Tumble Washer - PVC and 3D Printed Construction

Hello fellow makers, thinkers, do'ers, and instructable'rs! For my 2016 3D printing contest entry, there are a few things I would like to clarify first and foremost.

Originally I had planned a much different project, however with time constraints, I had to switch directions near the last minute. With that being said, this project is still a work in progress, however at the current state is roughly 85-90% complete. Currently I am on vacation, but certainly did not want to pass up the 3d printing contest this year. In conclusion, I am going to provide as much information as possible, accompanied by MANY photos. I have also made sure to include all files necessary for the 3D printing aspect of it.

The idea behind this design follows that of my original design intents. That is such that I believe many people discredit 3d printing technology (at home FDM in particular), and do not realize that many things can be made possible with the addition and integration of 3d printed parts. To further elaborate, I am saying that 3d printed parts can certainly have their shortcomings as far as strength when comparing to other materials and manufacturing methods. However, I believe that in many cases the maker/designer can utilize various techniques which effectively satisfy personal/company/industry needs. For a good example of this, please see my previous instructable "How to Create a Large 3D Printer using a Smaller 3D Printer - "Project Locus"".

https://www.instructables.com/id/How-to-Create-a-La...

Furthermore, a simple example of this would be a purely 3d printed beam (see photos in step). The beam by itself will likely be very weak when comparing to an off-the-shelf type of beam such as extruded aluminum. However, we can utilize 3d printing, and create a composite beam with something as simple as hanger straps. The beam itself (without hanger strap) would be very weak, particularly when stressed against the orientation of the layers. To create a composite beam of greater strength, we can print a few parts which effectively sandwich/house the hanger strap in the desired orientation (see photos). The key takeaway of the beam example is that neither a purely 3d printed beam nor a beam constructed purely of hanger straps would satisfy our needs. The integration of the two allows us to effectively harness the strengths of the steel strap where the printed parts may fall short.

---Project Motivation---

The main motivation for this project was derived from the continuous use and desire for clean shop rags (the typical red cloth type). While pursuing my contest entry at the time, I was making endless trips to various stores to gather supplies, and was running low on time. In addition to running low on time, I came to the realization that I did not want to spend even more money on shop rags.

Due to the nature of the use of shop rags, these become covered in all sorts of chemicals. Greases, cleaning solutions, sealants, and other substances end up covering these rags. The typical solution to acquiring new/usable rags, is to either

(a) buy more rags

(b) wash the current rags

(c) quit working on all projects all together, and change my lifestyle entirely

Since I have ruled out options (a) and (c), the solution remains that I would wash the rags. To wash the rags, I could use my household clothes washer, however I do not nearly like the idea of throwing these filthy rags in the same machine as my everyday clothes. Not only does the idea of greases and chemicals spreading to my clothes bother me, but I also do not want to ruin my machine.

---Design Overview----

The design of this tumbler allows multiple uses. My main desire for this tumbler was to effectively rinse, tumble, and wash shop rags until they are essentially "clean enough for re-use". Other uses for this tumbler could certainly include

- Tumbling freshly picked garden vegetables with soap and water

- Washing small parts in a water and degreaser solution

---Plan of Attack (Method of Approach)---

To accomplish this goal in such a short time period (1.5 weeks) I began designing and building purely on the fly, which is most likely where the phrase "winging it" was derived from. I knew a few things must be integrated, and the exciting thing was that most could be printed.

Upon reviewing this instructable, you will notice that I became very familiar with PVC pipe and fittings (sort of). Although I am not a plumber by any means, I found it to be very beneficial and time consuming to buy the small fittings and tubes available for less than a dollar each (versus printing them). For the most part, the PVC pipe used is 1/2" PVC, Schedule 40. In most cases I am not concerned too much with the actual operating pressure, which is why you'll notice I have interchanged the "conduit PVC" (grey) with the white schedule 40 PVC.

Given the nature of this project, and the contest, I would like to take a moment to mention a few things.

-It is important to calibrate your machine on a somewhat regular basis, to ensure accurate parts are created.

