It would have been nice if the holes in the sensor plates were the right size for the single transducer ultrasonic sensors such as the srf01, srf02 and maxbotics to fit with a grommet and additional mounting holes drilled for them.
Can we have a QTI sensor kit for the Stingray similar to the one for the BoeBot but with appropriate standoffs and fasteners for the Stingray?
How about the same for Ping?
Chris Savage (Parallax) said...
2) How do you like the mechanical/metal aspects of the Stingray (the chassis) and what changes would you make if you could?
I would make the rear wheel large so that the robot can flip and still run. The electronics could easily be moved inside (if you're not changing them that much). Also, a door mechanism to the inside would be nice.
Chris Savage (Parallax) said...
3) Regarding the Control Board...what enhancements or changes would you make to it. If none, please tell us what you like about it.
A place to plug in an ADC or three would be nice. DIP or SMD would be fine. Also, a place for video output (TV) would be nice.
Chris Savage (Parallax) said...
4) What accessories would you like to see for the Stingray?
Various battery connector transformers. Tamiya to Molex or barrel jack, or bullet to Molex or barrel jack. A big red emergency stop button. Encoders for sure. Spare set screws (I lost one...). Mechanical mounting parts for things like servos, IR distance devices, TV screens, lights, etc.
Also, some sort of case would be nice to fit over the electronics to protect them from accidental interference but allow quick access.
Chris Savage (Parallax) said...
5) Do you like the current battery pack? If not what would you have liked instead?
No, I don't have 1.2v AAs and don't want to spend the money to buy them. I would have preferred several Molex connectors with pigtails so that I can connect my own batteries.
Chris Savage (Parallax) said...
7) If basic sensors (other than the BOE-Bot IR sensors) were included, what type of sensor do you feel would be the most common choice?
I will probably use several Sharp IR sensors and a ping, maybe two. The Sharp sensors would be used since several can be used simultaneously without interference.
Additionally, bumper sensors would be great. I'll probably build some myself, but something that does double duty as a sensor and protector device would be great.
Chris Savage (Parallax) said...
8) Do you feel Parallax should provide end-user examples of the Stingray in action? If so, doing what (remember to consider question 7)?
Absolutely. I think there should be several demonstrations/example codes. First, a simple motor run test that shows the robot going in a spiral and/or box. It doesn't need any additional sensors for that. Then perhaps an "agility" round: make it spin, go really fast in a sin wave form, suicides, hill climbs, etc. The point isn't to give numbers, but to give a feel. All of that can be done without sensors.
Chris Savage (Parallax) said...
9) Is there anything else you'd like to offer for suggestions, comments, feedback, etc.?
I'd like to see pictures of various sensors mounted to the front of the robot. Things like a Ping, the sharp IRs, bumpers, whiskers, IR (LED and detector), etc.
Very nice robot. I expect my weekend will be pretty busy: I'm going to see if I can make it go to the lounge and back from my room by Monday morning.
I just got back in town and put together the stingray, which was waiting for me. Very easy to assemble. The only thing I would change at this stage was type of battery and location. If the battery compartment must stay where it is currently located, some type of access door should be added. Perhaps hinging one of the side sensor mount plates?
Of course, the batteries must go anyway. As has been mentioned by others, I will be replacing mine with 7.2 volt LiPo packs. AA batteries, well they just don't have the lasting power I need. When I am building/programming, the last thing I want to do is slow down or stop to change batteries.
I look forward to taking this back downrange with me in December, where I will have more time to add sensors and do some programming. Thank you so very much for this kit, it is a platform with enough real estate for sensors and servos to keep my busy for quite some time!
I've had a chance to play a little bit with·my Stingray. Here's my comments.
1) The documentation was clear and made it easy to build and test the bot. My only complaint was that my kit came with a bunch of electronics parts like LEDs, resisters, transisters, a 6pin IC, and other random stuff that I am not sure what all of it is.·I know some of it is the same as what comes with the Boe Bot since I have one and could compare. So, some sort of listing in the docs of what all those are would be nice (like in the Boe Bot docs).
2) I'm pretty happy with most of the mechanical/metal stuff. The built bot feels very sturdy, and it's not very heavy.
3) The only change I would want is minor. You provided thru-holes for access to the port pins directly as well as for the jumpers to disable the translators. I would have prefered that the pins be already soldered into the board. I am not the greatest at soldering yet, and am worried about damaging the board when I add those pins myself.
4) I have the PING for Stingray kit already, and I also got the introduction to sensors kit. I have the PING mounting bracket you sell for the boe bot that I managed to get mounted to the back of my Stingray using some VeX hardware I had, but a variant of the kit for the Stingray with hardware fo a rear or forward mounting would be cool. I, also,·really want wheel encoders.
