: mini pond/fountain pump workings

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Discussion Overview

The discussion revolves around the workings of a mini pond pump, particularly its unexpected behavior of reversing direction under certain conditions. Participants explore the implications of this behavior for a project involving a pond widget that utilizes the pump's axle for mechanical purposes rather than water flow. The conversation includes technical considerations, potential solutions, and troubleshooting ideas.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant describes the pump's behavior of reversing direction when encountering resistance, raising concerns about its impact on their project.
  • Another suggests contacting the manufacturer for support or using a different motor setup, such as a waterproof motor or placing the motor outside the aquatic environment.
  • Some participants speculate that the reversal might be a designed feature to expel debris, questioning whether it is programmed or triggered by resistance.
  • A participant proposes that the pump may be a shaded pole motor, which could run in either direction under certain conditions, and discusses the implications of pressure on motor operation.
  • Temporary solutions, such as installing a ratchet mechanism to control the direction of the axle, are suggested by multiple participants.
  • One participant shares their experience of the motor being finicky and the challenges faced in aligning the axle, leading to a decision to switch to a non-submersible motor.
  • There are discussions about using alternative methods to connect mismatched parts, such as using tubing or adhesives.

Areas of Agreement / Disagreement

Participants express a range of opinions on the nature of the pump's behavior, with no consensus on whether it is a designed feature or a malfunction. Multiple competing views on potential solutions and approaches remain throughout the discussion.

Contextual Notes

Limitations include uncertainty about the motor type and its operational characteristics, as well as the specific design features of the pump that may influence its behavior. The discussion also reflects varying levels of technical knowledge among participants.

Who May Find This Useful

Individuals interested in mechanical engineering, DIY pond projects, or troubleshooting small motor applications may find the insights and suggestions shared in this discussion relevant.

  • #31


Danger said:
Right, then... I see it now.
I have added a closeup to the above post.
Danger said:
You got to admit that the 'bass' pun wasn't too bad, though...?
Heh. Pun jumped right over my head. :-p

Danger said:
Although it might not matter to the design, is there turbulence of any sort in this pond? I ask only because of you mentioning the boat flopping around on a flimsier support structure.
There is turbulence from a babbling brook, yes, but that's not what I'm concerned about. The motion of the whole device is a bit jumpy due to friction and imperfect gears. Even as it is, the boat jumps and jerks a little. Bendy wires would greatly magnify this.

Danger said:
Also, if the boat and the fish are synchronized in revolutions around the centre,
The boat is not attached to the yellow gear at all. It is simply on a beam that sticks out from the main vertical axle (the red clippy bit in the centre). The fish axle is free to rotate, but the boat is held rigidly, always trailing the fish by 90 degrees.


Danger said:
you could link a loose piece of thread between them to make it appear as if the fish has already been hooked. It would have to be disproportionally thick, though, to make it visible from a distance.
You are good! It is like having a conversation with my own thoughts!

I'd thought of the string. The one problem with it is that there is nowhere to attach the string to on the fish axle. Every part of the axle/fish is rotating. It is theoretically possible to attach the string with a loose loop around some part of the axle but if that loop ever gets ... uh ... fricted ... it will seize and wind up on the axle like a scarf caught in a bicycle wheel.
 
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  • #32


Jeez, but I'm pissed off!
I just spent over an hour replying to your last post (I'm not slow; I'm watching TV at the same time). When I tried to post it, the PF server wasn't responding. Now it's lost.
I'll try to recreate it from memory.

DaveC426913 said:
It is like having a conversation with my own thoughts!
One, or perhaps both, of us should be frightened by that. :biggrin:
DaveC426913 said:
if that loop ever gets ... uh ... fricted ... it will seize and wind up on the axle like a scarf caught in a bicycle wheel.

Quite right; I hadn't considered that.
I've come up with a couple of ideas, but both would take a lot of work and probably aren't worth the effort.
The simplest would be to use a 'springy' solid plastic strand as the fishline, with the end entering the water just where the fish emerges. The fish grabs it, stretches it out as it goes around the axle, then releases it upon entering the water. The 'line' then snaps back to the starting point to repeat the cycle. I haven't started working on any details.

edit: I just recognized a fatal flaw in my second idea. It won't work.
I'll keep thinking on it, though.
 
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  • #33


Danger said:
Jeez, but I'm pissed off!
I just spent over an hour replying to your last post (I'm not slow; I'm watching TV at the same time). When I tried to post it, the PF server wasn't responding. Now it's lost.
I'll try to recreate it from memory.
I hate that. By habit now, any post longer than a few lines, I always hit Ctrl-C before doing anything that will refresh the page.

Danger said:
I've come up with a couple of ideas, but both would take a lot of work and probably aren't worth the effort.
The simplest would be to use a 'springy' solid plastic strand as the fishline, with the end entering the water just where the fish emerges. The fish grabs it, stretches it out as it goes around the axle, then releases it upon entering the water. The 'line' then snaps back to the starting point to repeat the cycle. I haven't started working on any details.

edit: I just recognized a fatal flaw in my second idea. It won't work.
I'll keep thinking on it, though.
You're overthinking it. The "10 foot rule" in train hobbying states that "if it looks good from 10 feet, it's fine".

What might be best is simply a rigid wire running from fishing rod to a loose loop that goes around the fish axle. The rigid line will ensure it keeps its shape/position but will ensure it does not bind on the fish axle.
 
  • #34


I was unaware of that rule, but it certainly simplifies things. I've always aimed for more of a 2 inch rule, but I'm not involved in model railroading. Given a 10 foot range, the wire loop should work great.
I have, however, modified my non-functional idea in light of that 10 foot rule. It's a lot easier than what I had in mind, but possibly more 'life-like' than the wire loop. That would be to have a length of maybe 30# test black fishline extending from the fishing rod around the fish axle, and back under water to the bottom of the boat. A light spring, such as from a really old typewriter, holds the line under the surface between the boat and the fish. A groove milled in the top of the fish engages the line, pulls it up when it rises, and then releases it when it hits the bottom of its rotation. The line pops back down into the water to repeat the cycle. The spring would be attached to an underwater boom extending from the boat.
 
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  • #35


Danger said:
I was unaware of that rule, but it certainly simplifies things. I've always aimed for more of a 2 inch rule, but I'm not involved in model railroading. Given a 10 foot range, the wire loop should work great.
I have, however, modified my non-functional idea in light of that 10 foot rule. It's a lot easier than what I had in mind, but possibly more 'life-like' than the wire loop. That would be to have a length of maybe 30# test black fishline extending from the fishing rod around the fish axle, and back under water to the bottom of the boat. A light spring, such as from a really old typewriter, holds the line under the surface between the boat and the fish. A groove milled in the top of the fish engages the line, pulls it up when it rises, and then releases it when it hits the bottom of its rotation. The line pops back down into the water to repeat the cycle. The spring would be attached to an underwater boom extending from the boat.

Hm. I do like the idea of having the loop go around the axle and back to the boat. That neatly eliminates any binding problems.

Then again, the rigid wire ending underwater is probably the best balance of realism and simplicity.
 
  • #36


DaveC426913 said:
Then again, the rigid wire ending underwater is probably the best balance of realism and simplicity.

Agreed. I was just trying to figure out how to make it look as if the fish was actually hooked.
Anyhow, I'm looking forward to seeing more pictures. Please keep me informed as to your progress.

How do I know that I have no life? When one of the highest points of my day is talking to you about a plastic fish. :-p
 

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