A short video about my experience so far balancing the four different diamond discs for my tiny grinder. royalty-free music: Tim Taj - Moments together Scott Buckley - Jul
A thoroughly enjoyable video, I have really enjoyed this series😊 I haven't done it for a few years but I remember it is possible to calculate the size and position of the imbalance mathematically using the static and dynamic balancing equations, and also graphically I believe, especially now you have the mass and the radius of the mass of putty you used to find equilibrium. I have a loose theory you could potentially able to calculate the mass to balance the system at a set radius, allowing you to add the mass on the arbor? Not 100% sure but seems like a good way to be able to fine tune it. This could give you solid data so you can achieve the level of accuracy you were aspiring for
I'm not sure about that Mark. If we forget for a moment that all material is deformable (elastic and plastic), then the contact surface between the two round shafts is zero, just like the surface between a shaft and such a blade. So the question in my opinion is, what setup will produce the most deformation. This deformation leads to a tiny contact surface area and is a major contributor to the friction because that distortion consumes energy and thus slows down. In theory, a razor-sharp thin cutting edge would deform heavily under the pressure of the shaft, due to an more unfavorable shape compared to a 'blunt' but smooth surface. But I don't have such blades, and it also seems to me very difficult to manufacture them really straight, so I can't test it.
@@Michel-Uphoff Razor thin is never used. Approximately 0.5mm edge, honed smooth. This is usually a hardened steel, or HSS. Principles of operation are the same.
@@KravchenkoAudioPerth I exaggerated it to make clear that somewhere there must be a goldilocks zone between a flat surface and a razor sharp edge. I could be that an .5mm edge makes the axle run smoother than a 8 mm shaft (of course with comparable surface finish and hardness), or the difference may be negligible in practice. I just don't know, didn't test that.
Dat heb ik gedaan (Ik heb ze met diamantpasta gelept) , maar echt helemaal zonder schokjes laten rollen is toch erg moeilijk. Desalniettemin is het wel gelukt om alle slijpschijven netjes uit te balanceren. Mogelijk stelde ik wat te hoge eisen, want ik wilde een vrijwel perfecte rolbeweging,
@@Michel-Uphoff Misschien de as waarmee je rolt dikker nemen ??? Ik heb zelf zo een as en dacht van rond 30mm . Ik vind het trouwens een mooie oplossing met die kneedbare pasta !!!!
Ook gedaan, met die 40 mm as die je in de video ziet. Dat maakte wel wat uit, maar in negatieve zin, want de as was zo zwaar dat de milligrammen onbalans te weinig bleken voor rotatie.
A thoroughly enjoyable video, I have really enjoyed this series😊 I haven't done it for a few years but I remember it is possible to calculate the size and position of the imbalance mathematically using the static and dynamic balancing equations, and also graphically I believe, especially now you have the mass and the radius of the mass of putty you used to find equilibrium. I have a loose theory you could potentially able to calculate the mass to balance the system at a set radius, allowing you to add the mass on the arbor? Not 100% sure but seems like a good way to be able to fine tune it. This could give you solid data so you can achieve the level of accuracy you were aspiring for
Nice deep dive.
Hi Uphoff, lot´s off info on the subject. Many Thanks !
Nicely done Michel. If you had chosen knife edge supports like planar blades you would have much less friction no?
Mark
I'm not sure about that Mark.
If we forget for a moment that all material is deformable (elastic and plastic), then the contact surface between the two round shafts is zero, just like the surface between a shaft and such a blade. So the question in my opinion is, what setup will produce the most deformation. This deformation leads to a tiny contact surface area and is a major contributor to the friction because that distortion consumes energy and thus slows down. In theory, a razor-sharp thin cutting edge would deform heavily under the pressure of the shaft, due to an more unfavorable shape compared to a 'blunt' but smooth surface.
But I don't have such blades, and it also seems to me very difficult to manufacture them really straight, so I can't test it.
@@Michel-Uphoff Razor thin is never used. Approximately 0.5mm edge, honed smooth. This is usually a hardened steel, or HSS. Principles of operation are the same.
@@KravchenkoAudioPerth I exaggerated it to make clear that somewhere there must be a goldilocks zone between a flat surface and a razor sharp edge. I could be that an .5mm edge makes the axle run smoother than a 8 mm shaft (of course with comparable surface finish and hardness), or the difference may be negligible in practice. I just don't know, didn't test that.
Dag Michel, ik ben benieuwd of je al plannen heb om de assen aan te passen dat het rollen beter gaat ?
Dat heb ik gedaan (Ik heb ze met diamantpasta gelept) , maar echt helemaal zonder schokjes laten rollen is toch erg moeilijk. Desalniettemin is het wel gelukt om alle slijpschijven netjes uit te balanceren. Mogelijk stelde ik wat te hoge eisen, want ik wilde een vrijwel perfecte rolbeweging,
@@Michel-Uphoff Misschien de as waarmee je rolt dikker nemen ??? Ik heb zelf zo een as en dacht van rond 30mm . Ik vind het trouwens een mooie oplossing met die kneedbare pasta !!!!
Ook gedaan, met die 40 mm as die je in de video ziet. Dat maakte wel wat uit, maar in negatieve zin, want de as was zo zwaar dat de milligrammen onbalans te weinig bleken voor rotatie.
@@Michel-Uphoff Snap ik .Tis idd niet eenvoudig. Maar een leuk experiment . Bedankt