@srlm- I'm not sorry, just anxious for school to start again!
@instinctz- It's only been since last October, but I see your point. The problem you must remember, though, is I am only 15. I am too young to get a constant job someplace like mickeydees. This is why I don't plan to start collecting all the electronics I will need until March, when my b-day is. If your excuse is I should find a small job for somebody to get the funds--I've tried that. However, I've found it to be hard to get a job in the winter; otherwise I'd have no trouble right now.
Also, I've kind of liked referring to my project as being affordable to the average hobbyist. If you look around at small robotics projects, such as the Robostool robot that came up in the forums recently, you'll find they will cost over $500 easily with little capabilities. My robot, on the other hand, shouldn't cost more than $500 with minimal capabilities and $800 fully loaded with sensors. That means for the same cost as the Robostool, which has capabilities of going 3mph with low hp and few sensors, I can make a 30mph 5-horse robot with twice the sensors. Quite a difference, don't you think?
Just to give you an idea of how this robot can be so cheap I've broken it down for you. Just remember, though, the prices are an estimate.
5hp used engine- $100
clutch-·$35
chain-·~$6
sprocket- $25
back hubs- 2x $10
back wheels, used (tires will need to be replaced soon) 2x $5
front wheels- 2x $15
front tires- 2x $20
windshield wiper motor (for steering)- free, had to clean out rust
alternator, used- $15
belt for alternator- $10
metal- I have no clue, but I don't expect it to exceed $30
total for the robot without sensors: ~$291, not including metal estimate
As you can see, by using old parts in my project·and making parts of my own, I've probably cut out at least $300, and the number just keeps growing every time I do something to save a little more cash.
I'm not sure. For all I know my alternator already regulates it. On the back of the alternator it has two leads labeled bat and gnd. The voltage coming off of these is always positive for bat no matter what direction I spin it, and the same is for gnd. I have no clue if it will regulate it, though, because I don't have it attached to my engine yet.
Earlier today I came across a small TV that was selling for $5 at a thrift store. I was thinking it would be great to put on my robot, and place a touch pad on it so I don't have to use buttons, however it doesn't have any input ports. It was only made to read the airwaves. You think there's a way I could attach it to a prop somehow?
Are there any stickers or numbers stamped on your alternator? Do know what it came off of? car, truck,etc...
Most modern day alternators have internal voltage regulators, but there are some like dodge that used the ECM to take the place of the external voltage regulator. Can you post some pics? that may help in identifying it.
-dan
it'll show what the connectors on that alternator are for. The way that site tells you to wire it should be avoided though, that offers no regulation and will most likely cook your battery if it ran long enough.
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Brian
uController.com - home of SpinStudio - the modular Development system for the Propeller
PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!
There's certainly some details you'll need to resolve.
If you're using an automotive battery it will handle the alternator's 13.6 to 14.4 V (assuming regulation, of course). If you are charging a small sealed lead acid battery it likely charges at 13.8 V and 14.4 could be too high. It appears that the alternator you have includes internal regulation (which you can disable by "putting a long metal object into that opening" as it says on Brian's link). Be certain what you're doing in this regard.
It still seems a little confusing to me, but I'm sure I'll figure it out soon enough. If I have trouble in the future I can easily turn to my welding teacher or somebody else for more answers.
I was having a conversation with some other guys in my welding class today, which started out with the normal questions about my robot such as "So what are you going to do with it?" and "When are you going to get it done?" However, one remark caught my attention. One of the guys said "I can't believe you are still working on it. If I was building it I would have given up a long time ago." The way I view it, though, is if you can't put your life to a task then it's just a life wasted.
Is ONLY to BYPASS the regulator····.......>>>>>>>>>>··............>>>>>>>>>
The only reason that any one should ever do this is to see if the alternator has output and should never be done for more than five seconds.
·This is not a good ··over five seconds because your voltage can and will go over 15 volts and higher and you will just fry allot of thing by doing this
I was an Auto Electric tech at one time
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ··Thanks for any··that you may have and all of your time finding them
What you have is the old style GM alternator (1974 or older) that uses an external regulator, 37 amp 12 volts negative ground.
What was shown in the link was the new style(1975 and newer)"SI" internal regulator alternator.
Terminals R and F would hook up to the external voltage regulator, BAT is the output to the battery.
If I remember right applying +12 volt to the "F" terminal should cause it to generate full power.
I'll have to see if I can find a good picture in one of my old service manuals if you want to see how your alt is wired internally.
I found pics of an external GM voltage regulator, hope this gives you a better idea of what I'm talking about.
