• Home
  • "BubsBuilds" Projects
      • Back
      • Assorted (hopefully) "Useful Stuff" Projects
      • Games
      • Generative Design Projects
      • Just Playin and Concept Demo Projects
          • Back
          • Print-in-Place
          • Flexure Fun
      • Pet Stuff
      • Printer Projects
      • Tool-related Projects
      • AgTech Projects
          • Back
          • Hydration and Hydroponics Projects
              • Back
              • Pumpin
              • Valvin
          • System-level Projects
              • Back
              • Project Fireplace
  • Tech Refs and Such

Latest Articles

  • Cam Valve - Gen3
  • Fractal Vise Jaws - Mechanical Bearings
  • High Flow Peristaltic Pump
  • Mech Tester
  • Axial Flow Compressor Concept Tester

Most Popular

  • 2020 Aluminum Extrusion stuff
  • Displacement Sensor - Double Compound Flexure-based
  • Bolt-Sorting Sieve
  • Flexure Fractal Vise Jaws
  • Saturn Platen Removal Tool
  • Precision Dosing Pump
  • Mech Tester

BubsBuilds Projects

Fractal Vise Jaws - Mechanical Bearings

Details
Category: BubsBuilds Projects
Last Updated: 30 August 2024
I've been tinkering with Fractal Vise designs for a while, but most of what I've focused on to date have been attempts at making flexure-based versions. But I recently decided it might be fun to try my hand at some mechanical bearing variants.
 
 
My main goal for this one was  for a low cost, easy to assemble version of everyone's favorite adaptive vice (ok, I can't confirm that "favorite" claim, but I'll still stand by it). 
 
Although there's certainly still room for improvement, I'm really pleased with how well this little guy works!  
 
If you want to see my previous, flexure-based designs, you can check those out here.
 
Printables | Thingiverse
 
BOM
 
Printed:
I printed parts from both FDM (with Sunlu PETG) and resin (with SirayaTech Fast) 
  • (16) L0 - the teeth
  • (8) L1 
  • (4) L2
  • (2) L3
  • (2) Bracket
COTS
  • (28) 3x16mm dowel pins
  • (2) 5x30mm dowel pins
  • (1) Panavise
 
 
 
No comments on “Fractal Vise Jaws - Mechanical Bearings”

Battery Racks

Details
Parent Category: BubsBuilds Projects
Category: Assorted (hopefully) "Useful Stuff" Projects
Last Updated: 10 February 2024
 
I don't remember when I first made one of these little racks for holding my camera batteries, but with each new camera battery type I've added to my shelf/bag, I've made a new  holder for em. I have found that the simple thing of 'contacts down = charged' / 'contacts up = needs charging' has been wildly helpful for me. So as a result I've also now started making some for other rechargeables.
 
For most of the below, the CAD files can be found on OnShape here  (the exceptions are the ones I made that predate OnShape)

Common Batteries

AA

Printables        |     Thingiverse
 
I've been gradually shifting over to rechargable AAs, so I now have quite a few in rotation.  So I   went with  a 22 position holder for these. I printed mine in Polymaker's translucent blue PETG. I really like the look of the filament, but the surface finish leaves a bit to be desired after my recent switch  to a 0.8 nozzle....clearly gots some tunin ta do. But it holds the batteries just fine, and looks aren't exactly top of my list of needs on this one :) 
 
 
 Based on my super thorough research (aka quick Google image search for AA battery drawings), AA batteries have a diameter between 13.50mm and 14.50mm. My calipering said mine land on the top end of that. So I went with a nominal hole diameter of 15mm for the holder. I have found that a 0.25mm radial clearance results in a snug fit with my printers.
 
I didn't actually print one of the below test cells, but if you want to dial in the fit to your liking I'd recommend printing one of these first. Then you can adjust the scaling in your slicer to get  it dialed in. The dimensions of the single match those of their full-sized buddies.
 
 BattRack_aa_sketch2_fde50.jpegbattrack_aa_model2_cdaf6.jpeg
 

AAA 

Printables         |     Thingiverse
 
For the AAAs, I basically just scaled the design above for the AAs. I printed mine   in Sunlu's black PETG.
 
