#31
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Bottle holder
On Wed, 22 May 2019 06:26:45 +0700, John B.
wrote: please awaken us and tell us exactly what "machine shop" features one requires to drill holes in a thin tube? Probably a V-block and a drill press. I have several of these: https://www.eastwood.com/drill-press-v-block-fixture-center-it.html More of the same: https://www.google.com/search?q=v+block&tbm=isch Add a proper installation tool: https://www.amazon.com/RZX-Riveter-Riveting-Setting-mandrels/dp/B07P7M4BKF/ Also, I suppose a sharp drill bit, which only seems to be found in a machine shop, would be useful. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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#32
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Bottle holder
On Mon, 20 May 2019 12:50:52 -0400, Frank Krygowski
wrote: And there are always hose clamps. https://cloudfront.zoro.com/product/..._J6zyfo5oy.JPG Mine have been holding fine without bringing themselves to my attention for at least thirty years -- I had to go out and look to make sure that that was what was holding my bottle cages on. Put a few turns of handlbar tape around the tube first, to prevent paint scratching and slippage. I'm puzzled by the comment that one could cut oneself on the metal strap. I've been scratched by various bike parts, but the hose clamps have never even thought about it. So I went back to the garage. I found that if I made a special effort, I could touch the corner of the end of one strap, and if I were to push hard, I could probable cut or at least bruise the end of my finger. I think I could see the end of the strap holding the other bottle cage on, but I couldn't touch it. -- Joy Beeson joy beeson at comcast dot net http://wlweather.net/PAGEJOY/ |
#33
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Bottle holder
On Tue, 21 May 2019 18:35:50 -0500, AMuzi wrote:
On 5/21/2019 6:26 PM, John B. wrote: On Tue, 21 May 2019 08:32:02 -0700, sms wrote: On 5/20/2019 5:21 AM, AK wrote: I want to get a bottle holder for my bike. It has no pre-drilled holes for the holder. I found some that clamp on but not sure if they would work with the wide tube that I would need to mount it to. https://www.dropbox.com/s/llqwef4nym...71257.jpg?dl=0 Andy Try these: https://www.amazon.com/dp/B001EIEHEC This web site may help you find a product that will work: http://nordicgroup.us/cageboss/ Well, your vaunted site, that claims to be an expert on rivnuts since 2002 is wrong in their statement that "A properly installed Rivnut does not exert any stress on the inner and outer walls of the tubing. The stress all radiates outward from the splines of the Rivnut into the circumference of the hole.The friction between the splines of the Rivnut and the hole keep it from rotating." There are some twenty, or so, different types of rivnuts today and a number of them do not, in fact, have "splines" and they all do depend on compression to resist torque loads and yes, some of them do have added features to resist torque loads to a even greater extent. You state that "Without a machine shop, It would be very hard for someone to drill perfectly sized holes, perfectly straight, and compress the Rivnut to the exact optimum tightness. In a steel frame it's not a big deal if it's not exactly right. In an aluminum frame it's a very big deal because the integrity of the frame will be compromised. And even if you managed to do it properly, you've still voided your frame warranty" To date, I have seen no evidence that you actually know what you are talking about so please awaken us and tell us exactly what "machine shop" features one requires to drill holes in a thin tube? Oh yes! I quote from the "installation Instructions" of a major supplier of "rivnuts" who says "These blind rivet nuts provide a robust, versatile alternative to standard nuts and bolts. A low profile design provides near-flush installation with no special hole preparation required" You might want to go into some detail about how rivnuts, that were originally designed for and used on aircraft structures, are installed? Do you actually suppose that an entire airplane is hauled into some mythical "machine shop" to have a 1/4" hole drilled in the wing. In fact your entire site is simply one large exhibit of miss-information, or to be less polite, "lies". But, perhaps I am wrong so you might take the time to demonstrate that you actually do know what you are talking about - with some reference to keep you from telling lies, of course. Are you telling me that aircraft rivnuts are assembled without drilling letter D then carefully reaming to a very round 0.25000"? A common 1/4" drill might be good enough for warplanes but risky on a chinese aluminum bicycle! Well, why not just drill, oh say 1/64th undersize and ream with a 1/4" (to use your terminology) drill. I'd probably use metric as I believe that the maker recommends a 7mm hole +0.1 - 0.0 for a M5- 0.8 rivnut . If you use a 0.250 reamer you'll have to wallow out the hole a bit :-) -- cheers, John B. |
#34
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Bottle holder
On Wed, 22 May 2019 07:56:31 +0700, John B.
