>Rob:
>
>I am using 2 "Tracked Vehicle Chasis" from TAMIYA (http://www.tamiya.com/).
>as the mobile platform. I found a better hackable one at http://www.robotstore.com
>
>3-354 - Bulldozer Kit - $37.95
>
>Or you can buy just the motor:
>
>3-709 - Twin Motor Gear Box Kit - $19.95
>
>The tread on the kit I am using can be made small or large (connect
>together).
>This way I could make the kit very small, depending on what I want. I hope
>this helps.
>
>Best regards,
>Steve
>
>Steven Kosmerchock
>Radio Frequency Systems
>Phoenix,  Arizona  USA
>(WORK) http://www.rfsamericas.com
>
>http://www.geocities.com/researchtriangle/lab/6584
>
>"Great spirits have always encountered violent
>oppposition from mediocre minds."--A.Einstein

>
> Steven Kosmerchock wrote:
> >Rob:
> >
> >I am using 2 "Tracked Vehicle Chasis" from TAMIYA (http://www.tamiya.com/).
> >as the mobile platform. I found a better hackable one at http://www.robotstore.com
> >
> >3-354 - Bulldozer Kit - $37.95
> >
> >Or you can buy just the motor:
> >
> >3-709 - Twin Motor Gear Box Kit - $19.95
> >
>
> Hi Steve, as you are using the exact motor system I have been
> planning to buy, and as they never seem to publish the info I
> want, can you tell me about how much current the motors draw in
> various loading situations?
>
> I want to use the L293D H-bridge chips, which are rated for 600mA
> tops [ie, with good heat sinking]. Did you need to use an H-bridge
> rated greater than this?
>
> thanks,
> - dan michaels
> ==============

>
> Roman Black wrote:
>
> >Dan, there are two very cheap, common and good motor driver
> >chips, the BA6209 and BA6219. These are the same size as
> >L293 and are good for 1.2A and 2.0A respectively. We use them
> >all the time in VCRs. They have direction/speed control with
> >two input pins. Speed control is analogue. They are about
> >$1.50 to $2 US if you shop around.
> >
> >I have full datasheets if you are interested, or you can get
> >datasheets at
> >www.rohm.com/products/databook/motor/pdf/
> >
> >These are a great cheap little chip.
>
> Thanks Roman, I'll check these chips out. Probably need
> a big heat sink and external clamping diodes, I would imagine.
>
> How much trouble have you seen with motor noise getting back
> through this kind of chip to the uC pins? I imagine the problem
> is worse at the higher currents. Are you using any specific
> filters to deal with this? I was thinking it might be good idea
> to put RC filters between PIC and the L293 control pins to be safe.
>
> - danM

>
> Tom Handley wrote:
> >   Steve, Dan and I are also building PIC-based robots and have looked at
> >the TAMIYA gearbox. My main concerns with using it is the torque and the
> >ability to hack a tach onto each motor. Right now I'm hacking a Radio SHack
> >R/C car and replaced the motor with decent results but it's just a test-bed
> >until I build a decent platform with dual motors.
> ................
>
> Hi Tom,
>
> Got some follow-up info --> good stuff available NO-wheres else that
> I could ever find. Went down and got the Tamiya twin-motor gear-train
> [$11.50 at one of the local hobby shops]. They use the "130" motors,
> apparently identical to the bantam weight FA130RA2270 shown in the
> Jameco catalog. Spec'ed at 1.5-3v, 200mA, 9100RPM, $0.99.
>
> Set it up for the slower 203:1 gearing, uses 4 gearsets with about
> 4:1 reduction each. It is actually quite torque-y, and hard to stall
> by squeezing the output shaft. You cannot move the motor shaft by
> trying to hand-turn the final "gear".
>
> Runs well at ~2.0v on the motor, drawing ~500mA @ 48RPM output
> --> motor doing about 9700RPM. 3v on the motor is a little much,
> drawing ~1000mA.
>
> All in all, looks pretty good for my first project, using "free" AOL
> CDROMs for the body, and running off a couple of L293D H-bridges
> and 3-4 AA's. Got enough info now to go ahead and design my new SBC.
>
> Ever get your car to run "slow" enough?
>
> best regards,
> - Dan Michaels