  
I didn't actually print one of the below test cells, but if you want to dial in the fit to your liking I'd recommend printing one of these first. Then you can adjust the scaling in your slicer to get  it dialed in. The dimensions of the single match those of their full-sized buddies...and yup, copy/paste fo sho
 
battrack_aaa_model2_2634d.jpegbattrack_aaa_sketch2_2d9d1.jpeg
 

Camera and Related Batteries

Sony  NP-FZ100

My two main cameras use these NP-FZ100 batteries (I use a Sony A7R IV for photos and recently upgraded to a Sony ZV-E1 for video...and hey, if you want to help me get out of that debt, please feel free to buy something from any of these affiliate links...come on, you know you need some filament....eh? :) ) So I recently decided to update this guy from a 4 slot to a 6 slot. I like the larger size, but I won't lie, I miss the cool look of the gyroid fill through the clear filament on my 4 slot...granted, this seems like my fault.
 

Six Slot version

Printables    |     Thingiverse
 
This is a recent upgrade to the below that's been my workhorse for a good bit. I printed the new one from Polymaker's translucent green PETG. 
 
 

Four Slot version

Printables    |     Thingiverse
 
This is one that I've been using for many years now, I love this little guy. It's been on many a backpacking trip (yeah, I'm an idiot, but I just love me some backcountry astro photography  ¯\_(ツ)_/¯) and still looks/works as great as it did the day I printed it. Not gonna lie, I have no idea which translucent PETG I printed this  in...but it's one of em.
 
DSC03095_1ca82.JPG
 
 
 
 

Single

Printables    |     Thingiverse
 
For test fitting, or for just throwing an extra battery in the bag. I don't think I'd made any singles prior to this most recent batch of holders. But I'm actually looking forward to this little dude. My A7RIV seems to be quite a bit more efficient than my A7ii  was. So I can frequently get by with just one in the camera and a backup for a day of out and about. I  printed this one with a few base layers of Sunlu's black PETG and finished out with Polymaker's translucent green PETG. 
 
 
 
BattRack_fz100_model1_5e81e.jpegBattRack_fz100_sketch4_3e07f.jpeg
 

Sony  NP-F970

Printables    |     Thingiverse
 
These big boys are for some LED light panels I have, plus I recently got myself a little video monitor that can run off of these as well (although it zaps em pretty quick, so I prefer to have it on DC when possible.)
 
I went with a Four Slot version, since that's how many of these I seem to have at present. I printed mine in Polymaker's dark green PETG, and I really dig the color on this stuff.  May be my favorite shade of green PETG that I've found to date. 
 
  but with how large these things are, I'm tempted to also make a Two Slot version that would be easier to put in a camera bag. If you'd be interested in a two slot variant, let me know in the comments (below or whereever ya like). Maybe a couple of echoed thoughts will be enough to overcome my inherent laziness :)
 
 But I did go ahead and toss together a single/tester, as with the others up yonder. I printed this one in Polymaker's translucent green PETG...also like some others up yonder.
 
battrack_f960_sketch10_62c30.jpegbattrack_f960_model1_85a0f.jpeg
 

GoPro 

 
 
For the GoPro batteries, I went with a six position holder. The GoPro batteries have a bit of a trick geometry for getting the same sort of fit I like with my other batteries. They have flanges around the ends that are wider than the bulk of the battery. So if you make them snug, these fairly thin surfaces catch on the layer lines of the print. I'm sure it could be dialed in, but to be honest I don't use my GoPros a ton, so they don't rank too high on my list to get 'just right' at present. This will definitely work well enough for now!
 
I do really like how it looks though. I put down a few layers of Sunlu's black PETG before switching to Polymaker's translucent blue. I really like the way the contrast came out.  Although the photo of it less so, so you'll just have to use your imagination :)  
 
 
 
No comments on “Battery Racks”

Caster Wheel

Details
Parent Category: BubsBuilds Projects
Category: Assorted (hopefully) "Useful Stuff" Projects
Last Updated: 19 March 2024
 
 
Playing around with an idea for some  caster wheels.  

Update - Load Testing to failure

 Failed at a little over 600 Newtons! (~140lbf)

 

Build

I think the little video above pretty much covers the build process. The only part not shown is inserting the heat sets into the FrameMount and one of the wheels.
 

