jamesp
Cave Dweller
Member since October 2012
Posts: 36,155
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Post by jamesp on Feb 13, 2022 19:26:45 GMT -5
This is the spring arm with no load. It seems to vibrate naturally at about 30hz to 50hz.
This is the spring arm loaded with the hopper clamp. It seems to vibrate naturally at about 4hz to 6hz. And the gravel is moving to the left and climbing the incline with linear excitation! This will hopefully solve the needed rotating action for mixing.
And this is the spring arm completely loaded with exception of tumbles. This one's easy, it does 16 cycles in the 8 second video meaning it is naturally vibrating at 2hz. Shorten the spring arm to stiffen it and it's natural vibration rate will increase greatly. Hopefully the bass shaker can -easily- shake it at 30hz to 150hz after being tuned by shortening it to make it stiffer. And/or a single spring can be connected between say the exciter arm and the base to stiffen the action. A damper/shock absorber could also be added between those two points to soften the vibration for soft rocks. There are other vibration affecting options since there is plenty of space to make mods.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,155
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Post by jamesp on Feb 13, 2022 20:09:35 GMT -5
jamesp I got actual numbers on the Mini Sonic and my memory was incorrect. Here are readings with dial in -- 1. Off position (1w of vampire power) . 2. Lowest power (5w) - test load not moving. 3. Mid power (11w) -- test load moving at a moderate rate 4. Highest power (27w) -- test load moving violently (no slurry to slow things down) I usually run it around mid-power, which is why I remembered the "around 10w" number. To me, this calls into question whether the fundamental design is any more efficient than the Lot-O. My conclusion is that the fundamental design of the Lot-O is much MORE efficient than the Mini-Sonic. Let me explain... With the Lot-O, the fundamental question regarding efficiency is whether an unbalanced rotating mass + springs is an efficient way to make vibrations and transfer them to the load in the barrels. (The answer appears to be YES!). The Lot-O's big efficiency problem is not a fundamental design problem, but rather, it's shaded pole induction motor. Shaded pole motors are low-drama work horses that are also very inefficient -- around 25%. So if the Lot-O uses 100w, 75w are lost as heat and 25W is the output power of the motor. 25w = 1/30 hp -- not a ton of power. My twin barrel Lot-O moves two barrels full of rocks while only drawing around 100w. It uses the same motor as the single barrel Lot-O, it just uses different fans with heavier weights. In the case of the twin barrel Lot-O, it is churching 15 pounds of rocks + media using about 25w of output power. Some of the torque generated by those 25w is overcoming the air resistance created by the fans. (Not the rotating mass of the fans, but the resistance with the air created by the fan blades.) I estimate that it would take about 5w just to spin the fans, so perhaps only 20w, or a little over 1/40 hp of output power, is being used to create vibrations via an off-balance rotating mass. 20w to churn 15 pounds of rocks + media is about 1.3w per pound. (The newer Lot-O tumblers use ball bearings so there should be an insignificant friction loss, which we can assume to be 0 when punching rough numbers. The older ones use sleeve bearings which probably create a little more friction, depending on how often you oil them.) I don't know the efficiency of the mini-sonic at the component level. I do know that it doesn't create much heat. Nothing like the Lot-O motor, which gets HOT. And since there are no moving parts in the Mini-Sonic, there is no friction loss and no fan to spin. I suspect that the solenoid is quite efficient at turning the input power into vibrations. Ironically, the more efficient the solenoid is at turning power into vibrations, the less inherent efficiency in the Mini-Sonic design. I will punch the numbers assuming 50%, 80%, and 90% efficiency for the solenoid with a 4 pound load of rocks + media. At medium power, the Mini-Sonic uses 11w. 50% efficiency = 5.5w of output power churning 4 pounds of rocks at a moderately slow rate = 1.375w per pound 80% efficiency = 8.8w of output power churning 4 pounds of rocks at a moderately slow rate = 2.2w per pound 90% efficiency = 9.9w of output power churning 4 pounds of rocks at a moderately slow rate = 2.475w per pound At high power, it uses 27w. 50% efficiency = 13.5w of output power churning 4 pounds of rocks at a very fast rate = 3.375w per pound 80% efficiency = 21.6w of output power churning 4 pounds of rocks at a very fast rate = 5.4w per pound 90% efficiency = 24.3w of output power churning 4 pounds of rocks at a very fast rate = 6.075w