DIY Media Rotator betarelease V01 - · PDF fileProduct Media Rotator (Horizontal, Vertical,20 Degree) DocID D0002 Version 0.1 Author Anthony Fernando Status Pre-release Editor Tekla

Product Media Rotator (Horizontal, Vertical,20 Degree) DocID D0002 Version 0.1 Author Anthony

Fernando Status Pre-release

Editor Tekla Labs Date 16May2011

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Product Overview Uses: Media rotators are primarily used to ensure the even mixing of solutions requiring constant, gentle stirring motions. Media rotators are typically used when long mix times are needed, with bacterial cultures, or occasionally in medical labs for assays.

How They Work: Media rotators continuously and slowly spin a disk that holds sealed vials. The electric motor that drives the rotation has been slowed down to a lower rotation speed by either geared connections or a potentiometer.

Advantages: Media rotators provide long-‐term rotation in a very maintenance-‐free setup. They have minimal parts and they can be built with a variety of flexible parts.

This Rotator can rotate a total of eight centrifuge tubes at constant speed (our design is for four 50 mL and four 15 mL tubes). Various speeds can be set. Power supply is a wall outlet. The motor rests on a platform that can be angled to rotate the centrifuge tubes while they are horizontal, vertical, or at approximately 20 degrees from vertical.

Figure 1. Tekla Labs media rotator with 50mL centrifuge tubes set at 20 degrees from vertical. Figure 2. Front view of design to show electronic components (vial holder disc removed).

Acknowledgements and Creative Commons Licensing Designed by Anthony Fernando (formerly of the University of California -‐ Berkeley) Design open-‐source courtesy of Tekla Labs.

This blueprint is made available under a Creative Commons Attribution-‐NonCommercial-‐ShareAlike 3.0 Unported licence. http://creativecommons.org/licenses/by-nc-sa/3.0/




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Contents Product Overview .................................................................................................................................................................. 1

Acknowledgements and Creative Commons Licensing ......................................................................................................... 1

Required Skills and Tools ....................................................................................................................................................... 2

Specifications ......................................................................................................................................................................... 3

List of Materials ..................................................................................................................................................................... 4

Details of Materials ................................................................................................................................................................ 5

Motors and Power Supplies: A variety of motors an power supplies can be used ............................................................... 5

Module 1: Rotator Body ........................................................................................................................................................ 6

Module 2: Vial Holder .......................................................................................................................................................... 10

Approximate time = 1 hour ......................................................................................................................................... 10

Module 3: Control Wiring .................................................................................................................................................... 12

Final Assembly ..................................................................................................................................................................... 15

Validation and Testing ......................................................................................................................................................... 18

Proper usage and maintenance ........................................................................................................................................... 18

Feedback .............................................................................................................................................................................. 19

Required Skills and Tools

Safety considerations during construction • Soldering iron becomes extremely hot. Hot solder and flux can give off harmful fumes. Conduct soldering in a

well ventilated environment and take standard precautions to secure hot iron. • Motor can become hot immediately after operation. • These safety considerations are, of course, in addition to normal precautions necessary when using the various

tools needed for this project.

Required skills Skill Module(s) Related documents

Soldering 3 Soldering How-‐To




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Required tools Tool Module(s) Related documents

Ruler 1,2 -‐ Soldering iron 3 Soldering How-‐To Screw Driver 1,2,4 -‐ Drill 1,2 -‐ Band Saw or Metal shears 1,2 -‐ Vice 1,2 -‐

Specifications

List of specifications 1. Vial holder rotates at an adjustable speed. Maximum rotation rate depends on the motor, power supply, and

potentiometer. An acceptable range is 0-‐80 RPM. 2. Vial holder can be adjusted to remain horizontal, vertical, or at approximately 20 degrees from vertical. 3. Rotator operates on plug-‐in wall power. Wall power allows the media rotator to operate for long periods of

time.