wrote: On Tue, 21 May 2019 10:26:46 -0700, sms wrote: On 5/21/2019 10:00 AM, Jeff Liebermann wrote: snip $12 for two straps? That seems rather expensive. It is. But a kluge of cable ties and associated bits and pieces is not going to work as well and by the time you buy all the parts you'll spend more time cobbling it together. There are also the Zefal Gizmo clamps https://www.amazon.com/dp/B01MSM1O1H and the Topeak Versa Mount https://www.amazon.com/dp/B077S5G4SL. Above all, don't use hose clamps! And don't drill holes in the frame for Rivnuts. Why ever not? Can you supply us with any evidence that installing a rivnut, or two, significantly weakens a frame? But lets figure it out. Frank tells us that he is a PE which means that he has both the "book learning" and the hands on experience to be an engineer so I'll leave the actual calculations up to him. Material Columbus double butted Niobium alloy seamless tube (The most famous Columbus round set) SL Seat Tube O.D. 31.7mm Wall thickness - 0.5mm Wall thickness at butt - 0.8mm (Note: Butted end for installation in Bottom Bracket) Material - Niobium is a special steel with Manganese, Chrome, Nickel, Molybdenum and Niobium. Mechanical Properties: UTS: 1050÷1150 MPa, Ys = 750MPa, Ap5 14%. Project: Two holes in tube to support bottle cage Holes on 7 cm. centers Fastener: M4 x 0.70 Rivet Nut, Large Flange, Smooth Body Recommended hole size - 6mm +0.1 - 0.0 Or maybe a M5-0.8 rivnut with a recommended hole size of 7mm +0.1-0.0 Questions: (a) actual loss in strength in actual PSI/MPa and % of tube strength lost, and (b) is this considered a significant loss in frame strength? -- cheers, John B. |
#35
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Bottle holder
On Tue, 21 May 2019 18:35:50 -0500, AMuzi wrote:
On 5/21/2019 6:26 PM, John B. wrote: On Tue, 21 May 2019 08:32:02 -0700, sms wrote: On 5/20/2019 5:21 AM, AK wrote: I want to get a bottle holder for my bike. It has no pre-drilled holes for the holder. I found some that clamp on but not sure if they would work with the wide tube that I would need to mount it to. https://www.dropbox.com/s/llqwef4nym...71257.jpg?dl=0 Andy Try these: https://www.amazon.com/dp/B001EIEHEC This web site may help you find a product that will work: http://nordicgroup.us/cageboss/ Well, your vaunted site, that claims to be an expert on rivnuts since 2002 is wrong in their statement that "A properly installed Rivnut does not exert any stress on the inner and outer walls of the tubing. The stress all radiates outward from the splines of the Rivnut into the circumference of the hole.The friction between the splines of the Rivnut and the hole keep it from rotating." There are some twenty, or so, different types of rivnuts today and a number of them do not, in fact, have "splines" and they all do depend on compression to resist torque loads and yes, some of them do have added features to resist torque loads to a even greater extent. You state that "Without a machine shop, It would be very hard for someone to drill perfectly sized holes, perfectly straight, and compress the Rivnut to the exact optimum tightness. In a steel frame it's not a big deal if it's not exactly right. In an aluminum frame it's a very big deal because the integrity of the frame will be compromised. And even if you managed to do it properly, you've still voided your frame warranty" To date, I have seen no evidence that you actually know what you are talking about so please awaken us and tell us exactly what "machine shop" features one requires to drill holes in a thin tube? Oh yes! I quote from the "installation Instructions" of a major supplier of "rivnuts" who says "These blind rivet nuts provide a robust, versatile alternative to standard nuts and bolts. A low profile design provides near-flush installation with no special hole preparation required" You might want to go into some detail about how rivnuts, that were originally designed for and used on aircraft structures, are installed? Do you actually suppose that an entire airplane is hauled into some mythical "machine shop" to have a 1/4" hole drilled in the wing. In fact your entire site is simply one large exhibit of miss-information, or to be less polite, "lies". But, perhaps I am wrong so you might take the time to demonstrate that you actually do know what you are talking about - with some reference to keep you from telling lies, of course. Are you telling me that aircraft rivnuts are assembled without drilling letter D then carefully reaming to a very round 0.25000"? A common 1/4" drill might be good enough for warplanes but risky on a chinese aluminum bicycle! If you ever actually watched a bunch of "tin benders", i.e. aircraft sheet metal workers, actually working you would be appalled. -- cheers, John B. |
