A Praxinoscope Made From Simple Mirrors from a Craft Store

A Praxinoscope is an early animation device, a variant of the zoetrope, invented by Charles-Émile Reynaud in 1877. It consists of a drum-like device with a series of mirrors arranged around the inside edge. Inside the drum, a strip of images is placed. When the drum is spun, the mirrors create an illusion of motion by reflecting the images in succession, giving the impression of animation. This was one of the early methods used for creating and viewing moving images before the advent of modern cinema.

This Praxinoscope is made with ten 1 inch x 1 inch mirrors that I bought at Michael's craft store.  When the Praxinoscope is spun in a clockwise fashion, the horses appear to gallop.  Also, the design on the outside of the drum blurs, the diamonds disappear and the area where the diamonds are located, appears to look like a solid white line.

I used 65 lb. cardstock. Here is the PDF.
https://drive.google.com/file/d/1F-QehlDANfskuuxgHzkUDRyhCkuiai7N/view?usp=sharing

Here is the .Studio file.
https://drive.google.com/file/d/19RHfAlW50y5J_f6aH06vJSh9llhTu-wf/view?usp=sharing

 Praxinoscope

 Using Glue Dots, affix ten 1 inch x 1 inch mirrors to the mirror base cardstock.

Notice that there is a tab on the left side and that the mirrors are alined to the bottom of the strip.

 Apply glue to the tab and adhere the tab to make a circle

 Bend the tabs of the decagon shaped piece  downward.  Apply glue to the tabs and insert the piece into the bottom of the mirrored circle.

 Bottom of the mirrored piece.  Notice there is a ledge.

 Inside of the mirrored piece.

Glue the sides of the second decagon shaped piece and place it in the mirrored piece. A ledge should show as before because it will help with the gluing process.

 Animation Disc Assembly with Embellishments

 Apply the embellishments as shown above.  There is a little overlap in the embellishments to allow for the curvature of the circle.  The overlap should be on the opposite side of the tab.

 Glue into a circle.  Bend the tabs at a right angle and apply glue to each of the tabs.

 Insert the round bottom piece of the animation assembly. Make sure that the glue adheres to each  of the tabs.

 Flip the piece over and apply glue to each of the tabs.

 Adhere the second round bottom piece to create a two walled base.

 Make the lid of the Box

 Apply the embellishments to the lid strip.  There is a sight overhang of the embellishments at the edge opposite to the tab.

 Glue into a circle, bend the tabs at a right angle and apply glue to each of the tabs.

 Bend the axle into a tube and apply glue to the tab.

 Adhere the glue and make sure that the axle becomes a tube.

Insert the axle tabs into the top of the lid circle.

 Apply glue to the embellished piece at the tabs. Attach the axle piece to the top.

 Make the bottom of the box.

 Glue the box base into a circle, bend the tabs at a right angle and apply glue to each of the tabs.

 Flip the box base over, apply glue to the tabs and attach the second base piece to the bottom of the box.

 Box base assembly is complete

 Make the animation strip by gluing the pieces into a circle.

 Insert the animation strip into the drum.  Thread the mirrored piece onto the axle.  If you are having difficulty threading the axle through the two holes of the mirrored piece, put a wooden dowel into the center of the axle and thread through the holes.  The wooden dowel gives support to the axle so that it  does not bend while threading through the holes.  Remove the dowel when threading is complete. Glue a Platonic solid as a finial to the axle.

Completed Praxinoscope

St. Patrick's Day Scavenger Hunt For Kids

St. Patrick's Day Scavenger Hunt For Kids At 

Grandma's House

Here is a PDF of an indoor St. Patrick's Day Scavenger Hunt For Kids.

https://drive.google.com/file/d/1tBvedud78-901vHwasZldruC4TyHSHfS/view?usp=sharing

Print out the PDF on your printer using the double sided feature. Cut out the twelve clues.  The back side of the clue tells where to hide that particular clue. The last clue is where the special surprise will be found.

A STEM PROJECT: Using Buffon's Needle Experiment To Estimate The Value of Pi

A TurtleStitch Program That Simulates Buffon's Needle Experiment to Estimate the Value of Pi

Buffon's needle is a classic probability problem named after the 18th century naturalist, Georges-Louis Leclerc, Comte de Buffon. The problem provides a way to estimate the value of π using probability and geometric principles. A needle is dropped on a plane surface that is ruled by parallel lines. The length of the needle is less than the distance between the two lines. What is the probability that the needle will fall on one of the parallel lines when the needle is thrown completely at random?

Using TurtleStitch, a block based programming language, you can recreate the Buffon needle experiment to calculate an approximation of π.  By calculating the probability of a needle crossing a line, the value of π can be estimated. The more trials that are conducted, the more accurate the estimation of π becomes. In my TurtleStitch program, change the number of needles dropped, to experiment with your estimation of the value of π. Here is my program in TurtleStitch  https://www.turtlestitch.org/run#cloud:Username=Elaine&ProjectName=Buffons%20Needle

Thanks to Bice Rapaccini for introducing me to Buffon's Needle.  I used part of her original TurtleStitch program. I randomly colorized the dropped needles and included the calculations to estimate the value of pi.

