The Armour Archive

I hate to post this, but I have heard about three differing opinions what progressive give is. One I found on Cunan and the other was by Tessa in Combat Archery.

I did a search of the Forum and I still get the same types of answers...
"Progressive give is the ability of the foam to provide increasing resistance as it becomes more compressed. The related term, bottoming out, means that the foam has reached its maximum compression and additional force will be transferred to what ever is supporting the foam. Progressive give must be judged relative to the expected forces. While it may be possible to compress foam in a vice, it may not have sufficient progressive give."

So, from a Society standpoint, how is this measured that is standardized?
or is it an opinion from one Marshall to another?

dheisey wrote:I hate to post this, but I have heard about three differing opinions what progressive give is. One I found on Cunan and the other was by Tessa in Combat Archery.

I did a search of the Forum and I still get the same types of answers...
"Progressive give is the ability of the foam to provide increasing resistance as it becomes more compressed. The related term, bottoming out, means that the foam has reached its maximum compression and additional force will be transferred to what ever is supporting the foam. Progressive give must be judged relative to the expected forces. While it may be possible to compress foam in a vice, it may not have sufficient progressive give."

So, from a Society standpoint, how is this measured that is standardized?
or is it an opinion from one Marshall to another?

It is an opinion from one marshal to another. Basic hand strength. If I can grab a polearm and squeeze the head and can NOT get 1/2" give OR I can feel the rattan under the give, the weapon fails.

If I squeeze and I can get 1/2" give while not bottoming out, the weapon passes.

Now, my fellow marshal may have stronger hands than me and can squeeze it more or less. But, that is WHY we TRAIN our marshals, so they can get a good idea of what is "good" and what is not BEFORE they become warranted and do things on their own.

What is the definition (real life here) of calibration? What constitutes a good shot? I can show you, but it is almost impossible to describe.

dheisey wrote:I hate to post this, but I have heard about three differing opinions what progressive give is. One I found on Cunan and the other was by Tessa in Combat Archery.

I did a search of the Forum and I still get the same types of answers...
"Progressive give is the ability of the foam to provide increasing resistance as it becomes more compressed. The related term, bottoming out, means that the foam has reached its maximum compression and additional force will be transferred to what ever is supporting the foam. Progressive give must be judged relative to the expected forces. While it may be possible to compress foam in a vice, it may not have sufficient progressive give."

So, from a Society standpoint, how is this measured that is standardized?
or is it an opinion from one Marshall to another?

mm.. You might want to consider that there are contextual differences in the meaning of the term. As you've just quoted, it must be judged relative to the expected forces.

This means that a crossbow quarrel is an entirely different matter than a 12 foot pike. It's also a little peculiar, in that in terms of actual safety - the quarrel point can be much stiffer than the pike point - but for judging the progressive give, one will apply much more pressure to the pike looking for it to compress and judging when/if it bottoms out.

Personally, I'm much less concerned about bottoming out in the sense used above, than I am about folding over, or other failure modes that put the material supporting the padding into an exposed position where it may make direct impact.

And no, so far as I know there is no published objective standard that allows a quantified measure.

Gavin

All good answers, and it helps me to understand the concept more.

Insane Irish wrote:
It is an opinion from one marshal to another. Basic hand strength. If I can grab a polearm and squeeze the head and can NOT get 1/2" give OR I can feel the rattan under the give, the weapon fails.

If I squeeze and I can get 1/2" give while not bottoming out, the weapon passes.

Let me see if I have this right...If I or a Marshal were to compress the thrusting point or great weapon and at maximum compression 1/2" of padding is between the weapon haft (rattan) and the outside edge, it should pass?

Oswyn also brigngs up a good idea that it easier shown than explained and I also understand that.

Kilkenny; herein lies the problem. That quote was the easiest to understand I could find, and that quote is from Tessa the Huntress's Combat archery page, so the concept is one based on an archery view.