-dan
I've been thinking a little more about the actual electronics onboard the robot. I've posted a picture of a·TV that's similar to what I would like to buy. If I get it I will probably use·this touch pad: link
If you have any ideas/suggestions please let me know. I always enjoy hearing someone else's opinion.
EDIT- sorry I cut you off, icepuck. I have now posted my response.
icepuck said...
What you have is the old style GM alternator (1974 or older) that uses an external regulator, 37 amp 12 volts negative ground.
What was shown in the link was the new style(1975 and newer)"SI" internal regulator alternator.
Terminals R and F would hook up to the external voltage regulator, BAT is the output to the battery.
If I remember right applying +12 volt to the "F" terminal should cause it to generate full power.
I'll have to see if I can find a good picture in one of my old service manuals if you want to see how your alt is wired internally.
I found pics of an external GM voltage regulator, hope this gives you a better idea of what I'm talking about.
-dan
@icepuck- Are you saying I need a external voltage regulator before I can work with my alternator? I still don't get why it would say bat but require a regulator before you hook it up. Maybe I'll just talk to my teacher tomorrow; I should understand things better that way since he can point it out on my alternator.
Regulated or not regulated, you'll still need to know what kind of battery you're going to use. Car batteries have huge capacity and they're very forgiving. They can charge at a much higher voltage without damage or heat. While 12.65 V may be 100% charged in a car battery with no load, it can still take 14.4 V from a spinning alternator to charge to that level.
But car batteries are darned heavy. I don't think they're the best battery to use for a "hybrid" robot. If you are going to carry a car battery around, skip the engine and run everything from a car battery. You could use a much smaller (and lighter) engine, and a smaller capacity SLA battery. If you go this route then you will probably need to design your own charger circuit, as SLA batteries often want 13.8 V for charger. 14.4V will be too much for them.
I'm watching this project and enjoying it. Start making some progress and show us some photos! Stick with it, to the end!
The regulator(internal or external) controls the voltage going to the rotor.The regulator uses battery voltage as an input to control the voltage to the rotor(via slip rings and brushes),which is nothing more than a rotating electro magnet.That magnetic field spins inside something called a stator, which is a stationary coil of wire, were the output voltage is generated as AC(alternating current).
Then the AC goes through six diodes(because it's a 3phase rectifier) and comes out of the BAT terminal as a DC voltage.
Maybe your teacher may know where to find or borrow a GM service manual(1966-1973 should do) locally, look in the charging section and read the part on the theory of operation for your alternator. That will do a better job of explaining things than what I can, since I can't seem to find the one that was in my dad's collection of old manuals.
Once you understand how it works you should be able to see that you have an option that don't have with a newer alternator.
...Using your software to control the voltage to what ever you want.
-dan
It may be convenient to control the voltage with the software, so I guess it's a good thing I got the cheapest, oldest alternator available. I probably won't even start working on this part until summer, but I eventually would like to use a 2hp motor (or something similar) for controlling the robot at the slower speeds. Not to throw too many ideas at you, but I'm thinking two of those things would be nice. One for controlling the motors power, and a second to control the power the electronics and the a/c inverter I would eventually like to get. Save the thought for later, though, 'cause I don't plan to work with the motor for a couple months.
@Ken- I was thinking it would be nice to have a car battery, especially since it would fit easily on my 4' long frame, but I could use a different battery instead. I know at a local CAL Ranch store here there are plenty of electric fence batteries. They are about half the size of car batteries.
What kind of batteries did you use for your robot?
I'm just going to worry about the batteries later. My main problem right now is finishing it in two weeks. If I drag on any longer I will be working on it during 3rd trimester which will be much harder.
BTW- I'm planning on taking a pic of the robot with the back wheels tomorrow. The only thing holding me back is the hubs which are not quite done.
Pi Guy, have you looked at using a motorcycle battery. They are smaller and lighter than a car battery but still 12V. Also if you can access the stator windings directly by removing or bypassing the diodes you can use the alternator as a motor to start your gasoline engine with a little additional circuitry.
A motorcycle battery might work. However getting the alternator to start the engine might be a little trickier. I have to extend my shaft as it is right now just to hold the pulley. The only problem is I can't get my clutch off to attach it! There are threads in the shaft, though and I was planning to use them. The only problem is if I use the alternator to try and start the engine it will probably just unscrew the extension!
Ah well, it impressed me when I saw it in action. Just one question though. Is the clutch screwed on? Most motor shafts I have seen have a keyed shaft so a gear puller should get it off.
Thanks Cole, I'll check into it. I still don't see why the pounds are such a large problem when the robot is made of 100% steel with heavy electronics and engine onboard. I'll think about it a little more, though.
@Kwinn- it uses a locking allen screw. Whenever I try taking it off I feel like I will break the wrench. Maybe part of that was just because I using the wrong size, though.