BOM

Printables    |   Thingiverse 
  • Printed Parts
    • FrameMount  
    •  Hub 
    • Retainer 
    • Wheel (x2) 
  • COTS
    • (2) M5 heat set - I used short ones
    • (30) 9.5mm balls   - I use this 3/8" slingshot ammo...kind of alot.
    • (2) M5x10 Fastener - I used a couple BHCS
Just pop in the heat sets, toss in some balls, and tighten...sounds so easy in theory, doesn't it? :)
 
If either of the bearings feel too tight, you can add a washer in between the mating parts to free things up a bit. You could also probably just extrude the face in your slicer also. For the one shown above, I had no spacers on the main bearing and one washer between the wheels. It puts the wheels on the sloppy side, but that's kinda what I want (I'm hoping this will make it hold up to pet hair and the like a smidge longer  ¯\_(ツ)_/¯)
 

 Design

CAD files available on OnShape, here.

A caster wheel is essentially just two rotational axes,  othogonal to each other and with a radial offset (and if you read on  all the way through the Design Notes below, you'll see that I managed to overlook this last one initially...oops.)  
To create these rotational axes, I decided to use my old favorite, bearing races integrated into the printed parts and fillin em with balls.
 caster_v3_xsec10_3b0fa.jpeg  casterwheel_v3_model_8a72a.jpeg  casterwheel_v3_xsec11_26a58.jpeg
 
The light blue part in the image above is the FrameMount. It provides one of the main bearing races and is also the attachment point to the structure to be wheeled about. 
The light grey part is the Hub. It houses the inner races for both the main bearing  and wheel bearing. It's also the part that I suspect to be the one that fails under heavy load :)
The dark blue part, shown best in the image on the left, is the Retainer. It is the other outer race for the main bearing and also provides the preload for the bearing.
And the yellow and dark grey parts are the wheels. They are both the same Wheel part  and in addition to being the wheels they, can you guess?...that's right, they're also bearing races, kinda repetitive, eh? 
 
Although only one ball is shown in each race in the above, they should be fully filled to ensure proper load distribution.
 
The nominal design includes small (0.5mm) gaps between the Retainer and FrameMount, as well as between the wheels. This is to allow for developing a preload in the bearing as these surfaces are brought into contact. The thin-walled geometry of the Retainer is intended to act as a  source of compliance, instead of using something like a spring washer or the like. I was too lazy to do the same for the wheels, and it shows in operation. However, in iterating on the design, I realized I actually kind of prefer these bearings to have a very low preload. This is mainly because I don't really care at all about the runout in these bearings (or at least so I believe today....we shall see), and I do want them to spin as freely as possible.
 
So I decided to just leave the gaps and such as is, and dial in the preload I want by inserting a washer or washers in this gap.
 
Printables    |   Thingiverse 

Design Notes

 V1 - Epic fail

 Well, isn't this embarrassing.  In my excitement at the idea of just nesting integrated bearings to obtain  a caster wheel (but also just kind of intrigued by the idea of using this concept for gimbals, trunions, etc.) I seem to have overlooked a very basic principle of caster wheels. An image of this model is shown below. Can you see the error of my ways? :)
casterwheel_v1_design1_1ef54.jpeg
 
No? It's ok, clearly I couldn't either. Yes? Well, where were you a week ago?
 
For a caster wheel to do its castering thing, it relies on the moment generated by the offset between the wheel/floor contact point and the axis of the main bearing. That way, when being pushed any direction where this moment is produced (any component of the push direction being normal to the rolling direction of the wheel) the main bearing rotates, aligning the wheel to the direction of the push. 
casterwheel_stock1_84349.jpeg
 
In my love of symmetry, I just completely overlooked this until I assembled the thing and was dumbfounded by it's lack of  desire to rotate. 
 