#36
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Bottle holder
On Tue, 21 May 2019 17:53:29 -0700 (PDT), Sir Ridesalot
wrote: On Tuesday, May 21, 2019 at 7:26:59 PM UTC-4, John B. wrote: On Tue, 21 May 2019 08:32:02 -0700, sms wrote: On 5/20/2019 5:21 AM, AK wrote: I want to get a bottle holder for my bike. It has no pre-drilled holes for the holder. I found some that clamp on but not sure if they would work with the wide tube that I would need to mount it to. https://www.dropbox.com/s/llqwef4nym...71257.jpg?dl=0 Andy Try these: https://www.amazon.com/dp/B001EIEHEC This web site may help you find a product that will work: http://nordicgroup.us/cageboss/ Well, your vaunted site, that claims to be an expert on rivnuts since 2002 is wrong in their statement that "A properly installed Rivnut does not exert any stress on the inner and outer walls of the tubing. The stress all radiates outward from the splines of the Rivnut into the circumference of the hole.The friction between the splines of the Rivnut and the hole keep it from rotating." There are some twenty, or so, different types of rivnuts today and a number of them do not, in fact, have "splines" and they all do depend on compression to resist torque loads and yes, some of them do have added features to resist torque loads to a even greater extent. You state that "Without a machine shop, It would be very hard for someone to drill perfectly sized holes, perfectly straight, and compress the Rivnut to the exact optimum tightness. In a steel frame it's not a big deal if it's not exactly right. In an aluminum frame it's a very big deal because the integrity of the frame will be compromised. And even if you managed to do it properly, you've still voided your frame warranty" To date, I have seen no evidence that you actually know what you are talking about so please awaken us and tell us exactly what "machine shop" features one requires to drill holes in a thin tube? Oh yes! I quote from the "installation Instructions" of a major supplier of "rivnuts" who says "These blind rivet nuts provide a robust, versatile alternative to standard nuts and bolts. A low profile design provides near-flush installation with no special hole preparation required" You might want to go into some detail about how rivnuts, that were originally designed for and used on aircraft structures, are installed? Do you actually suppose that an entire airplane is hauled into some mythical "machine shop" to have a 1/4" hole drilled in the wing. In fact your entire site is simply one large exhibit of miss-information, or to be less polite, "lies". But, perhaps I am wrong so you might take the time to demonstrate that you actually do know what you are talking about - with some reference to keep you from telling lies, of course. -- cheers, John B. That site that SMS linked to is just one of many reasons why anyone should take ANYTHING he says with a grain of salt. That's because he either outright lies or misrepresents data. Cheers Not to brag but I completed my apprenticeship as a machinist in 1950. I wonder what his qualifications are? -- cheers, John B. |
#37
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Bottle holder
On Tue, 21 May 2019 18:17:57 -0700, Jeff Liebermann
wrote: On Wed, 22 May 2019 06:26:45 +0700, John B. wrote: please awaken us and tell us exactly what "machine shop" features one requires to drill holes in a thin tube? Probably a V-block and a drill press. I have several of these: https://www.eastwood.com/drill-press-v-block-fixture-center-it.html Yes a vee block and a drill press... ever try to squeeze a drill press into a bicycle frame? Maybe https://tinyurl.com/y42ws9q4 More of the same: https://www.google.com/search?q=v+block&tbm=isch Add a proper installation tool: https://www.amazon.com/RZX-Riveter-Riveting-Setting-mandrels/dp/B07P7M4BKF/ Ah yes. But do you notice that this tool is described as "This is the most labor-saving riveting gun on the market" Do we need a "labor saving riveting gun" to install two rivnuts? At $69.98? When ParkTools tells us how to install rivnuts with simple hand tools that almost anyone has already? That would be what? ~$35 a rivnut versus ~$0.00 a rivnut for tooling? Also, I suppose a sharp drill bit, which only seems to be found in a machine shop, would be useful. :-) Why, you can actually buy a brand new, sharp, drill bit at Home Pro or, probably, many other shops. I see a M7 drill bit listed on the Internet at A$3.36. That is Australian dollars, about 1.37, or so to the U.S. dollar. So US$2.45 for a brand new sharp drill bit divided by two holes is $1.22 per hole versus, what did you post? $35 a hole? It appears that Y'all have a very large cache of "disposable income" :-) -- cheers, John B. |
