jcmusic Posted May 9, 2018 Share Posted May 9, 2018 I recently had a machine shop make a Brass pulley for me to try, it is working great but; I am seeing some yellowish dust which I assume is brass. Is this normal? I don't have much knowledge of Brass so I am looking for answers??? Will this stop after a while or not? The belt is made of Mylar.. I have cleaned it off a couple times but it is still producing it... Quote Link to comment Share on other sites More sharing options...
JJkizak Posted May 9, 2018 Share Posted May 9, 2018 5 minutes ago, canyonman said: I recently had a machine shop make a Brass pulley for me to try, it is working great but; I am seeing some yellowish dust which I assume is brass. Is this normal? I don't have much knowledge of Brass so I am looking for answers??? Will this stop after a while or not? The belt is made of Mylar.. I have cleaned it off a couple times but it is still producing it... A nice picture closeup would help. JJK Quote Link to comment Share on other sites More sharing options...
Chris A Posted May 9, 2018 Share Posted May 9, 2018 It's "copper rust." See https://en.wikipedia.org/wiki/Copper(I)_oxide. I'm not sure which kind of brass that you have, and it's clear that you have something that is making continuous contact that's flaking off the oxide layer that forms over time. I'd recommend liberal application of Johnson floor wax followed by polishing, or anything that will form a barrier to atmospheric oxygen without materially changing its appearance and has good wear resistance. I'd recommend periodically refreshing that coating, just like silver plated dinnerware. Chris Quote Link to comment Share on other sites More sharing options...
LarryC Posted May 9, 2018 Share Posted May 9, 2018 Given how precise and well-made those things have to be,, what's the situation with trying to get a replacement from the manufacturer? 1 Quote Link to comment Share on other sites More sharing options...
jcmusic Posted May 9, 2018 Author Share Posted May 9, 2018 6 hours ago, LarryC said: Given how precise and well-made those things have to be,, what's the situation with trying to get a replacement from the manufacturer? Not gonna happen that's why I had one made, the company is gone as far as I know... Quote Link to comment Share on other sites More sharing options...
dirtmudd Posted May 10, 2018 Share Posted May 10, 2018 1 hour ago, canyonman said: Not gonna happen that's why I had one made, the company is gone as far as I know... For what table....? Quote Link to comment Share on other sites More sharing options...
jcmusic Posted May 10, 2018 Author Share Posted May 10, 2018 My TT is a Redpoint Model D, very few of them made I think no two are the same color so I guess that and the price make the numbers small. Quote Link to comment Share on other sites More sharing options...
LarryC Posted May 10, 2018 Share Posted May 10, 2018 What response, or at least what information, do you get from companies that make TT pulleys, like VPI or Basis in the US, as to cost and feasibility? Probably why you turned to a machine shop! I would think it would be pretty horrifying! Can you find a quality used 'table? Naturally, I think of a Basis, but know one of those is probably way off your price list. I'd think that engineering a pulley would be a real chore as to materials, angles and dimensions, and ways to attach to the motor spindle, to think of a few things. Even a standard motor and pulley would have to be precisely matched with the platter diameter, so you're talking whole table+motor. Just thinking out loud.... 1 Quote Link to comment Share on other sites More sharing options...
jcmusic Posted May 10, 2018 Author Share Posted May 10, 2018 8 hours ago, LarryC said: What response, or at least what information, do you get from companies that make TT pulleys, like VPI or Basis in the US, as to cost and feasibility? Probably why you turned to a machine shop! I would think it would be pretty horrifying! Can you find a quality used 'table? Naturally, I think of a Basis, but know one of those is probably way off your price list. I'd think that engineering a pulley would be a real chore as to materials, angles and dimensions, and ways to attach to the motor spindle, to think of a few things. Even a standard motor and pulley would have to be precisely matched with the platter diameter, so you're talking whole table+motor. Just thinking out loud.... Larry, Actually it's not that bad the pulley is a very simple almost flat 1/2" tall held on by a set screw against the shaft. This is an external motor and pod with a belt so you move the motor pod to adjust belt tension. Quote Link to comment Share on other sites More sharing options...