per pound I would say that at medium (half) power the Mini-Sonic churns rocks at about the same speed at the double-barrel Lot-O. But the Lot-O barrel's cone shape creates a traffic jam at the bottom of the barrel, and churning power is used up unclogging the traffic jam. (That is the main reason why the Lot-O works so well in my opinion -- it's all about the barrel shape.) The Mini-Sonic, on the other hand, has a smooth, half rounded hopper which creates no such traffic jam and no additional grinding at the bottom of the barrel. Rocks can church freely without the additional friction created at the bottom of the Lot-O barrel. The barrel shape of the Lot-O would seem to require more power to spin a load than would be required with the barrel shape of the Mini-Sonic. So to conclude, the double barrel Lot-O uses around 20w of output power to create the vibration necessary to church around 15 pounds of rocks + media through two cone shaped barrels. The Mini-Sonic uses somewhere between 5.5w-24.3w of output power (if set between medium and full power, and depending on the efficiency of the solenoid) to church around 4 pounds through a trough shaped hopper. Here's the final thing to consider -- the Lot-O works faster than the Mini-Sonic. In my experience, it might work twice as fast. The Mini-Sonic is a fine polisher, but I find that it takes a very long time to break down 220 SiC (graded) and even takes 3-4 days to break down 500 SiC. 120/220 never seems to break down well in the Mini-Sonic. Whereas I can take rocks from SiC 220 to a high polish in 5-7 days in the Lot-O, I have never done so in less than 10-12 days in the Mini-Sonic. I have used the Lot-O for at least 100 loads, while I have probably only used the Mini-Sonic 10-15 times. I am very familiar with the Lot-O, but I claim no expertise with to the MIni-Sonic. Perhaps I am doing something wrong for it to take so long. Here's the bottom line: I believe that the fundamental design of the the Lot-O (unbalanced rotating mass + springs + barrel shape) is high-efficiency and high-effective design for a vibe tumbler. The Lot-O's only handicap is that it uses inefficient 100 year old motor technology. A highly efficient brushless DC motor should be able to run a double barrel Lot-O while using no more than 30-40w of input power. A smaller sized motor with a lighter rotating mass and less stiff springs (maybe?), should be able to run the single barrel Lot-O while using only 15-20w of input power. Not only are brushless DC motors high efficient (and speed controllable), but you wouldn't need cooling fans, which would eliminate another inefficiency in the Lot-O's factory design. I'm sure there are some small logical flaws and/or math mistakes in the above analysis, but I think my fundamental point is a valid one. Thoughts? This is a very thorough analysis Jonathan. Blown away by the detail of your findings. As far as power usage both Lot-O and Mini-Sonic seem to be totally miserly. I know you are into energy efficiency as it relates to your sophisticated wood heating system you built. Both those machines pass in flying colors IMO. A+ Your point about the Lot-O barrel shape hits home with me too. It is egg shape and each rotation of the rocks forces a high friction mixing path whereas the Mini-Sonic is a perfect cylinder with a vent on top. The cylinder shape offers much less forced mixing than the rocks rotating in an egg shaped hopper. That has to make a big difference. Egg shape gets an A+. The next step to look into is simply the rate of vibration. This thread is just about that. Hoping to break the standard 3000 to 3600 vibrations per minute(50hz to 60hz) every vibe on the market operates at due to 3000 to 3600 rpm motors(the Sonic is adjustable to 3600) and move into 5000 to 10,000 vibrations per minute(80hz to 170hz) with high response controlled amplitude and vibration characteristics. You mentioned ECM's, they can do the trick too because they can easily spin over 3600 rpm to well over 15,000 rpm with a controller. That is another way to increase the vibration rate. Keep in mind a motor is limited to fixed shape sinusoidal mechanical vibration output where a speaker type coil can produce variable sine, step, saw tooth, triangle, etc.(basically infinite) waveforms at extremely high response rates because that is what they have to do to make music. Industrial vibes all use motors probably because large coil type electrical high horsepower linear actuators would generate too much heat. Many of them have adjustable counterweights to change the sine wave shape and adjustable speeds to vary the frequency. It is difficult to say much about the power usage of a linear actuated coil type electromagnet. It seems efficient judging from the forces stereo speakers emit. A 25 watt amp cranking speakers at full volume creates a heck of a disturbance.
