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  1. Thread: RIP peachy?

    by DoulosDS
    Replies
    49
    Views
    103,512

    Hey Amir, I've sent you several emails with no...

    Hey Amir,
    I've sent you several emails with no response... please check your inbox and let me know your plans. Thanks!
    DonS
  2. Replies
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    30,740

    Peristaltic Pump Exploded

    OK, I received my $12 PS pump, and I am impressed with its simplicity. The motor shaft serves as the sun "gear," though it is smooth; the 3 rollers are the planetary "gears," driven by contact with...
  3. Replies
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    I'd bet we could print everything but the tube...

    I'd bet we could print everything but the tube and motor for under $1. The tube can be silicone fuel line from a RC hobby shop or site, and the motor can be salvaged from a car mirror adjuster. A...
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    30,740

    From the photos, I'm pretty sure it has brushes...

    From the photos, I'm pretty sure it has brushes and permanent stator magnets. I have no idea whether the rotor magnetic fields can be detected outside the motor, but I doubt it, with the steel...
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    30,740

    I suspect the most likely problem will be how to...

    I suspect the most likely problem will be how to attach a magnet to the motor shaft. The photos don't give me much hope at the commutator end of the motor, unless the magnet were very small and...
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    30,740

    Right; the motor controller would just keep the...

    Right; the motor controller would just keep the pump stopping point from drifting or dithering. The pump would always turn an integer multiple of 1/n for n lobes. My idea of sensing the pump lobe...
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    Hall effect is much more reliable and I expect a...

    Hall effect is much more reliable and I expect a less noisy signal... as well as able to handle higher RPMs.
  8. Replies
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    Anybody know how to get precise control of a DC...

    Anybody know how to get precise control of a DC motor? I'm thinking a microcontroller with a hall effect sensor on the motor shaft counting full turns. An A/D input would monitor the current or...
  9. Replies
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    Another comment on peristaltic pump accuracy: ...

    Another comment on peristaltic pump accuracy: those driven by DC motors, rather than stepper motors, have gear trains to provide the necessary torque. The $12 pump I found on Amazon has a maximum...
  10. Replies
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    30,740

    He says the 24 VDC pump does NOT pump 4500 ml/min...

    He says the 24 VDC pump does NOT pump 4500 ml/min but only 450 ml/min... the label was misprinted (then why use it to illustrate the 12 VDC pump?) and he didn't say whether he still had them for sale...
  11. Replies
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    159,644

    Sticky: Hi Amir, I'm Don Sander, an electrical engineer...

    Hi Amir,
    I'm Don Sander, an electrical engineer with a MS in electrooptical physics, and an inventor, entrepreneur, and scavenger of free anything. I recently lucked into a 55-gallon drum of clear...
  12. Replies
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    30,740

    Hi Flow Rate Pump Specs

    No, the pump is NOT as pictured. It is a 12 VDC pump with 500 ml/min max flow rate. It has 3 rollers on the rotor. I have asked the seller if he has any more of the 24 VDC pumps left... I will...
  13. Replies
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    30,740

    I was searching the whole forum for this info;...

    I was searching the whole forum for this info; then I found in on my own thread! I'm glad to hear my $12 PS pump can meter out one slice per 1/n revs in the smallest print tank I expect to use, and...
  14. Replies
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    "High" Flow Rate PS Pump

    9150 Here is the best inexpensive peristaltic pump I could find with a relatively high flow rate: 500 ml/min for $30 and free shipping. It doesn't provide much info on specs, like rotor RPM, number...
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    30,740

    9149 Found this pump on Amazon for $12, free...

    9149 Found this pump on Amazon for $12, free shipping. I was thinking I would need to replace the motor with a stepper, but I don't think that's necessary. I can add an optical sensor to detect the...
  16. Replies
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    30,740

    Amoose136, Thanks for your suggestion and...

    Amoose136,
    Thanks for your suggestion and drawing. I think the alternating rollers would reduce the error by half, but the accumulator only smooths the dynamic flow. Once the pump stops, if a...
  17. Replies
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    30,740

    You are probably right, however, any periodic...

    You are probably right, however, any periodic irregularity becomes glaringly obvious when viewing the surface quality of a smooth print; e.g. the rocket. Let me crunch some numbers before I...
  18. Replies
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    Peristaltic pumps have a lot of advantages, but...

    Peristaltic pumps have a lot of advantages, but one big disadvantage we would need to work around: they do not produce a uniform flow rate over time. The flow is pulsed or interrupted when the...
  19. Replies
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    Sticky: Pause, Pump, Print

    There are so many good ideas on these forums! As I read, I keep getting more inspirations...

    OK, the displacer would work fine, but an even better method uses a positive displacement pump,...
  20. Replies
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    179,032

    Sticky: Pause, Dunk, Print

    From another suggestion: the flag signal could also trigger dunking a displacer in the print tank to raise the resin level momentarily and ensure the previously printed slice is evenly covered with...
  21. Replies
    52
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    179,032

    Sticky: Slice Pause for Higher Viscosity Resin and Fewer Voids

    I lucked into a 55-gallon drum of clear UV cured resin, but I suspect it has a higher viscosity than Peachy Juice, though I may be able to thin it. (Does anybody know the viscosity of Peachy Juice...
  22. Replies
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    179,032

    Sticky: I like the bobbing displacer idea best. A...

    I like the bobbing displacer idea best. A negative buoyancy mass located in a corner or at the side of the build tank could be supported by a linkage to an eccentric on a small motor shaft. The...
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