I have heard many opinions just in my limited experience from many different Marshals and MIT. I have heard things like "would you allow someone to hit you with this?" (my answer is always sure, why not?) to " that isn't progressive give because I can compress it too much", but another Marshal passes it...
There seems to be no clear cut description or standard unless you go with a weapon that was designed and then is "generally approved" Society wide. Like the Mandrake thrusting points, spear heads and axes. I say general because some kingdoms will not pass these without padding or modification.
So, I am still interested in more opinions, and I value the Gentle's opinions that have shared thus far.

dheisey wrote:All good answers, and it helps me to understand the concept more.

Insane Irish wrote:
It is an opinion from one marshal to another. Basic hand strength. If I can grab a polearm and squeeze the head and can NOT get 1/2" give OR I can feel the rattan under the give, the weapon fails.

If I squeeze and I can get 1/2" give while not bottoming out, the weapon passes.

Let me see if I have this right...If I or a Marshal were to compress the thrusting point or great weapon and at maximum compression 1/2" of padding is between the weapon haft (rattan) and the outside edge, it should pass?

Oswyn also brigngs up a good idea that it easier shown than explained and I also understand that.

Kilkenny; herein lies the problem. That quote was the easiest to understand I could find, and that quote is from Tessa the Huntress's Combat archery page, so the concept is one based on an archery view.

I have heard many opinions just in my limited experience from many different Marshals and MIT. I have heard things like "would you allow someone to hit you with this?" (my answer is always sure, why not?) to " that isn't progressive give because I can compress it too much", but another Marshal passes it...
There seems to be no clear cut description or standard unless you go with a weapon that was designed and then is "generally approved" Society wide. Like the Mandrake thrusting points, spear heads and axes. I say general because some kingdoms will not pass these without padding or modification.
So, I am still interested in more opinions, and I value the Gentle's opinions that have shared thus far.

Just one comment with regard to "Sure, why not?" - That question that you seem to be dismissing is fundamental to our entire safety base in the SCA. The idea that we understand not to do unto others what we wouldn't want done unto us. So, while you may never go to a marshall with a weapon you made that you wouldn't be willing to be hit with (I'm assuming that you aren't one of those who would tape up a five pound sledge and tell the marshall "sure, why not?" when they ask if you would be willing to be hit with it), there are people who indeed build weapons that they don't want to be hit with.

There are a great many (most ?) of our combat standards in the SCA that are not quantified and in many cases not really quantifiable, or at least not economically quantifiable. So we have regional variations, differences of opinion, and a need to be accommodating in our understanding that some things are subjective and are going to vary.

Gavin

Kilkenny,
Let me ease your mind that I am not one of those people that would pad and tape a sledge and say sure, why not? I, by no means am an expert in SCA, but I am a reasonable man. I surely would not make a weapon that would intentonally cause harm to myself or others, because that would be wrong in our society. I would however have no objections being struck with a "kong" mace or a "door wedge" mace that has been described in this forum. But for some reason, I know a few that feel that "they would not want to be hit with it, so therefore, it will not pass". I have submitted to being struck with these weapons, and I will let even the person who says that they would not want to be hit it, hit me with it.
The biggest stickling point that always seems to made is the "progressive give" rule, which confuses me, and quite honestly even though subjective, cannot be quantified or qualified between more than two persons.
Should it go, no, because I will guarantee that there will be those who will erroneously or nephariously add items to push the edge of the envelope.
I don't mean this as a rant or a complaint, but that I am trying to get some idea of the hows and whys, vs. a personal opinion.
Everyone who has posted to this thread so far has helped me understand this and I appreciate the patience thus far.

dheisey wrote:There seems to be no clear cut description or standard unless you go with a weapon that was designed and then is "generally approved" Society wide. Like the Mandrake thrusting points, spear heads and axes. I say general because some kingdoms will not pass these without padding or modification.