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Post by holajonathan on Feb 13, 2022 20:26:57 GMT -5
jamesp I got actual numbers on the Mini Sonic and my memory was incorrect. Here are readings with dial in -- 1. Off position (1w of vampire power) . 2. Lowest power (5w) - test load not moving. 3. Mid power (11w) -- test load moving at a moderate rate 4. Highest power (27w) -- test load moving violently (no slurry to slow things down) I usually run it around mid-power, which is why I remembered the "around 10w" number. To me, this calls into question whether the fundamental design is any more efficient than the Lot-O. My conclusion is that the fundamental design of the Lot-O is much MORE efficient than the Mini-Sonic. Let me explain... With the Lot-O, the fundamental question regarding efficiency is whether an unbalanced rotating mass + springs is an efficient way to make vibrations and transfer them to the load in the barrels. (The answer appears to be YES!). The Lot-O's big efficiency problem is not a fundamental design problem, but rather, it's shaded pole induction motor. Shaded pole motors are low-drama work horses that are also very inefficient -- around 25%. So if the Lot-O uses 100w, 75w are lost as heat and 25W is the output power of the motor. 25w = 1/30 hp -- not a ton of power. My twin barrel Lot-O moves two barrels full of rocks while only drawing around 100w. It uses the same motor as the single barrel Lot-O, it just uses different fans with heavier weights. In the case of the twin barrel Lot-O, it is churching 15 pounds of rocks + media using about 25w of output power. Some of the torque generated by those 25w is overcoming the air resistance created by the fans. (Not the rotating mass of the fans, but the resistance with the air created by the fan blades.) I estimate that it would take about 5w just to spin the fans, so perhaps only 20w, or a little over 1/40 hp of output power, is being used to create vibrations via an off-balance rotating mass. 20w to churn 15 pounds of rocks + media is about 1.3w per pound. (The newer Lot-O tumblers use ball bearings so there should be an insignificant friction loss, which we can assume to be 0 when punching rough numbers. The older ones use sleeve bearings which probably create a little more friction, depending on how often you oil them.) I don't know the efficiency of the mini-sonic at the component level. I do know that it doesn't create much heat. Nothing like the Lot-O motor, which gets HOT. And since there are no moving parts in the Mini-Sonic, there is no friction loss and no fan to spin. I suspect that the solenoid is quite efficient at turning the input power into vibrations. Ironically, the more efficient the solenoid is at turning power into vibrations, the less inherent efficiency in the Mini-Sonic design. I will punch the numbers assuming 50%, 80%, and 90% efficiency for the solenoid with a 4 pound load of rocks + media. At medium power, the Mini-Sonic uses 11w. 50% efficiency = 5.5w of output power churning 4 pounds of rocks at a moderately slow rate = 1.375w per pound 80% efficiency = 8.8w of output power churning 4 pounds of rocks at a moderately slow rate = 2.2w per pound 90% efficiency = 9.9w of output power churning 4 pounds of rocks at a moderately slow rate = 2.475w per pound At high power, it uses 27w. 50% efficiency = 13.5w of output power churning 4 pounds of rocks at a very fast rate = 3.375w per pound 80% efficiency = 21.6w of output power churning 4 pounds of rocks at a very fast rate = 5.4w per pound 90% efficiency = 24.3w of output power churning 4 pounds of rocks at a very fast rate = 6.075w per pound I would say that at medium (half) power the Mini-Sonic churns rocks at about the same speed at the double-barrel Lot-O. But the Lot-O barrel's cone shape creates a traffic jam at the bottom of the barrel, and churning power is used up unclogging the traffic jam. (That is the main reason why the Lot-O works so well in my opinion -- it's all about the barrel shape.) The Mini-Sonic, on the other hand, has a smooth, half rounded hopper which creates no such traffic jam and no additional grinding at the bottom of the barrel. Rocks can church freely without the additional friction created at the bottom of the Lot-O barrel. The barrel shape of the Lot-O would seem to require more power to spin a load than would be required with the barrel shape of the Mini-Sonic. So