>Alexandre Souza wrote:
>>>Got some follow-up info --> good stuff available NO-wheres else that
>>>I could ever find. Went down and got the Tamiya twin-motor gear-train
>>>[$11.50 at one of the local hobby shops]. They use the "130" motors,
>>>apparently identical to the bantam weight FA130RA2270 shown in the
>>>Jameco catalog. Spec'ed at 1.5-3v, 200mA, 9100RPM, $0.99.
>>
>>        Where can I find it? No local hobby shops uses to sell tamya
>merchandise!
>>
>
>Check the websites. Tamiya has a list of dealers in the US by state,
>maybe for other countries. The 130 motor is Jameco P/N 166676, but
>Jameco does NOT sell the twin-motor geartrain.

>Tom Handley wrote:
>>   Steve, Dan and I are also building PIC-based robots and have looked at
>>the TAMIYA gearbox. My main concerns with using it is the torque and the
>>ability to hack a tach onto each motor.
>
>
>Hello again, Tom,
>
>I was wondering if you were still going this route, or whether the
>flame had sputtered. Well, you're building, I'm still dreaming, in
>betweenst <-- :) --> all the other projects. I am however designing
>my own botboard based upon a PIC74/77, and hope to send away for pcbs
>in a week or so. Most available boards use the 68HC11 chips.
>Preliminary info:
>
>http://www.oricomtech.com/projects.htm
>
>I have been researching various motor options and plan to use the
>Tamiya twin-motor set on my initial effort. Not wanting to do a lot
>of mechanical fabs, I plan to build it using a couple of "spare"
>AOL CDROMs for the body. I figure 9 drilled holes will do the whole
>thing.
>
>Once I know a little more about motor current reqs, I can design
>the motor drive on my SBC. Hopefully the L293D chip @ 600 mA will
>handle the small motors for a small bot - but probably not for a
>larger one.
>====================
>
>.............>
>>   As far as IR sensors, I lost the link but there's a simple design using a
>>PIC12C508, two IR LEDs pointing front-left and right, and a typical Sharp IR
>>receiver. You can adjust the sensitivity via software by changing the
>>modulation frequency.
>
>
>I put up a lot of robo-hack links on my page, with special emphasis
>to sites with motor control and IR sensor stuff. There are also some
>ultrasonic sensor systems and cool bat detectors. K.Leang has some
>good all-around info.
>
>http://www.oricomtech.com/emerge5.htm#Hobby2
>http://www.leang.com/robotics/info/roboinfo.html
>
>best regards,
>- Dan Michaels
>Oricom Technologies

>
> Roman Black wrote:
> >
> >Hi Dan, use some light machine oil on the bronze motor bearings,
> >will extend motor life a lot. Also see if you can get some
> >"super-grease" for the multiple gear gearbox, it will make it
> >quieter and reduce wear. This super sticky grease will even
> >help a bit with backlash. If you can enclose around the gears
> >with anything this is even better, just fill it with a couple
> >cc's of grease. You can get good long term results from these toy
> >motors with some professional lubing.
> >-Roman
> >
>
> Tamiya includes some grease with the geartrain. Haven't used
> it yet. Don't know how super it is. So far tried w/o same, and
> very noisy. The way the cage is built, it would be quite easy
> to enclose. All in all, the Tamiya dual-motor is a nice system
> for the price.
>
> best regards,
> - Dan Michaels

