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LinuxGuy
04-26-2008, 09:19 PM
I've decided to try building some RSRs (Really Small Robots). I envision these to be not much longer or wider than a Lynxmotion Bot Board II (http://www.lynxmotion.com/Product.aspx?productID=252&CategoryID=66), and not more than 3" high at most.

I need to find some locomotion components that would allow this robot to carry a small complement of electronics, including MCP (Master Control Processor), and an array of sensors. These RSRs will probably be wheeled, but some could possibly be tracked. As small as these robots would be, it might be appropriate to use continuous rotation servos for locomotion.

Sensors will be needed both for obstacle avoidance and tracking, as well as environmental condition reporting. There would be ultrasonic (SRF08), IR, and thermal (TPA81) sensors as well as a small camera.

Communications will be through ZigBee wireless link, and Bluetooth. The RSRs should not require high bandwidth data transmission except for video and images. If bandwidth becomes a problem, WiFi will replace Bluetooth. Otherwise, all data will be transmitted via ZigBee.

I'm not worried about processing power, as I believe I can get as much as I need onto these RSRs in a single main board. Some processing options I am considering are a Blackfin Camera Board, since it already has a good camera, and lots of processing power. It can even run uCLinux, FreeRTOS, and some other RTOS' now, or be programmed bare-metal (no OS). Of course, I am looking seriously at Hammer (http://www.tincantools.com/product.php?productid=16133&cat=0&page=1&featured) for main processing also, when the Hammer-RDP board becomes available, which runs full Linux or can be programmed bare metal if desired. There is also a possibility I might consider using an i.MX21 COG (http://www.virtualcogs.com/store/product_info.php?cPath=22&products_id=32&osCsid=bac7d7f9d493f7d8ef9fcd96a21c0ca6), or i.MX31 COG (http://wiki.virtualcogs.com/index.php?title=VCMX310) (when it becomes available).

I am, of course, open to looking at existing robots and kits. The Stinger (http://www.trossenrobotics.com/store/p/5390-Stinger-Robot-Platform.aspx) is interesting, but I need to find out the dimensions. If the Stinger (http://www.trossenrobotics.com/store/p/5390-Stinger-Robot-Platform.aspx) falls within my specifications, I'd seriously consider trying it out for this project.

RSRs must be as light as possible to allow them to be lifted, placed in another location, and then activated.

8-Dale

Adrenalynn
04-26-2008, 09:59 PM
The stinger is far outside your size specs - 3-4x or so:

Length: 11.6 inches (294.6 mm)
Width: 10.3 inches (261.6 mm)
Height: 2.5 inches (63.5 mm)

These: http://www.trossenrobotics.com/store/p/4212-118-1-16mm-Spur-Gearmotor-FF-050.aspx with the shafts cut down a half inch, and bolted straight up to like the greendot sumo tires and hubs would rock. That particular gearing I linked to would give you GOBS of torque, and still be fast. Your bot could carry 5+ lbs easy.

Combine them with two of these (which I really like - and are really tiny, smaller than a quarter) http://www.trossenrobotics.com/store/p/4265-BaneBots-Motor-Controller-9A-peak-.aspx

and you've got an easy winner.

I've been contemplating putting all that inside a standard household smoke detector and making a "miniature roomba"

LinuxGuy
04-26-2008, 10:17 PM
The stinger is far outside your size specs - 3-4x or so:

Length: 11.6 inches (294.6 mm)
Width: 10.3 inches (261.6 mm)
Height: 2.5 inches (63.5 mm)
Yes, unfortunately, the Stinger (http://www.trossenrobotics.com/store/p/5390-Stinger-Robot-Platform.aspx) would not work for what I want to do with RSRs, but I already know I still want one of these! I went through the very helpful assembly guide earlier (with narration!) and the Stinger (http://www.trossenrobotics.com/store/p/5390-Stinger-Robot-Platform.aspx) is very solidly built! I could stuff all sorts of electronics inside a Stinger (http://www.trossenrobotics.com/store/p/5390-Stinger-Robot-Platform.aspx). :veryhappy::veryhappy:


These: http://www.trossenrobotics.com/store/p/4212-118-1-16mm-Spur-Gearmotor-FF-050.aspx with the shafts cut down a half inch, and bolted straight up to like the greendot sumo tires and hubs would rock. That particular gearing I linked to would give you GOBS of torque, and still be fast. Your bot could carry 5+ lbs easy.
This is the kind of thing I am looking for! Yes, indeed, I believe this would work out very well. I just have to find a suitable chassis to bolt everything on to. Perhaps an EC-02 (http://www.trossenrobotics.com/store/p/3328-SES-Electronics-Carrier.aspx) electronics carrier would work for the chassis.


