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A silly project – just for the fun of it. – A grabber toy.

Dr. Suess grabbing device.

Dr. Suess grabbing device.

Sometimes projects are highly planned out. Sometimes not. Sometimes you know exactly how you are going to do something because you have lots of experience doing it. Sometimes you try something new and experiment. This was one of those projects were I had very little idea how I was going to get it done but I was going to have fun trying.  This last week was Dr. Suess week at my Granddaughter’s school to celebrate the birthday of the famous children’s book author.  Also both she and I had stay-at-home days because of snowy weather.    (Note I started writing this back in early March… I am just now getting back to it.)

Before the snow hit I went out and bought some colored jumbo craft sticks (tongue depressors) to make the scissor mechanism.   I knew I wanted a pivot point exactly in the center of the sticks and I wanted each of the scissors links to be exactly the same length. so the mechanism would not bind.   That was all easy enough to accomplish, but how was I going to provide a bearing for it?   That was one of those things that falls into the category of: “I will cross that bridge when I get to it.”   Each of the holes was drilled with the smallest drill bit I had available, a 1/16 inch bit.   Smaller holes are easier to start accurately and if necessary I can always make the holes larger.

A close-up of one of the bearings on the scissor mechanism.

A close-up of one of the bearings on the scissor mechanism.

The thing I found that worked perfect for bearings for this light duty purpose was plastic toothpicks.   I used a strip of blue masking tape between the two sticks to provide a smooth surface so the sticks would slide against each other easily.  Now that I found a bearing, how was I going to prevent it from coming loose and a method of holding the sticks tightly against each other.   After a little experimentation I found that the hollow plastic stick of a cotton swab fit tightly over the plastic toothpick.   I used a hotmelt glue gun and glued one side of the toothpick to the craft stick.  On the other side I used the hotmelt to glue the plastic tube of the cotton swab to the toothpick while being careful to not glue to the actual stick.   This allowed the parts to rotate in respect to each other.

The materials for mixing the silicon rubber and molding it.

The materials for mixing the silicon rubber and molding it.

Next it was necessary to fabricate the hands.   I have been experimenting with a combination of silicon rubber caulk and corn starch.  I learned of this procedure in an Instructables article by an author named mikey77.   The details are here: “How To Make Your Own Sugru Substitute”.  I usually make a 2 part silicon to 1 part corn starch and I already have measured out 1/2 teaspoon of starch in the photograph.   Earlier I did some experimentation and found that 1 teaspoon of the caulk weighs close to 4.5 grams and it is much more convenient to weigh it than measure it with a measuring spoon.   I simply put the mixing cup on a gram scale and then squirt out 4.5 grams into the cup.   My mould in this case is the flexible plastic top to a food supplement bottle, the blue circular piece of plastic.   One piece had already been moulded at the time of this picture and cut into the palm shape of the hand.   That is the white piece of rubber in the left side of the picture, just below the ball point ink pen.

My Granddaughter mixing the silicon rubber.

My Granddaughter mixing the silicon rubber.

I let my 6 year old Granddaughter do the initial mixing of the silicon rubber.   This let her play “mad scientist” wearing the rubber gloves and goggles, but it also let her be involved with making things instead of just going out and buying something.  The goggles were very necessary with her because getting the silicon rubber in your eyes would be a major problem.  The rubber out-gasses acetic acid so we only made a small amount and kept it well away from her face.  The nitrile gloves protect skin from being exposed.

 

 

 

 

 

The hand ends of the scissor mechanism were coated with the silicon rubber.

The hand ends of the scissor mechanism were coated with the silicon rubber.

One of the properties of silicon rubber is it does not adhere very well to most things. I started to call that a problem, but it really is just something you have to work with. It is a good thing when mixing it up and moulding it, because you can easily remove it from most things. It is a problem if you are trying to get it to stay fixed on something. But, as with everything in life, to all problems there is a work-around. The silicon rubber does adhere to itself very well,  Officially, I think, this is called cohere. My work around to get the hands to stay on the final set of scissor sticks was to drill a hole in the stick and apply the rubber on both sides of the stick and also through the hole so it would have to actually have to be sheared to pull off.  I did not worry at this point of making things smooth,  I only wanted a firm base to attach the hands.

 

 

Building Silicon rubber hands

Building the hands.

The next step was to actually make the hands to attach to the scissor arms. I had made several of the silicon rubber disks using the top of the vitamin supplement bottle as a mold. As I said earlier I cut it into an oval shape to make the palm of the hand and cut curved pieces to form the fingers. In the picture I am gluing those pieces together.  I used some popsicle sticks to support the palm up above the board to provide support for the fingers while the glue set-up.   The glue in this case was again a little dab of the silicon caulk and corn starch mixture.

Dr. Suess grabbing device.

Dr. Suess grabbing device.

After the fingers set-up I then attached the hands to the silicon rubber on the ends of the scissor arms using the mixture as a glue again.   The final device is shown in final two pictures.   One shows it collapsed and the other shows it extended.

 

 

 

 

 

 

Homemade "Dr. Suess" grabbing device extended.

Homemade “Dr. Suess” grabbing device extended.

On any project, the final step is to evaluate it and determine if it met the goals.  Although this is in many ways a silly project it is no different.

Goal 1:  Create a toy.   I would have to give myself a grade of about 50% on this.  Although the toy worked well enough it needed better bearings and was flimsy and flexed a lot in the direction of the bearing axis.   I am sure I could improve that a lot by using thicker plastic, plastic washers,  possibly even plastic screws.  The question then comes down to why?  This served the purpose…. which is Goal 2.

Goal 2:  To show my Granddaughter that it is possible to make things ourselves.  We don’t have to go out and “buy happiness”… we have brains and can be creative.   For that I have to give myself a grade of 100%.   Even though the toy turned out to be flimsy, it was played with as long as a purchased one, if we could find one, would have been played with.   AND!   WE DID IT OURSELVES.

Goal 3:   An excuse to learn new skills and to learn something about working with silicon rubber.   For that I have to also give myself a grade of 100%.   Since the time of this project I have worked on several other things using silicon rubber made this way.   I will be posting some of that in future posts.   I have learned several things since I built this.   However, as in all thing… baby steps!

 

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