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Stage Prototype
Project Need Agility / Dexterity, Cognitive
Created By Makers Making Change
Capabilities Needed 3D Printing, Electronics
Time to Complete —
Cost to Build —
Creative Commons License attribution-sharealike-4-0-international

Overview

This is a cost-effective 3D printable accessibility switch based on an initial design 3 by Kevin Cross 4. The switch is 50 mm L x 18 mm W x 15 mm H and uses a standard 3.5 mm cable. Using the specified model of tactile switch, the activation force is 0.3 – 0.4 N (30-40 gf).

Usage

The switch is well-suited for use by a finger. This switch can be plugged into any standard AT interface. It can also be used with the Xbox Adaptive Controller. Multiple switches can be used to get input from more than one finger. The original design is also available in a dual side-by-side version.

Assembly 

[@mmc_jake]

Some feedback from a user:

“The Makers Making Change Gray [Light Touch Switch] is about 5 cm in length and only requires 1 mm of movement to activate it. It is about the same width, height, and length as a 4.5 cm Micro Light switch or traditional Ultra Light switch, as shown in Figure 6. A Micro Light switch requires about 3 mm of
movement for activation.


Its tapered edge is useful and ergonomic as an individual can lay a finger on top of the switch or place
the switch between two fingers. It is easily mounted on flat surfaces using Velcro.

[The MMC Light Touch switch] requires more force than a comparable Micro Light switch, though the amount of force required varies according to position where force is applied. More force is required closer to the hinge of the switch and less force is required at the bottom. The switch seems durable and sturdy and would likely withstand excessive force to resist damage.

It has nice aesthetic features with a smooth, rounded surface. It may be worth considering rounding the bottom edge as well so an individual may hold the device between two fingers (as shown in Figure 7) without risk of pressure injury.


The hinge on an Ultra Light switch is located on the same side as the wire output as shown in Figure 6.
On the Makers Making Change [Light Touch Switch], however, the cord position is reversed on and is
placed on the opposite side of the hinge. Both placements are useful. It would be worth exploring
placing the wire on a different design on the same side as the hinge. This would allow fitting the switch
between smaller joints as shown in Figure 8.


[@imtiazjadavji]

I was looking around the site and saw the the light touch switch was quite popular and saw the comment about the wire coming out of the hinge side. I took a crack at modifying the original design.

Check it out remixed on [Thingiverse](https://www.thingiverse.com/thing:4742847) or [here](https://mmcdevices.assistivehardware.ca/designs#h.hd7kfjfbbp3h)

Let me know what you think and if there is any feedback.

[@chadl]

Wow, we were just talking about how we would love a remix of this. Will put on printer in the morning and give it a go!

[@mmc_jake]

Hey @imtiaz – nice work on the remix and welcome to the community.

We’re going to do a few internal test builds over the next week and should have some feedback then. With the popularity of this style of switch, there is likely an opportunity to do a more substantial remix that doesn’t necessarily have to follow all the same dimensions.

[@imtiazjadavji]

So here are my results:

* 4mm high in the front (original 10mm)
* 19mm tall (original 15mm)
* 18mm wide (original 18mm)
* 54mm length (original 50mm)

More details [here](https://mmcdevices.assistivehardware.ca/lts2)
Let me know what you think.


[@mmc_jake]

One of the pain points on this switch design has been the hinge pin. The spring pins are great but can be hard to source, pen ink chambers are convenient and available in small quantities but can be messy.

We experimented with 3D printed pins in the past but they can be tricky to print and you need to be conscious of print orientation for strength. Here is a new attempt based on some updated techniques:

[LTS_Pin_v0.1.stl|attachment](upload://1s1T9Ze2wY1GFGNK53DYGsmbWFC.stl) (5.9 KB) [LTS_Pin_v0.1.f3d|attachment](upload://AqJpOflDjATw6IaiAovaWGz3oQv.f3d) (147.6 KB)

The pins are printed on the side for strength and connected together to improve printability.


The two pins are slightly different sizes to accommodate for printing tolerances.

Once the pin is inserted the switch can be tested. If the switch needs to be adjusted, it’s easy to hold and remove the pin.

Once the switch is functioning correctly, side cutters can be used to cut the pin flush.


Et voila.

Feel free to give this design a test and let us know if you have any suggestions for improvements or other ideas.

[Author]

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