Combine them with two of these (which I really like - and are really tiny, smaller than a quarter) http://www.trossenrobotics.com/store/p/4265-BaneBots-Motor-Controller-9A-peak-.aspx

and you've got an easy winner.
I will have to consider this. I was thinking more along the line of using a Sabertooth 2x5 (http://www.trossenrobotics.com/store/p/5103-Sabertooth-dual-5A-motor-driver.aspx) if I use regular motors, and it appears you've given me an excellent option for that. These RSRs are starting to get expensive, but that's OK. What I want to do with them is way cool.

I have to consider how I am going to power all of this too. The battery supply (single battery preferred) would have to power everything and be as low profile as possible.


I've been contemplating putting all that inside a standard household smoke detector and making a "miniature roomba"
That would just be way too cool! It would be way flat enough to go under pretty much anything. Give it a ZigBee link and it could be part of a swarm. :veryhappy:

8-Dale

LinuxGuy
04-26-2008, 11:05 PM
Would a Sabertooth 2x5 (http://www.trossenrobotics.com/store/ProductDetails.aspx?itemID=5103) be able to control four of these 118:1, 16mm Spur Gearmotor, FF-050 (http://www.trossenrobotics.com/store/ProductDetails.aspx?itemID=4212)?? Two on each side would be wired in parallel (if I remember all this correctly). I'm much more comfortable with the Sabertooth 2x5 (http://www.trossenrobotics.com/store/ProductDetails.aspx?itemID=5103) since I already have and use one of them, and it is less expensive than getting four of these BaneBots Motor Controller (9A peak) (http://www.trossenrobotics.com/store/p/4265-BaneBots-Motor-Controller-9A-peak-.aspx).

8-Dale

Adrenalynn
04-26-2008, 11:34 PM
I'll answer more completely after my pizza gets here, but with a few noise and trim issues, yes, a 2x5 would control 4 of those motors. At stall they're rated 1.8A. The 2x5 is rated 5A continuous (per-side), 10A peak - and I know the 2x10 is under-rated. So you're looking at around 4A per side if you stall it - well within peak delivery. Just make sure you fuse the motor power wires at like 3A total per-side, so you don't burn-up your motors if you stall out - 'cause the controller is going to deliver stall current until the batteries die or the motor burns and shorts.

LinuxGuy
04-27-2008, 12:25 AM
I'll answer more completely after my pizza gets here, but with a few noise and trim issues, yes, a 2x5 would control 4 of those motors.
What sort of noise and trim issues?


At stall they're rated 1.8A. The 2x5 is rated 5A continuous (per-side), 10A peak - and I know the 2x10 is under-rated. So you're looking at around 4A per side if you stall it - well within peak delivery. Just make sure you fuse the motor power wires at like 3A total per-side, so you don't burn-up your motors if you stall out - 'cause the controller is going to deliver stall current until the batteries die or the motor burns and shorts.
Ah, OK, so fusing it is then.

I'm designing a Mini-Stinger type body for the RSRs. I really like the Stinger (http://www.trossenrobotics.com/store/p/5390-Stinger-Robot-Platform.aspx) styling, so I hope I am not stepping on anyone's toes by doing that. It's going to be mostly wheel on each side, but has a small angled tail section. I have the profile of the body all drawn now, with the bend points. I have to learn how to work the sheet metal features of Alibre Design (http://www.alibre.com) now. :veryhappy::veryhappy: My Mini-Stinger will be SES compatible, and will end up being 4 1/2" wide by approximately 3" long. The electronics bay will be 3" by 2 1/2" total.

8-Dale

JonHylands
04-27-2008, 07:49 AM
Dale, you should really look a lot closer at mini-sumos. For example, the one I'm building now, Seeker 2x (http://www.huv.com/miniSumo/seeker2x), fits in a 4" x 4" x 1" block.

It really is quite doable to build at that scale. Look around at what different people are doing for mini-sumos. I have all the parts I'm using listed on my page above...

- Jon

Alex
04-27-2008, 08:42 AM
Dale - Have you ever taken a look at the SunSpot:

http://www.sunspotworld.com/

I haven't heard many people talk about them (probably mainly because Sun wants to do all the sales, distribution and marketing and they don't want to sell to resellers or distributers), but I've always been really interested in seeing these in action. Check out the specs, it's a pretty incredible system

LinuxGuy
04-27-2008, 12:26 PM
Dale, you should really look a lot closer at mini-sumos. For example, the one I'm building now, Seeker 2x (http://www.huv.com/miniSumo/seeker2x), fits in a 4" x 4" x 1" block.
I had not even considered using a mini sumo chassis, and am amazed I didn't think of that. Thanks for the suggestion, Jon! That would be small enough and yet large enough I could put a Serializer (http://www.trossenrobotics.com/store/c/3105-Robotics-Connection-Serializer.aspxhttp://www.trossenrobotics.com/store/c/3105-Robotics-Connection-Serializer.aspx) on it if I wanted to.


