Design Challenge #1

Super neat! I love these car projects. So clever!:oncoming_automobile:

This ammo is too fun. I love the creativity shared on this site!!


I like this idea too…I have done the derby as a scout…the regatta fits with where I live too. :thumbsup:


El Camino ?

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Business in the front, party in the back!


Alrighty guys. Here is my design entry.

Keep in mind i have never designed for laser cutting so I welcome all critics.

Its a puzzle box. Put a marble in and try to get it out the other end. Normally I would have glued it together. But at @dan request. No glue. Any ball or marble smaller than .5" should work great. I like the little steel bearings personally. (which might not be in the accepted list of materials)

Its designed to be cut from .25" acrylic just so you can try and see whats going on in there. The latches can also be acrylic, i just colored them for clarity.

And here is the layout.
Puzzle box print drw.AI (35.8 KB)

This was my first time going from solidworks to sliced AI files. The work flow was a little rocky. Let me know if you have any tricks or tips.


This one gets my vote!

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It has now :grinning: Courtesy of Fabs-R-Us aka looking for an excuse to lase something.

I fired up the laser after work. Here’s how it looks. I did not verify your penny count, I just filled the tray. Also, I would suggest making the ears of the trigger mechanism another 5 or 6mm longer on each side. That will keep it from sliding out when moving it side to side engaging/disengaging it.

Here are a couple of pics. 1/4" Baltic birch plywood. Nuts & bolts from Lowes and pencil by Ticonderoga.


Once you start designing these, you can’t stop! It’s fun to make some new ones. I’ve not tried it yet in 1/8" material, but here’s a VW Bus inspired one in 1/4".

I kind of like the chunkiness of 1/4". To me, they look more like toys than models.


That’s a great idea! I can’t wait to see what it looks like in real life.

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Very cool to see it realised!
Definitely going to see about replacing the pencil/axle and the rest of the hardware.

Does it feel sturdy? Did you need to use any glue?


I didn’t do anything to the file so there’s an opportunity to do a little kerf tweaking - it’ll stay together with just a press fit but won’t be up for any real handling. So I did use a little glue and 23ga pins.

The bolts were a bit long - they didn’t have M6x50 cap socket screws so I went with normal hex bolts. The 50 and 30 lengths were both long. The 50 actually bumped into one of the side supports occasionally. Dremel took care of that. A 25 and 45 would be fine (or 1" & 1 3/4") would be good.

Overall though for a first iteration of a design, pretty spot on.

BTW, pretty decent counterweight with pennies - although I only had the new zinc ones. Older full copper pennies would loft heavier objects and lead sinkers or fishing shot (or 50 cal wadcutter bullets) would increase the projectile payload capacity.

My wife said I should 3D print a cow. :smiley:


Okay, I’m out. I thought I could meet or beat siege weapons but I can’t compete with this.

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You can always design something else…:upside_down:


Haha I promise you can. Other peoples stuff always seems so much cooler just because you didnt come up with it. I still think all the model cars we have been talking about are just amazing. I couldn’t touch those myself.



Nah, that’s fair. It’s a pretty neat puzzle.




Surely we should make the cow’s legs slot on so that it can stand on its own (and explode when it’s thrown.)



Thanks for the first giggle of the day.

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