To the best of my recolection the Mandrake tips are hollow rubber stiffened by adding varying amount of closed cell bits inside. This alows the tips to be tuned for local tip calibration standards. I don't think that these justify a "standard" in any way... or has the design changed?

Personally I think that the rule was written intentionally vague to allow interpretation by marshals from various regions and to addapt to the ever changing styles of the SCA. SCA combat seems to go through developmental phases between sharp crisp cracks to forcefull dull thuds and tips vary accordingly... or maybe that's just me traveling around.

In the siege community, following last Pennsic, an effort was made to better define "progressive give' as it applied to ballista ammo. It was determined that most of the tennis ball tips were bottoming out at impact. a new inspection method was proposed based on the experiments. Tips will now be checked with a lever arm scale and a fixed weight. Tips must undergo X deflection at Y load. Mind you the X and Y were selected by measuring existing bolts that marshals said "felt right" not by any complicated match.

We also determined some other stuff. The first is 99.9% of all tips bottom out. The second is when a tip dosn't bottom out nobody takes the shot. Essentially we (and this applies to heavy weapons also) are using thrusting tips to burn off a small upper percentage of the energy and letting the rest be rattan-tip on body impact.

If I had the time I might be inclined to set up a test stand at Pennsic or other large events and find a way to measure tip stiffness consistantly just as an experiment but until someone does I don't think it will ever be possible to define progressive give any more accuratly then we define porn. "I know what it is and I enjoy playing with it when I find something good."

Sean

Sean Powell wrote: In the siege community, following last Pennsic, an effort was made to better define "progressive give' as it applied to ballista ammo. It was determined that most of the tennis ball tips were bottoming out at impact. a new inspection method was proposed based on the experiments. Tips will now be checked with a lever arm scale and a fixed weight. Tips must undergo X deflection at Y load. Mind you the X and Y were selected by measuring existing bolts that marshals said "felt right" not by any complicated match.

Sean

Do I correctly understand this to be a static testing method ?

Velocity is a really important element in this kind of testing, especially with things like ballista bolts that are, well, ballistic.

Are you familiar with the variance in behavior in Silly Putty when you compress/stretch it slowly versus doing either swiftly ?

I don't have an off the top of my head suggestion for a better testing method. I do suggest some thought be given to finding one.

Gavin

Kilkenny wrote:

Sean Powell wrote: In the siege community, following last Pennsic, an effort was made to better define "progressive give' as it applied to ballista ammo. It was determined that most of the tennis ball tips were bottoming out at impact. a new inspection method was proposed based on the experiments. Tips will now be checked with a lever arm scale and a fixed weight. Tips must undergo X deflection at Y load. Mind you the X and Y were selected by measuring existing bolts that marshals said "felt right" not by any complicated match.

Sean

Do I correctly understand this to be a static testing method ?

Velocity is a really important element in this kind of testing, especially with things like ballista bolts that are, well, ballistic.

Are you familiar with the variance in behavior in Silly Putty when you compress/stretch it slowly versus doing either swiftly ?

I don't have an off the top of my head suggestion for a better testing method. I do suggest some thought be given to finding one.

Gavin

Silly Putty is a non-newtonian fluid. There are a number of others out there but a close aproximation can be made with neoprene foam and tape which squishes at hand speeds but dosn't re-inflate quickly so the second thrust is a rock... ever see one of thos on the field?

Yes this is a static test but this is a static test to confirm only a portion of a weapon behavior. It's what we do with rattan weapons. Test tips staticly to estimate performance dynamicly.

Ballista bolts are strictly regulated by weight and length. Engines are strictly regulated in launch velocity by measuring their projectile distance with a conforming bolt. The physics of accuracy optimizes on bolts with a certain amount of drag but not too much. Limitations in available (and allowed) material have produced a weapon that is VERY consistant between manufacturers, engines, and kingdoms. Tips will be 95% made from solid pool noodle and 5% made from layers of blue camp pad. Any of the other funky less porus materials are too heavy and you can not get the right length and weight at the same time.

