It is the time of year when a lot of people in certain parts of the world carve pumpkins. [Gonkee] is carving a watermelon, which we assume is similar. He decided to make a CNC machine to do the carving for him. The unusual part is the use of two lazy Susans to make a rotary carving machine. You can see the result in the video below.
The hardware is clever and there is software that lets you do drawings, although we were hoping for something that would process gcode or slice STL. That would be a worthy add-on project. There were a few iterations required before the Melon Carver 3000 worked satisfactorily. Seeing a carving tool operating on two circles gives us a lot of ideas. We aren’t sure how sturdy the mounts are, so don’t plan on carving aluminum without some changes, but we suspect it is possible.
Then again, a laser head mounted on the frame would have probably made short work of the melon, and wouldn’t require much mechanical stiffness. It would, however, take a little effort to keep it in focus. So many ideas to try!
Watermelon is a popular hacking medium, apparently. There’s even one that holds a GameBoy.
Yeahhh, you need to replace that drill w/either a milling bit or a router bit. Drills don’t go side-ways well no matter how hard we all try.
I’m still always tempted…
Or use a drill saw bit https://www.amazon.com/Original-Saw-Drill-Extremely-Guaranteed/dp/B0721NTLQN which has a softer shank, so it won’t slip as bad in a drill chuck.
A drill bit saw lacks chip evacuation and cuts via individual sub teeth. Also if you are struggling with shaft slip in a drill chuck when cutting something as soft as watermelon, your problem is with binding at the cutting face rather than the grip on the bit
Bought some of those on impulse, and had a really hard time doing anything useful with them.
But carving melons? That seems to be what they’re made for!
It’s just a watermelon. I’m thinking a nail with it’s head cut off would do the job though the edges might not be so clean.
It’s pretty cool to look at, but it would be better to regard the whole thing (not just the carved watermelon) as an art project.
The whole thing flexes while carving the melon, to the extent that even the simple figure drawn is distorted.
The one drawing completed is (fittingly) a pile of poo.
The whole thing is fascinating to watch, but not really practical.
I expect Gonkee learned a lot doing it, and probably had lots of fun. The end result is not a practical tool.
Since Gonkee claims to be an artist, just assume the machine is part of the art and be happy.
Need to look at this as kind of a super Eggbot ( https://egg-bot.com/ ) except here the “stylus” rotates thru multiple axis as well as the “egg”.
Nice! I’m sure most of us are thinking of it as art but once properly dried that watermellon shell can make quite a bit more durable of a container than one might expect.
Bloody Youtube content. Looks fun, but a list of parts and a written description would be nice.
At least you know one of your servo is on the list.
At least you know your servos are on that list.
Why isnt the moving parts done horizontal? Would be stiffer
Not a watermelon, a PUMPKIN CNC evil laugh AAAHHAHAHAHHAHAHAHHAHAHA
Next, measure the resistance between the melon and the drill bit, so you can automatically move the depth for non-spherical melon.
It could be good for pumpkins at Halloween. Perhaps a miniature version for eggs would be good.
A camera or lidar and you got yourself a automated 3D scanner.
Carnegie Melon Award?
Only if appropriately carved into the mellon.
Very jazzy. Melonius Funk. Funny video. Loved it
“Why is there watermelon there?”
“…I’ll tell you later.”
To Do list.
1. Integrate with touch probe
2. Add additional movement for 360 degree rotation.
3. Use Endmills
4. Cut foam
5. ?????
6. Profit.
I don’t know if that was horribly amusing, or amusingly horrible, lol?
eitehr way, it’s ‘cutting edge stuff’
Stepper motors instead of servos, and a small router motor with a proper bit, and it would’ve worked much better.
“It took two weeks and another two years of my life to build this project” lmao 🤣
That’s a pretty fun project. It does have a form over function wibe to it how ever. To be fair, spherical stock kind of sucks to begin with. Perhaps work holding could be done with vacuum. That could also simplifie a rotating work piece resulting in 360 degree rotation. You probably need a stiffer rail for the spindle and better tooling though. And perhaps another axis to move the tool in and out of the melon. Surface mapping would do a lot as well :)