Without knowing the baseline diameter, you do not know the true clearance between the pellet and the moderator bore.
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Moderator Test
- Thread starter OldSpook
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Matter of degree of what? You stated the test you performed was on the sound relationship between moderator bore size and pellet. Well, the actual final pellet size is a product of the barrel choke and that varies significantly from barrel to barrel. If you do not know one of the two required for a comparison, the results are dubious at best. You also said you are using a sound meter. There are all kinds of sound meters and none of the sound meters I have seen tell you what they are hearing. Is the noise it is hearing the escaping air or perhaps the ringing of the moderator tube or perhaps the actual pellet because the pellets themselves create a great deal of noise? Might even be the hammer slapping the valve. My point here is no sound meter knows what it is hearing, it hears just noise. At the end of the day, it is only personal perception and even that is not necessarily what some non-human is hearing down range. I can only say from my personal experience of making these things that I cannot perceive any sound difference in sound reduction with different mod bore sizes and I have used up to .040" clearance and as little as .010". Could be my ears of course, but I'm betting my ears are better than any sound meter in distinguishing different sounds......jus sayin
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I would also like to say that making moderators from 3D plastic would not be my first choice of material. There are a lot of forces being applied to a moderator especially with internal baffles. A lot more than you would think. 3D plastic material is very unstable and weak in my experience. Perhaps there is some high tech out there that I'm not aware of, but the stuff I have worked with is essentially useless for performing real work function, it just moves all over the place with temperature change and applied forces, even if those forces are light.
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Ok, ... It is a matter of degree because you don't have an exact measurement either. By your argument your measurements are meaningless as well. They are just "less" meaningless, right? In a world where .4mm is a small measurement, the tolerances you are describing are very difficult to achieve.. and may not even be necessary. You might be able to thread a needle at a thousand yards but you are going to spend a lot of time setting that up which you could spend more productively.
Really? noise is what they hear. It is up to you to decide what they are "measuring".
Yea, that part is your job. It is your job as the engineer to understand these "pesky" details and measure the right things.
No sir, it may be only "personal perception" at the end of YOUR day. At the end of my day it is about what I can measure. It seems that almost every person who builds moderators says, "Don't trust your meter. Trust your ears." That's convenient, don't you think? It is fine in a world where one fellows "great" is six decibels louder than the next fellow's "crappy". Builders say, "you can't trust the measurements you make." because that is what they WANT you to believe. It is an excuse for not understanding WTF they ARE measuring or how to measure it for that matter.
Good for you. I can measure them. I don't even bother with minuscule clearances like the ones you are describing. If I can't build to those tolerances then why should I bother? I had better find another way, or give up. I have observed that anything tighter than about 0.5mm windage doesn't seem to make a whole lot of difference. That may be because I have trouble measuring it. That might be due to the viscosity of HPA itself. I have not really spent a lot of time thinking about it. I'll bet I've spent more time thinking about it than you have though.
Look, I'm trying to design a moderator that can be put into production. I want to design something that I can manufacture in volume, easily, which is effective enough and which can be priced at half the average cost. There is NO REASON people should have to pay $100 for a moderator for their air rifles. This ain't the same world the PB people have to live in. I am pretty damn confident I can do that without EVER making a measurement smaller than 0.04" Scratch that, I have done that already.
I have measured the differences you say you can't measure. You have not really tried to measure them at all. 0.04" clearance (1/2mm windage) is the limit for me. That is as tight as I am willing to run my bore. You wan't to build tighter than a half mm windage on the bore, help yourself. I'll buy three more printers and build ten moderators in the time it takes you to machine one. The ones I build will all be within a dB of the same performance as yours. If you want to trust my ears
they will be better than that. jus' sayin' ... right back at ya ...Do some tests at half a mm or 1 mm windage. Take your 4.5mm rifle and test it with a muzzle orifice of 5.5mm then test it with an orifice of 6.5mm. Duplicate the tests I did. You will be able to measure a difference. Show me your numbers don't tell me about your "feelings". I gave you numbers. You don't like them, oh well then, trust your ears. Don't ask me to do that.
