3D Printed Peristaltic Pump for Feeding Tube Patient

[frank26080115]

This is a 3D printed peristaltic pump, four pieces are printed on a Ultimaker2, and it also uses ball bearings, vinyl tubing, a motor gearbox, and a control circuit.

http://www.bocabearings.com/innovati...?ProjectID=221

If you like it, I would really appreciate a vote in the contest that it's entered in. Thanks

The 3D CAD models are publicly shared on Onshape, if you do not have an Onshape account, you can get a free account. The link to the models: https://cad.onshape.com/documents/21...cf435bbd13d291

To export the model files, right click on the tabs on the bottom on the screen, where each tab is one sub component.

Some other details are on my blog: http://eleccelerator.com/3d-printed-peristaltic-pump/

[Roxy]

So your first post is a plea to vote for your design on another site? Hmmmm....

I printed a Peristaltic Pump and I ran it with an electric drill. It held up fine without bearings.

Using bearings gives the pump extra durability. I’ve seen plenty of designs with just 3D printed rollers, I didn’t feel those would be durable enough.

But you 'feel' it needs bearings and you are entering a contest to use some company's bearings? Hmmmmm.....

I feel like I'm being played.

And if it didn't hold up fine.... And could not run for years without a failure.... Wouldn't it just make sense to print up 2 or 3 spares?

Other than that.... Good Job. That is cool....

[frank26080115]

So your first post is a plea to vote for your design on another site? Hmmmm....

I printed a Peristaltic Pump and I ran it with an electric drill. It held up fine without bearings.



But you 'feel' it needs bearings and you are entering a contest to use some company's bearings? Hmmmmm.....

I feel like I'm being played.

And if it didn't hold up fine.... And could not run for years without a failure.... Wouldn't it just make sense to print up 2 or 3 spares?

Other than that.... Good Job. That is cool....

I did not use that company's bearings. All mechanical components were from McMaster. Trust me, under pressure, you want everything to arrive fast and from one place. I'm pretty sure none of the competitors actually went out of their way to buy bearings from some company in Florida. It's more like, oh cool, a contest about bearings, what have I done lately?

Did you suspect I work for them?

That "feel" is what people might call intuition, or instinct, or experience. Ball bearings exist to allow something to rotate while under a lot of load without wearing out, if I didn't use bearings, my options were to use a bushing, or have bare plastic grind up against metal. If I didn't use rollers at all, then the vinyl tubing would just be shredded from friction.

Why would I not just use a couple dollars on ball bearings? This is for family, not for sale. I'm not going to cheap out.

Would you honestly prefer a device that didn't use ball bearings, broke in 1/4th of the time, but I gave you three of them? Ok... you might. How long does it take to print one piece? How many times did I have to re-print the center rotor to adjust for tolerance? Do I expect to replace the motor and electronics too or do I expect my family members to rewire the old circuit?

Can my grandmother even hold a cordless drill? I honestly did think about using a drill for a motor. But guess how much shipping cost me with my current design, for 2 day service from USA to China. Now add 3 pounds for a drill, battery, and charger to the weight of the package.

And why wouldn't I put in my best effort to make it the easiest to use by making it a self contained unit?

Trust me, I had all of this planned well in advance while I was still in China, purchased the parts so they'd arrive almost exactly as I arrived back in the USA. I even signed up for a FedEx account just for this.

edit: also, there's at least one guy in the hackaday comments who knows the drawbacks of not using bearings in a peristaltic pump, http://hackaday.com/2015/11/10/3d-pr...ties/#comments

[Roxy]

I'm glad you have given this careful thought. I do appreciate the complexity of the project.

Can my grandmother even hold a cordless drill? I honestly did think about using a drill for a motor. But guess how much shipping cost me with my current design, for 2 day service from USA to China. Now add 3 pounds for a drill, battery, and charger to the weight of the package.

My only point here is the version I printed I ran with an electric drill at very high speed for a while. It was just fine. The one I printed was self-assembled and printed in one piece. It used herringbone gears to keep everything centered. Obviously, doing separate pieces would have produced a better finished unit with tighter tolerances. Even so, it could run for a long time at high speed with no problems.

But you want to use ball bearings... That is fine and probably better. But as long as you are being argumentative, lets nit pick. You keep talking about how important it is to use ball bearings. In your posts, in the article and in the comments on the article. I don't believe that you need BALL BEARINGS to get the benefit of using bearings in the design. Is it just possible that a Roller Bearing would work even better? It would certainly give you a wider surface to center the tubing on.

[frank26080115]

Roller bearings can probably take more load radial. I've never handled one in my life. I knew any bearing is magnitudes better than no using bearing, so after that I stuck with what I knew. The prices are similar so I figured that there's some sort of tradeoff that I didn't really know about first hand. So in the end I stuck with what I was familiar with.

Research indicated that roller bearings take more radial load and less axial load, and ball bearings have less friction. I have some experience with pneumatics during my days building potato guns, and I know how to calculate torque with my rotor size, I judged that the radial loads involved would never a few dozen pounds, and ball bearings can take that easily. Roller bearings are rated to thousands of pounds.

The tubing is centered naturally, the casing itself has as slight taper so the tube centers itself. The bearings are tapered. No need to make the rotor assembly any thicker.