TheClark Posted November 15, 2018 Author Share Posted November 15, 2018 8 hours ago, albertareef said: Congrats! By comparison, 20 mls min was way higher than our standard lab applications. I have a punch list of things to fix, but there is promise here. There is resonance in the case, it should be dead silent. The tubing moves. Their design pins the tubing down with screws, but I think we can do better than that. Seems like it would tear up the tubing over time. The pump back siphons when not running. I believe that increasing circumference of the pump head top portion will allow two rollers to be under more pressure and prevent that. I put in an order for some geared stepper motors, my 100 dollar pump is getting spendy lol... Hopefully when it is done, it will help others... Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 17, 2018 Author Share Posted November 17, 2018 First pumps came. They are awesomely powerful, but I have to redesign the pump head. So its going to be a while.... Quote Link to comment Share on other sites More sharing options...
albertareef Posted November 17, 2018 Share Posted November 17, 2018 BTW - the tubing we used to get often had “stops” welded into it to prevent the creep across the heads - definitely a specialized part. 1 Quote Link to comment Share on other sites More sharing options...
pdxmonkeyboy Posted November 18, 2018 Share Posted November 18, 2018 if you made a wheel with 3 or 4 rollers wouldnt that stop the back siphoning? and increase flow? Sent from my SM-G930V using Tapatalk Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 18, 2018 Author Share Posted November 18, 2018 On 11/16/2018 at 6:10 PM, albertareef said: BTW - the tubing we used to get often had “stops” welded into it to prevent the creep across the heads - definitely a specialized part. Ok, more good info, wish I lived close it would be fun to pick your brain (ha, that is kind of a pun). Many of my consumer grade pumps use fittings on the ends of the tygon, then these fittings snap into the pump. Might be a bit cheaper than that option, but still intriguing! 1 Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 18, 2018 Author Share Posted November 18, 2018 3 hours ago, pdxmonkeyboy said: if you made a wheel with 3 or 4 rollers wouldnt that stop the back siphoning? and increase flow? Sent from my SM-G930V using Tapatalk Ya, for sure! It turns out, there are three rollers / bearings now. The circle on the pump head that the rollers turn against is less than 50% of a circle if that makes sense? I want it to be more like 75% based on my cheaper peristaltics lying around. That ought to do the job. Family visiting from out of town though, so this weekend is shot! 1 Quote Link to comment Share on other sites More sharing options...
pdxmonkeyboy Posted November 18, 2018 Share Posted November 18, 2018 hey now, put the family in a motel, and get to work on this thing!! .Sent from my SM-G930V using Tapatalk 2 Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 20, 2018 Author Share Posted November 20, 2018 Ok, back at it tonight for a bit. First off, here is the standard and the geared stepper. The geared stepper is powerful, a 5:1 reduction. Even with efficiency loss it should be 4:1 effective worst case. The gain in torque is excellent, but there were many changes such as the shaft size, connection points, dimensions. This drove a need to redesign the pump head and attachment to the case. So I modeled this up tonight. It is redrawn from scratch in fusion (working with STLs is a pita)... The major changes are: - New mounting points for the gear box - New 8mm D shaft - Increased diameter of rotation that rollers are engaged with the tubing (help with back siphon) I hope to also add - keeper nuts for the pump top to hold it tighter and prevent threads from stripping out. - keeper for the tubing better than a screw into the tubing (not a fan of that...) - keeper on the shaft, just gotta find a place to fit it in... Will print tonight and start iterating over the next few days until this thing pumps like a boss. 2 Quote Link to comment Share on other sites More sharing options...
albertareef Posted November 20, 2018 Share Posted November 20, 2018 Looks promising! Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 20, 2018 Author Share Posted November 20, 2018 8 hours ago, albertareef said: Looks promising! I sure hope so! Definitely should have the torque at least. Cannot wait to give it a shot tonight or at lunch. Quote Link to comment Share on other sites More sharing options...
SuncrestReef Posted November 20, 2018 Share Posted November 20, 2018 Just curious...What's your background? Are you a mechanical engineer by profession, or is this just a side hobby in addition to reefing? Looks very cool! 1 Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 20, 2018 Author Share Posted November 20, 2018 3 hours ago, SuncrestReef said: Just curious...What's your background? Are you a mechanical engineer by profession, or is this just a side hobby in addition to reefing? Looks very cool! Thanks! Total side hobby like reefing. Like my signature Reef hacker at heart Day job is software engineer. 3d printing is amazing and I have learned so much including many hours of CAD via Fusion 360. Highly recommend it to those who want to have even less of life All the mechanical engineers like @Blue Z Reef and I think @Bicyclebill are probably biting their tongues looking at my amateur design. However, this is a high leverage model from the original design, which sure helps. 3 Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 20, 2018 Author Share Posted November 20, 2018 Printed. These are rough prints with a large nozzle to speed up prototyping. The final will look quite a bit better. 2 Quote Link to comment Share on other sites More sharing options...