to conclude, the double barrel Lot-O uses around 20w of output power to create the vibration necessary to church around 15 pounds of rocks + media through two cone shaped barrels. The Mini-Sonic uses somewhere between 5.5w-24.3w of output power (if set between medium and full power, and depending on the efficiency of the solenoid) to church around 4 pounds through a trough shaped hopper. Here's the final thing to consider -- the Lot-O works faster than the Mini-Sonic. In my experience, it might work twice as fast. The Mini-Sonic is a fine polisher, but I find that it takes a very long time to break down 220 SiC (graded) and even takes 3-4 days to break down 500 SiC. 120/220 never seems to break down well in the Mini-Sonic. Whereas I can take rocks from SiC 220 to a high polish in 5-7 days in the Lot-O, I have never done so in less than 10-12 days in the Mini-Sonic. I have used the Lot-O for at least 100 loads, while I have probably only used the Mini-Sonic 10-15 times. I am very familiar with the Lot-O, but I claim no expertise with to the MIni-Sonic. Perhaps I am doing something wrong for it to take so long. Here's the bottom line: I believe that the fundamental design of the the Lot-O (unbalanced rotating mass + springs + barrel shape) is high-efficiency and high-effective design for a vibe tumbler. The Lot-O's only handicap is that it uses inefficient 100 year old motor technology. A highly efficient brushless DC motor should be able to run a double barrel Lot-O while using no more than 30-40w of input power. A smaller sized motor with a lighter rotating mass and less stiff springs (maybe?), should be able to run the single barrel Lot-O while using only 15-20w of input power. Not only are brushless DC motors high efficient (and speed controllable), but you wouldn't need cooling fans, which would eliminate another inefficiency in the Lot-O's factory design. I'm sure there are some small logical flaws and/or math mistakes in the above analysis, but I think my fundamental point is a valid one. Thoughts? This is a very thorough analysis Jonathan. Blown away by the detail of your findings. As far as power usage both Lot-O and Mini-Sonic seem to be totally miserly. I know you are into energy efficiency as it relates to your sophisticated wood heating system you built. Both those machines pass in flying colors IMO. A+ Your point about the Lot-O barrel shape hits home with me too. It is egg shape and each rotation of the rocks forces a high friction mixing path whereas the Mini-Sonic is a perfect cylinder with a vent on top. The cylinder shape offers much less forced mixing than the rocks rotating in an egg shaped hopper. That has to make a big difference. Egg shape gets an A+. The next step to look into is simply the rate of vibration. This thread is just about that. Hoping to break the standard 3000 to 3600 vibrations per minute(50hz to 60hz) every vibe on the market operates at due to 3000 to 3600 rpm motors(the Sonic is adjustable to 3600) and move into 5000 to 10,000 vibrations per minute(80hz to 170hz) with high response controlled amplitude and vibration characteristics. You mentioned ECM's, they can do the trick too because they can easily spin over 3600 rpm to well over 15,000 rpm with a controller. That is another way to increase the vibration rate. Keep in mind a motor is limited to fixed shape sinusoidal mechanical vibration output where a speaker type coil can produce variable sine, step, saw tooth, triangle, etc.(basically infinite) waveforms at extremely high response rates because that is what they have to do to make music. Industrial vibes all use motors probably because large coil type electrical high horsepower linear actuators would generate too much heat. Many of them have adjustable counterweights to change the sine wave shape and adjustable speeds to vary the frequency. It is difficult to say much about the power usage of a linear actuated coil type electromagnet. It seems efficient judging from the forces stereo speakers emit. A 25 watt amp cranking speakers at full volume creates a heck of a disturbance. How cool would it be if you could use audio files to create vibe tumbling recipes that would be shared with others? The hardware would have to be the same, I suppose. But I love the idea of being able to experiment with frequencies, amplitude, and durations, and then being able to share the exact "recipe" with someone else.
