Oral B Electric Toothbrush Head Holder

Details

This is a brush head holder compatible with Oral B Oral B Braun Pro 1000 Cross Action Precision Clean 7000 9600 500 3000 8000 Electric Brush Heads (link to heads I use on Amazon).  This is designed to be easy to clean and secured on any countertop/wall.  A critical aspect of this design is the need to smooth the surface to ensure that the water that comes off the brush head does not penetrate the print or create spaces that cannot be cleaned.  This is important to ensure that the brush head stays clean and ensure the silicon pad can stick to the holder.  I will provide details on how to smooth the surface further below, I did not use vapor smoothing.

All forward facing features are smooth with sweeps and angles designed to keep the water collected at the bottom of the holder and not drip around it.  All surfaces allow easy access for cleaning by hand with a wipe.

Example of an early prototype, after an attempt at cleaning, without smoothing.

This design also ensures that if multiple heads are used than they will never come into contact with one another even if they are not placed in the holder correctly.  The base is spaced to keep the brush heads apart.  Again this helps ensure cleanliness when multiple brush heads are used for the same electric toothbrush.  

Print Settings

Due to the critical nature smooth surfaces of this print ABS is required for the acetone smoothing process.  To aid that process tight layer lines are a good idea and somewhat thick walls should be used in case one gets too aggressive with sanding or acetone application.  Note the bottom surface has a feature to help align silicon sticky pads or command strips and will require support unless you bridge settings are very good (supports are not needed anywhere else on the model).  

• Nozzle: .4 (line width .4)
• Layer height: .1
• Supports (normal): ON
• Walls: 4
• Top/bottom: 6

Smoothing

After printing with as fine a layer line you are comfortable with I suggest a light sanding of the entire part with a grit lower than 220 (recommend 400).  I used 220 from a woodworking project and I think it was too aggressive, I can see some scratches from the sandpaper on my parts.  

Acetone application - Please use proper PPE: safety glasses, gloves, chemically compatible containers, and a well ventilated area.

In a well ventilated, I recommend putting a small amount (few tablespoons) acetone in a small glass jar/container and applying it with a Q-tip to the sanded surface of the part. Do this in long consistent strokes, don't dab the surface and do many small strokes or it leave the surface inconsistent and possibly get the Q-tip stuck on the surface.  Try not to touch the surfaces with recently applied acetone because they will be tacky and touching will mare the surface.  Let the part dry, this should only take a few minutes and you can check by touching the back surface to test if it feels tacky.  Repeat the process a few times until you think the surface is smooth enough, this depends on your layer settings, sanding, and application of the acetone.

If you have experience with ABS smoothing and have a better method please let me know in the comments so others can see.

Fixturing

To keep the holder easy to clean it needs to be easy to remove.  Double sided tape or command strips on the back of the holder in the recessed surface will work very well at fixing the holder in place but will be difficult to remove (feel free to do this if you want to mount it to a wall floating above the countertop).  Instead of tape I have used sticky silicon pads commonly used to adhere a phone to dashboard of a car.  These pads are inexpensive, easy to cut (scissors), easy to apply, and clean without losing stickiness over time.  

Cleaning Pads

Select the links in the above text to find anything I have mentioned here like the silicone pads or example of brush heads.  My family have used these for a decent amount of time and have been happy with them so far.  They do take more effort than most things you can use right off the printer but it's very convenient and I like that I can keep them cleaner than most options at the store.

If you want to check you brush head compatibility see the drawing in the attached images I used to create the CAD for the brush head I use.