Thursday, July 21, 2016

Sketchup Rockinghorse

A friend of mine runs a campground that features horseback riding and equine events. One day while he was pitching ideas to us for expanding the fun on the farm, he asked if I knew anyone who could build some adult sized rocking horses.  Well, of course I volunteered myself for the task... because horses and kids... and my kids love horses.  So I set out to design an easy to build Rocking Horse that could be cut out of one sheet of plywood and assembled with screws and glue.



My own design efforts didn't thrill me, so I moved from paper to Google Sketchup to try and model it.  My transition from Lightwave to Sketchup is far from complete, so I ended up finding a child size Rocking Horse  model in the Sketchup public domain library to work with.

Following a tutorial for using Sketchup to prepare CAM tool paths for Mach3, I took the component geometry for the horse, cleaned it up by closing gaps and removing extra points and lines, and then sank each part into a virtual sheet of 3/4" plywood.  I then deleted the exposed geometry, leaving the outline of each piece on the surface of my sheet of plywood. From there, I took a screenshot, saved it as a jpg and then imported it into Excel so that I could control the scale and page setup to print the image at 1/3rd scale on six sheets of 8-1/2 x 11 paper.  I then used entirely too much glue to secure the trimmed sheets to 1/4" aspen plywood, which is the proper thickness for my 1/3 scale model.

After cutting everything out with the jigsaw and scraping and sanding the paper off, I was able to glue and nail it together.  The final result, I will admit, is rough if not illustrative.

Parents think I'm crazy, and the Doctor says I've cracked, but they don't understand me, Lord, 'cause I' just wanna get back....
"I wanna get back - back to the rocking horse..."
The final full size build should sit just a bit higher that chair height to allow adults to comfortably sit upon it.  We'll add old, not good for actual use saddles, and mop string for manes and tails. The next step, I hope, money permitting, is to build a large enough CNC mill to handle 4 x 8 sheets of plywood.  I've never built a CNC mill, but I think I can get it done for around $1200 based on conversations with peers who have made their own.  I also have it on good authority that Dave Gatton is "the man" when it comes to DIY CNC mills.

2 comments:

Mark Barton said...

Jerry,

I came across this https://www.inventables.com/ - not sure if it will go big enough for you?

This also looks like an interesting service - https://www.ponoko.com/

Cheers

Mark

J E Carter II said...

X-carve may well be just big enough for what I want to do. Thanks, Mark!