5) I didn't use the provided battery pack at all and instead went with my 7.2v packs that I use with my VeX stuff as well as my R/C cars. I hacked up some temporary wiring for now, but have ordered the connector parts I need to make a clean adapter from Mouser.· I think I nice option in the kit would be an adapter for doing this (like many others have mentioned).
6) I don't think you need to offer a charger. Just an adapter to standard Tamiya battery connectors.
7) If you wanted to include sensors, I think the most commonly wanted thing would be wheel encoders. My kit came with the stuff that you put in the boe bot, so the IR, whiskers, and stuff. I think this bot is a little big and fast for the IR sensor setup to be really effective. Same for the whiskers.· Anyway, I agree more with what others have said, just·offer separate·sensor packs geared towards the Stingray (like the 3 PING one).
8) I was able to make a simple program that made the bot move in a rough square on the floor using the motor test code. It took a while tweaking the numbers to get the timing right on the turns. Wheel encoders would have made that easier. I also tried out the PING Stingray test demo code I found on the store page. It works pretty nicely. I think if you provide other sensor packs geared towards the Stingray than doing demo code like for the PING back would be enough.
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Check out the Propeller Wiki·and contribute if you can.
"6) Should Parallax offer a charger or do you think the average customer has the charger for the batteries they're inclined to use (I know this fits me)?"
"7.2v RC packs (in Ni-MH and NI-Cd) and Chargers are readily available at RadioShack, but perhaps include a connector or two to support them."
Just want to pop in and say I love my Stingray! Have been fooling around with it every day now since receiving the replacement robot board and am constantly awed by the number of opportunities for customizing this 'bot. I am definitely in agreement that we need additional standoffs and deck plates.
It would also be nice to leave an area around the "center of gravity" to install accelerometers and a digital compass or two.
I received mine as a holiday gift and assembled it quickly without problems so the docs were more than adequate in that area. I also downloaded the schematic which should have been included with the docs. I also discarded the six AA battery pack, in its place is a radio shack 7.2 volt RC battery pack for which I had to buy the plugs and make my own adapter, so I think that would make an excellent optional item.
So far I've installed the QME-01 wheel encoders and the 3 Pings onto the bot. which work quite nicely.
The single biggest issue I have with the controller board is the 3V-5V level shifters and the single row of direct inputs (should be +V,Gnd,data) so we can just plug and go as designed, IT IS A KLUGE. Those level shifters seem to be ok on input but try to do some output fugetaboutit and the documentation is sorely lacking. Yeah I know Chris, I can bypass the shifter - big deal. In my opinion if you want to save some production costs, dump the stupid shifters and provide some optional plug on boards that fit onto the three pin direct i/o described above. If I had known about the I/O issues I would have passed on the entire bot and went with the MAX series. It just takes the fun out of it.
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Never force anything - Always get a bigger hammer.
I love my stingray and more importantly, I think it was money well spent. It's size, design and documentation·are great. I do think the drill/mill patern could use some work. There is plenty of space on top but the drill and slot patern limits one to few options for board configuration or more·drilling. I'd also echo another comment about opening the top. Perhaps an intermediate mounting frame with a piano hinge and some thumb screws.·A set of·various length 4-40 threaded spacers in multiples of 4 would be cool as an accessory. Extra screws and nuts in the kit would be good.
As for the·board, an 8 channel AD converter with jumpers for both digital and analog connections would be nice. This would enable monitoring of power input conditions (battery level) and pots for feedback loops. 8 bits would be fine, 10 or 12 great. I'm not too sure about the level converters. Seems like they cause more problems than the solve. I'm thinking that letting the customer deal with the 3.3 - 5 volt transitions might be better.
All in all, it's a great product and I admire your effort to ask us customers what we think.
Jim-
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The Stingray is a real beauty, so much potential with that fabulous Propeller Robot board. I'm into accurate navigation and this bot is ALMOST up to it... I haven't even finished assembling my kit, but I already know that the motors are undergeared for accurate odometry. The 30:1 gear ratio is too low; 120:1 or higher would be more useful. Besides my gut feel, I have read:
1) Multiple posts talk about "how fast this thing is" or "it crashed into my desk at full speed". High speed is not conducive to accuracy. Low speed control is necessary.
2) In the Stingray encoder thread, one poster could barely tell that dynamic braking was on. He's getting lots of overshoot. Classic undergearing symptom.
3) The same poster notes that he gets random stalling below a certain medium speed. A Prop and PWM should be able to make this thing creep forward at glacial speeds.
