Shopsmith Forums

I don't really know what DVR motor is or how it works but I suspect motors like it were used in computer perpherals like printers and disk drives long ago.

I know in one printer there was a motor that could start, stop, reverse instantly and was use to move the print characters in front of the right hammers at near instant speed. The circuitry always knew where the motor shaft was, how fast and how quick to speed it up or slow it down and stop it. If you tricked it you could get it to thrown the print bar across the room like an arrow.

In another printer there was a motor called stepper that knew how much to move the paper up and down. You could specify variable line spacing and it knew exactly how far to move the paper up or down to make the spacing right and it was doing this all while moving the paper through the machine in a blur. In fact ink was too slow and they used lazer to print with. So fast that it could print at a speed equalivant to being able to print everyone in world all 6 billion people names and address in a 24 hour period. That is fast!!!!!

Then there was the plotters that could draw perfect circles as fast as an instant. Each axis had a motor that the computer could speed up/slow down and knew exactly where in the rotation the drive shaft was at all times and again it reacted so fast that 2 inch in diameter circle was done as fast as I can the word "quick"

I also know these motors were very strong. It was almost impossible to stop them and once they were stopped I could never figure a way to apply enough force to their output shaft to make them move.

Ed in Tampa wrote:I don't really know what DVR motor is or how it works but I suspect motors like it were used in computer perpherals like printers and disk drives long ago.

I know in one printer there was a motor that could start, stop, reverse instantly and was use to move the print characters in front of the right hammers at near instant speed. The circuitry always knew where the motor shaft was, how fast and how quick to speed it up or slow it down and stop it. If you tricked it you could get it to thrown the print bar across the room like an arrow.

In another printer there was a motor called stepper that knew how much to move the paper up and down. You could specify variable line spacing and it knew exactly how far to move the paper up or down to make the spacing right and it was doing this all while moving the paper through the machine in a blur. In fact ink was too slow and they used lazer to print with. So fast that it could print at a speed equalivant to being able to print everyone in world all 6 billion people names and address in a 24 hour period. That is fast!!!!!

Then there was the plotters that could draw perfect circles as fast as an instant. Each axis had a motor that the computer could speed up/slow down and knew exactly where in the rotation the drive shaft was at all times and again it reacted so fast that 2 inch in diameter circle was done as fast as I can the word "quick"

I also know these motors were very strong. It was almost impossible to stop them and once they were stopped I could never figure a way to apply enough force to their output shaft to make them move.

'Similar' (stepping motors with very strong magnets), but dvr = no (very)rare earth magnets.

It shall be interesting how this 'technology' is developed.

The following is from an Teknatool April 2007 release:
[ATTACH]22856[/ATTACH]

Since we are adding to our own wish list for the PowerPro motor / controller future features, the ultimate value added might be the detection of our skin contact with a saw blade or similar cutting tool.

The marketplace already has one saw capable of this feature, although I do not know any specific details.

artlinux wrote:Since we are adding to our own wish list for the PowerPro motor / controller future features, the ultimate value added might be the detection of our skin contact with a saw blade or similar cutting tool.

The marketplace already has one saw capable of this feature, although I do not know any specific details.

I do hope yer tongue is causing the exterior of yer cheek to protrude outward further than its normal relaxed amount.


I can think of many reasons that is not a good thing. I suggest you research those 'specific details' and then come back and tell us if your 'thinking' has changed.

The only videos I have seen of the sawstop in action show them either touching the side of the blade (not the teeth) or using a flacid hot dog that is dripping in salty water. I'd be interested to know how far the teeth would cut into a hand when used "normally".

I know...I know... using it "normally" wouldn't hurt me, but you know what I mean

joshh wrote:The only videos I have seen of the sawstop in action show them either touching the side of the blade (not the teeth) or using a flacid hot dog that is dripping in salty water. I'd be interested to know how far the teeth would cut into a hand when used "normally".

I know...I know... using it "normally" wouldn't hurt me, but you know what I mean

I have said this before, but have stated that I would like to see a video(or better yet be there in person) of you know who touching the blade with a different part of his anatomy while advancing it towards the blade at a greatly increased velocity(or I said something similar:D). Then maybe Roy can quickly retrieve the workpiece from the saw, bite into it, chew upon the bite and declare it did not hurt it a bit(assuming Roy can tolerate the 'taste')!:rolleyes:










I know! Bad taste on my part. The less prudish will see the humor!;)


P.S. just noticed the adjective used in the previous post describing the hot dog!

I'd seen that comment before from you, but not quite so eloquently stated


By the way, you had me almost in years from laughter!

[quote="JPG40504"]I do hope yer tongue is causing the exterior of yer cheek to protrude outward further than its normal relaxed amount.


I can think of many reasons that is not a good thing. I suggest you research those 'specific details' and then come back and tell us if your 'thinking' has changed.]
The suggestion of another safety system like touch sensing layered upon other safety aspects of otherwise well designed machinery may seem like a bad idea. The idea reminds me of the many air bags in a car. I have no interest in testing how well designed a car may be in withstanding a head on crash into something but it is still comforting to know that measures are awaiting some terrible mistake to help you with survival.

Rather than consider another safety measure designed into a SS as a bad idea, I would rather consider that if DVR motor controller can be modified in the future to provide an added safety measure we will all be better protected.

The specific details are not so important to me just now. In order to design a better safety idea, considering what went before and improving on it if possible or discarding the idea, is the designers job. My general goal is safety - sorry if that seemed to make my cheek protude with a poorly explained idea!

Art

artlinux wrote:The suggestion of another safety system like touch sensing layered upon other safety aspects of otherwise well designed machinery may seem like a bad idea. The idea reminds me of the many air bags in a car. I have no interest in testing how well designed a car may be in withstanding a head on crash into something but it is still comforting to know that measures are awaiting some terrible mistake to help you with survival.

Rather than consider another safety measure designed into a SS as a bad idea, I would rather consider that if DVR motor controller can be modified in the future to provide an added safety measure we will all be better protected.

The specific details are not so important to me just now. In order to design a better safety idea, considering what went before and improving on it if possible or discarding the idea, is the designers job. My general goal is safety - sorry if that seemed to make my cheek protude with a poorly explained idea!

Art

Let me say this clearly: I have no aversion to creating a safer version of a shopsmith provided it could be done with a reasonable amount of effort and $.

I just do not believe a sawstop like 'system' will be effective on a shopsmith. The multi-function aspect will make that a very difficult task indeed.

Bear in mind a cabinet saw has a fixed arbor(albeit it tilts) - i.e. no movable quill. Add to that the need for attaching various SPT's which all have different, sharp, moving parts.

Do realize the arbor shaft of the sawstop must be insulated electrically from the work table.

Although the sawstop can be considered a safety 'improvement', extrapolating it to imply it's applicability to a shopsmith is just plain wishful thinking. Same can be said for chain saws!

Those 'details' that you so easily dismissed as unimportant to you are the details that a 'designer' is encumbered with and cannot be dismissed so callously as somebody elses 'job'.

Do realize that being 'comforted' that a safety device is just waiting for you to do something carelessly and is there to protect you from yourself is folly. Sure it is better to have a layer of protection, but not if it produces complacency in the process. It is that complacency that makes me concerned about the 'safety' of future generations.

While I am not advocating a return to common practices of a few decades ago, we could use some of the respect for moving machinery that has been lost due to an over emphasis on eliminating risk.

Sorry about the soapbox, but we share the same concern, we just have a difference idea of how best to minimize the risks. I consider it a user's responsibility, not the equipment designer's.