So I figured I would share this; originally it was intended as a short term work around for my Hagetaka project, but ended up working out really well and turning into a full blown project.
I ran into payload issues with Hagetaka (my reverse knee legged mech project) with as much as I was loading onto it for the Mech Warfare competition, so with 2 weeks left until the competition I decided to tear Hagetaka apart and try to go the ‘tried and true’ route by building a standard configuration biped. I spent roughly 30 hours on my Sherline CNC to make this happen; only ended up recycling some of the leg brackets from Hagetaka.
Named Giger, after one of my favorite artists of all time, this humanoid is built entirely from custom 5052 aluminum. It boasts 16 RX-64s and 6 RX-28s, and uses much of the same onboard electronics that Hagetaka did (custom Gumstix based controller, etc). He stands about 55cm tall and weighs about 4 kg.
I ended up liking the result of this bot quite a bit, so will be keeping this one intact and furthering its development. The initial walking gait was hastily thrown together and not entirely stable, and now that I’ve got some free time I’ll be going back to refining it and posting some video in the near future.
Hagetaka is being rebuilt using EX-106s, I’ll post pictures and my progress on that when the time comes. =)
Anyway, here are some pics! Enjoy!
With some Bioloid humanoids at Robogames for size comparison:
And here’s some work I did in Inventor modeling the robot for future changes (arms being reworked, as is upper torso):
Everything is designed in Autodesk Inventor Pro 2008 in full 3D then exported to DXF as a flat pattern.
I use LazyCam Pro and Mach3 for CAM/CNC software and a Sherline 2000 CNC Mill w/ Xylotex steppers and driver. I do my bends with a cheapo $250 Brake from Harbor Freight.
Some of the metal brackets in the legs (about 10 total) were fabbed by Big Blue Saw for the Hagetaka project, but I’ve since then replicated them using my own tools. The rest of it was built on my Sherline. All of the material is 5052 2mm aluminum.
I’ll have to check into LazyCam for the sheet metal designs. I’m just doing them in Vector CAD/CAM. Actually I have Mach3, but like to use my own CNC controller program. My brake came from HF also, but at about $50. you must have the one they advertised lately, built like a press? I almost ordered it, but I really haven’t done much sheet metal work. I did make some brackets for my Micromouse, and for Creepy.
5052? it probably bends better then 6061. But as most of the stock I get is scrap, I can’t complain!
Naw, not really active on any CNC forums. I lurked there for a bit while I was learning to use the CNC… even then I still havent jumped into too much 3D work.
Looks like the price has gone down since I picked mine up.
5052 is great, bends a LOT easier than 6061 (which would be nearly impossible to break without fracturing at this thickness) and is still very sturdy and lightweight. It has the tendency to melt easily however, so I have to take about 10 passes to cut through 2mm to avoid heavy burring. Pretty cheap too!
I might have to start looking for 5052 instead of my usual. but then, I don’t have to bend the chassis! My scrap 1/16" stuff is probably 5052, it drills and machines just a little gummy, and is not hard to bend.
Yeah the one I have now I have to muscle some of the bends. I’m using pretty tough aluminum, 5052 2mm, so I’d hate to step down to anything with less bending force.
It walks, just not well enough Making walking gaits for big heavy robots from scratch is no easy task. Turning left and right is perfect, but my walk forward and reverse sequences are far from it. I’ll post video when it doesn’t embarrass me, going a different route with the walking gait atm.
Quick update:
Used a spare RX-28 I had to add the gripper. I definitely took notes from Jim’s Johnny 5 gripper and went the straight forward route. The right arm is likely going to turn into just an airsoft gun, instead of a gripper it will just be a mount.
Oh, c’mon now and go ahead and embarass yourself. You’re among friends. How will we know if you are making progress if we can’t watch over your shoulder?
I’ll get some video up this week, I promise! I’ve made a lot of progress on this over the weekend.
Also, figured I would share some prototype hands I’m working on. These should be completely doable on my CNC, but I’m also looking at just using roller chain for the fingers as well.
And a 3 finger version as well:
They would use zipties running down the inside of each finger, coming through a slot on the back of the hand and attached to the servo hinge bracket, still a work in progress and I’ll likely scale them down a bit.
Ah yes, I see you were inspired by the Melissa humaniod hands as I was. I made some hands using Viacad 2D/3D also. The zip tie method was a clever idea that orginated from Craft House. Very cool design.
Making walking gaits for big heavy robots from scratch is no easy task. Turning left and right is perfect, but my walk forward and reverse sequences are far from it. I’ll post video when it doesn’t embarrass me, going a different route with the walking gait atm.
I’ve made a lot of progress on this over the weekend.