-Slicers are not all created equal, and each printer seems to have their favorite slicer. In this build, you'll notice I am printing parts on both of my printers. The Delta style printer is a Rostock Max V2, which is an absolutely AMAZING printer. Per the manufacturer's recommendation, they suggest using (and provide excessive information on) using MatterControl as a slicer. The only reason I do not use this slicer is because it doesn't run correctly on my windows 7 computers. https://www.seemecnc.com/products/rostock-max-comp...

- For my Rostock Max V2, I have had great luck with using Cura as a slicer.

- For the other printer (the one I designed and built, "Project Locus"), I use Craftware. For whatever reason, Cura seems to mess with my printer, and Craftware excels with it. The features of Craftware are phenomenal. Automatic support material generation, along with click-and-place support material generation are just a few of the features in which Craftware excels.

https://craftunique.com/craftware

- Furthermore, Craftware provides more than enough features to allow the user to fine-fine-fine tune their printer. While some slicers only allow "simple" and "advanced" modes, Craftware allows customization all the way down to certain offsets of perimeters. Features such as this enable the user to achieve extremely accurate parts, which includes accurately sized holes.

- Not all filament is created equal. While it can be tempting to purchase the cheapest filament possible, don't. I have made the mistake before of purchasing filament based purely on the price, and ended up with a lot of mediocre/bad filament. Filaments I have tried, and had good luck with are:

--- WYZ Works Filament http://www.wyzworks.com/

--- SeeMeCNC Filament https://www.seemecnc.com/

--- Hatchbox Filament http://hatchbox3d.com/

- The use of ABS filament is particularly useful on the pump parts, and/or wherever you'll need to bond to pipes. I speak from experience when I say that it can be difficult to find an adhesive which will successfully and reliably bond PLA filament to PVC pipe. To combat this issue, ABS filament comes to the rescue. You'll see on parts such as the dual screw pump, that I have bonded parts with ABS cement. ABS cement is available in the plumbing section of hardware stores, and works great for sealing and bonding ABS parts. 3d printed or not, the adhesive is meant for ABS, and is indifferent with respect to the parts' origin when it comes to bonding.

I had originally built a triangular prism design, however I have since transitioned to a trapezoidal prism design. With that being said, please keep that in mind when viewing these pictures. The next step will provide further insight into the mounting of the spool.

---Materials Required, per side---

- A pack of standard (6mm diameter) plastic airsoft bb's.

- Polyethylene tubing, 1/4" I.D. (6.35mm). You'll really only need a foot or two for this step

- 1/2" PVC for frame pieces

- (2) 3D printed center spool mount

- (3) 3D printed frame mounts (connects legs that reach out to main frame)

The idea behind the center spool mount bearing lies in the sense that for this application, we simply don't need a super low coefficient of friction for rotation that a bearing would provide. To get past this on a cheaper budget, we can create a similar setup using tubing and bb's.

The airsoft BB's are not meant to rotate. The purpose of the BB's is to provide an inner skeleton structure for the tubing to maintain it's shape (diameter) while accomplishing the desired circular bend.

---Materials---

- (1) Cardboard paper tube, 3" diameter, 24" long. I acquired mine from an exhausted roll of shipping packing paper. This is not particularly specific, pvc would work here as well. If using something else, please make sure to scale the 3d printed parts accordingly and you should be fine. (to match the outer diameter of the tube with their respective printed parts).

- (1) Metal conduit piece to serve as the center rotation axis. Again, this is not specific, just what I had on hand. The tube I used is roughly 3 feet long, and a little over 1" in diameter. The lighter the better.

- Duct Tape, I used this to wrap the cardboard in to protect it from the water/cleaning solution during use.

- Silicone RTV sealant, applied as shown to seal up any caps to protect the cardboard tube.

- Galvanized picture hanger wire - these small (~8" sections) serve as the spokes of the spool itself.

- 1/4" I.D. Polyethylene tubing - I used this to wrap around the circumference of the wire cage as a safety measure to protect hands from getting cut.

- Zip ties - To attach tubing to perimeter/circumference of the wire cage

- Wire mesh - can be found in the fencing section of the hardware store, very common. I have had good luck with the mesh I am using in similar projects.

