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Recent content by mrpi

  1. mrpi

    Thermal Study Help Needed! Initial Temperature from thermal study time step always goes to '1'

    Ok, so I got it to work by decreasing the value in the Time Steps box by 1, so for 1600 time steps I set the value to 1599 etc. However, I noticed that if you press 'enter' or the check box to close the Properties window then re-open the Properties window it will not always save the value (as...
  2. mrpi

    Thermal Study Help Needed! Initial Temperature from thermal study time step always goes to '1'

    Hello, I apologize if this has been discussed in the past but my searches did not turn up anything. I am running a set of transient thermal studies, and I would like Study 2 to use the temp profile results from Study 1 etc. I see the check box for "Initial Temperature from thermal study' box...
  3. mrpi

    Advice on having a custom fan made?

    MintJulep, I emailed Rotron, and they said the pressure is a little low for their products and recommended a couple other fan mfg. Dougt115, I doubt I'll be able to gear down due to the cost of a gear reducer. But I have seen a blade come off a Chevy fan and cut a hole in the hood, so I hear...
  4. mrpi

    Advice on having a custom fan made?

    I'm designing a custom motor for an industrial grinder. This is a brushless servo motor intended to replace a synchronous AC motor. Due to mounting constraints, I would like to install the cooling fan on the non-drive end of the motor shaft. All my previous experience is defense products in...
  5. mrpi

    Gear Bore sizing?

    Thanks for the reply Terry, It is not necessary to have the bearing located 'within' the gear, although I am trying to minimize axial stack height. I guess I did not include any dimensions, but these are 5in Pitch Diameter gears so I can fit a big bearing in there and still preserve wall...
  6. mrpi

    Gear Bore sizing?

    I'm using three straight spur gears to move a gearbox away from a pivot. This is in a low speed lift application, and the gearbox OD is larger than the allowable pivot diameter. It basically just flips a [heavy] panel 180°. Backlash is not critical as it moves from stop-to-stop, but I am a...
  7. mrpi

    Adding material to a complex curved surface?

    Oops! Beat to fit, paint to match.http://files.engineering.com/getfile.aspx?folder=c6c484d7-b260-4d00-ac4e-3d57f1bb1f6e&file=Problem_Part.jpg
  8. mrpi

    Adding material to a complex curved surface?

    Here's a jpg of the problem I'm having, I need a little more material out in the middle of the part. My last resort will be to just loft in more material from one end to the other. Beat to fit, paint to match.
  9. mrpi

    Adding material to a complex curved surface?

    I have a part that was made using lofts, the surface is a shallow complex curve. This part was provided to me as a "split" type feature and I do not have the curves that generated the original lofts. I found that I need a little more material in the middle of the part. Basically what I want to...
  10. mrpi

    Overall density of stator laminations??

    I have the weight of the iron laminations AND the copper windings. I was trying to differentiate between the two. But you're probably right about not worrying about it! Honestly, I dont really know how waste heat is generated within the motor itself. Maybe that would have been a more...
  11. mrpi

    Overall density of stator laminations??

    So if .9~.95 is the magnetic stacking factor, I would imagine that the "density factor" would be significantly greater, seeing as the magnetic field is related to the inverse-square? Beat to fit, paint to match.
  12. mrpi

    Overall density of stator laminations??

    Huh, I thought it was thicker. Thanks! Beat to fit, paint to match.
  13. mrpi

    Overall density of stator laminations??

    But there is some kind of paint or coating between the layers, thus lowering its density. I guess I was after the "bulk" density of the assembled lamination stack. Beat to fit, paint to match.
  14. mrpi

    Overall density of stator laminations??

    I'm trying to estimate the transient heating of brushless DC motor stator. (run it for 90 seconds, how hot will it get). I was going to assume the heat is generated in the windings (copper) and is transmitted by conduction to the laminations (steel) then into the stator housing (aluminum). I...
  15. mrpi

    Applied gravity in one sirection and then the other

    Maybe the complex curved surface created by the displaced shape is stiffer than the original flat disk? I'm trying to think my way backwards through the stiffness matrix generation, and I dont know for sure, but I dont think the math will be the same "forwards" as "backwards" like you're doing...

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