Rb, the short rails will be the same section as the long rails.
I do have a beam falling dead center on the long rails (5 short rails).
Are you saying that using the max deflection formula while having a center cross rail is too conservative? ("if you don't have a cross rail at the middle...
Sorry I misspoke! There is no free lunch. You are right the load has to transfer down to the four corners some how and the cross members will only help stiffen the unit some, therefore there can be a slight decrease over the theoretical ~3/16" deflection. The short rails were also to be 2x1...
Thanks Rb, factoring in the cross members reduces the psi in half from 3.333 to 1.63 dropping the deflection to a little over 1/16" at midspan assuming that the weight will transfer evenly over the entire area, but as you point out it will not and discrete loads will occur at points on the rail...
Thanks guys, the loading will be UDL because their will be 3/4" plywood fastened to the frame with cabinetry on top. The major concern was the deflection at mid span of the long rails.
Based on 2x1 Al. rect. tube with a section mod. of 0.3317, elasticity of 10mil psi, and 3.3lb/in (200lb per...
1. Yes, at the four corners the 4" casters will be meeting the ground.
2. That is were I am getting stuck at - if the load is spread across the entire frame how will I calculate load on the cross members, what equation should I use to evaluate the model?
3. Yes
How would I go about calculating deflection of the long beams in the model? I am assuming a 400 lb weight spread uniformly across the top of the platform (grid of 1x2 either steel or al. rect. tube). Long tubes (beams) are 60" long. Their will be 4" caster at the four corners bringing the load...
From my limited experience with concrete, is there a reason pozzolan is not being used instead of more water to improve workability? In cold weather it might retard curing, but in warmer climates the gain in workability may offset the slower onset of final strength and ultimate strength should...
Good to know, thank you. My original thoughts and expanded info are on MS One Note, but people maybe reluctant to download a file and understandably so. I have redone it, not as nice as one note though, into a webpage. Please check it out and let me know if I am in the right forum for this type...
Hello all, I am trying to determine load and shear that will be placed on a rack and its components. Can you help me formulate the equation so I can determine if the components will be suitable?
Thanks!
Bill, I think ccjersey has it right. The end of the rotor is a sealed bearing that spins freely by hand with no grinding and takes some time to spin down. I will have to look at the opposite end next time I am in the shop.
Excellent point Bill, I understand now what you were referring to earlier. Thanks for the explanation. I guess then it would be wise to also replace the bearings. When you say bushing, are you referring to the bearings that allow the rotor to turn or something else?
No, you raise good points. I both counted the windings as they came off, and not trusting myself to only count, I also after unwinding took the mess of wire and wrapped it around a ruler to give me total length. I came within 4" on the smaller gauge winding and within 5" on the larger gauge...
Bill, the motor is not expensive but replacing the motor is not likely to happen. The machine that it came out of is nearly $600 and out of my range to replace right now. For me to spend $50 and get it running again is more likely, as long as it works :) Thanks for the tip on the bushings, I am...
