Society of Robots - Robot Forum
General Misc => Misc => Topic started by: Truckstop on August 04, 2009, 04:33:12 AM
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Hi this is MAX. the robot im currently building. hes is the predecessor to another robot i have planned called Goliath. Goliath is a robot miner design, however MAX is designed more as a toddler. MAX will allow me to add, update, prototype, and advance, software, hardware, for the up coming Goliath Project.
I will post pictures, Source Code, And schematics as they become viable, (working not just scribbles). Max and Goliath are both inspired by the robots, Johnny 5 from short circuit, and Glitch. From the game metal arms. MAX's main goal to to prove a design plausible, then from there to test various hardware and software, and to have fun, Enjoy,
Truckstop.
P.S.
Any comments or questions are greatly appreciated.
The body is from a Old car Jump Box, the arm is from OWI and the arm controller board is from OWI's beetle kit, the h-bridges are perfect. the arm has simple limit switch's right now but i plan on adding Pots to it for position data. tracks are also in the pictures, only one is together right now.
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hello, i am new to the site. been bopping around here and there for awhile and finally decided to post, sadly it is for help, i do plan on posting something's that may help someone else in the future.
Don't be silly that what the forum is designed for, tohelp people solve problems ;D
Can you give a few mesurments so we can comprehend the size of the bot that is about to be created.
And if you can some drawings like cad drawing would be good.
Any way i found for my tred design the best elevation to hae at th fron is a 37 degree elevation, but that will be different for every bot as it depends on the size of the tred(circumfrence). Post some measurments and i will do some calculations if you want me to.(When i can find some spare time.)
Sounds good so far, heep us updated. ;D
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I'm thinking something around 2.5 feet long by 1.5 feet wide all the way up to 4 - 4.5 feet long and 3.5 - 4 feet wide, if i get up around the 4 foot long range i will make the 3.5 inch wide tracks wider probably to about 4.25 inch's not sure on height yet but probably around 4-5 inch's at least, i plan on making a humanoid upper torso that can be mounted to it and use it as both a automaton and a telepresense project, but don't want to get to ahead of myself, sadly i don't have a digital camera or a decent program for drawing on the computer, lol i cant even watch you tube videos, but you would never guess that i'm using an old Macintosh power book 145cs running OS 9.2 to post to the forum, i also have a 486 laptop running windows 98 for programming, there old but cheap and work great, i have claris works but don't like it, iv always been a pen and paper kind of guy, i also love Macintosh, anyway i am rather flexible on the size if it needs to be bigger? i was simply going to have a 45 deg* angle at each end as the ends will be exposed not covered up, but if you know of a better deg* that would be cool, i wont ask ya to spend too much of your time on it tho, just looking for quick ideas a gentle nudges in different directions ill try to barrow a camera from a buddy to get some more photos posted, nothings assembled yet except the tracks, my inspiration for the track drive came from a robot called pasiv created by Michael Burton. heres a link to his bot,
http://photogallery.burtonwerks.com/GalleryFilmstrip.aspx?gallery=109843&photo=3656494
The similarity will end with the track drive, i don't have a photo of the track i currently made but it does look like pasiv's except for the center stabilizer and the cleanliness, BTW i did e-mail Michael Burton asking permission to use his track design. The three pictures included are as fallows the track, my actual Motor I'm using and Todd, one of my smaller robots made from a hacked toy,
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how big are the rollers that the treads run on? (looking for radius/diameter)
the radius of those can dictate how the tread is to be laid out.
i like the way those treads look btw, i never even though of using bike chain for treads
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the rollers i will be using will be about 2.5 inch in diameter and .75 inch diameter and the full width of the track, the drive gears i plan on being the full width of the track and about 1.5 - 2 inch in diameter
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also, do you plan on having fixed rollers, or do you plan on having your rollers on some sort of suspension, or a combination of fixed and suspended rollers?
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not sure, i was thinking suspension? allowing them to move independently but at the same time suspension would complicate things, i think for now it will be fixed and leave room to upgrade to some sort of suspension setup in the future
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fixed would indeed be much simpler.
i would recommend looking at tanks. their treads are designed for being able to climb over things. you might even be able to find dimensions which you could then scale down to your size
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yeah that's where i got the idea of a 45 deg* angle but wasn't too sure if it would work on a smaller scale, also i was worried that if i simply scaled it down it would not be heavy enough or could topple over, i actually even have a rc toy tank, but its too small and honestly is a piece of junk,
Thanks for the great input.
may the Google be with you
EDIT: I'm also considering a tri track design if anyone has any knowledge with these and there performance
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Picture update!