It really is quite doable to build at that scale. Look around at what different people are doing for mini-sumos. I have all the parts I'm using listed on my page above...
I see that now. Hmmmm, I bet I could fit the new mini stinger body I am designing into mini sumo size too.

8-Dale

LinuxGuy
04-27-2008, 12:55 PM
Dale - Have you ever taken a look at the SunSpot:

http://www.sunspotworld.com/
I just browsed the website. Unfortunately, Sun wants $750.00 USD for a SunSPOT kit, which would be way out of my range. They would be very interesting to tinker with though, and they are so small.


I haven't heard many people talk about them (probably mainly because Sun wants to do all the sales, distribution and marketing and they don't want to sell to resellers or distributers), but I've always been really interested in seeing these in action. Check out the specs, it's a pretty incredible system
Yes, it is definitely a very interesting system. Something like this makes me want to dig into JAVA more than I have in the past. SunSPOTs would definitely fit into what I want to do and they have a 180 Mhz ARM920T processor.

8-Dale

Alex
04-27-2008, 01:22 PM
Yeah, the cost really throws most people off as well. But, there is just sooo much packed into that little thing:D

Adrenalynn
04-27-2008, 02:06 PM
Just a couple notes I promised last night:

If you're building a trike like the Stinger-style, it doesn't matter. If you're running two motors on each side in parallel -

Motors never spit-out the same numbers exactly. Subtle differences in winding, how the gear-train is assembled and the precision there-in, the amount of inductance on the wire, precision of the caps, ... Even a few RPM difference between a pair can put a lot of strain on a motor and gear-train, shortening the life quite a bit, and potentially making for a twitchy control system. When you have a motor on each side, you can adjust your "trim", and cancel that out. Ditto four motors on four channels.

Noise on the four motor system comes primarily from electro-magnets and also from metal on metal parts creating electrical noise. The key there is extra filtering.

LinuxGuy
04-27-2008, 02:39 PM
Just a couple notes I promised last night:

If you're building a trike like the Stinger-style, it doesn't matter. If you're running two motors on each side in parallel -
I decided to stay with the true Stinger type design with just two motors, one each side. That's a lot easier to deal with and I am already quite familiar with two wheel drives.

8-Dale

LinuxGuy
04-27-2008, 02:42 PM
Yeah, the cost really throws most people off as well. But, there is just sooo much packed into that little thing:D
Yes, definitely, that does keep people like me from being able to tinker with cool stuff like the SunSPOTs. :sad: If Sun really wanted to get their stuff out into the public like they claim, they wouldn't target just educational institutions. I wonder how much it really costs to build a SunSPOT..

8-Dale

Matt
04-27-2008, 02:53 PM
Hmm, I'm trying to think of the cheapest and smallest way to do this. If you want to shrink down smaller than a serializer board you could glue two continuous turn servos back to back and put some of these servo city wheels (http://www.servocity.com/html/precision_disk_wheels.html) on them. Then just find a little caster ball (http://www.pololu.com/catalog/category/45) for the back end. Continuous turn servos would be far easier to control & calibrate than little DC motors.

The Pololu Micro Serial Servo Controller (http://www.trossenrobotics.com/store/p/5125-Pololu-Micro-Serial-Servo-Controller-assembled-.aspx) is really tiny so that would be a great controller.

For range sensing you could mount 4 GP2D120 (http://www.trossenrobotics.com/sharp-ir-distance-sensor-gp2d120.aspx) on the top pointing out. I would recommend grinding off the edges to shrink them down or stack 2 on 2. You would want to get them as tight as possible since they have a 1.5 inch blind spot. I don't know how to feed their signals to a wireless adapter, maybe someone else can answer that.

Finally, I'd suggest using a simple serial to bluetooth adapter (http://www.trossenrobotics.com/store/c/3098-Bluetooth.aspx) to offload the communications to a nearby computer.

Of course, if you don't mind the bot being a little larger, the serializer is a great way to do it. That takes care of all your control, input, and wireless issues in one fell swoop!

PS Servo City's small mechanical parts section (http://www.servocity.com/html/mechanicals___accessories.html) totally rocks. Should be in every bot builders bookmarks.

