Wooden robot?

yes thats right i was building for the annual Savage Soccer Competition Hosted by WPI and realized that the vex steel is really heavy, vex aluminum would have cost an arm and a leg and more importantly would have arrived to close to the competition deadline so i went to Lowe’s and bought 4 sheets of 24x24x1/4 birch a friend of mine that is a student at WPI helped me laser cut them (he had nothing to do with the competition and didn’t assist me with that part) here is the 2nd iteration of the result

http://sphotos-b.xx.fbcdn.net/hphotos-ash4/259842_417408654999524_491622521_n.jpg

for all of those in the Mass/New England area i suggest you checking out savage soccer its only 4 weeks and its tons of fun

laser cut wood in vrc, any takers?

Hi

Great effort with the robot. Wood has some amazing properties and, as you say, is pretty darn cheap. The design reminds me of something - is it a piano? It wooden pass inspection in VEX competition and it may struggle against a chain-saw intake. :smiley:

Good luck with the savage soccer, Paul.

It wooden pass inspection in VEX competition.

I tip my hat to you sir.

I’m not exactly sure how it resembles a piano, I’ve heard it looks a bit like a boot from the side but that’s all. Also that pun was pretty great haha

Sorry, I could not resist that pun :slight_smile:

A few questions please.
I guess the sheets of wood are layered plywood?
The placement of the holes cut in the timber needs to be very accurate for gears to mesh properly and for the whole structure to stay square. Did you try making this without using the laser cutter initially? Do you think this project would be possible to make using a drill press?
The holes look reasonably charred from the laser. Did you have to dampen down the surface of the timber before cutting it, or use some other method to stop it from igniting?
Considering weight, strength and stiffness of your robot, if wood was a legal material to use and cost was not a factor, which would you use purely based on performance, wood or metal?

Cheers, Paul

I assume that sheet plastic was cost prohibitive. Would your design have changed if you had been able to bend your building material?

Wood is much stiffer for the same weight. I think this is brilliant – nice work!

I can answer some of the questions regarding laser cutting (I did the cutting on this project).

The wood used was relatively cheap (3 layer?) plywood. We did some pieces using more expensive aircraft grade plywood, but the laser struggled with this where the design called for thicker wood. Nothing a bigger laser couldn’t have fixed though, and the cheaper stuff was more than adequate.

Paul knew he’d have access to my school’s laser cutter from the beginning, and designed around this, not attempting any handmade parts. However, I have no doubts that a skilled operator could have pulled a similar design off with a drill press. It would obviously take more time and effort, but VEX gears are pretty forgiving. They have a larger diametrical pitch than they need to, operate at low speed, are made of a plastic which will wear rapidly if mounted too close together, and the involute tooth form means that both ratio and pressure angle will be maintained through variable spacing. One advantage of the laser was that square holes could be created for seating VEX bearing blocks.

The laser does burn through the wood, and does flare up a bit in cutting. However, the localized nature of a laser, and the powerful ventilation system pretty much eliminates any ignition risk. Nothing special had to be done to the wood before hand, and there was no appreciable difference in kerf size or tolerance due to burning wood. I suppose protection could have prevented some of the minor charring present on the wood surface, but no functional problems were encountered.

The laser cutter used was a VLS 4.60, with a 60W laser. It’s a great tool for prototyping and construction of small robots, since there is no real CAM work involved. Here’s another laser cut robot, this one from acrylic plastic.

The robot was extremely stiff and rigid, to be honest i had the same concerns.
if cost was not a factor i think i would go with wood, its lighter than comparable strength aluminum, its really rigid and birch did not snap that easily (i only had one part break but it broke initially due to an under designed part) plus its a head turner, aluminum robots are common, wooden robots you don’t often see I’m considering staining the wood haha

Plastic was an option but it was much more expensive, wood was $5 a sheet acrylic was $12. but acrylic dose not bend and we could not cut polycarbonate with the laser cutter. if i could bend the building material the dump plate may have looked a bit different and functioned a bit better (although i have not complaints about the way it worked) but thats all i can think of off the top of my head

Thanks but i must say it was Joe who put wood on the table for a usable material “if it can survive on a rocket going mach one, it will get you through savage soccer”

I thank you again good sir

Unfortunately the video dose not depict half of the beauty of this robot, i was fortunately able to see it in person and the 9 bar (i think) linkage on it is a work of art, there was engraving around the base and a passive gripping system. they went all out on this project where others just strapped a claw with an elbow to a linear slide on a wheel base. its just really hard to see because its clear.

Wood is good on bigger robots, too.


http://www.chiefdelphi.com/media/photos/35536
[http://www.chiefdelphi.com/media/photos/22924

This is a beautiful implementation of wood in VEX, though… I had been thinking about making a (non-competition legal) VEX machine out of aluminum on our waterjet, but making it out of wood on our laser suddenly looks like much more fun.

Nicely done!

Jason](http://www.chiefdelphi.com/media/photos/22924)

This is why I like custom parts :smiley: I only wish we could do this in future games! :smiley:

  • Andrew

http://www.chiefdelphi.com/media/photos/35536
[http://www.chiefdelphi.com/media/photos/22924

This is a beautiful implementation of wood in VEX, though… I had been thinking about making a (non-competition legal) VEX machine out of aluminum on our waterjet, but making it out of wood on our laser suddenly looks like much more fun.

Nicely done!

Jason](http://www.chiefdelphi.com/media/photos/22924)

I’ve seen some of those before but i still don’t think i trust wood that much haha and thanks. yes its much more fun, and very unique looking kinda like old cars.

Yeah they make everything better imagine if first made us use an erector set, it wouldn’t be as much fun

Custom parts lie in the “be careful what you wish for” category. Now, don’t get me wrong… after seven years of FRC coaching, I’m a big fan of custom building. But once you’ve invested time and money into a custom part and find it doesn’t work… well, you can’t exactly undo a few nuts and put it back together in a new configuration.

The lack of custom built parts in VRC seems to enhance the iterative design process, as everything can be stripped down, reassembled and re-used.

The lack of custom parts also levels the playing field between teams with shops and those without. While I think every school should have decent shop facilities and technology education teachers to instruct students in the proper use of tools… they don’t.

Standarized parts also speed up and simplify the robot inspection process, and greatly reduce the ways that a student can be permanently maimed playing VRC.

So I get where you are coming from… and agree that custom parts are cool… but I’m actually okay with them not being allowed in VRC. Besides… there is no rule that you can’t do something custom with VEX parts… it’s just that you can’t use it in a VRC game.

And Paul… this is another one of my favorite wooden FRC machines.
Jason

Cool control system on that robot.