Ok so i finally bought a digital camera, but it was cheap so the pixs aren't too good, i think im going to go with this track design, it will allow alot of clearance under it and should distribute weight pretty good, there will be a plate on the side to cover most the innards and hold the parts together, the bottom rollers will be connected in pairs of two and each will pivot as on Pasiv, however i wall have 3 sets as max will be longer, i have also decided on a name. MAX (Mobil Autonomous eXperiment)
Also included is the start of the two massive Dual H-Bridge controllers for the 24V 450Watt motors, there's the heat sink there mounted to, it also has a thermal sensor on it so i can add a command if the motor drivers over heat, the heat sink then mounts into the large blue heat sink and has a fan to blow air over the internal heat sink and mosfets. i am designing a custom Dual H-Bridge that can use PWM for speed control, small scale experiments look promising and the NPN mosfets i currently have are rated for fast switching, Yes the blue thing used to be a 120 ac inverter, It fried. I don't wanna talk about it. ;D
(off topic... Mini discs are cool.. you know it ;D)
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you seem to be on the right track all on your own :P
but, it never hurts to have people to bounce ideas off of.
Keep us updated i really want to see how this turns out
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Thanks this forum is awesome and the people are cool too, i will do my best to update, sadly i got layed off this morning so now i haft to find another way to fund my project, I have a few more schematics and drawings i would like to post soon, right now i got allot of track built and need to focus on the cog, gear, roller Assembly, I wish to post everything i have on the project but need to sort it and figure out which is data and what is repetitive BS. More to come
Truckstop
Edit: Also looking for suggestions for caps to use on the motors, for the noise filter/back emf filter. The motors are big, 24volt at 450 Watt (~28 Amp) they measure around 3.25 inch in diameter and 4 inch long. there big and iv never caped a motor this large. i am planing on using a secondary battery for the motors to help with noise but still would like to have the filter
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sorry to here the bad news :(
Max (mobile autonamous eXperimentis a good name ;D
Nice track designs, sounds like they should work, Nice idea to keep the first version of MAX rollers fix.
As for the caps, i think you will need one rated twice as much as the input voltage there for you will need a cap rated for 50v.
I have never had to deal with such big motors before, i guess you would use an electrolityc cap, ind i don't even know where to start with the size you should use.
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Just an Update on MAX,
Iv been making more track, also i ordered a pair of parallax 2p-40 micro controllers and a pan and tile device from lynxmotion, it is for a robot arm trainer i got from frys a long time ago and wish to experiment with. also picked up some new gears. Included with this post is some pictures of the track in assembly in case anyone is wondering i am using Bell speedy Chain 1/2 in x 3/32 in (1.3 cm x 0.24 cm) , it takes allot of chain to do this type of drive system, my tracks are 3.5 inchs wide. I would suggest not doing this kind of drive unless you need a rock solid track, the chain is very strong and after i add the rubber stubs the traction should be superb. it can get expensive for large track system. small tracks can be also made from bike chain. the roller gears im using are the larger gear from bicycle derailleurs and the smaller ones also.
Truckstop
Note i want to correct an earlyer post where i said i had 15 feet of track, I meant to say 15 inch's, i now have 2 feet
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very nice, i also imagine building the chain this way to be tedious
how exactly do you construct it?
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yes it is very tedious. and breaking chain kills your hands after awhile, well i went up and bought a box of grade 8 #6 - 32 bolts and matching lock nuts, about 8 Dollars a box and each box is a half pound after wards i bought the chain as well i scan craigslist dailey for chain or anything i might see to get chain. the tracks are assembled as the photos in my previous post shows,
I start by breaking the chain into 3 link lengths that have open ends on both ends and a closed link in the middle.
So if a open link looked like this ( = Open link )
And a closed link looks like this ( oo closed link)
then the 3 link strand would look like this, =oo= ? Not sure if its very clear but ill try to post more detailed pictures as well.. then you take two 3 link Strands and meet them with a closed link (a single link) and run your bolt through both holes like this
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=00=00=00=
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the bolt holds the links together instead of the pins that were in there. after wards you add a closed link as a spacer and then keep adding 3 link strands connected with a closed link,
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=00=00=00=
00
=00=00=00=
00
=00=00=00=
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you do this until your desired track width is acquired, im using 4 inch long bolts to make 3.5 inch wide tracks. but you can use any length bolt you want depending on your track length. After you reach your width now you want to make it longer, you do this by ( i call it sewing) more chain length's into the end with more closed links like inserting two bolts in every hole of the closed link. Like so
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=00=00=00= 00 =00= =00=00=00=00=00=
00 00 00
=00=00=00= 00 =00= Turns into this =00=00=00=00=00=
00 00 00
=00=00=00= 00 =00= =00=00=00=00=00=
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Its a little confusing but its how im doing it if you do it after awhile its like second nature, assembling the tracks is easy and even fun, i listen to music or watch a movie why i do it, but breaking the chain is a pain in the a$$. i find it best to take a brake after you get a bunch of pieces separated. because even with a good pair of gloves your hands will hurt after awhile. also the chain breaker gets warm after awhile, its good to lube it with some 3 in 1 oil once in awhile too....
EDIT: Spell Check, Added update..