#38
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Bottle holder
On Tue, 21 May 2019 21:21:12 -0400, Joy Beeson
wrote: On Mon, 20 May 2019 12:50:52 -0400, Frank Krygowski wrote: And there are always hose clamps. https://cloudfront.zoro.com/product/..._J6zyfo5oy.JPG Mine have been holding fine without bringing themselves to my attention for at least thirty years -- I had to go out and look to make sure that that was what was holding my bottle cages on. Put a few turns of handlbar tape around the tube first, to prevent paint scratching and slippage. I'm puzzled by the comment that one could cut oneself on the metal strap. I've been scratched by various bike parts, but the hose clamps have never even thought about it. So I went back to the garage. I found that if I made a special effort, I could touch the corner of the end of one strap, and if I were to push hard, I could probable cut or at least bruise the end of my finger. I think I could see the end of the strap holding the other bottle cage on, but I couldn't touch it. One can only assume that some of our illustrious readers are somewhat accident prone :-) -- cheers, John B. |
#39
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Bottle holder
On 5/21/2019 8:56 PM, John B. wrote:
On Tue, 21 May 2019 10:26:46 -0700, sms wrote: On 5/21/2019 10:00 AM, Jeff Liebermann wrote: snip $12 for two straps? That seems rather expensive. It is. But a kluge of cable ties and associated bits and pieces is not going to work as well and by the time you buy all the parts you'll spend more time cobbling it together. There are also the Zefal Gizmo clamps https://www.amazon.com/dp/B01MSM1O1H and the Topeak Versa Mount https://www.amazon.com/dp/B077S5G4SL. Above all, don't use hose clamps! And don't drill holes in the frame for Rivnuts. Why ever not? Can you supply us with any evidence that installing a rivnut, or two, significantly weakens a frame? But lets figure it out. Frank tells us that he is a PE which means that he has both the "book learning" and the hands on experience to be an engineer so I'll leave the actual calculations up to him. Material Columbus double butted Niobium alloy seamless tube (The most famous Columbus round set) SL Seat Tube O.D. 31.7mm Wall thickness - 0.5mm Wall thickness at butt - 0.8mm (Note: Butted end for installation in Bottom Bracket) Material - Niobium is a special steel with Manganese, Chrome, Nickel, Molybdenum and Niobium. Mechanical Properties: UTS: 1050÷1150 MPa, Ys = 750MPa, Ap5 14%. Project: Two holes in tube to support bottle cage Holes on 7 cm. centers Fastener: M4 x 0.70 Rivet Nut, Large Flange, Smooth Body Recommended hole size - 6mm +0.1 - 0.0 Questions: (a) actual loss in strength in actual PSI/MPa and % of tube strength lost, and (b) is this considered a significant loss in frame strength? Actually, I don't think this is calculable. Even approximately calculating the maximum stress in a bike's down tube is difficult without modeling the entire frame using finite element analysis (FEA), and even then you have to make significant assumptions about the magnitude and nature of the loads. If you did use that or some other method to approximate stresses on a plain tube, there are charts to allow approximating the stress concentration factor from a hole in the tube. Something like this: https://classes.mst.edu/civeng110/co...tration/10.gif but for a tube instead of a solid shaft. You'd multiply by that factor to get the new peak stress. BUT that factor, if available, would doubtlessly be for an unreinforced hole. Much of the point of a Rivnut is to reinforce the tube wall where it's installed. The clamping action (and resulting compression stress in the wall) reduce the tendency for fatigue cracks, which is what you'd be worried about. (Fatigue cracks start in tension.) And the extra material of the Rivnut itself provides more reinforcement. Alternately, you could do a very detailed FEA model of the tube plus Rivnut, first to approximate the results of the installation, then to approximate the stress distribution under load. But I suspect your model would need elements as small as a few thousandths of an inch. Set aside some serious computer time for the matrix calculations. That's not going to be done by this (or probably any other) retired PE. If anyone would do it, it would be either NASA or some poor Mechanical Engineering student working on a thesis; and even then, the results couldn't be trusted until they were verified in a lab. In real life, manufacturers would probably do a few prototypes and test them, until they determined that "Yep, these work fine. A Rivnut in a hole is as strong as the original tube without a hole." Once that was settled, only a few wackos would be say "Never use Rivnuts!" Which is where we find ourselves today. -- - Frank Krygowski |