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Brian
fully equipped rock polisher
Member since July 2020
Posts: 1,506
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Post by Brian on Feb 13, 2022 20:37:35 GMT -5
This is a very thorough analysis Jonathan. Blown away by the detail of your findings. As far as power usage both Lot-O and Mini-Sonic seem to be totally miserly. I know you are into energy efficiency as it relates to your sophisticated wood heating system you built. Both those machines pass in flying colors IMO. A+ Your point about the Lot-O barrel shape hits home with me too. It is egg shape and each rotation of the rocks forces a high friction mixing path whereas the Mini-Sonic is a perfect cylinder with a vent on top. The cylinder shape offers much less forced mixing than the rocks rotating in an egg shaped hopper. That has to make a big difference. Egg shape gets an A+. The next step to look into is simply the rate of vibration. This thread is just about that. Hoping to break the standard 3000 to 3600 vibrations per minute(50hz to 60hz) every vibe on the market operates at due to 3000 to 3600 rpm motors(the Sonic is adjustable to 3600) and move into 5000 to 10,000 vibrations per minute(80hz to 170hz) with high response controlled amplitude and vibration characteristics. You mentioned ECM's, they can do the trick too because they can easily spin over 3600 rpm to well over 15,000 rpm with a controller. That is another way to increase the vibration rate. Keep in mind a motor is limited to fixed shape sinusoidal mechanical vibration output where a speaker type coil can produce variable sine, step, saw tooth, triangle, etc.(basically infinite) waveforms at extremely high response rates because that is what they have to do to make music. Industrial vibes all use motors probably because large coil type electrical high horsepower linear actuators would generate too much heat. Many of them have adjustable counterweights to change the sine wave shape and adjustable speeds to vary the frequency. It is difficult to say much about the power usage of a linear actuated coil type electromagnet. It seems efficient judging from the forces stereo speakers emit. A 25 watt amp cranking speakers at full volume creates a heck of a disturbance. How cool would it be if you could use audio files to create vibe tumbling recipes that would be shared with others? The hardware would have to be the same, I suppose. But I love the idea of being able to experiment with frequencies, amplitude, and durations, and then being able to share the exact "recipe" with someone else. That's an interesting idea, Jonathan. Not only could it be tailored to different stages (more agressive in the early stages --> less agressive in polish), but it could also be programmed to quickly generate slurry and then taper off in aggressiveness as the stage proceeds. With such an easily manipulated vibration source, the possibilities are endless.
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Post by holajonathan on Feb 13, 2022 22:37:55 GMT -5
How cool would it be if you could use audio files to create vibe tumbling recipes that would be shared with others? The hardware would have to be the same, I suppose. But I love the idea of being able to experiment with frequencies, amplitude, and durations, and then being able to share the exact "recipe" with someone else. That's an interesting idea, Jonathan. Not only could it be tailored to different stages (more agressive in the early stages --> less agressive in polish), but it could also be programmed to quickly generate slurry and then taper off in aggressiveness as the stage proceeds. With such an easily manipulated vibration source, the possibilities are endless. Someone could develop a whole list of "tracks" (really just programs) for specific uses. For example: final polish with fragile material. Or, polish with 95 ceramics + 3 or 4 cabochons. No need to make the tracks longer than a few second each, provided that the playback device has a "loop [X] times function." I have experimented a lot with tweaking the function of my Lot-O tumbler depending on how I am using it. I replaced the original Lot-O tuning bar (wooden dowel rod) with a plastic rod made from a slippery but durable plastic. (Acetyl copolymer, I think). Now, I slide it around regularly depending on what I am doing. Just the other day, I wanted to remove saw marks from some small 1/4" thick Montana agate slabs. I threw about 20 into the Lot-O with a ton of ceramics and moved the tuning rod to the position where it sends max vibrations to the barrel -- right before the point where the whole machine starts buzzing and breaks the springs After about 12 hours with 1 TBS of SiC 220 grit and the saw marks were all gone. A very thick slurry had developed for such a short time, and the slabs had at least a 500 grit finish. This would have taken 24-36 hours with the original Lot-O tune. The hangup is that without identical (and perhaps even calibrated) hardware, the same input would not generate the same output. You could still use the same "programs" (audio tracks) with different hardware, but experimentation would be required to determine their function and best use. jamesp owns a metal fabrication business and is a very capable engineer and fabricator. So once he develops a great design, he can produce about 100 of them for sale to RTH members. It could be the official RTH vibe tumbler, and we could all share tumbling recipes the 21st century way. What say you, Jim? I'll be your first customer.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,155