Luckily, I did realize my error prior to just iterating on my oopsie. So, on to V2
 

V2

2024/01/12 - Design notes

The below image shows the main bearing concept xsec (I haven't patterned the balls yet). The light blue part on top is the rigid attachment point that will go to the frame being wheeled about. The dark blue part will be what attaches to  the wheel, and the grey piece is the retainer. The  thin walls and contour of the retainer is intended to provide some compliance. There is a nominal gap of 1mm between the retainer and the frame mount. The frame mount will have an M5  heat set, and tightening this M5  will deform the compliant retainer, preloading the bearing. The plan is to fully close this 1mm gap, but as usual, 3d printed flexural elements can be difficult to predict/calculate, so I'm just going with an 'estimate and test it' approach.
 casterwheel_design1_c1487.jpeg
 I think I have the main bearing where I want it. I'm curious how this bearing config will feel. Given that it's getting late, I think I may just print this assembly overnight  and see how I like it in the morning.
 
 

2024/01/13 - Design notes

I lied above. I was apparently more tired than I realized, and those parts didn't even make it to the slicer :) 
So  instead I went ahead and finished out the V2 design this morning.  As you can see in the image below, I may have overcompensated a smidge with my offset.  The extent of the offset was really more the result of liking the small(er) overall package size this offered. My assumption is that this connection structure between the main bearing and wheel bearing will be the failure point when overloaded, but I also wouldn't be surprised if the loads on the retainer are higher than I am expecting, letting it earn the award for weakest link...I suppose we shall see.
 
casterwheel_v2_design2_f67da.jpeg
 
 
All of the parts fit comfortably on a single build mk3 build plate, and with my print settings that yields a print time of right about 6 hours.  Total material consumed should be ~190 grams.
 
casterwheel_v2_print1_a0ead.jpeg
 
2024/01/13 - Build comments/takeaways 
  • Good  lord was this thing a pain in the ass to assemble!  The configuration of the main bearing allowed the balls to easily fall too far out of position to be self-aligned during preload...aka balls went f*&%ing everywhere :)
  • The wheel bearing, however, was substantially easier and self-aligned quite  well in repeated tests.
  • The wheel bearing could use a better-defined  preload. I inserted stacked washers in between the wheels to set the  spacing, but ended up going with basically zero preload in the bearing. Although  this makes the bearing pretty sloppy, I'm not sure I actually mind for this application. As long as it stays assembled and allows free rotation, I don't really care about runout.  May go with an intentional zero preload design for V3.
  • As usual, support structures suck :) Although not a significant problem to remove on this one, I really don't like having the decreased surface finish so close to the bearing race surface. Changing the geometry to get the outer diameter of the main bearing race is  tangent to the flat on top of the wheel bearing (to remove the ring of supports shown in the above screen shot.
  • IT CASTERS (I know this isn't actually a verb...but hey, it's the internet, I can make up whatever I want, right? :) ). Other than the assembly woes, it does indeed function as desired! No clue what a realistic load operating range it will be suited to, but at least it does it's base function. 

V3 

2024/01/14 - Design notes

 There were two main issues from V2 that I want to address in V3, which I'm hoping will be the final rev for the time being. 
  • The main issue with V2 was with the reality of assembly for the main bearing. Although it is full constrained when assembled, it was an absolute nightmare keeping the balls in their races while putting it together.  Since the wheel bearing assembly was substantially easier to work with, I'm going to replicate that bearing configuration for the main bearing as well.  The below cross section shows the revised bearing along side the V2 config.  Essentially it moves the ball plane definition to the Hub, instead of in the FrameMount and Retainer.  
  • Also visible in the below cross sections, the wheel axis was moved down to make the outer diameter of the wheel race tangent to the top surface of the main bearing race
  •  
 casterwheel_v2_xsec1_0d8a3.jpeg  casterwheel_v3_xsec1_51980.jpeg
 
 
casterwheel_v3_sliced_9d015.jpeg
 I think V3 seems good enough to call it for now on this bad boy! (at least until I actually install it on something and realize it's deficient is some yet-unknown way :) ). 
 
No comments on “Caster Wheel”
  1. LilWinch
  2. Productive Susan
  3. Folding Table Leg Hinge
  4. Pulley - V1
  5. Bolt-Sorting Sieve
  6. General Purpose Turntable - Gen1
  7. 2020 Aluminum Extrusion stuff
  8. Desktop stands, holders, and the like
  9. Hooks and Hangers
  10. Assorted Frame-making Hardware

Subcategories

Assorted (hopefully) "Useful Stuff" Projects Article Count:  12

Like the bucket of assorted fasteners on that bottom shelf, this category is for stuff that I didn't know how to group...oh, and speaking of those fasteners, check out the little sortin fella!