JJkizak Posted May 10, 2018 Share Posted May 10, 2018 40 minutes ago, canyonman said: Larry, Actually it's not that bad the pulley is a very simple almost flat 1/2" tall held on by a set screw against the shaft. This is an external motor and pod with a belt so you move the motor pod to adjust belt tension. The tolerances are so tight on that stuff it almost requires a press fit on the shaft. JJK Quote Link to comment Share on other sites More sharing options...
jcmusic Posted May 10, 2018 Author Share Posted May 10, 2018 35 minutes ago, JJkizak said: The tolerances are so tight on that stuff it almost requires a press fit on the shaft. JJK Well almost the size is 157mm the pulley fits perfectly it is the brass residue that has me concerned... Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted May 10, 2018 Share Posted May 10, 2018 Just curious why brass..? Maybe stainless steel would be a good option or other material that doesn’t oxidize as easily. miketn 1 Quote Link to comment Share on other sites More sharing options...
richieb Posted May 10, 2018 Share Posted May 10, 2018 --- or possibly bronze, bearing bronze specifically. Much higher resistance to corrosion, more expensive but a more industrial material as opposed to standard brass. 1 Quote Link to comment Share on other sites More sharing options...
Don Richard Posted May 10, 2018 Share Posted May 10, 2018 Brass is relatively soft, so bronze, stainless steel, titanium. Quote Link to comment Share on other sites More sharing options...
Skelt Posted May 10, 2018 Share Posted May 10, 2018 Brass and bronze the alloy chart is quite extensive. The Machine shop you used probably chose C 360 for its machinability. Is is very soft and has little strength. C865 is known as high strength yellow brass. C863 has a much higher tensile strength and hardnessC969 is very wear resistant. Those engineered alloys are more expensive but I cannot imagine you need a very large piece of material. They are much more difficult to machine though. Sent from my SM-G900V using Tapatalk Quote Link to comment Share on other sites More sharing options...
LarryC Posted May 10, 2018 Share Posted May 10, 2018 "Brass is relatively soft, so bronze, stainless steel, titanium." It seems to me the TT pulleys I've seen are stainless steel, apparently pressed on. I've never seen a set-screw on a TT pulley and I'd worry about unbalanced rotation even at that slow speed of rotation. I suspect AJ Conti had his reasons to be super-critical about accurate machining, perfect roundness, perfectly balanced rotation, and resonance control, in his remarkable-sounding turntables. 1 Quote Link to comment Share on other sites More sharing options...
jcmusic Posted May 10, 2018 Author Share Posted May 10, 2018 9 hours ago, JJkizak said: The tolerances are so tight on that stuff it almost requires a press fit on the shaft. JJK Yes the original one was a press fit but, they wear out and then you need to have a set screw added. So I just had the shop make it with the set screw, as I said before it is working great I was just not expecting the residue I am seeing... Quote Link to comment Share on other sites More sharing options...
jcmusic Posted May 10, 2018 Author Share Posted May 10, 2018 9 hours ago, mikebse2a3 said: Just curious why brass..? Maybe stainless steel would be a good option or other material that doesn’t oxidize as easily. miketn My other one is made from SS but it is for the smaller shaft motor, this new motor has a larger shaft. Quote Link to comment Share on other sites More sharing options...
jcmusic Posted May 10, 2018 Author Share Posted May 10, 2018 Well the shop said they would make me another from SS if I wanted it, I am gonna see how this brass one works for a while first.. Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted May 10, 2018 Share Posted May 10, 2018 I believe you are seeing the results of a Chemical reaction between the brass and rubber belt and if that’s true it will probably continue and cause deterioration of the belt also. If you google brass reacting with rubber you will see information about issues and reactions. miketn edit: I see you have a Mylar belt which may also be reacting evidenced by the yellowish dust you described. Quote Link to comment Share on other sites More sharing options...
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