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Post by jamesp on Feb 14, 2022 8:28:51 GMT -5
Y'all can run with this one. Any input or fabrications I come with are yours to do with as you will. It is good to see others running with the concept and can see the endless applications. As with most vibes the devil is in the mechanical design to achieve optimum vibration dynamics. Don't let that part of the equation be taken lightly. My motivation is to make a vibe with minimal components and the most basic of spring systems. Not one factory made vibe did not utilize an engineer familiar with vibration analysis and design. And use a vibration analyzer in the process. I am not one of those people. I have used vibration analysis diagnostic instrumentation for locating damaged bearings. But that is not much different than plugging a diagnostic computer to a modern automobile. There is probably not any data on accel/decel, velocity, amplitude, frequency, etc parameters for lapidary out there. Just be aware that every vibe out there is likely a sine wave vibration which is likely the best waveform for the application. And be aware that sharp reversals in a vibe generate deceptively powerful forces that will easily damage the surfaces of our rocks. In this chart the safer sine waves are the lower amplitude(flatter)waves. They all have the same frequency. The taller waves have sharper reversals that WILL damage rock surfaces. The unknown is 'how flat' the wave should be. A quantity. Since I have fabrication tools I am open to giving the mechanical design a try for the team. Tim has about got me fixed up with the shaker controls for testing. Maybe others will attempt some mechanical set ups.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,155
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Post by jamesp on Feb 14, 2022 11:42:38 GMT -5
holajonathan I wanted to mention something about this tumble you did. It has to do with loading the hopper with ceramics and the effects of different types of ceramics. "I threw about 20(Montana agates) into the Lot-O with a ton of ceramics and moved the tuning rod to the position where it sends max vibrations to the barrel -- right before the point where the whole machine starts buzzing and breaks the springs" The high percent ceramic fill has rarely been discussed on RTH. I believe cab makers keep a vibe loaded with ceramics just to polish a handful of cabs. 1st point: Our quartz has a density of +/- 2.6 grams per ml White AO ceramics(like Rock Shed's) has a density of +/- 3.8 grams per ml So a 4 pound capacity Lot-O barrel filled with AO ceramics weighs 3.8/2.6 x 4 pounds = 5.8 pounds. Taking the density issue to extremes...Zirconium ceramics are known for their super high density of up to 5.9 grams per ml. They are used in industrial vibes for 'shot peening' steel surfaces because of the increased dynamic forces.(it is only Mohs 8) A Lot-O barrel full of zirconium oxide would weigh a whopping 5.9/2.6 x 4 pounds = 9 pounds. Zirconia media is avoided when tumbling aluminum parts because it deforms aluminum surfaces in many cases. Going back to the heavy hopper, increasing the hopper weight to that degree can have negative effects on the mechanical system. example in hand: I bought in a box of used Zirconium oxide media and filled the 14 pound Vibrasonic barrel to smooth the sharp edges and it weighed about 30 pounds. I would have never noticed till I picked it up to install it on the Vibrasonic table and noticed the extreme weight difference. The excessive weight also overloaded the motor which kicked the thermal breaker. And I about burned my fingers when I stuck them down in the zirconia coated with super hot slurry coating(the 1/3hp motor heats up the tumbles being enclosed just below the hopper. The motor was seriously HOT). 2nd point: If you want to put a fast track finish on agate use 70-80-90% AO ceramic media. Not only does the increased density increase the abrasive action(if it doesn't damage the rock surfaces) but most ceramic media we use is aluminum oxide ceramic with a hardness of just over Mohs 9. That is why it wears so slowly. The ceramic media accelerates finishing both because of it's higher weight and it's extreme hardness. The ceramic medias used in industrial vibes are highly application dependant. Some AO ceramic media is fused with small particles for finishing and polishing, some are fused together with larger particles for high removal rates. However either one will obtain a polish after use. ETA - Zirconia media is only Mohs 8 and is slow to abrade/polish Mohs 7 rocks. about useless for Mohs 7 rocks. It is tough, i.e. much less brittle than AO ceramic media. Both are tougher than quartz though. The zirconia was the first ceramic media to abrade the blue polyurethane coated hopper also. Blue polyurethane particles were mixed in with the slurry. A first.
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Post by RickB on Feb 14, 2022 12:36:52 GMT -5
Use a JBL with blue tooth - frequency test
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,423
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Post by Wooferhound on Feb 14, 2022 15:08:21 GMT -5
Use a JBX with blue tooth - frequency test
That looks like the way that Blue Man Group ends all their shows . Sounds like it would tumble some rocks too .
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,423
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Post by Wooferhound on Feb 14, 2022 17:08:23 GMT -5
Use a JBX with blue tooth - frequency test
That looks like the way that Blue Man Group ends all their shows . Sounds like it would tumble some rocks too .
