Stainless steel rocket tooling ? warning?

[val77]

hello all

Today I ask you a question

a friend will make me a rocket tooling

only if there is a danger is made ​​of stainless steel?

[val77]

What do you think?

[a_bab]

The first condition required by a material used for making rocket tools (and any other pyro tools) is the ability NOT to spark it hit.

For rocket tools things like brass, aluminium (hard grade), bronze and stainless steel are used.

 

It certainly looks like you didn't do your homework concerning rocket making, otherwise you would have not asked this <silly> question.

 

I'll remind you some very basic rules and other things:

 

STARTUP

The minumum set of tools are:

-rocket tools (spindle, ram, sleeve (PVC+clams, clamshell system etc)

-press with blastshield/hammer (ONLY for BP!)

-reliable tubes

-good fuel making skills, and consistency doing it

While some of these can be altered somehow (I've seen rocket tools made of wood mainly), these would be a bare minimum

 

SAFETY

1. Start small! You don't jump straight to a 3 pounder without having enough experience.

2. Divide your amounts! NEVER have more fuel then needed for a motor around you; once made the engine should be put aside, away from your workplace (preferable in a different room). Don't have around live shells/trays of stars etc while making engines!

3. Use gloves! If the engine goes off you'll be happy you did.

4. NEVER hold the engine in your hands while being pressed!

 

CATOS

-weak tubes, inconsistent pressing, too large increments, wrong tools, too much solvent left in the fuel (for whistle)

 

ACCIDENT CAUSES

The event of accidentaly having an engine ignite on you while pressing can be traced to very few causes, all boiling down to fuel being subjected to stress between the spindle and the ram

1. Fuel pinching

- the most likely is fuel pinching between the ram and the spindle. The friction can be enough to cause the ignition; since the engine is fully contained it will explode violently. This can happen both during the pressing, or while trying to release a stuck spindle off the ram. Some easy to follow rules: pay attention to your set of rams and their order. Some people use a single ram (very slight taper on spindle). ALWAYS clean your ram hole before adding the increment. Oh, did I mention be careful about your ram order?

2. Ignition due to shock

- again, the ram is the cause: the spindle will hit the bottom hole of the ram causing the fuel to ignite/explode thus making the whole engine going off.

3. Tube/support failure

- if the support fails suddenly the tube will be also ripped, and the ram can colide against the spindle. A less dramatic effect since there will be less containment (depending on the fuel; whistle and strobe will likely explode).

 

 

That's all out of my head right now.

Read all you can, visit the rocket section (on several forums), decide what rocket is good for you (BP is the usual choise for beginners), identify a good tube source/master the tube rolling before starting out.

[val77]

tools will just rocket black powder

and security I already know the basics I rocket outside my home in a great garden

and until now I do my rocket rocket engines without tools

 

donc je peut faire base et broche en inox et ramers aussi en inox ?

sorry but I do not know all the properties of metals

and it will be for 14mm motor

Edited August 19, 2012 by val77

[a_bab]

Oui, tu peut les faire en inox achetée au Weber Metaux

[mabuse00]

I think stainless steel for the spindle is OK, since there are some commercial tooling sets that use it too.

But only in combination with aluminium rammers, so that you can never have a collision steel -> steel.

 

It will last longer than aluminium, providing that you clean and oil it immediately after use.

[val77]

thanks for your response

[dagabu]

Stainless steel is also known as a dry metal, it will gall and hold other materials and metals longer and with more friction then brass or bronze. It also has some iron in it, there is no stainless steel that does not.

 

Pinching is a known issue but two documented cases of a rockets igniting while being made, both happened at or within 10 feet of my work area by others, were caused by twisting the motor off the spindle. This is the single most hazardous part of making rockets on a press.

 

There is no reason to oil stainless steel spindles, it cannot be seasoned as steel can be and it will not rust unless it is an inferior grade and it should not be used for rockets in any case.

 

-dag

[val77]

this is high quality stainless stell

[dagabu]

Even 440 surgical stainless steel has iron and is a dry metal, it will grab the comp more then brass and bronze will.

 

-dag

[a_bab]

Dag, I forgot about twisting - but as I said, it's always something about spindle/fuel relationship (friction, pinching, shock).

[WSM]

The stainless steel I prefer is 300 series, which is listed as non-magnetic and non-sparking by the US Government. Take a magnet with you when shopping for stainless steel to be used in your tools. If the magnet is attracted, reject that material.

 

Bon courage.

 

WSM

[dagabu]

The stainless steel I prefer is 300 series, which is listed as non-magnetic and non-sparking by the US Government. Take a magnet with you when shopping for stainless steel to be used in your tools. If the magnet is attracted, reject that material.

 

Bon courage.

 

WSM

 

303 is even better, it has lead in it which makes it a lot easier to turn. It is also called free machining nickel-chromium steel.

-dag

[WSM]

303 is even better, it has lead in it which makes it a lot easier to turn. It is also called free machining nickel-chromium steel.

-dag

 

Hey! That's 300 series too! Dag's right.

 

WSM

Edited August 23, 2012 by WSM

[dagabu]

304 series is the most common and 316 is surgical but both are difficult to turn and chatter a lot more then 303. Series 440F is also free machining but is almost impossible to find now days.

-dag

[WSM]

304 series is the most common and 316 is surgical but both are difficult to turn and chatter a lot more then 303. Series 440F is also free machining but is almost impossible to find now days.

-dag

 

All true. For spindles, I use 303 which is free turning, as dag says, due to the 1% lead in the alloy. I have a few tools made of 304, and they were a monster to turn compared to 303.

 

WSM

Edited August 23, 2012 by WSM

[WSM]

I think stainless steel for the spindle is OK, since there are some commercial tooling sets that use it too.

But only in combination with aluminium rammers, so that you can never have a collision steel -> steel.

It will last longer than aluminium, providing that you clean and oil it immediately after use.

 

Actually, my best tool sets have a stainless steel spindle and brass rammers. Brass rammers hold up much better than aluminum to normal wear and tear and seems to last longer with less damage overall. Aluminum rammers with a Nituff coating would probably last much longer, in my opinion.

 

I agree with dag about stainless; it doesn't need oiling to preserve it, though a light rub with graphite or silicone oil may help pressed composition release from it a bit better (your milage may vary).

 

WSM

[WSM]

Actually, my best tool sets have a stainless steel spindle and brass rammers. Brass rammers hold up much better than aluminum to normal wear and tear and seems to last longer with less damage overall. Aluminum rammers with a Nituff coating would probably last much longer, in my opinion.

I agree with dag about stainless; it doesn't need oiling to preserve it, though a light rub with graphite or silicone oil may help pressed composition release from it a bit better (your milage may vary).

WSM

 

Aluminum rammers with a Nituff coating will last a lot longer than bare aluminum rammers, I mean. Properly cared for brass rammers will last a lifetime or longer.

 

WSM

[dagabu]

True that W.

 

Brass (Bronze) spindles in conjunction with brass rammers is the best possible combination and are much easier to remove when jammed.

 

-dag

[Swede]

There's an old machinist's ditty regarding stainless steels that goes something like this...

 

"303, she's for me, 304, she's a wh-re"

 

I've made tooling from 303 and never hesitated to use it. I also use 303 SS media for ball milling for everything except BP.

[dagabu]

I love that saying but had forgotten it.

 

Val, Dont get me wrong, 303 SST is by far better then Aluminum but is inferior to brass or bronze for spindles. Use what ever you think you can handle but just be aware of the pit falls.

 

-dag