Again, I apologize for not being able to elaborate verbosely, however I do believe that having lots of pictures can be much more beneficial than a well written description in most cases.

The purpose of the main pump is to provide means of circulating water/cleaner flow with the water off. By having this pump integrated, the machine can be operated via drill power and effectively rotate/rinse the items being tumbled. The inlet of the pump will be such that it is fed "used" fluid, and at the outlet will be fluid to be dropped from overhead. The overhead dropping point will be the PVC which can be seen running along the top of the frame rails near the end of the instructable (which has 6 drilled holes, evenly spaced, facing downward).

---Materials---

- 5/16" or 8mm rod, ~200mm (7.9") long.

- Small spring, this allows the pump prop to rotate in a near fixed position (axially), but also allows some misalignment due to slightly bent rods.

- 3" PVC Pipe Cap, schedule 40 (pump body)

- 3" PVC pipe lid, (not pressure rated, should fit inside of a 3" pvc pipe)

-(2) nylock nuts

- (5) 10-24 x 3" flat head machine screws

- (5) 10-24 nuts

- Silicone RTV sealant (for creating gaskets to seal pump housing).

Finding the center of the cap (location of rotation axis)

This step is important, but not necessary. It allows us to find the center of the cap, via experimental methods. By balancing the cap on a pick, we can find the point which represents the center of mass. I say this is not necessary because this only tells us the location of the center of mass of the body (which will not be rotating). However, it does provide a quick and accurate way to find the center to drill the axis location. When drilling this hole, you'll want to drill it out to the shaft diameter (either 5/16" or 8mm).

The "Dual Archimedes Screw Pump" is based on the following principle:

https://en.wikipedia.org/wiki/Archimedes%27_screw

The purpose of this pump is to provide a simple way of filtering the used water before being recirculated. Screw pumps are particularly useful for this, as they allow even large particles to be moved along with the fluid. Placing this pump strategically will allow the pump to transfer the chunks/debris from the solution to a remote location (as waste).

The pump body is created by cutting a section of ABS pipe to length, and then cutting it lengthwise ("hotdog style") - to split the pipe in half. Once cut in half, the pipe halves are bonded together using ABS cement in a side-by-side manner. The ABS cement seems to be enough to bond these, however if you're feeling suspicious, you may be able to use an epoxy such as JB weld as a substitute/in addition to the ABS cement.

Since I modeled the pipe in CAD anyway, I have included the ABS pipe housing file in STL form if anyone wants to try and print it versus cutting the pipe through manual methods.

---Materials---

- 3d printed screw pump worm gear

- (1) 8" section of ABS pipe, 1.5" diameter

- (2) 608 Bearings, allows rotation of screw pumps

- (2) sections of 8mm or 5/16" threaded rod, ~8" in length. I recommend you cut these to size once the other parts are printed/made.

- (4) nylock nuts for the 8mm or 5/16" threaded rod (whatever size you chose).

- (6) washers for threaded rod, 1/4" size is what I used

- (2) small sections of 1/2" pvc pipe, 0.75" in length (19.05mm). These will likely go away if I redesign the pump in the future, however I used these on the fly to allow proper rotation of the worm gear when installed.

I have created two screws using two different ways. The main reason to create a screw one way vs the other depends on a couple of factors.

- The screw printed in 4 pieces took ~1.5 hours to print, however required roughly 45 minutes of post-processing work to bond the pieces together. To create the screw this way, I used Netfabb Basic, and then split the file into 4 pieces. Following the splitting, I then imported the four parts into my slicing software to layout the parts as shown. https://www.netfabb.com/products/netfabb-basic

- A primary reason that one would want to print the screw this way, is in the event that your printer is not tall enough/does not allow you to print the worm gear in one piece. Also, there is hardly a need for support material in this configuration. The lack of support material means less wasted material, and can sometimes mean a better looking part.

---What's left to do---

To finish the integration of this part into the tumble washer assembly, pulleys will need to be created (simple), which will allow the belt drive to drive the pump. Since both of these screw pumps are right-hand thread, they will both be spinning/rotating the same direction during operation.

