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Recent content by AHartman

  1. AHartman

    Is this the right calculation?

    That makes sense. So maybe what I'm missing is that I took the area of the nozzle (very small, .0016 sq. in) and should instead look at the area of the outlet tube? That will certainly drop my output velocity, but it seems like I'll have a significant pressure drop across the nozzle which will...
  2. AHartman

    Is this the right calculation?

    Thanks for the input, bimr. How do you get your flow resistance estimate? I think the problem with my original calculation was that the output velocity V2 was 160 ft/s, but when I took my flow and area, that's what I got. That makes me think the application of my equation is incorrect...
  3. AHartman

    Is this the right calculation?

    Hi all, I'm trying to find the power added to my working fluid (water @ 20 deg C) by a theoretical pump to see how much power I have to apply to the motor. The pump draws from a bag, through flexible tubing, then out through more flexible tubing and a small plastic nozzle. The conditions are...
  4. AHartman

    Peristaltic pump pressure calculation

    Thanks, BigInch. If I need a 30 psi output pressure, how do I know what size tube to pick? Also, how do I know the torque on the motor so as to size the motor correctly?
  5. AHartman

    Peristaltic pump pressure calculation

    If I know that I need 1.5 L/min max flow rate and cannot exceed 50 psi, how do I size the tubing/roller(s)/motor for a peristaltic pump? I'm designing a disposable, handheld medical pump and want to see if a peristaltic approach can work. Any suggestions of places to look for calculations, or...
  6. AHartman

    Advice on LCP-POM wear?

    Hi all, [Cross posted to a materials sub-forum] I'm designing a pair of hubs with 3 rollers sandwiched between them as part of a peristaltic pump. I'm trying to determine if POM rollers (compounded w/ PTFE and silicone, LNP's Lubricomp KP004) will have excessive wear if rolling against LCP...
  7. AHartman

    Advice on LCP-POM wear?

    Hi all, I'm designing a pair of hubs with 3 rollers sandwiched between them as part of a peristaltic pump. I'm trying to determine if POM rollers (compounded w/ PTFE and silicone, LNP's Lubricomp KP004) will have excessive wear if rolling against LCP (Vectra or similar, compounding not decided...
  8. AHartman

    Plastics material library?

    Hi all, Some google-ing has left me hi-and-dry as to a reasonably good plastics material library for ProE/Mechanica Wildfire 4.0. When I have a model and want to set it's material, I have about 15 choices, and all but 3-4 are metals. The attachment is a screen capture of my (limited)...
  9. AHartman

    Hypoid gear vendor/mfr in North Texas?

    @gearcutter - I agree 100%, but these design decisions were made 2 years ago when I wasn't even with this company! :) My preference is DEFINITELY to get it all done under one roof with a reasonable 3rd party verification, but I need to know who to call/e-mail, and that's why I originally...
  10. AHartman

    Hypoid gear vendor/mfr in North Texas?

    @gearcutter - We don't have any in-house expertise in gears, so we can't say for certain if the set is designed correctly. The brass worm was designed at one vendor and the nylon gear designed at a different vendor, but they worked in conjunction with the same design data. @bithkits - The...
  11. AHartman

    Hypoid gear vendor/mfr in North Texas?

    Can anyone recommend a good hypoid gear vendor or manufacturer in North Texas (Dallas/Fort Worth)? I've got a worm gear set in a handheld medical device we're developing, and the noise and efficiency have proven too difficult a problem to tackle. I want to investigate a different type of gear...
  12. AHartman

    Free optical design software?

    Hi all, This is my first post in the optics area, and I'm mostly a novice, so please excuse my ignorance. I'm working on an optical system with an emitter and detector located on different sides of a plastic tube with a cross-section such that there are flat internal and external surfaces to...
  13. AHartman

    Enveloping worm gear quieter?

    Tmoose: Thanks for the info and link, I'll certainly check it out. The worm isn't actually providing the pumping action. It's turning a roller for a peristaltic pump. -Adam
  14. AHartman

    Enveloping worm gear quieter?

    hydtools: The motor runs at 32 dB (tested in an anechoic chamber) and gets louder when installed in the case, but without any gear train. We know that this means the case is amplifying motor noise, and we're working a parallel effort to address the problem from that angle. Installing the gear...
  15. AHartman

    Enveloping worm gear quieter?

    Hi everyone, I have a pretty basic question and haven't really ever done a gear design before, so excuse me if the question is ignorant. I've been asked to reduce noise in a hand held pump system that uses a worm gear on a small DC motor to turn a gear to get the pumping action. The worm and...

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