LinuxGuy
04-27-2008, 03:14 PM
Hmm, I'm trying to think of the cheapest and smallest way to do this. If you want to shrink down smaller than a serializer board you could glue two continuous turn servos back to back and put some of these servo city wheels (http://www.servocity.com/html/precision_disk_wheels.html) on them. Then just find a little caster ball (http://www.pololu.com/catalog/category/45) for the back end. Continuous turn servos would be far easier to control & calibrate than little DC motors.
I like the idea of using motors instead. My robots tend to gain weight, and they outgrow continuous rotation servos. I like those Banebots motors Adrelalynn suggested, and there are several in that same size. Those motors are actually only $2.00 more than the Hitec CR servos Lynxmotion sells, and the Sabertooth 2x5 (http://www.trossenrobotics.com/store/p/5103-Sabertooth-dual-5A-motor-driver.aspx) is plenty small. :happy:


For range sensing you could mount 4 GP2D120 (http://www.trossenrobotics.com/sharp-ir-distance-sensor-gp2d120.aspx) on the top pointing out. I would recommend grinding off the edges to shrink them down or stack 2 on 2. You would want to get them as tight as possible since they have a 1.5 inch blind spot. I don't know how to feed their signals to a wireless adapter, maybe someone else can answer that.
I like to stack a PING (http://www.trossenrobotics.com/parallax-ping-ultrasonic-range-sensor.aspx) on top of a GP2D120 (http://www.trossenrobotics.com/sharp-ir-distance-sensor-gp2d120.aspx), because what one doesn't see, the other usually does. If done right, I think I can get this arrangement to work for left, right, and center. TR stocks that nice dual sensor bracket (http://www.trossenrobotics.com/store/p/3264-Dual-Scanner-Servo-Arm-Bracket.aspx), made for doing exactly that. :veryhappy:


Finally, I'd suggest using a simple serial to bluetooth adapter (http://www.trossenrobotics.com/store/c/3098-Bluetooth.aspx) to offload the communications to a nearby computer.

Of course, if you don't mind the bot being a little larger, the serializer is a great way to do it. That takes care of all your control, input, and wireless issues in one fell swoop!
I went through the Serializer (http://www.trossenrobotics.com/store/p/5196-Robotics-Connection-Serializer-WL.aspx) manual and got the dimensions for it. I am going to increase the size of my mini-stinger body design so it can hold a Serializer (http://www.trossenrobotics.com/store/p/5196-Robotics-Connection-Serializer-WL.aspx), so I will have that as an option. Using the Serializer (http://www.trossenrobotics.com/store/p/5196-Robotics-Connection-Serializer-WL.aspx), I would have all the I/O I need for an RSR, and it does wireless (including ZigBee, which is a requirement). With a
Serializer (http://www.trossenrobotics.com/store/p/5196-Robotics-Connection-Serializer-WL.aspx), I would not need the Sabertooth 2x5 (http://www.trossenrobotics.com/store/p/5103-Sabertooth-dual-5A-motor-driver.aspx).


PS Servo City's small mechanical parts section (http://www.servocity.com/html/mechanicals___accessories.html) totally rocks. Should be in every bot builders bookmarks.
I will definitely check this out. I just hate having to order stuff from more than one or two sources if I can help it.

8-Dale

Matt
04-27-2008, 03:38 PM
>>>>I went through the Serializer (http://www.trossenrobotics.com/store/p/5196-Robotics-Connection-Serializer-WL.aspx) manual and got the dimensions for it.

Can you post it? I went looking but gave up! (Note to Dave, let's put it on the product page!)

Matt
04-27-2008, 03:43 PM
Just one more thought. By using the continuous turn servos you skip the $60 motor controller. That was my thinking there.

Adrenalynn
04-27-2008, 03:49 PM
Board outline on PDF Page 43 in the user manual, Matt.

3.552 wide by 3.751 long, maximum dimensions, presumably in inches. Bolt-holes are PC104 footprint.

LinuxGuy
04-27-2008, 03:54 PM
Can you post it? I went looking but gave up! (Note to Dave, let's put it on the product page!)
It's 3.751" x 3.552", and there is a dimensioned drawing on page 41 of the Serializer manual. :veryhappy: Yes, that info should be on the product page for sure. We need to know how large components are when designing bodies and mounting hole patterns.

8-Dale

Adrenalynn
04-27-2008, 03:58 PM
Beatcha! :P

LinuxGuy
04-27-2008, 10:20 PM
I've finally got a design for a mini-Stinger top body I like now. It's a bit larger than I wanted to make it though. However, I think having it big enough to be able to mount a Serializer (http://www.trossenrobotics.com/store/p/5196-Robotics-Connection-Serializer-WL.aspx) is a good thing. The Serializer (http://www.trossenrobotics.com/store/p/5196-Robotics-Connection-Serializer-WL.aspx) just has too many possible functions to ignore it, and it is probably the only I/O board an RSR will need. The overall size of the body will be 5.8" x 5.6", which is still considerably smaller than the full sized Stinger (http://www.trossenrobotics.com/store/p/5390-Stinger-Robot-Platform.aspx).

I am also designing a body just large enough to have a 3" x 3" space for boards.

I'll post both body sizes after I figure out how to use the sheet metal functions of Alibre Design (http://www.alibre.com). It's time to get dust off the training CDs again.