Update. So i have now fried two different H-Bridge boards. After some tests with a amp meter i found out that my 28 amp motors actually pull about 33 amps at full swing under a 10 pound load. (ill post a pic of the burnt board when i can) so for now im going to use 4 40 amp automotive relays i found in the back of my truck to drive each motor, these relays will be driven by 5V micro relays and those relays will be driven by 2N2222 transistors. the motors will be geared low so reaction time is not too impotent but i hope it wont lag too much. test data to be posted soon. this should suffice until i can get ahold of some good high amp transistors.
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One possible design outcome. i also found some plans and parts this morning for another robot i started called Goliath. If max ends up working as well as i hope Goliath will be next in line for construction.
I just wanted to say if anyone thinks max looks like J5, you are correct. J5 was a big inspiration in my getting into robotics.
EDIT: its a fire extinguisher on his back btw..
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very nice, what did you CAD max up in?
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i diddent as my computer is to slow to run a cad. i simply found these online and noticed a striking resemblance to what i have been drawing. Thus i posted them as a possible Design outcome, however i rather like the tank and nozzle therefor after i saw it i integrated the idea. the head will more likely be different.
I don't mean to steel other peoples designs. my computer is just really slow and i cant run allot of the software others do. plus like i said it looks so much like what i'v drawn up i diddent see any harm..
Truckstop
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I like it a lot. I was thinking about using bike chain for treads but im still tight on money for other stuff. Good luck.
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Thanks. Yeah it can get expensive but most the chain i have i got used for cheap or free. talk to some local bike shops that do repair and i bet they will give you a good deal. i got one here that when i went in i explained what i was doing and they just gave me a bunch of stuff for free, ( Various used gears, jockey wheels, and bits o chain) also mention adding a sticker to your project to advertise for them, they tend to really like that as there getting something for there contribution. You should also note if you use bicycle chain it does not get the best traction, im going to bolt pre-cut strips of solid rubber to my tracks when there finished.
Good luck to you as well
Truckstop
UPDATE: so as of now i was using 8 power hungry relays to act as a H-Bridge driver for MAX's motor control but today i stumbled across these BB Motor controllers that use PWM and are rated at 12 Amp , 45 Amp peak. http://www.trossenrobotics.com/store/p/4267-BaneBots-Motor-Controller-45A-peak-.aspx
Does anyone have any experience with these? i should be able to order them next week and believe they will cure my motor problem
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UPDATE..
So the new 2p-40 Basic stamp came in the mail today. so exciting. i have decided to use a microprocessor network to run allot max's systems with a simple 2 wire interface for serial communication, Here's a picture of how the network is connected.(im playing with a new drawing program, Please ignore the unlicensed stretched across the image) i will post some simple bs2 code to get the network running. this is the sample code as my code is not finished as of yet. right now the network i have constructed consists of a basic stamp 2p-40, A Basic Stamp2 home work board, and a Basic Stamp1, The BS1 module is the only finished module, it is connected to a battery monitoring circuit and a DS1302 (parallax Clock Chip) for system time and date keeping. this module has an extra pin that the master chip watch's for a trigger on, this tells the master stamp that the battery is running low and it needs to start a "search and destroy" program to search out a charging station. this function above all gets highest priority, if power gets to low it will go into a sleep mode where it will shut down different things and beep until i plug it in, yes i plan on having another stamp to control power on the network.
Advantages of a network of processors are that it allows you to string a large program between different microcomputers, allowing faster program execution as a single chip does not haft to deal with every bit it only asks the network for what it needs then continues, disadvantages can include more complicated programming.
only the slave code is posted, and is a screen shot directly from my programmer. the master code isent finished yet. i will post it when it is.
EDIT: Added the power dist.jpg. its a simple idea iv been playing with, several 7805 ICs heat sinked and mounted to a board, each one with a 3 pin header, the 3 pin header each has its own 5 volt regulated power source and the signal pin on each header is routed to another header in which will connect all the signals to the master MCP. With it you can run multipal sensors, servos, microcomputers, each isolated by there own power source. add another transistor to each power regulator and you now have control of whats turned on and whats not as well. im also experimenting with optocouplers.
Truckstop
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posting the layout of Max's main board. ignore the top half, as its reference material. the bottom half is the circuit layout.
On another note. iv been considering changing the subject of this topic, to something like watch max grow or whatever. sense its turning into a build page. but should i also put it in another area instead of mechanics and construction? I'm trying to get my web server back up and running as well. but I'm having issues with a stupid router... if i get it working ill post regular updates on a web page y'all can view...
The teather control box is also in the works. ill post it when its ready...
so hears how the teather will work. when the tele pin is triggered the master stamp go's into a security mode(not finished yet) where you will need to show him a RFID badge to gain control over the teather port, if the badge is accepted then it go's into wait mode where it will wait for a specific command before it
takes back control. during this wait mode the teather control can serial out and in commands to the stamp network accessing information and even issuing commands to the master MCP.
Thanks
Truckstop
P.S. has anybody done networking like this or similar to this with other microcomputers besides the stamp series? just curious
EDIT: forgot to upload image lol
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This looks so cool, I would like to see the finished project! can you post it when it's all done?