Casters: Difference between revisions

From
No edit summary
No edit summary
 
(28 intermediate revisions by the same user not shown)
Line 1: Line 1:
==Problem==
{{Parts infobox
|image          = Caster.scad.png
|designers      = [[User:Tim|Timothy Schmidt]]
|date            =  
|vitamins        =
|materials      =
|transformations =
|lifecycles      =
|parts          = [[Slew bearings]], [[Bolts]], [[Nuts]], [[Washers]]
|techniques      =
|tools          =  [[3D printers]]
|files          =
|git            =
|suppliers      =
}}
 
[[Category:Parts]]
[[Category:Motion parts]]
 
=Introduction=
A caster is an undriven wheel that is designed to be attached to the bottom of a larger object (the "vehicle") to enable that object to be moved.
 
Casters are used in numerous applications, including shopping carts, office chairs, hospital beds, and material handling equipment. High capacity, heavy duty casters are used in many industrial applications, such as platform trucks, carts, assemblies, and tow lines in plants.
 
Casters may be fixed to roll along a straight line path, or mounted on a pivot or pintle such that the wheel will automatically align itself to the direction of travel.
 
=Challenges=
Determining the best use of space is a process, not an end result. This is especially true when space
Determining the best use of space is a process, not an end result. This is especially true when space
is at a premium. Furniture and equipment are easier to move when they have wheels.
is at a premium. Furniture and equipment are easier to move when they have wheels.
Line 5: Line 31:
be easy to lock and unlock with a foot or a hand.
be easy to lock and unlock with a foot or a hand.


==Approach==
=Approaches=
==Rigid casters==
 
==Swivel casters==
Subcomponent count and 3D printability of existing caster designs were surveyed. Eleven revisions of test caster were designed, printed, and destructively tested to arrive at a working locking mechanism and feature construction given the constraints imposed
Subcomponent count and 3D printability of existing caster designs were surveyed. Eleven revisions of test caster were designed, printed, and destructively tested to arrive at a working locking mechanism and feature construction given the constraints imposed
by the FDM 3D printing process. Initial designs used 608 roller skate bearings. Later designs increased the number of axes with a preloaded bearing and decreased subcomponent count and cost by integrating printed bearing races into existing printed components.
by the FDM 3D printing process. Initial designs used 608 roller skate bearings. Later designs increased the number of axes with a preloaded bearing and decreased subcomponent count and cost by integrating printed bearing races into existing printed components.
====Current components:====
==Current components:==
* 6mm stainless steel balls
* 6mm stainless steel balls
* Stainless M8x130 bolt, nut
* Stainless M8x130 bolt, nut
Line 17: Line 46:
* Printed locking lever (0.4 hours)
* Printed locking lever (0.4 hours)


====Interoperability:====
==Interoperability==
====Development targets====
===Vitamins===
 
[https://www.surpluscenter.com/New-Arrivals/5-X-2-Swivel-Plate-Caster-w-Brake-WC6650-01-PAL-TLB-1-5780-SB.axd Casters for 3 inch frame]
* Locking caster v12
===Alternatives===
 
*Children's bicycle wheels
**Modify a standard fork (actually 2) from a child's bicycle
**Weight capacity is still a concern
*Furniture casters
**Available in heavy-duty 8"+ (20cm), 600+ lb (270 kg) varieties
**May need some sort of shock absorption for [[Wheelchairs]]
**Can they handle the shear shock of running in to obstacles (curbs, potholes, rocks, steep ramps, etc.)


[[Category: Parts]]
=References=
* [https://en.wikipedia.org/wiki/Caster Wikipedia: Caster]
* [https://www.thingiverse.com/thing:2680517 Sehome Swerve Drive 2]
* [https://www.thingiverse.com/thing:31194 Simple Furniture Caster M8-M4]
* [https://www.thingiverse.com/thing:2789451 Print-in-place caster wheel]
* [https://grabcad.com/library/3-in-rubber-light-duty-swivel-caster-with-brake-harbor-freight-tools-61855-1 3 in. Rubber Light Duty Swivel Caster with Brake Harbor Freight Tools 61855]

Latest revision as of 00:36, 29 October 2022

Part: Casters
Designers: Timothy Schmidt
Tools: 3D printers
Parts: Slew bearings, Bolts, Nuts, Washers

Introduction

A caster is an undriven wheel that is designed to be attached to the bottom of a larger object (the "vehicle") to enable that object to be moved.

Casters are used in numerous applications, including shopping carts, office chairs, hospital beds, and material handling equipment. High capacity, heavy duty casters are used in many industrial applications, such as platform trucks, carts, assemblies, and tow lines in plants.

Casters may be fixed to roll along a straight line path, or mounted on a pivot or pintle such that the wheel will automatically align itself to the direction of travel.

Challenges

Determining the best use of space is a process, not an end result. This is especially true when space is at a premium. Furniture and equipment are easier to move when they have wheels. But after you’ve moved them, they should be as stable as possible. So the casters should be easy to lock and unlock with a foot or a hand.

Approaches

Rigid casters

Swivel casters

Subcomponent count and 3D printability of existing caster designs were surveyed. Eleven revisions of test caster were designed, printed, and destructively tested to arrive at a working locking mechanism and feature construction given the constraints imposed by the FDM 3D printing process. Initial designs used 608 roller skate bearings. Later designs increased the number of axes with a preloaded bearing and decreased subcomponent count and cost by integrating printed bearing races into existing printed components.

Current components:

  • 6mm stainless steel balls
  • Stainless M8x130 bolt, nut
  • 2x printed M8 thrust bearings
  • Printed flexible roller (1 hour)
  • Printed hub (1.5 hours)
  • Printed retaining ring (0.5 hours)
  • Printed locking lever (0.4 hours)

Interoperability

Vitamins

Casters for 3 inch frame

Alternatives

  • Children's bicycle wheels
    • Modify a standard fork (actually 2) from a child's bicycle
    • Weight capacity is still a concern
  • Furniture casters
    • Available in heavy-duty 8"+ (20cm), 600+ lb (270 kg) varieties
    • May need some sort of shock absorption for Wheelchairs
    • Can they handle the shear shock of running in to obstacles (curbs, potholes, rocks, steep ramps, etc.)

References