8-Dale

LinuxGuy
04-28-2008, 03:28 PM
Dale, you should really look a lot closer at mini-sumos. For example, the one I'm building now, Seeker 2x (http://www.huv.com/miniSumo/seeker2x), fits in a 4" x 4" x 1" block.
I really like the Seeker 2x (http://www.huv.com/miniSumo/seeker2x) body! How much would it cost to make one of those bodies that I could use these motors (http://www.trossenrobotics.com/store/p/4212-118-1-16mm-Spur-Gearmotor-FF-050.aspx) and standard 1.5" tires with?

8-Dale

JonHylands
04-28-2008, 03:43 PM
You mean the motor mount? That's a few hours of machining on the lathe and mill...

Are you asking how much it would cost for me to make something like that for you, or something else?

- Jon

Adrenalynn
04-28-2008, 03:46 PM
If you lay it out in CAD, there are plastic cutting services that would cut it in acrylic or lexan very inexpensively.

I have a couple that I have used off and on if you need any pointers.

[edit] Sorry - I was referring to the body. Motor mounts should obviously be heavier.

LinuxGuy
04-28-2008, 09:27 PM
You mean the motor mount? That's a few hours of machining on the lathe and mill...
I mean the entire body shell and chassis that could use the motors (http://www.trossenrobotics.com/store/p/4212-118-1-16mm-Spur-Gearmotor-FF-050.aspx) I've decided to use. I'll use these hubs (http://www.trossenrobotics.com/store/p/3391-Mounting-Hub-3mm-pair-.aspx) and tires (http://www.trossenrobotics.com/store/p/3391-Mounting-Hub-3mm-pair-.aspx). I know the body/chassis would not be quite as low as Seeker 2x, but it should still be plenty low enough for what I want to do. Maximum clearance will be 3".


Are you asking how much it would cost for me to make something like that for you, or something else?
Yes, I am asking how much it would cost to make that for me. I just need a body for the RSRs that can take enough of a payload, mostly electronics, for the RSRs. These are eventually going to be part of a swarm, using ZigBee to communicate.

8-Dale

JonHylands
04-29-2008, 06:56 AM
Well, you would need to design something different, because the chassis I designed for Seeker 2x is very special-purpose, and wouldn't work well anywhere except on a mini-sumo ring.

To answer your question, it would probably cost more than you're interested in spending. I've spent around $1000 just in parts for Seeker 2x, and that doesn't include dozens of hours put into design and machining so far. Robots this size work better if they are designed from the ground up, and unless you've done this sort of thing before and know what will work and what won't, it will be a long process of trial and error.

Seeker 2 (http://www.huv.com/miniSumo/seeker2) was modified many times to get it to where it is today, and I put probably a couple hundred hours into designing, building, and re-building it. I've taken all that I've learned from that mini-sumo, and put it into the design of Seeker 2x.

- Jon

Adrenalynn
04-29-2008, 12:41 PM
You know, I was just sitting here looking at a cheap aluminum external hard drive enclosure and thinking... hmmm... Ya know? ;)

LinuxGuy
04-29-2008, 12:48 PM
You know, I was just sitting here looking at a cheap aluminum external hard drive enclosure and thinking... hmmm... Ya know? ;)
Something like that could work. Maybe even a 3.5" floppy casing, now that you mention this sort of thing. :) It wouldn't look as nice as the body/chassis I am designing based on the Stinger (http://www.trossenrobotics.com/stinger-robot-kit.aspx) (which I really want, after looking at it closer), but it would work for prototyping.

Hmmmmm.. 3.5" floppy drives are el cheap now. :happy: It even has a mouth! :veryhappy::veryhappy:

8-Dale

Adrenalynn
04-29-2008, 01:18 PM
I like the external drive chassis because they tend towards being *really* pretty extruded aluminum. The one I'm looking at even has a pretty acrylic covered blue LED light bar on one side, and orange on the other.

It has extruded "fins" for heat sinking, and a slide on cover. The insides are nice and flat, as is the top and bottom.

I'm really starting to warm-up to the idea, actually... ;) I'll see if I can take a photo or two.

LinuxGuy
04-29-2008, 01:47 PM
I like the external drive chassis because they tend towards being *really* pretty extruded aluminum. The one I'm looking at even has a pretty acrylic covered blue LED light bar on one side, and orange on the other.
I am going to have to look into this more. I know a Hammer-RDP would fit nicely into a floppy case/chassis.


It has extruded "fins" for heat sinking, and a slide on cover. The insides are nice and flat, as is the top and bottom.