2020 Aluminum Extrusion Hardware

Quick Bolt Sorter

General Purpose Turntable - Gen1

Games Article Count:  1

Generative Design Projects Article Count:  3

During the good financial decision-making times of Covid lockdowns, etc. I decided it was a good idea to buy a license for the Fusion360 Generative Design extension...Good news, I did finally pay that off :) I had worked around, and been somewhat involved in a handful of Topology Optimization/Generative Design projects through my work, and I've found the tech super interesting for some time. So after the free trial, and feeling like I was just starting to gain some level of competence in Fusion360's tool....I done did it, and bought the year. Ok, now that I'm done justifying that to myself...I mean you...

<engineering/design> What I really like about Generative Design is that it forces the designer to think about the thing they are trying to design from it's core requirements: Forces, Interfaces, and Keep Outs. I think it's far from perfect, especially given the still very primitive Design For Manufacture capabilities these tools have (among other shortcomings, but this one is certainly a big one to me.)

<precision engineering> One last also (for now), but ALSO, what I find exciting about these tools from a precision engineering perspective, is that the above-mentioned focus on forces and interfaces, these tools are extremely well-suited to kinematic/exact constraint designs! I think every one of the Generative Design projects below features at least some aspects of kinematic constraint (I say, "I think" because I may or may not be writing this before I go through my files and remind myself what all I actually made vs what I just thought about making ¯\_(ツ)_/¯ )

Generative Design Projects

 

 

 

JFS Projects Article Count:  13

AgTech (aka finding a way to complicate and digitize gardening) Projects Article Count:  11

Hydration and Hydroponics Projects Article Count:  8

Peristaltic Pumpin Article Count:  4

A lot of projects I work on/have worked on seem to involve the controlled movement of fluids. Below is a bit of a history of my builds involving attempts at obtaining this controlled movement for incompressible fluids. I haven’t done much myself with making custom solutions for the compressible stuff, but if you’re interested in such things, I thoroughly enjoy Major Hardware’s “Fan Showdown” series :)

This article/section is by no means intended as a thorough overview on the design and operation of pumps. While I will try to give some overview on operating principles and design considerations as I go, this is mainly just going to be a wander through my personal builds and experiences.

Peristaltic Pumps

What is a peristaltic pump?

I’m sure there are innumerable sources online for (much better) detailed discussions of the workings of peristaltic pumps. So I’m just going to hit the highlights, and I’ll try to remember to find some promising links and add them below, should a deep dive seem intriguing to ya.

Basic Operation:

The fluid being pumped is carried into the pump in a compliant tubing. This tube is routed around some portion of a circular/cylindrical path around the axis of the pump and then exits the pump. This is one interesting/attractive aspect of peristaltic pumps, the fluid never has to leave the tube that it is in, making these pumps well-suited to situations where contamination and/or leaks are highly undesirable. The housing that features the cylindrical wall that the tubing is being routed along can be considered the Stator, and that is generally the nomenclature that I tend to use.

So if there’s a Stator, there must be a Rotor…? Yup, the rotor includes some set of features that extend out to some defined gap between this feature and the Stator wall. These features, which in many peristaltic pumps are rolling element bearings, pinch the tubing to the point of sealing (ideally) the tube. As the rotor turns, this contact point proceeds around the circumference. Because the pinched point of the tube is sealed, the volume of fluid in the tube ‘ahead’ of the pinch point are, as a result, pushed forward. So, keep rotating, keep pushing….pretty much as simple as that!

Pros:

  • Positive Displacement Pump
    • Because the pinch point is (ideally) fully sealing the tubing, the amount of fluid moved is directly proportional to the movement of the pump. This makes them very good choices for things like dosing pumps or other applications where the desired volume of fluid to be moved needs to be deterministic.
    • This is a large driver for my initial interest in using peristaltic pumps. Their deterministic flow is/was very attractive for my plant growth experiments. They can give very repeatable watering volumes and nutrient concentrations.
  • Fluid Isolation
    • Because the fluid never leaves the tubing, these pumps can be suitable for moving hazardous materials. For example, I have been using a peristaltic pump for transferring 99% IPA
  • Relatively Simple Construction
    • Because the fluid does not have to be sealed within the pump, these pumps lend themselves well to DIY builds. No shaft seals, gaskets, etc. or complex (at least to do well) impeller design needed.
  • Self-priming and Head height
    • If well-sealed, these pumps are capable of self-priming (and even pumping air) and of achieving pretty impressive head heights (the measure of how high above the pump it can pump a column of water)