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quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,341
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Post by quartz on Feb 15, 2022 0:25:28 GMT -5
I've been watching your project closely and with great interest. Looks like collectively you are coming up with something really new and interesting, wish time would allow me to maybe a part of it too, lots for me to learn. jamesp, looking at your spring arm idea, may I toss an idea into the mix? Hopefully the sketch is meaningful; a couple pieces of square stock joined by 2 little pieces of maybe keystock to form a slot, then welded at an angle of your choice to the end of the base plate, thereby making your spring arm easily adjustable for length. Based on what I learned from making the little vibes I built, you will end up needing all the versatility of adjustment you can build into the machine to get it to run properly. Another thought too, attaching the arm mechanically rather than welding the spring arm solid would likely reduce the likelyhood of the constant vibration acting to fatigue the metal at the weld joint and break the arm off. My 2cts.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,155
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Post by jamesp on Feb 15, 2022 2:42:41 GMT -5
Please bring on the ideas quartz. You know this stuff. An adjustable arm would be a big help. Yes. Especially during the tuning process. Just like some musical instruments are adjustable - guitar strings for example. I have key stock, have made such sliding mechanisms before. Thanks. For setting up various geometries in a hurry welds will work. If a working geometry is found the joinery can be altered. It would be nice to have clamping adjustable ***angles too. They would need a heck of a clamp. It is the geometry and general design I need help with. I have great random tight vibrational rock movement but am challenged to get the rocks to ***roll. But am only on the first geometry set up...there are infinite numbers of variations. Am hellbent on using the strip steel springs for simplicity of varying the build and cheap cost. They are mild steel, not spring steel. This may be a wrong path...but prototype vibration at hopper is very desirable. Lots of vibrational energy. Just no roll... Today I shortened the 8" vibration arm to 4" and switched from 2"x1/8" to 2"x3/16" and it made a big difference in high speed tight vibration movement in the hopper. Running strong double welds for super rigidity. The strip springs have great high speed short travel high energy vibrational performance. Don't touch your teeth to it ! The mechanical design may be more of a challenge than I expected. I have been placing the head of a 9000 rpm grinder with an intentionally off-balance grinding wheel against the vibration shaking point. It does a quickie job of vibrating prototypes at high frequencies in a crude fashion. All it takes is a few seconds to see the action. I'm sure you are aware of how much a 4.5" angle grinder with an off-balance grinding wheel or wire wheel can numb your hands and wrists ! The edge of the spinning wire wheel pushed against the edge of the vibrating plate will transmit some really high frequency vibrations. There may be capacity limitations, don't know. If it doubles or triples the finishing speed who cares.
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quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,341
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Post by quartz on Feb 15, 2022 14:35:38 GMT -5
jamesp, have you tried or given thought to putting the shaker between the base plate and the "tumbler barrel", again a sliding means would give quicker answers than re-fabbing the thing. To me this is a little like a pump, pushes better than pulls. Apologies for the big white space on my sketch, my scanner doesn't give a real accurate picture before posting, thought I had it down tighter to the drawing.
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,423
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Post by Wooferhound on Feb 16, 2022 8:10:20 GMT -5
Been having some car trouble which was slowing things a bit. Working much better now . . .
In my early testing the machine was very well behaved and did not vibrate very much. I have everything setup on an unused dining room table that can Not Be Damaged according to the Boss.
As soon as I tried to put on Hoppers weighted with rocks, everything got much More Aggressive and stuff wanted to bounce around a lot. I can't keep testing on this table, but I don't have a lot of options for placement around here.
Thinking this must be mounted down to a Heavy Block to get proper motion. The Voice coil is actively Pushing Up then alternately Pulling Down.
I'm making a 4 inch Hopper this morning. Should get both of my new Oscillators in the Mail Tomorrow.
Starting to get serious around here . . .
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jamesp
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Post by jamesp on Feb 16, 2022 8:40:24 GMT -5
jamesp, have you tried or given thought to putting the shaker between the base plate and the "tumbler barrel", again a sliding means would give quicker answers than re-fabbing the thing. To me this is a little like a pump, pushes better than pulls. Apologies for the big white space on my sketch, my scanner doesn't give a real accurate picture before posting, thought I had it down tighter to the drawing. Hand drawing is a gift. Thanks. No matter how much space it takes up, computers don't care ! Yes. This idea of reversing them is on the attack list Mr. Larry. No big deal to cut and re-weld that arrangement. I have lots of scrap, it is easier to simply weld up a new design each time than cutting and re-welding. I can see a dozen prototypes piled up for the scrap metal guy to pick up lol. I am waiting on cables for connecting the bass shaker before proceeding with alterations at this point. It generates it's own vibration type and I need to cater the designs to it's characteristics. It may not have enough shaking power for the strip steel designs... I use a lot of various thicknesses of 1.5" and 2" and 2.5" strip steel for the center ring of my fire pits. So I have about 7 different variations of those strip steels. The hardness(annealed state) this strip steel is critical as a I have to bend them into 6-8-10-12-14 inch circles on a hand bender. Hot rolled strip is real soft and bendable. But it is rarely hot rolled by itself anymore. Now they shear strips off of coiled sheet and the process hardens the hell out of the strips to spring like steel. I often have to pile the strips on the ground and build a large fire on them to anneal them. Just saying that the strip steel I am using is basically medium hardened common mild steel that is not brittle even at the weld.
