Bill Space
05-07-2013, 6:16 PM
Hi,
I saw mention in previous thread(s) that the saw stop system somehow checks itself and can determine if it is functional or not. This was related to the question about painted blades possibly insulating themselves from the main part of the saw (electrically).
I can see how the SS system could be set up to check for something that might be touching the blade when the blade is stopped, something that might cause the system activate when when the motor was started.
But, is the system able to detect a blade that is electrically insulated (by paint) from the saw arbor? I believe this is unlikely to happen, but it could.
As a mental exercise, lets say we somehow attached cutting tips to a plastic disc. Could/would the SS system detect this? Would the system either prevent the saw from starting, or somehow still protect the operator if he placed his finger against the blade while it was turning?
More realistically, say it was a standard painted metal blade, but there was paint on the bore of the arbor hole and the sides of the blade, and that this insulated the blade from the arbor as far as DC resistance goes. Does the SS system use AC and essentially pass current through capacitive coupling between the blade and the arbor, with the paint being the dielectric? If so perhaps this could be the way the issue of insulating paint is eliminated.
Just curious...as I see how the system could easily determine if,while the motor was stopped, the setup was sensing something that would cause the system to activate if the motor was started, but I don't see how the system could easily determine if there was something present that would inhibit the system from activating when needed.
I know the SS system is a great improvement over what we normally have to protect us in the worst case (nothing but luck). But I would like to understand what the limitations are, something that must be there, as nothing is absolutely perfect...well, almost nothing, just in case my wife is watching...:-)
Anyone?
I saw mention in previous thread(s) that the saw stop system somehow checks itself and can determine if it is functional or not. This was related to the question about painted blades possibly insulating themselves from the main part of the saw (electrically).
I can see how the SS system could be set up to check for something that might be touching the blade when the blade is stopped, something that might cause the system activate when when the motor was started.
But, is the system able to detect a blade that is electrically insulated (by paint) from the saw arbor? I believe this is unlikely to happen, but it could.
As a mental exercise, lets say we somehow attached cutting tips to a plastic disc. Could/would the SS system detect this? Would the system either prevent the saw from starting, or somehow still protect the operator if he placed his finger against the blade while it was turning?
More realistically, say it was a standard painted metal blade, but there was paint on the bore of the arbor hole and the sides of the blade, and that this insulated the blade from the arbor as far as DC resistance goes. Does the SS system use AC and essentially pass current through capacitive coupling between the blade and the arbor, with the paint being the dielectric? If so perhaps this could be the way the issue of insulating paint is eliminated.
Just curious...as I see how the system could easily determine if,while the motor was stopped, the setup was sensing something that would cause the system to activate if the motor was started, but I don't see how the system could easily determine if there was something present that would inhibit the system from activating when needed.
I know the SS system is a great improvement over what we normally have to protect us in the worst case (nothing but luck). But I would like to understand what the limitations are, something that must be there, as nothing is absolutely perfect...well, almost nothing, just in case my wife is watching...:-)
Anyone?