Create a review for a woodworking tool that you are familiar with (Shopsmith brand or Non-Shopsmith) or just post your opinion on a specific tool. Head to head comparisons welcome too.
does everything the original machine did only better.
This is what you are going to hear in the shop one of these days, I just know it.
I've been reading back through many of the threads that have posted here on the forum. This one has once again caught my attention. I am going back into the shop with a couple grandiose ideas of how I might improve my wood working experience without spending much money.
This thread is sort of a preview of what I have in mind and what I expect a Shopsmith Mark V will one day offer. Greater horsepower, electronic speed control, digital gauges and displays all while maintaining backward compatibility.
The inputs that were made by the various members of this forum are inspirational. I just wish I had the capital to invest in the development effort. Incorporating this sort of change into the existing Mark V would be revolutionary. Happy days will be here again. In the meantime, I have to cleanup my built in depth gauge and document the adjustable tilting outfeed table.
Let's see some other ideas put into service. How about it Shopsmithers. Let us see what have you done to improve your woodworking experience. I know there are a lot of good ideas out there that are just waiting for incorporation. Wait no more.
"Making Sawdust Safely" Dusty
Sent from my Dell XPS using Firefox.
My only question is about "electronic variable speed". Do you have in mind a DC motor or AC variable frequency system; or, some type of servo-motor that "turns the crank" on the conventional belted system.
Keep in mind the fact that when you decrease speed via belts and gears, the torque is multiplied proportionally. This is not the case with DC motors and AC variable frequency systems. With these systems the torque output is constant as you decrease from the base speed. While you do get a slower speed, you won't have enough torque to turn large & heavy bowl stock or drill with 3" forstner bits.
I agree that it is time for shopsmith to offer more HP by going from a 48 to a 56 frame AC induction motor. This could probably be accomplished with not so drastic modifications to the present headstock. This would allow a homeowner to have the choice between a Headstock that will operate on a 15 amp or a 20 amp breaker. Even higher HP could be offered on 240V.
dusty wrote:does everything the original machine did only better.
Greater horsepower, electronic speed control, digital gauges and displays all while maintaining backward compatibility.
Let's see some other ideas put into service.
Wait no more.
This is what a 510xpermental might look like. It as greater horsepower and electronic speed control. To change it back to original condition you just put the original motor pan with motor back in place.
I have a digital read out for it but have not been happy with the performance tests of the readout.
Tain't so! DC motor at lo speed have higher torque(as well as higher current)[the reason for the higher torque].
This higher current also contributes to warmer temperatures[maybe an alternative to purchasing a GARAGE HEATER]!
JOHN What HP does it have@ what RPM(table?)......I assume you leave SS speed control @ Max....or slow down for extra lo end range?...What is Max RPM??????
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Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
My only question is about "electronic variable speed". Do you have in mind a DC motor or AC variable frequency system]
I do not envision using the same headstock but maybe. I envison a system with no belts and pulleys and a control panel inserted where the present speed control dial is located.
What sort of motor?.....I have no idea. I am not an electrical design engineer; that I see as a design question to be answered by someone with book learnin in that field.
I am just a dreamer.
PS I just saw John's version. (I think I have seen this somewhere before. Was it posted here on the forum?" That is certainly going in the right direction. Sure wish I could cut some wood with it. You know what they always say..."The proof is in the sawdust".
"Making Sawdust Safely" Dusty
Sent from my Dell XPS using Firefox.
If you are saying that a DC motor's torque increases inversly, proportional to decrease in speed (constant HP), then I respectfully disagree. For example, a DC motor rated at 1 HP at it's base speed of 1800 rpm, cannot produce 1 HP say at 180 rpm. It would in fact produce 1/10 the HP of its base speed rating.
Mechinical methods such as gears and belts do multiply torque, and provided that the "works" are beefy enough to withstand the higher torque, they are constant HP, minus of course losses due to friction. For example, a 1 HP helical gearmotor with a 180 rpm output has a gear casing much larger than the motor itself. It has to have a lot of "beef" in the transmission in order to withstand the high torque. Worm gear systems are an exception. They produce much less output torque as speed reduces due to higher frictional losses. There is no free lunch. HP, speed, and torque have an intertwined relationship.
Shopsmith's mechanical variable speed system has a lot going for it. The prospect of replacing it with DC or Variable frequency motor systems has come up several times on this forum. I merely wish to point out that a new electronic system would in many ways reduce the level of performance that we have in our present mechanical system.
A DC motor has the following things going on when running:
A Magnetic field is created either by a magnet or a field winding.
For the most part(there are exceptions) these motors also have an armature with additional windings. These windings are connected to by way of brushes or some other commutating method.
When a dc motor is in motion the armature rotating in the magnetic field generates(YES GENERATES) a current in the armature windings counter to the applied current causing it to run in the first place.
Thus the actual run current is less than what it would be if it were NOT rotating.
If the armature is rotating at a slower speed, this generated current is less and does not oppose the run current as much.
All this assumes the applied VOLTAGE is the same.
When a given voltage is applied to a DC motor it will draw current limited only by the resistance of its windings(low resistance/high current[ignoring inductance factors//it is not instantaneous]).
As the armature rotates it generates the previously mentioned counter current and this counter current will increase until an equilibrium point is reached.
This takes time(inductance/inertia) but is very quick if the current is not limited externally/initially.
You do not apply running voltage to a dc motor without a means of limiting this startup/slo speed current. Smaller motors are limited by the higher resistance of their windings.
Larger motors NEED current limiting when starting. If slowed down due to mechanical load, they WILL draw higher current than at 'normal' speed. This higher current WILL allow motor to deliver higher mechanical power to whatever is being driven. It will also cause the motor to get HOT due to increased current(the resistance doesn't change [until temp increases]).
Again this assumes the applied VOLTAGE is constant. If the voltage decreases due to current then that also becomes a current limiting factor.
Very Short Course END!:D
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╟JPG ╢
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Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
At the risk of high jacking my own thread, I have to say that your dissertation on motor theory sounds correct and you have made your point. What is needed now is an engineering tech to mock this thing up and run some "real world" tests.
If I would put this beast in my table saw and found that it slowed even just a little bit, even just momentarily, I would go back to what I have now.
Someone may have already done this, I seem to remember a post. Maybe not on this forum. I report back if I locate it.
In the meantime, it would be nice to see some of those improvements that have been made to improve your woodworking experience.
"Making Sawdust Safely" Dusty
Sent from my Dell XPS using Firefox.
Happy days will be here again.
In the meantime, I have to cleanup my built in depth gauge and document the adjustable tilting outfeed table.