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jamesp
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Post by jamesp on Feb 16, 2022 8:58:50 GMT -5
Been having some car trouble which was slowing things a bit. Working much better now . . .
In my early testing the machine was very well behaved and did not vibrate very much. I have everything setup on an unused dining room table that can Not Be Damaged according to the Boss. As soon as I tried to put on Hoppers weighted with rocks, everything got much More Aggressive and stuff wanted to bounce around a lot. I can't keep testing on this table, but I don't have a lot of options for placement around here. Thinking this must be mounted down to a Heavy Block to get proper motion. The Voice coil is actively Pushing Up then alternately Pulling Down. I'm making a 4 inch Hopper this morning. Should get both of my new Oscillators in the Mail Tomorrow.
Starting to get serious around here . . .
Good luck Tim. If you are like me you might find the mechanical design a challenge. I chose to build the vibration components hanging out on a bouncy strip steel arm in an attempt to isolate the vibrations from the base. Bowl vibes are isolated(free standing), they don't depend on a heavy foundation, as is the Vibrasonic and Mini-sonic. It is the Lot-o that needs a heavy foundation but take heed - it is about the best performing vibe out there. If you want me to send the Mini-Sonic hopper just let me know. It's yours if you want it. It is heavy for a 4 pound hopper. But any hopper is going to weigh a good bit when loaded with rocks ! For this project I chose to keep it small at a 4 pound hopper till it is known how powerful the speakers and bass shakers are. Bass shakers mounted on chairs are often mounted on an extension arm(then to the centerpost of the chair). This extension arm is like a longer wrench, it gives more leverage to intensify the strength of the vibrations. Something to consider if the bass shakers/speaker lacks power to shake 4 pounds of rock...
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jamesp
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Post by jamesp on Feb 16, 2022 10:15:35 GMT -5
quartz If it is a hassle to post drawings we will do fine without them. Your verbal description is easy to interpret.(hint hint) keep sending ideas . Both of your suggestions are in line with what may be the way to go. The 6" pipe is numbing a bit of the transmitted vibration(some of the vibration energy is being dissipated in the 2/3rds pipe section 'saddle'). That changes a good bit when the plastic hopper is pressed into the saddle though. However the saddle will become rigid once the clamping all-thread is installed and tightened on to the hoppers. May not matter then. clamping screws like this one used on the Vibrasonic(I cut the dang pipe saddle too short to have room for the screws, may make another):
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quartz
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breakin' rocks in the hot sun
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Post by quartz on Feb 17, 2022 0:00:19 GMT -5
Wooferhound, the 4" vibe tumbler I built a few years ago had 2 concrete block cap blocks bolted to the base frame [lead anchors installed in the blocks] one each end, giving about 65 lbs. of "ballast." The 10"dia.x 12" long one I'm working on now has 4 of those blocks in the base frame,130 lbs., w/o the ballast it would walk right out of the building and also have very little rock rolling activity. The blocks also have to be held in the base or they will take off. I'm getting a pretty good roll with glass now but running a way too much motor, working at mounting much smaller one.
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jamesp
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Post by jamesp on Feb 17, 2022 6:59:10 GMT -5
Check out the reciprocating movement using pivot arms of a typical vibratory conveyor. It tosses the tumbles both up and to the right as it advances back to the left while tumbles are floating in air to carry another load to the right. It depends on gravity to pull the tumbles back down. On this unit the shaking is done purely by a direct drive crankshaft(eccentric)instead of a counterweight. *Basically linear vibration motion... Some of these units do use motors with counterweights mounted strategically to provide the shaking but also use the same two pivot arm principle. Replace the flat conveyor table with a cylindrical or oval or egg shaped hopper and the rocks should roll in the hopper readily.
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jamesp
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Post by jamesp on Feb 17, 2022 7:19:20 GMT -5
This vibratory conveyor uses a pure linear vibration exciter, basically a bass shaker/speaker type coil. 2 linkage pivot design. However it appears the pivot arms are some form of fixed length flexible material that flexes left/right and right/left. This is interesting. This could be done on a small scale.(again replace table with properly shaped hopper).
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