albertareef Posted November 20, 2018 Share Posted November 20, 2018 So it looks like it's using 6 pressure wheels? Should be able to get some reasonably smooth flow I would think. Other tweaks to consider based on my memory of commercial units is having a groove in that top pressure cap to providing seating for the tubing. You could even have alternate caps for different gauge tubbing to accommodate different flow ranges. These are typically around half the depth of the tubing as I recall - which allows for 100 compression but helps support the tubbing more fully. At least that is my recollection... granted it's been a while. If I can find time at some point, I could try and dig some out of the basement at work and get some shots. 1 Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 21, 2018 Author Share Posted November 21, 2018 20 minutes ago, albertareef said: So it looks like it's using 6 pressure wheels? Should be able to get some reasonably smooth flow I would think. Other tweaks to consider based on my memory of commercial units is having a groove in that top pressure cap to providing seating for the tubing. You could even have alternate caps for different gauge tubbing to accommodate different flow ranges. These are typically around half the depth of the tubing as I recall - which allows for 100 compression but helps support the tubbing more fully. At least that is my recollection... granted it's been a while. If I can find time at some point, I could try and dig some out of the basement at work and get some shots. Dig some out and PM me for my address! project cancelled! Lol... Yes, they allow for six bearings/rollers, but the as-built only shows 3. I only have 3 bearings right now, they are spendy little suckers so I wanted to be sure. Those are good ideas. Most of the ones I have lying around here have a tubing channel, just not this design. 1 Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 21, 2018 Author Share Posted November 21, 2018 Progress tonight! The new pump assembly and motor works! Items fixed: - Plenty of torque - Back siphoning fixed - Motor runs cooler - Motor runs quieter It is so crazy accurate, impressive. I was able to drive it up to 32 mls / minute. My goal is about 150-200 as I run 128 mls/min right now. It is going to require a new pump head and the larger tygon tubing I have on hand. So back to CAD and back to ebay/ali/amazon for bigger bearings. 1 Quote Link to comment Share on other sites More sharing options...
Blue Z Reef Posted November 21, 2018 Share Posted November 21, 2018 Keep up the good work! Would love to do one when you get the bugs figured out HaHa! I’d definitely need your help with the wiring/programming end of things...circuits was never my forte (hence why I’m not an EE/SE lol). Honestly at 32 ml/min (roughly 12 plus gallons per day) would be great for a dual head auto water changer pump! If you need some acrylic cut out to fancy the final rig up (side covers or something), let me know, just need a 2D cad file and we’re good to go! 1 Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 21, 2018 Author Share Posted November 21, 2018 9 hours ago, Blue Z Reef said: Keep up the good work! Would love to do one when you get the bugs figured out HaHa! I’d definitely need your help with the wiring/programming end of things...circuits was never my forte (hence why I’m not an EE/SE lol). Honestly at 32 ml/min (roughly 12 plus gallons per day) would be great for a dual head auto water changer pump! If you need some acrylic cut out to fancy the final rig up (side covers or something), let me know, just need a 2D cad file and we’re good to go! Thanks Jeff, will be glad to help. I am hoping to do a custom PCB order to really simplify the wiring if enough people are interested. You have acrylic cutting connections too! Nice 1 Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 21, 2018 Author Share Posted November 21, 2018 Last night's design. It's brand new, from scratch. Goals: - Run bigger tubing - Use commodity fidget spinner bearings (easy to source, cheap) Here it is ready to print: 3 Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 21, 2018 Author Share Posted November 21, 2018 The not so glamorous side of 3d printing. This was because my 'infill speed' was too high for the nozzle size in use. It couldn't melt plastic fast enough. Fast forward to a good looking, working version (on right) Now I gotta say, these version is HUGE!. Seems like I am going to lose 50% of the gearing advantage by going this big (2x diameter of original). Mechanical engineers please confirm These 608 bearings are just too huge... Ah well, might as well finish it off and see... 1 Quote Link to comment Share on other sites More sharing options...
TheClark Posted November 22, 2018 Author Share Posted November 22, 2018 Original next to big guy 1 Quote Link to comment Share on other sites More sharing options...
TheClark Posted December 13, 2018 Author Share Posted December 13, 2018 Been working in the evenings on a completely new set of pump hardware. This is brand new from scratch, nothing to do with the original pump hardware. Still a work in progress, but here is a render: - Smaller, better gearing ratio. - Rotors lock together like a puzzle, reinforced with screws through middle of shaft - Able to run the 10mm tubing - Bolts directly onto the motor, the motor shaft gives the whole pump rotor strength - Designed to be bolted onto a geared stepper motor, for plenty of power - Tubing locks into place in housing, tubing will not drift while pumping 3 Quote Link to comment Share on other sites More sharing options...
albertareef Posted December 14, 2018 Share Posted December 14, 2018 7 hours ago, TheClark said: Been working in the evenings on a completely new set of pump hardware. This is brand new from scratch, nothing to do with the original pump hardware. Still a work in progress, but here is a render: - Smaller, better gearing ratio. - Rotors lock together like a puzzle, reinforced with screws through middle of shaft - Able to run the 10mm tubing - Bolts directly onto the motor, the motor shaft gives the whole pump rotor strength - Designed to be bolted onto a geared stepper motor, for plenty of power - Tubing locks into place in housing, tubing will not drift while pumping Cool! I want to see this bad boy up and running. Curious to see what kind of flow rate range you achieve with your motor choice. Quote Link to comment Share on other sites More sharing options...
TheClark Posted December 14, 2018 Author Share Posted December 14, 2018 1 hour ago, albertareef said: Cool! I want to see this bad boy up and running. Curious to see what kind of flow rate range you achieve with your motor choice. Thanks! It's working! Going to make one change to the housing to keep the rollers engaged a few more degrees in the rotation. My goal is around 100 mls/min, but with the pump turning slow. Idea is, that the tubing should last longer for the same amount of mls pumped. Theory is moving slow is less wear on the tubing. It is looking very good! Still gotta design a new case for the electronics, but this is a huge step forward. Quote Link to comment Share on other sites More sharing options...
TheClark Posted December 14, 2018 Author Share Posted December 14, 2018 Tonight's changes were a flange I guess on rotor, to keep the tubing in place. The dang thing works! Allot of next steps but seeing a light at the end of the tunnel here... 2 Quote Link to comment Share on other sites More sharing options...
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