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List of Materials Part Part Description Module PartID Quantity Cost (USD)

20” x 10” x 1/16” Sheet metal

Rotator body 1

Heavy Duty Zip Ties

To secure the motor to the rotator bridge 2

Toggle Switch On/off switch 1 25Ω Potentiometer

To set various speed settings, can be bought with knob

1

Potentiometer knob

To adjust the potentiometer resistance 1

DC Motor Spins the vial holder 1 AC to DC Converter

Convert power from AC at the wall outlet to DC for the motor to use

1

Power cord compatible with AC/DC Convertor

To connect the rotator’s electronics to the wall outlet power source

Solder Connects electronics; can also wire by hand -‐ Epoxy or JB Weld

To connect the vial holder disc to a connection compatible with the DC motor

2

Metal Screws with washers.

Connects rotator bridge to rotator body 4

Vial Clips with self tapping screws

Holds the centrifuge vials to the vial holder disc 8




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Figure 3. Overview of materials used

Details of Materials Motors and Power Supplies: A variety of motors an power supplies can be used M001 – Rotator body Cut from aluminum. This part can be made in a variety of ways, as long as the basic geometry of a rotator is maintained. M002 – Heavy duty zip ties These are a quick and fast ways to connect a motor to a rotator bridge. Many other methods (bolts, brackets, etc.) are acceptable ways to connect the motor to the bridge. M004 – 25Ω Potentiometer The potentiometer must be rated to the wattage needed to power the electric motor so that it does not overload. M011 -‐ Vial Clips with self tapping screws Clips designed to hold broom handles were obtained from a hardware store to function as clips that could hold 50 mL and 15 mL vials.




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Module 1: Rotator Body

Approximate time = 2 hours

Step-‐by-‐step instructions 1. Using the drawings provided, trace out the design on your piece of sheet metal. The holes marked by

arrows indicate the holes used to adjust the rotator angle between horizontal, vertical, or at approximately 20 degrees from vertical. For the prototypes built for Tekla Labs, both steel and 5052 Aluminum were used, the latter being much easier to work with while providing sufficient strength.

Figure 4. Rotator body schematics (units are in inches) and picture.




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2. Using either a band saw or metal shears, cut material along the cutting lines. If desired, use a belt

sander or metal files to round off any sharp edges or corners.

Figure 5. Metal shears were utilized for the particular piece of equipment, but a band saw would be a suitable alternative.

3. Using a 0.5” drill bit, drill out the holes that were marked for the switch and potentiometer. Depending on the specific parts you have, the drill size might vary.

4. Using a 10-‐32 clearance drill bit, drill out the mounting holes marked towards the edge of the sheet.

It’s not necessary to stick to the exact dimensions specified (it’s probably the case that what you have access to will be sufficient).




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Figure 6. All holes drilled out.

5. Using the bending feature on the metal shears, or a vice, bend the aluminum sheet along the fold lines to the specifications in the drawing (once again, exact dimensions are not necessary, and “eye-‐balling” where things need to be should be fine).

Figure 7. The sheet undergoing the bending process and the final product on the left.

6. With the left over sheet metal, sketch, cut, and bend the bridge for the media rotator and drill out the respective holes.




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Figure 8. The step by step build process for the bridge of the rotator.




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Module 2: Vial Holder

Approximate time = 1 hour

Step-‐by-‐step instructions 1. Using the remaining sheet metal, sketch out a circle according to the specifications listed in the

drawing and with a band saw and belt sander cut out and smooth out the disk (exact precision is not necessary).

Figure 9. Build process of the disk

2. Clamping the disk down, you can use a drill and locations to place mounting holes for the vial holders (It’s important that the holes are equally spaced along the perimeter of the circle so that everything is balanced when spinning).




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Figure 10. Drilling the holes for the vial holders.

3. Attach the vial holders and epoxy the motor mount to the back of the disk. The connection of the circular plate to the motor was connected with “JB Weld” to a connector. Epoxy would also work.

Figure 11. Attaching the vial holders with tapping screws and using epoxy to attach the motor mount.




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Module 3: Control Wiring

Approximate time = 1 hour

Step-‐by-‐step instructions 1. Insert the potentiometer and toggle switch into the holes of the frame.

Figure 12. Potentiometer and switch secured to frame.