The best testing method would be a blue-tooth capable acclerometer that could be mounted behind the bolt head and downloaded to a computer after launch. Yes I speced one out while looking at this problem. We could measure acceleration, peak impact, duration of impact, how long before the tip bottoms out and all sort of other interesting stuff... but other then building a series of "good enough" bolts that were field tested by people being struck and saying "Make it perform like THIS" we've got not a lot to go on. Once we have this mythical golden standard bolt to compare to I don't know that dynamic testing is necessary. Especially if "I know what a good tip should feel like".

Besides, Siege ENGINEERS are ENGINEERS and like tuning or tricking out their engines for optimum performance. Stick Jocks know the answer is to just hit the bad guy harder next time. It would be interesting to have a measured standard but I'm dead set against having that standard and equipment be mandated inspection criteria.

Sean

Sean Powell wrote:

Kilkenny wrote:

Sean Powell wrote: In the siege community, following last Pennsic, an effort was made to better define "progressive give' as it applied to ballista ammo. It was determined that most of the tennis ball tips were bottoming out at impact. a new inspection method was proposed based on the experiments. Tips will now be checked with a lever arm scale and a fixed weight. Tips must undergo X deflection at Y load. Mind you the X and Y were selected by measuring existing bolts that marshals said "felt right" not by any complicated match.

Sean

Do I correctly understand this to be a static testing method ?

Velocity is a really important element in this kind of testing, especially with things like ballista bolts that are, well, ballistic.

Are you familiar with the variance in behavior in Silly Putty when you compress/stretch it slowly versus doing either swiftly ?

I don't have an off the top of my head suggestion for a better testing method. I do suggest some thought be given to finding one.

Gavin

Silly Putty is a non-newtonian fluid. There are a number of others out there but a close aproximation can be made with neoprene foam and tape which squishes at hand speeds but dosn't re-inflate quickly so the second thrust is a rock... ever see one of thos on the field?

Yes this is a static test but this is a static test to confirm only a portion of a weapon behavior. It's what we do with rattan weapons. Test tips staticly to estimate performance dynamicly.

Ballista bolts are strictly regulated by weight and length. Engines are strictly regulated in launch velocity by measuring their projectile distance with a conforming bolt. The physics of accuracy optimizes on bolts with a certain amount of drag but not too much. Limitations in available (and allowed) material have produced a weapon that is VERY consistant between manufacturers, engines, and kingdoms. Tips will be 95% made from solid pool noodle and 5% made from layers of blue camp pad. Any of the other funky less porus materials are too heavy and you can not get the right length and weight at the same time.

The best testing method would be a blue-tooth capable acclerometer that could be mounted behind the bolt head and downloaded to a computer after launch. Yes I speced one out while looking at this problem. We could measure acceleration, peak impact, duration of impact, how long before the tip bottoms out and all sort of other interesting stuff... but other then building a series of "good enough" bolts that were field tested by people being struck and saying "Make it perform like THIS" we've got not a lot to go on. Once we have this mythical golden standard bolt to compare to I don't know that dynamic testing is necessary. Especially if "I know what a good tip should feel like".

Besides, Siege ENGINEERS are ENGINEERS and like tuning or tricking out their engines for optimum performance. Stick Jocks know the answer is to just hit the bad guy harder next time. It would be interesting to have a measured standard but I'm dead set against having that standard and equipment be mandated inspection criteria.

Sean

All good to read. Seriously, it's always reassuring to me to find that the people who are really focusing on something are ahead of me - they're supposed to be

Friend of mine built a silly putty mace years ago. Talk about the textbook example of evil.

I built a "normal" foam mace at one point, had marshalls telling me it was fine but so soft I would not get acknowledgement. Had opponents telling me I didn't need to hit quite so hard. Funny, it was a neoprene...

Gavin