I'm really starting to warm-up to the idea, actually... ;) I'll see if I can take a photo or two.
I have some RGB LED (http://www.sparkfun.com/commerce/product_info.php?products_id=105)s I have been looking to use in a project. How about a mood strip of these LEDs across the front of an RSR? I have some 16 channel PWM LED driver chips from TI, but I think those are not in a DIP. I will have to rummage through my "other micro" box. I bet a strip of RGB LED (http://www.sparkfun.com/commerce/product_info.php?products_id=105)s would work really cool on a robot. :veryhappy::veryhappy:

I need to separate my interface chips from the microcontrollers and get the DIP stuff together. I just placed a sample order with TI (http://www.ti.com) too. :happy: Hmmmm, Maxim (http://www.maxim-ic.com) has some really cool chips too. I really must learn how to wire up and use SPI also.

8-Dale

Wingzero01w
04-29-2008, 05:14 PM
I have some RGB LED (http://www.sparkfun.com/commerce/product_info.php?products_id=105)s I have been looking to use in a project. How about a mood strip of these LEDs across the front of an RSR? I have some 16 channel PWM LED driver chips from TI, but I think those are not in a DIP. I will have to rummage through my "other micro" box. I bet a strip of RGB LED (http://www.sparkfun.com/commerce/product_info.php?products_id=105)s would work really cool on a robot. :veryhappy::veryhappy:

I need to separate my interface chips from the microcontrollers and get the DIP stuff together. I just placed a sample order with TI (http://www.ti.com) too. :happy: Hmmmm, Maxim (http://www.maxim-ic.com) has some really cool chips too. I really must learn how to wire up and use SPI also.

8-Dale

Im also looking into making my boe-bot into a very powerful robot in a small package. As a project im looking at making a custom board that either runs a Microchip dsPIC or a Parallax propellor (thats soon to get a nice update). Both chips are 44 pin packages that run @ 80 mhz. They might also be worth looking into.

LinuxGuy
04-29-2008, 05:27 PM
Im also looking into making my boe-bot into a very powerful robot in a small package. As a project im looking at making a custom board that either runs a Microchip dsPIC or a Parallax propellor (thats soon to get a nice update). Both chips are 44 pin packages that run @ 80 mhz. They might also be worth looking into.
The Propeller Chip is interesting. I bet I could stuff a full Subsumption engine in there. The dsPICs (30F and 33F) will run up to 120 MHz.

I have a couple of high end dsPICs on SchmartBoards too. I have to switch into Windows to program my PICs/dsPICs. I'm not too comfortable using SDCC, but maybe I should give it a try. I hve a small box of PICs and dsPICs.

I think I might be able to program my Renesas H8SX/1664 kits using GCC. I'll have to check into that. I have quite a bit of processing power laying around here doing nothing at the moment. I think some of it could work well for RSRs in small form factor bodies.

8-Dale

Wingzero01w
04-29-2008, 05:55 PM
The Propeller Chip is interesting. I bet I could stuff a full Subsumption engine in there. The dsPICs (30F and 33F) will run up to 120 MHz.

I have a couple of high end dsPICs on SchmartBoards too. I have to switch into Windows to program my PICs/dsPICs. I'm not too comfortable using SDCC, but maybe I should give it a try. I hve a small box of PICs and dsPICs.

I think I might be able to program my Renesas H8SX/1664 kits using GCC. I'll have to check into that. I have quite a bit of processing power laying around here doing nothing at the moment. I think some of it could work well for RSRs in small form factor bodies.

8-Dale

Ive been looking at the propellor chip for quite awhile and im eagerly waiting V2 with more RAM, or more Cogs... not sure if they decided yet. Also, how do you get ahold of dsPIC chips? i always try to get into the sample section of the microchip website but they state that i need to put in a company which i dont have.

Ive heard of Schmartboards but never really understood them or looked into it. How are they as far as soldering/prototyping go, i need a solution for something like that.

Never really looked into Renesas chips, only time i ever visited their website was via the panasonic semiconductor section. They look pretty nice, ill have to look into them one day.

LinuxGuy
05-03-2008, 11:36 PM
I finally finished v1.0 of a possible body for an RSR. Well, this isn't really an RSR the way I have defined it, but it is barely large enough to acommodate a Serializer controller. For autonomous operation, there would be another controller on board.

8-Dale

LinuxGuy
05-31-2008, 08:02 PM
I've been doing some more work on body designs for my RSRs. I have three different bodies in the design stage with the largest one being closest to completion - that's the Mini-RSR. This one has been heavily inspired by RoboticsConnection's Stinger Robot Platform (http://www.trossenrobotics.com/store/p/5390-Stinger-Robot-Platform.aspx). This is also the one that made me decide to see what I can do with even smaller robots. This RSR will be a two wheeler in the style of the Stinger (http://www.trossenrobotics.com/store/p/5390-Stinger-Robot-Platform.aspx).

