The customary engineering unit for mass moment of inertia in the US is a bit atypical compared to the SI units. The unit is borne out of the basic Newtonian equation:
T = J*a
where:
T - torque (system unit specific)
J - Mass moment of inertia (system unit specific)
a - rotational acceleration...
I like the way that Peetey and bronzeado talk about vars. Completely abstracting reactive power from real power can get very confusing very quickly.
The way that makes most sense to me is that vars are stored power. It is power that is available to return to the source. Leading and lagging...
Prions, Keith? Aren't those the proteins that cause mad cow disease? [smile]
It is interesting how the availability (and presumably demand) changes so much in various areas. I don't know if this is due to marketing, cost/value perception or environmental benefit perception. For my money I'll...
Now that's funny. Sure, I see a few Prius on the road around here. But not as many as you would think given all the hype. There are Priuses sitting on the lot at the dealership (at least according to my local Toyota dealer's ad on the radio) so it's not like Toyota can't keep up with...
Interesting discussion.
Aside from the infrastructure question (which is a HUGE point) it still doesn't make economic sense to go electric. You can't recover the extra cost of the vehicle in fuel cost savings...yet. In the US it doesn't even make sense to go Diesel unless you drive a huge...
Thanks for the reply, Tmoose.
After reading your post I realized I was being myopic. If the roll body itself had a defect causing the spring rate to change it would create forces at the required frequency. The roll body in question is steel so there is significant enough weight there that a...
Thanks for the reply, Greg.
I have seen descriptions of how shaft assymetry can lead to half critical excitation. But all those explanations were for live shaft applications. In my application the shaft is stationary and the roll body rotates around it. If the assymerty isn't rotating I'm...
I recently had a customer contact me about a tension control issue on his machine, a web processing machine wiith loadcell based tension control. He said the machine ran fine except for a small speed range during accel and decel. I had seen this before and told him the machine was passing...
I'll toss my hat in with everyone else so far. I have a hard time coming up with something I don't like about Automation Direct (supplied by Koyo) plcs. I find them easy to program. They always seem to work. I have yet to run into a plc dead out of the box. I have used only the 205 and 405...
I'm kind of new to motion systems and most of my experience is in AC induction and brushless motors so unfortunately this is a question as opposed to any helpful comments.
It is stated up front in this thread that the current DC motor used in this application is having problems because it...
Thanks for the responses, everyone. Elastic compression is something I should have intuitively considered since I made it an initial requirement. But I can certainly see how this would allow for full energy/momentum transfer. I'm still trying to get my mind around the non-centered collision...
My, my. Someone tosses that dirty 'h'-word out there and people get all bent out of shape.
Just to quell some fears, I'm not a student and this is not a homework problem. I'm the result of a very 'focused' (read 'limited') formal education. I'm a tech scool product so I haven't had any...
Hi Greg-
Granted, I'm a lousy pool player. But I've had more cue balls follow targets into the pockets than stop on the table. I think the mechanism that stops the cue ball is tangential motion at the bottom of the cue ball opposing the direction of travel (back english). This removes energy...
I am having trouble reconciling conservation of momentum and conservation of energy. If two bodies of equal mass, one stationary and one moving, collide and both bodies exhibit perfect elastic deformation at the contact point (infering no loss of energy due to plastic deformation of damping)...
Hi electricpete-
I need to stop posting stuff so late. After reading them again my comments were pretty disjointed.
As you state, the energy required to incrementally add charge to a cap effectively increases with the square of the charge, due to the voltage increase in the cap. That part makes...