#40
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Bottle holder
On Tue, 21 May 2019 22:47:31 -0400, Frank Krygowski
wrote: On 5/21/2019 8:56 PM, John B. wrote: On Tue, 21 May 2019 10:26:46 -0700, sms wrote: On 5/21/2019 10:00 AM, Jeff Liebermann wrote: snip $12 for two straps? That seems rather expensive. It is. But a kluge of cable ties and associated bits and pieces is not going to work as well and by the time you buy all the parts you'll spend more time cobbling it together. There are also the Zefal Gizmo clamps https://www.amazon.com/dp/B01MSM1O1H and the Topeak Versa Mount https://www.amazon.com/dp/B077S5G4SL. Above all, don't use hose clamps! And don't drill holes in the frame for Rivnuts. Why ever not? Can you supply us with any evidence that installing a rivnut, or two, significantly weakens a frame? But lets figure it out. Frank tells us that he is a PE which means that he has both the "book learning" and the hands on experience to be an engineer so I'll leave the actual calculations up to him. Material Columbus double butted Niobium alloy seamless tube (The most famous Columbus round set) SL Seat Tube O.D. 31.7mm Wall thickness - 0.5mm Wall thickness at butt - 0.8mm (Note: Butted end for installation in Bottom Bracket) Material - Niobium is a special steel with Manganese, Chrome, Nickel, Molybdenum and Niobium. Mechanical Properties: UTS: 1050÷1150 MPa, Ys = 750MPa, Ap5 14%. Project: Two holes in tube to support bottle cage Holes on 7 cm. centers Fastener: M4 x 0.70 Rivet Nut, Large Flange, Smooth Body Recommended hole size - 6mm +0.1 - 0.0 Questions: (a) actual loss in strength in actual PSI/MPa and % of tube strength lost, and (b) is this considered a significant loss in frame strength? Actually, I don't think this is calculable. Even approximately calculating the maximum stress in a bike's down tube is difficult without modeling the entire frame using finite element analysis (FEA), and even then you have to make significant assumptions about the magnitude and nature of the loads. If you did use that or some other method to approximate stresses on a plain tube, there are charts to allow approximating the stress concentration factor from a hole in the tube. Something like this: https://classes.mst.edu/civeng110/co...tration/10.gif but for a tube instead of a solid shaft. You'd multiply by that factor to get the new peak stress. BUT that factor, if available, would doubtlessly be for an unreinforced hole. Much of the point of a Rivnut is to reinforce the tube wall where it's installed. The clamping action (and resulting compression stress in the wall) reduce the tendency for fatigue cracks, which is what you'd be worried about. (Fatigue cracks start in tension.) And the extra material of the Rivnut itself provides more reinforcement. Alternately, you could do a very detailed FEA model of the tube plus Rivnut, first to approximate the results of the installation, then to approximate the stress distribution under load. But I suspect your model would need elements as small as a few thousandths of an inch. Set aside some serious computer time for the matrix calculations. That's not going to be done by this (or probably any other) retired PE. If anyone would do it, it would be either NASA or some poor Mechanical Engineering student working on a thesis; and even then, the results couldn't be trusted until they were verified in a lab. In real life, manufacturers would probably do a few prototypes and test them, until they determined that "Yep, these work fine. A Rivnut in a hole is as strong as the original tube without a hole." Once that was settled, only a few wackos would be say "Never use Rivnuts!" Which is where we find ourselves today. And yet again an acknowledged authority tells us that SMS doesn't know what he is talking about :-) -- cheers, John B. |
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