from a friend(Took out to eat).

Bolts for Lexan $2.50 home depot.

 

I really like the set up,and actually glad I did't waste my money with a 2 way piston and power pack. The ram returns just as fast as it comes down under power.

The only complaint I have is,it's too fast. I have to sit and almost flick the lever lighning fast to get it to not move to fast. I have heard of some type of relief valve that can help the press move slower,but I'm not sure how to find it and were it goes on the press.

The power pack is rated at 2500 PSI,and only puts max pressure to my Wolter gage to 5400 after it goes through the piston.

 

I feel so spoiled now. This thing took rocket making to a whole new level.

[cplmac]

That's a real nice little setup you have their HK! You're right, it is very fast. Is the up down handle an on off switch or an actual valve? A valve should give you infinate adjustability. Also, the HPU should have a relief valve built in, but generally relief valves deal with pressure more than flow. I bet a larger cylinder would go slower, but I also bet that is not a route you are interested in. All in all nice setup.