Cons:

  • High drive torque
    • Because of the preloading needed against the tubing, and the rolling friction, even with good rolling elements (more below on this), it can be quite easy to end up with designs that require quite a lot of drive toque.
  • Tubing wear
    • With the relatively large deformation and high number of cycles, the tubing will eventually fail, either due to material wear, fatigue cracking, or who knows what else. Because this failure mode can cause fluids leaking into your pump not designed to experience this fluid, this failure can potentially be quite problematic. So the use of high-quality tubing material and a plan for periodic maintenance, are worthwhile.

Test Build 1

A couple of years back, I had a concept for an in-line-mixing hydroponics system. The idea being that the supplies to the system would be just pure water and nutrient concentrates, and a series of pumps and valves would allow precise dosing mixes to each target plant in a system (I refer to this concept as Rail Yard Hydro, since it moves the fluids around the tubing network quite like rail cars are moved around a rail system. I’m planning to add a separate page diving into that one a bit deeper since it is the design scheme I am using in my current projects.)

Well, to facilitate this plan, I wanted to find an option for a dosing pump that I could integrate in to my control system (aka Arduinos and Raspberry Pi’s :)). Unfortunately, I quickly found that a servo-driven peristaltic pump could easily set me back north of $100….so I set out to spend many multiples of that making my own!

Actually, when I saw the pricing, I decided I should see if I could make myself a cheapo, manual version that I could use to just test out some basic questions on the Rail Hydro idea (mainly verifying that I could induce good material mixing in-line and that there was no cross-contamination between fluid reservoirs.) And so, ‘twas this endeavor that resulted in the pump I’m apparently referring to as “Test Build 1”

Design Objectives:

  • Be a peristaltic pump
  • Provide a full seal (at 100mm head)
  • Be hand-cranked
  • Not require any parts that would have to be ordered (I’m impatient)

The Build

She ain't pretty (especially after a good while of getting knocked around), but the pic above shows the dual pump setup I rigged up for my testing needs. I was VERY pleasantly surprised that, other than a tweak to the hand wheel, these things worked pretty damn well!

I decided upfront that I was going to go with a resin printed build, because I thought the high stiffness and good surface finish throughout the 'pinch region' would give me a better chance. Since I was already going to have the good surface roughness, I might as well also integrate the main bearing into the printed parts.

In the image of the model, below, the Stator is the part shown in green, and the Rotor is shown in blue(ish.) Riding on the rotor are roller skate bearings to provide the contact with the tube. Race 1 has v-grooves on both sides of the race, providing the main constraint for locating the rotor, and Race 2 has a v-groove on the Stator, but only a single plane of contact on the Rotor side. This keeps from over-constraining the bearing.

The absurdly overkill bolt running through the center is a real showcase of "using what I had on hand" :) in that these were the only bolt/nut sets I had on hand with the length I was looking for.

Valving Article Count:  3

System-level Projects Article Count:  3

Project Fireplace Article Count:  3

Just Playin and Concept Demo Projects Article Count:  8

Print-in-Place Designs Article Count:  1

Flexure Fun Article Count:  5

Pet Stuff Article Count:  1

Printer Stuff Article Count:  3

Tool-related Projects Article Count:  6

WIP Article Count:  3

A temporary home for projects I'm currently working on.

Page 1 of 16

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10

Login

  • Forgot your password?
  • Forgot your username?
  • Create an account

Please note, many of the links contained in my articles are “Affiliate” links through that vendor. Unless specifically otherwise mentioned in the context of the link, these are items that I purchased and used from that same product page for whatever the project (or prospective project) was. I use these Affiliate links to help recoup a little of what I spend on project materials, etc. (if you’d like a sense of scale….in the week that I write this, I have brought in a startling $0.75 :) ).

TERMS OF SERVICE

  • Policies
Copyright © 2022 - 2025 JFS Agri, LLC