I also have a Micro-RSR which will be just large enough to have a Hammer-RDP stack for the electronics package or any smaller or similar boards. This one will be 4WD.

The smallest RSR, the Nano-RSR, will be around 2 1/2" wide and 3" or so long. This one won't have many possibilities for electronics because it is so small. Some candidates for the electronics are New Micros (http://www.newmicros.com) Pluga(TM) boards, which are under 2" x 2" in most cases. Another possibility would be a Virtual COGs (http://www.virtualcogs.com) i.MX21 COG, which also fits this size target. This is also the one I am most interested in actually having fabricated because it is so small. Believe it or not, this one will also be 4WD. :veryhappy:

I believe I will be able to use the Bane Bots FF-050 sized motors for all of these, but wheel diameters will definitely change between the various RSRs. Of course, I will have to cut down the shaft, but that is not difficult with a decent hack saw. I may not use the same FF-050 motor on each RSR size though. I think this will be the first RSR I will actually build. :veryhappy: This one will use 1" wheels. I just have to figure out how I am going to power this small RSR. I need to check some battery dimensions for 7.2V packs.

Feedback is always welcomed. :veryhappy:

8-Dale

Wingzero01w
05-31-2008, 09:34 PM
Wow thats really cool, the pluga pod looks like a really good product. I can't wait to see your RSR, especially the nano.

LinuxGuy
05-31-2008, 11:47 PM
Update:

The Nano-RSR is 3.1" wide x 4.1" long (New Micros PlugaPod[TM] boards). I just completed what I think will be the final body design for this one. :) I had to fake the 2-56 size standoff until I can get real world dimensions. I have the hole size right now. This is definitely the one I am most excited about now, and probably the most difficult to squeeze everything into and onto.

The Micro-RSR is 4.35" wide x 3.85 " long (Hammer-RDP).

The Mini-RSR is 5.5" wide x 5.95" long (Serializer). Body design is complete.

They are all 1" high, without wheels or electronics. None of these RSRs are really large, which is important since they will be carried by a larger robot.

I'll have more pictures after I complete the Micro-RSR body.

8-Dale

Adrenalynn
06-01-2008, 10:47 AM
Whatcha runnin' for power and motors?

LinuxGuy
06-01-2008, 10:54 AM
Whatcha runnin' for power and motors?
I don't know how I am going to power the Nano-RSR yet. The motors will be Bane Bots FF-050 size for all of them. I need a real small 7.2V battery pack, which may not be available for a reasonable price.

I've come to the conclusion that no matter how large or small a robot is, it will cost at least $150.00. Of course, I could go with other motors, like those from Solarbotics, but there doesn't seem to be any wheels that match those in the sizes I want to use (1" to 1 1/2" diameter). I can get wheels in that size range for the Bane Bots FF-050 motors.

The Nano and Micro RSRs will be 4WD. Can you imagine a Nano-RSR with 110 oz/inch torque on four motors? No, I am probably not going to do that for the Nano or Micro, but might for the Mini. :veryhappy:

I've completed body designs for all three RSRs now.

8-Dale

Adrenalynn
06-01-2008, 11:00 AM
Run 'em at 6v (with lower torque and speed) and use some of the little heli/plane batteries? I have 6v @ 1400mA/h that are about 2"x2.75"x1/2". No problem with undervolting those motors, as we've already proven with my theoretical query that Meta sourced the answer on...

LinuxGuy
06-01-2008, 12:13 PM
Run 'em at 6v (with lower torque and speed) and use some of the little heli/plane batteries? I have 6v @ 1400mA/h that are about 2"x2.75"x1/2". No problem with undervolting those motors, as we've already proven with my theoretical query that Meta sourced the answer on...
Yes, that's a good plan! It will be a real snug fit on the Nano RSR, but it will fit. :veryhappy: That battery would run an RSR for a long time, which is good. The motors will be the heaviest load on the battery. The Micro and Nano RSRs will be 4WD, and the Mini RSR will be 2WD, inspired by the RoboticsConnection (http://www.roboticsconnection.com) Stinger Robot Platform (http://www.trossenrobotics.com/store/p/5390-Stinger-Robot-Platform.aspx).

Do you have a link to a source I can get these batteries from?

8-Dale

LinuxGuy
06-01-2008, 12:20 PM
I've completed the first revision of the body designs for all three RSRs I am working on now. Attached is a 3D PDF showing the assembled bodies. I have not added the mounting holes for motors,electronics, or battery tie downs yet.

You can see all three Really Small Robots in full 3D now. Just click each image and you will be able to zoom and rotate the model to see it from any angle. There will be a control bar at the upper left of the model. You will need Adobe Acrobat Reader v7.0 or later.