$P$

A STEM Project: Make Your Own Slice Form With A Locking Base

Circus Party With A Locking Slice Form Base  

Paper is an amazing material to create slice forms. Slice forms can only be made with pliable materials which can be maneuvered to allow for each slice to be slid into place.  Wood, metal or hard plastic will not suffice.  In this blog posting, I have created a slice form base that does not fall apart when the figure is picked up from a surface. Two of the slices have a special slit design which creates the locking mechanism. 

In this blog posting, I made a Circus Party slice form which exemplifies how to make your own design.

Looking at the above slice, you can see the locking mechanism. It is a small slit that zig zags to the top of the right slit. The lion on top of this slit spans over the slit to hold the two pieces of paper together.  In my design, front facing slices #2 and #4, have this feature. When designing your own slice form, the figure that is placed on top of the slice must be large enough to span this gap. 

There are two types of slices to make a slice form base.  There are side slices and front slices.   I recommend numbering your slices to keep everything orderly because the placement of the slices matter.

To design your own slice form, the figure is placed on top of the slice and welded to the slice using the Silhouette software in the Modify window. The special slices, #2 and #4 need to have a figure which spans the locking mechanism.The side slices can be modified but I do not recommend doing this until you have mastered the front slices.

There are five front facing slices.  Add your designs to these slices.  Cut out these slices along with the five side facing slices to make your slice form.

Here is the PDF.  I used 65 lb cardstock. https://drive.google.com/file/d/1O0DfzzdcSz5DRDgaN3pqTcean3oSx854/view?usp=sharing

Here is the .Studio file.

https://drive.google.com/file/d/1EtNhWHBvjbZHGWmUl6StnKs3CEncUpK6/view?usp=sharing

Here is the SVG. The file goes beyond the viewable area.  Zoom out to see the entire file.

https://drive.google.com/file/d/1k0oi7hMtz2fX3HFidJ1Gg4XdO88dNuAS/view?usp=sharing

Please notice that I have numbered all of my side slices in pencil so that they can be erased after the project is completed. Slide all of the side slices onto the #3 front slice. Placement of the slices matter so make sure all of the side slices from left to right start at #1 and end with #5.

Slide the #2 front slice into place.  This may require the slice to be moved up and down and bent to be put into place.

Slide the #4 front slice into place. Repeat for the #1 front slice and then the #5 front slice.

The result is a grid like pattern which will not fall apart when picked up.

The circus party with a locking slice form base can lay flat and fit into an A4 envelope.

Overall Pattern For An American Girl Little Bitty Baby Doll

Overall Pattern For An American Girl Little Bitty Baby Doll 

I designed an overall pattern for the American Girl Little Bitty Baby Doll.  The overalls are easy to make except for the straps.  They are hard to turn inside out once it has been sewn.  An easier method for the straps is to only sew one side of the strap, go around the curve and then sew a third of the way down on the other side of the strap.  Turn the strap right side out and then press the raw seam inward. Top stitch the entire strap. 

I have included a T-shirt pattern in the design and a dress for the Little Bitty Baby doll.  I made the dress here in this blog posting. https://papercraftetc.blogspot.com/2023/07/dress-patterns-for-american-girl-bitty.html

Here is the PDF for the overall pattern. Print out the pattern with your printer.  There is a one inch square for reference if the pattern does not get printed correctly.

https://drive.google.com/file/d/1JxrpzqMceoZXsZT1ZKilkn769hIu9_dS/view?usp=sharing

Here is the .Studio file for Silhouette Cameo users. Cut the pattern piece with your Silhouette.

https://drive.google.com/file/d/1zJYHguSkK-d6vae31-2Fi-DzMyl4SQQd/view?usp=sharing

Here is the file as an SVG. Cut the pattern piece with your Cricut or other paper cutting machine. The file goes beyond the viewable area.  Zoom out to see the entire file.

https://drive.google.com/file/d/1NFCQN3h5itgCW3Qj-DwSx0CuW7E3kzjV/view?usp=sharing

1. Sew the crotch together on both the front and back pant legs. Press the seams open. Sew the front bib onto the front pant leg. Fold the back pant leg to the same length as the front bib and press the seam that is formed. Turn the folded fabric in half to create a pocket.

2. Place the 1/4 inch elastic inside of this pocket. Insert a 4 inch piece of elastic into this pocket.Sew a seam at the bottom of the folded fabric.  Make sure that you don't sew the enclosed elastic.  Tack the elastic to the pant leg as shown on the right side of the photo.

3. Turn the hem of the pant leg twice by an 1/8 inch.  Place all of the pant legs on top of one another to make sure that they are all even. Iron the pant hems.  Sew all of these hems.

4.  Sew the inseam.

5. Sew the right side seam.  Pull the elastic so that the waist is 2 3/4 inches. Tack the elastic down and cut the excess elastic.  Sew the left side seam.

6. Place two dots an 1/8 inch from the side of the bottom of the remaining bib piece on the wrong side of the fabric as shown above.

7. Pin this bib piece right sides together onto the other bib piece.  Start sewing at the dot and sew a 1/8 inch hem around the top. 

8. End the sewing at the second dot.

9. Clip the corners of the bib. Turn the bib inside out.

10. Fold the bottom of the bib up 1/8 inch and hand sew this seam. Zigzag the raw edges of the pant legs.

11. Sew the two straps and turn inside out.

12.  Sew the two straps onto the back of the pants at the bottom of the elastic seam.

13.  Sew on the snaps

Front View

Back View