Also, I wanted to say I got put a little behind on schedule this week. I guess it's just bad luck. Maybe if I stopped telling you the dates I planned to get things done I would actually complete it on time!
I know what you mean about the allen screws. They really torque them down on small engines. When I raced go-carts I always expected to snap at least one or two head bolts before the came loose. As for announcing schedule dates for work on my hobby projects, I try never to do that if at all possible. You never know what else is going to come up.
I would say that in your application the weight might not be a huge diffrence but one of the nice things about the AGM batteries is that there useally a little smaller for a givin Amp hours and they can be mounted in any direction with out fear of spilling acid.
Sorry I haven't been responding, guys. School got in my way and I tripped.
@Kwinn- I sure agree with you, especially about stating those dates.
@Cole- I decided to lift one of those car·batteries the other day just to see how heavy they were, and I think I may want to go lighter now. I'm thinking I might·go for one of those motorcycle batteries instead.
I have pics I wanted to post, however the camera they are on is currently at school. I'll post them along with any new progress tomorrow.
Right now I just about have the back wheels fastened. All I have to do is finish the holes for the pins and find enough bolts to fully fasten the wheels. Once that is done I just might try and ride it with only the two wheels
Since I have ~4 hours to work on my 'bot tomorrow expect some progress on the steering as well. My only excuse for not finishing it yet is not having the·wheels necessary to make sure the measurements were correct. Tomorrow I should be able to get at least one of the 14" wheels to school, making it possible for me to complete my work with the steering.
I took a pic for you on Thursday, but unfortunately I wasn't able to post it until now. The photo is a little misleading, though. Even though I have the front wheels on, the robot can't turn yet. They were just placed on a solid metal bar so they can't pivot. I will try and complete that part of the robot next week. When it is done the wheels will move out a couple inches (making them not look so squished) and a joint will be added allowing them to pivot. Next, a bar will go across which will be attached to the motor.
In the pic you can see the alternator close to where it will be mounted. It will still take some time to attach it, though.
I also have engine problems to take care of. I originally thought it was the spark plug, but after replacing it the engine still won't start. I'll tell you when it does.
Comments
@instinctz- It's only been since last October, but I see your point. The problem you must remember, though, is I am only 15. I am too young to get a constant job someplace like mickeydees. This is why I don't plan to start collecting all the electronics I will need until March, when my b-day is. If your excuse is I should find a small job for somebody to get the funds--I've tried that. However, I've found it to be hard to get a job in the winter; otherwise I'd have no trouble right now.
Also, I've kind of liked referring to my project as being affordable to the average hobbyist. If you look around at small robotics projects, such as the Robostool robot that came up in the forums recently, you'll find they will cost over $500 easily with little capabilities. My robot, on the other hand, shouldn't cost more than $500 with minimal capabilities and $800 fully loaded with sensors. That means for the same cost as the Robostool, which has capabilities of going 3mph with low hp and few sensors, I can make a 30mph 5-horse robot with twice the sensors. Quite a difference, don't you think?
Just to give you an idea of how this robot can be so cheap I've broken it down for you. Just remember, though, the prices are an estimate.
5hp used engine- $100
clutch-·$35
chain-·~$6
sprocket- $25
back hubs- 2x $10
back wheels, used (tires will need to be replaced soon) 2x $5
front wheels- 2x $15
front tires- 2x $20
windshield wiper motor (for steering)- free, had to clean out rust
alternator, used- $15
belt for alternator- $10
metal- I have no clue, but I don't expect it to exceed $30
total for the robot without sensors: ~$291, not including metal estimate
As you can see, by using old parts in my project·and making parts of my own, I've probably cut out at least $300, and the number just keeps growing every time I do something to save a little more cash.
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PG
What's your plan for managing the alternator current/voltage?
Are you going to design a battery charger circuit or use an automotive regulator?
Ken Gracey
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PG
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PG
Most modern day alternators have internal voltage regulators, but there are some like dodge that used the ECM to take the place of the external voltage regulator. Can you post some pics? that may help in identifying it.
-dan
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PG
it'll show what the connectors on that alternator are for. The way that site tells you to wire it should be avoided though, that offers no regulation and will most likely cook your battery if it ran long enough.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Brian
uController.com - home of SpinStudio - the modular Development system for the Propeller
PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!
SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board
If you're using an automotive battery it will handle the alternator's 13.6 to 14.4 V (assuming regulation, of course). If you are charging a small sealed lead acid battery it likely charges at 13.8 V and 14.4 could be too high. It appears that the alternator you have includes internal regulation (which you can disable by "putting a long metal object into that opening" as it says on Brian's link). Be certain what you're doing in this regard.