8-Dale

lnxfergy
06-01-2008, 12:21 PM
I've come to the conclusion that no matter how large or small a robot is, it will cost at least $150.00. Of course, I could go with other motors, like those from Solarbotics, but there doesn't seem to be any wheels that match those in the sizes I want to use (1" to 1 1/2" diameter). I can get wheels in that size range for the Bane Bots FF-050 motors.

8-Dale

Not sure which solarbotics motors you were talking about, but if you mean the $5 white ones, then Solarbotics does make a 30mm (about 1.2") wheel for them: http://www.solarbotics.com/products/gmw/

http://www.solarbotics.com/assets/images/gmw/gmw_ps.jpg
Just slip a rubber band around it (maybe tack it down with a little super glue), and you are set to go.

-Fergs

LinuxGuy
06-01-2008, 12:25 PM
Not sure which solarbotics motors you were talking about, but if you mean the $5 white ones, then Solarbotics does make a 30mm (about 1.2") wheel for them: http://www.solarbotics.com/products/gmw/
While these would probably work, I have a better selection of torques and wheels by using the Bane Bots FF-050 motors and just cutting the shafts to the length I need for each RSR.

I appreciate the suggestion! :veryhappy:

8-Dale

Adrenalynn
06-01-2008, 12:25 PM
Camcorder batteries are even smaller, higher voltage, higher drain. My 8.4v Panasonic batteries are 2.2x1.6x0.75. They're also expensive...

Here's inexpensive high drain fairly small NiMH http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=95

JonHylands
06-02-2008, 08:44 AM
A little off topic, but not much - I designed and started to build an underwater RSR a couple years ago...

NanoSeeker (http://www.huv.com/nanoSeeker)

It is 6" long, 1.25" diameter, and it has 3 motors inside, two batteries, and an ARM7. It also has a 6-axis IMU, a depth (pressure) sensor, and a magnetic power switch.

Unfortunately, the drive motor/prop combo didn't produce enough thrust to move it at more than a snails pace, and I put it away and started working on other things.

Here's a picture of the prototype in the pool...

http://forums.trossenrobotics.com/gallery/files/1/3/2/0/nanoseeker-pool-01.jpg

- Jon

LinuxGuy
08-07-2008, 08:09 AM
Camcorder batteries are even smaller, higher voltage, higher drain. My 8.4v Panasonic batteries are 2.2x1.6x0.75. They're also expensive...
Good suggestion! I am going to look into these as I get closer to actually building one of my RSRs. That time is getting close too, now that I can finally proceed with finishing the basic hardware assembly on W.A.L.T.E.R. I still have to design the lazy susan turntable assembly, and have already redesigned the second deck to accomodate that and a single large center hole for cable pass through.


Here's inexpensive high drain fairly small NiMH http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=95
Very nice, as well as being heftier power wise than the 6V @ 1600 maH batteries sold elsewhere. It would be easy to add an appropriate battery cable to these too! :veryhappy:

8-Dale

LinuxGuy
08-07-2008, 08:13 AM
A little off topic, but not much - I designed and started to build an underwater RSR a couple years ago...

NanoSeeker (http://www.huv.com/nanoSeeker)

It is 6" long, 1.25" diameter, and it has 3 motors inside, two batteries, and an ARM7. It also has a 6-axis IMU, a depth (pressure) sensor, and a magnetic power switch.
This is a very interesting idea for an RSR! How did it work other than the speed issue?


Unfortunately, the drive motor/prop combo didn't produce enough thrust to move it at more than a snails pace, and I put it away and started working on other things.
Do you have any plans to pursue this at some point? It would be a shame to see this not completed.


Here's a picture of the prototype in the pool...

http://forums.trossenrobotics.com/gallery/files/1/3/2/0/nanoseeker-pool-01.jpg
Oooooooh, a robotic torpedo! :veryhappy:

8-Dale

JonHylands
08-07-2008, 08:39 AM
This is a very interesting idea for an RSR! How did it work other than the speed issue?


Well, the other parts seemed to work well, at least for the stuff I actually put together (which wasn't much). Machining parts that small (and making them accurate) is hard to do.



Do you have any plans to pursue this at some point? It would be a shame to see this not completed.


I would love to, if I had the time. All it really needs is either a different drive motor, or a different propellor.



Oooooooh, a robotic torpedo! :veryhappy:


Well, a very small torpedo. The whole thing is just 6" long, and 1.25" in diameter.

Here's another pic, this time of the inside:

460

Yes, those are hand-machined linear actuators using geared pager motors...

Adrenalynn
08-07-2008, 12:02 PM
Oooooooh, a robotic torpedo! :veryhappy:


I can only WISH that was the first thing I thought of. :o

LinuxGuy
08-07-2008, 12:24 PM
I can only WISH that was the first thing I thought of. :o
OMG! It's only disturbing in that I picked up on that right away.. :p :o

8-Dale