I'm betting they aren't even close. TBH I know they aren't even remotely as good as a microphone. One is a machine the other is subjective, an opinion. One day your background noise level is six dBs higher than the next. On that day your ears can't hear the difference they could hear on a day when the noise floor was lower. Sure a dB is subjectively defined as the smallest change in sound level a human can usually detect. While 3 dBs is generally accepted to be the difference in sound level which the average person can EASILY detect. That means absolutely nothing without context. The same context you want to apply to a microphone by the way.
Your opinion is subjective. I don't trust your feelings. I trust my microphone and my ability to use it in a way which gives me meaningful data. You don't have to like that or accept it. You are welcome to dispute it, but unless you can produce actual data and not your "feelings" it means nothing to me. Your mileage may vary with other folks.
If you have some measurement data you wish to share, I'd be delighted to study it.
It would not be my first choice either. I'd rather have an injection molding shop and a ten thousand dollar budget. I already have the designs.
I'd also really like living in a country where the **AGENCY WHICH MAY NOT BE NAMED** doesn't play fast and loose with the definition of a silencer when they are obviously MADE WELL ENOUGH TO BE ATTACHED TO A FIREARM... The ones you are building very likely would not pass the "not intended for use on a firearm" test...
That's probably just me, though... your mileage may vary.
Well you see, you probably haven't done every sort of "real work function". There are literally dozens of different kinds of plastics and millions of applications. Some are used in the aerospace industry due to their lightness/strength/stability. Maybe you just aren't particularly knowlegable WRT plastics?
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I'm not quite sure why you think my comments are so confrontational. They are not meant to be. I fully support your efforts and wish you the best of luck and success. That said, I submit that additive manufacturing will very likely never be used for production. It is way to slow and way too inconsistent in accuracy, not to mention material strength. Now, if you are using a plastic material that meets the strength and accuracy the application demands, please let us know. I use CF, aluminum and stainless because they work and allow me to easily hold my already stated dimensions and I know of no plastics that can. Please also note that I have stated here on many different threads that moderator bore size has very little effect in moderator performance and in fact so has DannyFL and most all other moderator manufacturers. I just measured my KOI and it was ordered from DonnyFL in 22 cal. Its bore size is 7 mm and it works just fine. So, I hate to say this, but I think you are reinventing the wheel with this test. The differences you may detect will be so small as to be irrelevent.Ok, ... It is a matter of degree because you don't have an exact measurement either. By your argument your measurements are meaningless as well. They are just "less" meaningless, right? In a world where .4mm is a small measurement, the tolerances you are describing are very difficult to achieve.. and may not even be necessary. You might be able to thread a needle at a thousand yards but you are going to spend a lot of time setting that up which you could spend more productively.
Really? noise is what they hear. It is up to you to decide what they are "measuring".
Yea, that part is your job. It is your job as the engineer to understand these "pesky" details and measure the right things.
No sir, it may be only "personal perception" at the end of YOUR day. At the end of my day it is about what I can measure. It seems that almost every person who builds moderators says, "Don't trust your meter. Trust your ears." That's convenient, don't you think? It is fine in a world where one fellows "great" is six decibels louder than the next fellow's "crappy". Builders say, "you can't trust the measurements you make." because that is what they WANT you to believe. It is an excuse for not understanding WTF they ARE measuring or how to measure it for that matter.
Good for you. I can measure them. I don't even bother with minuscule clearances like the ones you are describing. If I can't build to those tolerances then why should I bother? I had better find another way, or give up. I have observed that anything tighter than about 0.5mm windage doesn't seem to make a whole lot of difference. That may be because I have trouble measuring it. That might be due to the viscosity of HPA itself. I have not really spent a lot of time thinking about it. I'll bet I've spent more time thinking about it than you have though.