Ken Gracey
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PG
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PG
Item # 4 at this web Link
Is ONLY to BYPASS the regulator···
The only reason that any one should ever do this is to see if the alternator has output and should never be done for more than five seconds.
·This is not a good ·
I was an Auto Electric tech at one time
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··Thanks for any·
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Sam
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PG
What was shown in the link was the new style(1975 and newer)"SI" internal regulator alternator.
Terminals R and F would hook up to the external voltage regulator, BAT is the output to the battery.
If I remember right applying +12 volt to the "F" terminal should cause it to generate full power.
I'll have to see if I can find a good picture in one of my old service manuals if you want to see how your alt is wired internally.
I found pics of an external GM voltage regulator, hope this gives you a better idea of what I'm talking about.
-dan
Post Edited (icepuck) : 2/18/2009 2:45:57 AM GMT
If you have any ideas/suggestions please let me know. I always enjoy hearing someone else's opinion.
EDIT- sorry I cut you off, icepuck. I have now posted my response.
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PG
Post Edited (Pi Guy) : 2/18/2009 3:17:12 AM GMT
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PG
Post Edited (Pi Guy) : 2/18/2009 3:12:48 AM GMT
Regulated or not regulated, you'll still need to know what kind of battery you're going to use. Car batteries have huge capacity and they're very forgiving. They can charge at a much higher voltage without damage or heat. While 12.65 V may be 100% charged in a car battery with no load, it can still take 14.4 V from a spinning alternator to charge to that level.
But car batteries are darned heavy. I don't think they're the best battery to use for a "hybrid" robot. If you are going to carry a car battery around, skip the engine and run everything from a car battery. You could use a much smaller (and lighter) engine, and a smaller capacity SLA battery. If you go this route then you will probably need to design your own charger circuit, as SLA batteries often want 13.8 V for charger. 14.4V will be too much for them.
I'm watching this project and enjoying it. Start making some progress and show us some photos! Stick with it, to the end!
Ken Gracey
Parallax, Inc.
Then the AC goes through six diodes(because it's a 3phase rectifier) and comes out of the BAT terminal as a DC voltage.
Maybe your teacher may know where to find or borrow a GM service manual(1966-1973 should do) locally, look in the charging section and read the part on the theory of operation for your alternator. That will do a better job of explaining things than what I can, since I can't seem to find the one that was in my dad's collection of old manuals.
Once you understand how it works you should be able to see that you have an option that don't have with a newer alternator.
...Using your software to control the voltage to what ever you want.
-dan
@Ken- I was thinking it would be nice to have a car battery, especially since it would fit easily on my 4' long frame, but I could use a different battery instead. I know at a local CAL Ranch store here there are plenty of electric fence batteries. They are about half the size of car batteries.
What kind of batteries did you use for your robot?
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PG
BTW- I'm planning on taking a pic of the robot with the back wheels tomorrow. The only thing holding me back is the hubs which are not quite done.
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PG
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PG
here one That weight only 10 pounds
http://www.batterystuff.com/batteries/motorcycle/sYB14L-A2.html
and heres one that only ways 6 pounds
http://www.jegs.com/i/Braille+Auto/147/B106/10002/-1#
@Kwinn- it uses a locking allen screw. Whenever I try taking it off I feel like I will break the wrench. Maybe part of that was just because I using the wrong size, though.
Also, I wanted to say I got put a little behind on schedule this week. I guess it's just bad luck. Maybe if I stopped telling you the dates I planned to get things done I would actually complete it on time!
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PG
@Kwinn- I sure agree with you, especially about stating those dates.
@Cole- I decided to lift one of those car·batteries the other day just to see how heavy they were, and I think I may want to go lighter now. I'm thinking I might·go for one of those motorcycle batteries instead.
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PG
Right now I just about have the back wheels fastened. All I have to do is finish the holes for the pins and find enough bolts to fully fasten the wheels. Once that is done I just might try and ride it with only the two wheels
Since I have ~4 hours to work on my 'bot tomorrow expect some progress on the steering as well. My only excuse for not finishing it yet is not having the·wheels necessary to make sure the measurements were correct. Tomorrow I should be able to get at least one of the 14" wheels to school, making it possible for me to complete my work with the steering.
Stay tuned as I make more progress with my robot.
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PG
Post Edited (Pi Guy) : 3/27/2009 3:06:59 AM GMT
In the pic you can see the alternator close to where it will be mounted. It will still take some time to attach it, though.
I also have engine problems to take care of. I originally thought it was the spark plug, but after replacing it the engine still won't start. I'll tell you when it does.
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PG
Post Edited (Pi Guy) : 3/8/2009 1:19:18 AM GMT