2. With the potentiometer and switch secured into the frame, you’re ready to begin the wiring process; throughout the wiring process, the diagram shown below will act as a good reference and can help clarify any questions you might have.




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Figure 13. Basic wiring diagram illustrating the circuit.

Figure 14. Basic breakdown of a potentiometer.

3. Solder the positive (+) wire of the AC-‐DC converter to one of the points on the switch and another

separate wire to the negative terminal of the potentiometer.

Figure 15. Positive AC-‐DC wire soldered to switch and negative terminal of potentiometer to separate wire.




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4. Solder another new wire to the (+) output of the potentiometer.

Figure 16. Output wire soldered to potentiometer.

5. Connect the open terminal from the switch to the positive (+) terminal of the potentiometer.

Figure 17. Wire connecting the switch to the positive (+) terminal of the potentiometer.




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Final Assembly

Approximate time = 30 minutes

Step-‐by-‐step instructions 1. Attach the bridge to the frame of the media rotator with screws and washer, and zip-‐tie the motor to

the top of the bridge. Depending on the size and shape of your motor, a more secure mounting bracket may be constructed using sheet metal. One suggested design is below.

Figure 18. Bridge attached with screws and washer and motor zip-‐tied to bridge.

Figure 19. One suggested V-‐style bracket alternative to mount the motor on the rotator bridge.

2. Depending on the type of motor that you have sourced, the method you use to connect the terminals

will vary, for this particular setup the motor we found required slip-‐on connectors. Connect the positive output (+) from the potentiometer to the positive terminal of the motor and attach a new wire to the ground (-‐) of the motor.




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Figure 20. Close up of the negative terminal connection to the motor.

3. The last step is to connect the negative terminal from the motor, potentiometer and AC-‐DC converter

together.

Figure 21. All the grounds soldered together.




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4. After connecting all the grounds, you’ll have your finished media rotator.

Figure 22. Finished rotator.




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Validation and Testing

Inspection 1. The rotator should spin smoothly and at a continuous speed without wobbling. 2. Adjusting the resistance in the potentiometer should change the speed of rotation.

Testing 1. Fill two 50 mL tubes with about 25 mL of water. Both vials should contain an equal amount of water. Insert the

tubes into opposite vial clips on the rotator. 2. Plug in media rotator and flip on/off switch to on. Gradually turn knob to higher setting. Rotator disc should

spin faster as potentiometer resistance is lowered and motor is operated at a higher speed. 3. The water in the in tubes should become thoroughly mixed throughout the tubes as the rotator spins. The

rotator should not wobble as it spins.

Proper usage and maintenance

Usage 1. To adjust the rotator between horizontal, vertical, and 20 degrees from vertical settings, remove the bolts that

are securing the rotator bridge to the rotator body closer to the back of the rotator. 2. Pivot the rotator bridge to the desired angle and align bolt holes on the rotator body and rotator bridge. Insert

the bolts to fasten the bridge into position.

Operator safety 1. When working with hazardous chemicals, rotator should be kept in secondary container to catch any spills. 2. Always ensure samples are sealed completely in their vials. 3. Only adjust the angle of the rotator when the motor is turned off.




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Maintenance 1. Always balance the rotator disc when using it. This means that the vials should be placed on the rotator disc

with radial symmetry and so that it is evenly balanced.

Figure 23. An evenly balanced media rotator with four vials.

2. Keep electrical components dry. 3. Unplug when not in use.

Feedback The Tekla Labs community wants to hear from you! Please give back to the Tekla Labs community by letting us know if you:

-‐ find alternative materials or building tools to use -‐ use another approach for building a module or part of a module -‐ come up with a whole new design for this type of equipment (or another equipment piece!) -‐ had any other problems or solutions to share -‐ need help with specific parts of this Tekla Blueprint. What is unclear? How can we make this better?

To get involved in the Tekla Labs community, visit our website www.teklalabs.org.

Documents

DIY Media Rotator betarelease V01 - · PDF fileProduct Media Rotator (Horizontal, Vertical,20 Degree) DocID D0002 Version 0.1 Author Anthony Fernando Status Pre-release Editor Tekla