My plan is to look around for lower geared motors. Worst case, I'll make a 4:1 reducer to add onto the existing motors. Will advise.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ·"If you build it, they will come."
erco,
Lynxmotion has a motor that is really close to the swame thing as the stingray motors except it's 50:1 ratio. http://www.lynxmotion.com/Product.aspx?productID=96&CategoryID=11
It might require drilling a hole or two to match up the mounting screws. I have been tempted to get a pair to test with, but I kind of wanted something more in the 100:1 or more catagory...
Roy
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Check out the Propeller Wiki·and contribute if you can.
@Chris: In the assembly instructions, the circlips that retain the wheels on the hex motor shafts are referred to as "O-rings", those should be called snap rings.
@Roy: yes, we definitely want 100:1 or more. The manufacturer does list several ratios above 100.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ·"If you build it, they will come."
Obviously, I don't really understand this. I thought I could just drive it more slowly... Can you explain it more.
I think what you are saying is that I can run it more slowly, but it is like driving at 15 mph with the car in 4th gear. If it was in 1st gear, it would go slower with much more power (less likely to stall). Correct, yes?
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Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
Whit: Your car analogy is exactly right. My old Hero 2000 robot probably weighs 80 pounds, but it can creep along at micro speeds with LOTS of torque for fine position control, all because it's geared low enough. If a robot motor stalls at low speed, it's geared too high. Period. That's less efficient power-wise, and will also accelerate and brake inconsistently, which makes odometry difficult if not impossible.
I had lots better luck with my Scribbler after I swapped out the gearmotors for lower speed, more torque.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ·"If you build it, they will come."
Comments
Can we have a QTI sensor kit for the Stingray similar to the one for the BoeBot but with appropriate standoffs and fasteners for the Stingray?
How about the same for Ping?
Ron
I would make the rear wheel large so that the robot can flip and still run. The electronics could easily be moved inside (if you're not changing them that much). Also, a door mechanism to the inside would be nice.
A place to plug in an ADC or three would be nice. DIP or SMD would be fine. Also, a place for video output (TV) would be nice.
Various battery connector transformers. Tamiya to Molex or barrel jack, or bullet to Molex or barrel jack. A big red emergency stop button. Encoders for sure. Spare set screws (I lost one...). Mechanical mounting parts for things like servos, IR distance devices, TV screens, lights, etc.
Also, some sort of case would be nice to fit over the electronics to protect them from accidental interference but allow quick access.
No, I don't have 1.2v AAs and don't want to spend the money to buy them. I would have preferred several Molex connectors with pigtails so that I can connect my own batteries.
I will probably use several Sharp IR sensors and a ping, maybe two. The Sharp sensors would be used since several can be used simultaneously without interference.
Additionally, bumper sensors would be great. I'll probably build some myself, but something that does double duty as a sensor and protector device would be great.
Absolutely. I think there should be several demonstrations/example codes. First, a simple motor run test that shows the robot going in a spiral and/or box. It doesn't need any additional sensors for that. Then perhaps an "agility" round: make it spin, go really fast in a sin wave form, suicides, hill climbs, etc. The point isn't to give numbers, but to give a feel. All of that can be done without sensors.
I'd like to see pictures of various sensors mounted to the front of the robot. Things like a Ping, the sharp IRs, bumpers, whiskers, IR (LED and detector), etc.
Very nice robot. I expect my weekend will be pretty busy: I'm going to see if I can make it go to the lounge and back from my room by Monday morning.
Post Edited (SRLM) : 11/14/2009 4:36:16 AM GMT
Of course, the batteries must go anyway. As has been mentioned by others, I will be replacing mine with 7.2 volt LiPo packs. AA batteries, well they just don't have the lasting power I need. When I am building/programming, the last thing I want to do is slow down or stop to change batteries.
I look forward to taking this back downrange with me in December, where I will have more time to add sensors and do some programming. Thank you so very much for this kit, it is a platform with enough real estate for sensors and servos to keep my busy for quite some time!
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Dan Taylor
1) The documentation was clear and made it easy to build and test the bot. My only complaint was that my kit came with a bunch of electronics parts like LEDs, resisters, transisters, a 6pin IC, and other random stuff that I am not sure what all of it is.·I know some of it is the same as what comes with the Boe Bot since I have one and could compare. So, some sort of listing in the docs of what all those are would be nice (like in the Boe Bot docs).
2) I'm pretty happy with most of the mechanical/metal stuff. The built bot feels very sturdy, and it's not very heavy.
3) The only change I would want is minor. You provided thru-holes for access to the port pins directly as well as for the jumpers to disable the translators. I would have prefered that the pins be already soldered into the board. I am not the greatest at soldering yet, and am worried about damaging the board when I add those pins myself.