In addition to creation of the pulleys, a mount will have to be created to keep the pump in place.

This stage of the project is where I left off. And by where I left off, I mean this is where the project was paused before going out of town this weekend. I plan to create a mounting platform of sorts for an electric drill to mount.

The reason I chose to use an electric drill versus other methods of driving the rotation and pumps, is fairly simple. Almost everyone has access to a drill, and if not, they are readily available. The options which were discarded were:

- Pneumatic (air) powered rotation

- DC motor/Arduino Controlled, mainly due to lack of time and because it's simply not necessary.

I plan to have the electric drill driving a main pulley (likely the spool), and then have a homemade belt routed to drive 3d printed auxilary pumps by means of 3d printed pulleys.

The homemade belt is to be made by using a combination of the following components:

- Elastic, can be found easily at any store which sells arts and crafts. Commonly used for creating/repairing wastebands on pants.

-Ninjatek ninjaflex filament, will be bonded in such a fashion to either create a V-Belt type of belt on the elastic, or something more similar to a serpentine belt as found on full size car engines. http://ninjatek.com/

- Silicone RTV, will be used to help encapsulate/seal the flexible filament to the elastic.

Again, I'm sure with enough looking or other motivation, you could find a belt of the right size, however I am trying to illustrate that you can make almost anything with very common materials. In particular, the use of flexible filament in raw form is very cool to me. I have done initial experiments to determine and compare the spring constant of the flexible filament vs. elastic. vs silicone, and results seem promising. (For more information on spring constants, see: https://en.wikipedia.org/wiki/Hooke%27s_law )

The tumbler will integrate Air power, which will ideally be optional (but preferred). Under the assumption that most of those who would be creating this tumbler also have some sort of compressed air source, the addition of air will provide great benefits.

---Venturi Effect---

The Venturi Effect is a well-known, and widely used concept utilized in the field of fluid mechanics. This will be utilized in the tumble washer system to allow a misting/washing system for the rags/vegetables/parts being tumbled. Simply put, one can create an effective spray nozzle system with nothing more than compressed air and a stationary fluid source. The stationary fluid source in our case will be the recycled cleaning solution.

---Design/Setup---

Sure, in concept this all works great. However, concept and ideas only go so far. This system is not yet equipped with the system, however many tests have been completed. The tumbler will have a suction tube(s) placed at a location near the lowest point of the fluid cavity (tarp). I say near the bottom, because if it were actually at the bottom, we would likely have issues with the tube clogging frequently. In effort to avoid clogging, one could use a screen or filter setup, however I believe the optimal position for the pickup tube will be such that one of the pumps feeds the fluid to a remote reservoir before being re-sprayed.

If you have any interest in creating the same workbench I have created (as seen in many pictures), it is shown here. The bench is created from two "discount shelf" pieces from my local hardware store (Menards). These two shelf pieces cost me $2 each. The printed braces are secured using #10 woodscrews of appropriate length. The more braces you use, the better. I have found 3 to be plenty for how I use it.

The washer allows a garden hose to be hooked up to the "inlet". Besides initial filling of the reservoir (tarp), the hose hook-up also allows the machine to have a rinse function. That is to say, once the user is satisfied with the cleanliness of the items, they can have the machine rotate via drill, and allow the hose to run and rinse the items. The outlet of the water comes through the top PVC pipe, which has 6, 1/8" holes drilled along the length of the pipe. These holes were drilled in an evenly spaced manner, and face downwards.

As mentioned, the current state of the project is unfinished, but very close to completion. Due to previous project plans falling through, and new ones arising (this one), I was unable to entirely finish this project. I am currently out of town, however plan to finish this project once I return home. If anyone has any ideas/comments/suggestions, I'd love to hear all feedback. Constructive criticism is strongly encouraged, as well as any suggestions for future additions/improvements.

I appreciate those who have taken the time to read through this, and am very excited to continue making with the fellow members of instructables. I absolutely love this website, and am constantly in awe with what everyone is creating. With that being said, I look forward to continuing to grow and expand my knowledge with everyone here!

Thanks for looking, and of course, cheers!

-Pat