Look, I'm trying to design a moderator that can be put into production. I want to design something that I can manufacture in volume, easily, which is effective enough and which can be priced at half the average cost. There is NO REASON people should have to pay $100 for a moderator for their air rifles. This ain't the same world the PB people have to live in. I am pretty damn confident I can do that without EVER making a measurement smaller than 0.04" Scratch that, I have done that already.
I have measured the differences you say you can't measure. You have not really tried to measure them at all. 0.04" clearance (1/2mm windage) is the limit for me. That is as tight as I am willing to run my bore. You wan't to build tighter than a half mm windage on the bore, help yourself. I'll buy three more printers and build ten moderators in the time it takes you to machine one. The ones I build will all be within a dB of the same performance as yours. If you want to trust my ears
Do some tests at half a mm or 1 mm windage. Take your 4.5mm rifle and test it with a muzzle orifice of 5.5mm then test it with an orifice of 6.5mm. Duplicate the tests I did. You will be able to measure a difference. Show me your numbers don't tell me about your "feelings". I gave you numbers. You don't like them, oh well then, trust your ears. Don't ask me to do that.
I'm betting they aren't even close. TBH I know they aren't even remotely as good as a microphone. One is a machine the other is subjective, an opinion. One day your background noise level is six dBs higher than the next. On that day your ears can't hear the difference they could hear on a day when the noise floor was lower. Sure a dB is subjectively defined as the smallest change in sound level a human can usually detect. While 3 dBs is generally accepted to be the difference in sound level which the average person can EASILY detect. That means absolutely nothing without context. The same context you want to apply to a microphone by the way.
Your opinion is subjective. I don't trust your feelings. I trust my microphone and my ability to use it in a way which gives me meaningful data. You don't have to like that or accept it. You are welcome to dispute it, but unless you can produce actual data and not your "feelings" it means nothing to me. Your mileage may vary with other folks.
If you have some measurement data you wish to share, I'd be delighted to study it.
It would not be my first choice either. I'd rather have an injection molding shop and a ten thousand dollar budget. I already have the designs.
I'd also really like living in a country where the **AGENCY WHICH MAY NOT BE NAMED** doesn't play fast and loose with the definition of a silencer when they are obviously MADE WELL ENOUGH TO BE ATTACHED TO A FIREARM... The ones you are building very likely would not pass the "not intended for use on a firearm" test...
That's probably just me, though... your mileage may vary.
Well you see, you probably haven't done every sort of "real work function". There are literally dozens of different kinds of plastics and millions of applications. Some are used in the aerospace industry due to their lightness/strength/stability. Maybe you just aren't particularly knowlegable WRT plastics?
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Oh, I didn't mean to give you that impression. No, in order to be confronted, one must feel threatened or intimidated.
That's kind of you.
See the link. Any part on any printer he sells which is orange is 3d printed. He prints printers. Makes pretty good money at it and is considered a ground breaker in the field. Very knowledgeable and open minded. Thinks outside of the box.
If all you have in your toolbox is a hammer ... How do you scale a machine shop full of machinists? Increase your payroll. How do you scale a machine shop full of printers? You buy more printers. One costd you every week the other costs you one time.
Yeah, you need some pliers to go with that hammer.
PETG, ABS, Nylon, there are others which will do the job.
If all you have in your toolbox is a hammer ...
You measured the hole in an end cap not the bore. Some people incorrectly call that the "wipe'. You measured about 1.5mm of clearance on a .22 moderator. What you measured works out real close to 0.057 inches. What is that sixteen or seventeen thou more than your largest reference?
This one which is about 0.344" (just a "RCH" less than 9mm ) is for a 25 caliber Tatsu, something like 1.19mm windage per side? What is that? 0.0937" total over the diameter? ... I can do that with an FDM printer all day long.
That said, you may be confusing things that I said in one thread with things that I said in a different thread. Bore size does have less impact on the performance of a moderator than the hole in the muzzle by far yes. There is a thread here, which you must have misunderstood. Maybe rereading it will help.
Oh, I don't believe you "hate to say it" but no worries opinions being what they are. Never the less you are probably right. I just can't help myself. I'm too stupid to quit so I will endeavor to persevere.
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