4) I have the PING for Stingray kit already, and I also got the introduction to sensors kit. I have the PING mounting bracket you sell for the boe bot that I managed to get mounted to the back of my Stingray using some VeX hardware I had, but a variant of the kit for the Stingray with hardware fo a rear or forward mounting would be cool. I, also,·really want wheel encoders.
5) I didn't use the provided battery pack at all and instead went with my 7.2v packs that I use with my VeX stuff as well as my R/C cars. I hacked up some temporary wiring for now, but have ordered the connector parts I need to make a clean adapter from Mouser.· I think I nice option in the kit would be an adapter for doing this (like many others have mentioned).
6) I don't think you need to offer a charger. Just an adapter to standard Tamiya battery connectors.
7) If you wanted to include sensors, I think the most commonly wanted thing would be wheel encoders. My kit came with the stuff that you put in the boe bot, so the IR, whiskers, and stuff. I think this bot is a little big and fast for the IR sensor setup to be really effective. Same for the whiskers.· Anyway, I agree more with what others have said, just·offer separate·sensor packs geared towards the Stingray (like the 3 PING one).
8) I was able to make a simple program that made the bot move in a rough square on the floor using the motor test code. It took a while tweaking the numbers to get the timing right on the turns. Wheel encoders would have made that easier. I also tried out the PING Stingray test demo code I found on the store page. It works pretty nicely. I think if you provide other sensor packs geared towards the Stingray than doing demo code like for the PING back would be enough.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Check out the Propeller Wiki·and contribute if you can.
"7.2v RC packs (in Ni-MH and NI-Cd) and Chargers are readily available at RadioShack, but perhaps include a connector or two to support them."
YES this is silly, it is an issue.
It would also be nice to leave an area around the "center of gravity" to install accelerometers and a digital compass or two.
Antenna masts for the tail of the Stingray.
So far I've installed the QME-01 wheel encoders and the 3 Pings onto the bot. which work quite nicely.
The single biggest issue I have with the controller board is the 3V-5V level shifters and the single row of direct inputs (should be +V,Gnd,data) so we can just plug and go as designed, IT IS A KLUGE. Those level shifters seem to be ok on input but try to do some output fugetaboutit and the documentation is sorely lacking. Yeah I know Chris, I can bypass the shifter - big deal. In my opinion if you want to save some production costs, dump the stupid shifters and provide some optional plug on boards that fit onto the three pin direct i/o described above. If I had known about the I/O issues I would have passed on the entire bot and went with the MAX series. It just takes the fun out of it.
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Never force anything - Always get a bigger hammer.
As for the·board, an 8 channel AD converter with jumpers for both digital and analog connections would be nice. This would enable monitoring of power input conditions (battery level) and pots for feedback loops. 8 bits would be fine, 10 or 12 great. I'm not too sure about the level converters. Seems like they cause more problems than the solve. I'm thinking that letting the customer deal with the 3.3 - 5 volt transitions might be better.
All in all, it's a great product and I admire your effort to ask us customers what we think.
Jim-
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Signature space for rent!
Send $1 to CannibalRobotics.com.
1) Multiple posts talk about "how fast this thing is" or "it crashed into my desk at full speed". High speed is not conducive to accuracy. Low speed control is necessary.
2) In the Stingray encoder thread, one poster could barely tell that dynamic braking was on. He's getting lots of overshoot. Classic undergearing symptom.
3) The same poster notes that he gets random stalling below a certain medium speed. A Prop and PWM should be able to make this thing creep forward at glacial speeds.
My plan is to look around for lower geared motors. Worst case, I'll make a 4:1 reducer to add onto the existing motors. Will advise.
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·"If you build it, they will come."
Lynxmotion has a motor that is really close to the swame thing as the stingray motors except it's 50:1 ratio. http://www.lynxmotion.com/Product.aspx?productID=96&CategoryID=11
It might require drilling a hole or two to match up the mounting screws. I have been tempted to get a pair to test with, but I kind of wanted something more in the 100:1 or more catagory...
Roy
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Check out the Propeller Wiki·and contribute if you can.
@Roy: yes, we definitely want 100:1 or more. The manufacturer does list several ratios above 100.
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·"If you build it, they will come."
Obviously, I don't really understand this. I thought I could just drive it more slowly... Can you explain it more.
I think what you are saying is that I can run it more slowly, but it is like driving at 15 mph with the car in 4th gear. If it was in 1st gear, it would go slower with much more power (less likely to stall). Correct, yes?
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Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
Post Edited (Whit) : 2/1/2010 5:32:47 PM GMT
I had lots better luck with my Scribbler after I swapped out the gearmotors for lower speed, more torque.
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·"If you build it, they will come."