>
> Henry Low wrote:
> >hey guys, I tot this was suppose to be a thread abt the PIC16F877??
> .............
>
> To inject some PIC back into this thread ..... here is a rough
> sketch of my PICoBotboard plans:
>
> - modify my existing PIC40 SBC for use as a botboard. This board can
>   use '74/77/etc:
>
>      http://www.oricomtech.com/sbc40.htm
>
> - new layout - remove SRAM and add cktry for motor control, plus
>   sound, IR, ultrasonic, and bumper sensors:
>
>           --------+       bank of 8 uncommitted LEDs + series-Rs
>                   |
>                   |  1 A/D
>                   |<---/-- 4-input R-divider [input from bumper sw,
>                   |                       output to PIC A/D channel]
>                   | 2 DI/O
>                   |<---/--> IR LED + QSE156QT optologic detector
>             PIC40 |
>                   |  2 A/D
>                   |<---/--- LM324 [4 opamps - setup as 2-stage hi-gain AC-
>                   |            coupled amps for mike and ultrasonic rcvr]
>                   | 10 DI/O
>                   |---/----> L293D [2 ea - setup as H-bridges]
>                   |   2 PWM [motor speed - to enable inputs]
>           --------+   8 DI/O [control signal inputs]
>
> - LEDs can be jumpered to provide visual indication of subsystem operation.
>
> - The L293D chips can be setup as 2 H-bridges to drive the Tamiya
>   twin-motors. For other apps, the channels can be separated to drive
>   up to 8 individual motors.

> > that I'm going to use, but I know they can easily pull 12 Amps.
> >
> > Happy Holidays,
> >
> > Duane

> Now if you can tell me about a 2A to 10A h-bridge with
> good sat voltage I would be *very* happy!! I have been
> looking for something like this for a long time. :o)
> -Roman

>
> Roman Black wrote:
> >This is a bit of an ask, would it be possible to
> >have four h-bridge chips

> Um, not with maintaining the present SBC footprint. Also,
> adding 4 chips would pretty much eat "all" the PIC I/O pins.
> Each chip requires 4 control and 2 enable lines - and I am
> keeping them as separated as possible to allow flexibility.
>
> However, you "can" use the 4 separate drivers of the H-bridge
> chips individually, so you can drive 8 separate windings as
> it is. Wouldn't this run 2 stepper motors ok?
>
> I guess because 2 drivers are hi-side and 2 lo-side, you could
> not handle a stepper with any common lines common to all 4
> windings. Have to mix and match:
>
> Hi-side-drvr-----+           Vss
>                  |            |
>            W1  @@@@@        @@@@@  W2
>                  |            |
>                 gnd       lo-side drvr
>
> Wouldn't this work?
> - danM
>

>
> Roman Black wrote:
>
> >>
> >> Hi-side-drvr-----+           Vss
> >>                  |            |
> >>            W1  @@@@@        @@@@@  W2
> >>                  |            |
> >>                 gnd       lo-side drvr
> >>
> >> Wouldn't this work?
> >> - danM
> >>
> >
> >I think it would, but 8 wire steppers are very rare. Normally
> >they are 5 and 6 wire, especially the "free" type you strip
> >from old printers etc. When you buy steppers new sometimes
> >you can ask for 8 wire format. :o)
>
> Hi Roman,
>
> 5-wire would definitely be a problem - one common for all
> windings - but 6-wire sounds ok, if you simple think of doubling
> the scheme shown above. Got any idea how popular 5- vs 6-wire
> steppers are?

>  The 16F876's
>>Port B goes to a standard 74x30 8-Input NAND gate used to expand the
>>interrupts to 7 channels with the output going to RB0/INT.
>
>Why do you need all these interrupts? I figure my thing wouldn't
>be moving very fast, so I can poll the sensor ports. Also, with the
>L293 chips controlled by dedicated I/O pins and the 2 PWM channels
>used for speed control, it wouldn't require any processor cycles
>for real-time control over the motors.
>
>The bot will either run very slowly or else run a few inches, and
>stop and take sensor readings. Slow-lane robotics here.

>Hi Tom,
>
>Got some follow-up info --> good stuff available NO-wheres else that
>I could ever find. Went down and got the Tamiya twin-motor gear-train
>[$11.50 at one of the local hobby shops]. They use the "130" motors,
>apparently identical to the bantam weight FA130RA2270 shown in the
>Jameco catalog. Spec'ed at 1.5-3v, 200mA, 9100RPM, $0.99.
>
>Set it up for the slower 203:1 gearing, uses 4 gearsets with about
>4:1 reduction each. It is actually quite torque-y, and hard to stall
>by squeezing the output shaft. You cannot move the motor shaft by
>trying to hand-turn the final "gear".
>
>Runs well at ~2.0v on the motor, drawing ~500mA @ 48RPM output
>--> motor doing about 9700RPM. 3v on the motor is a little much,
>drawing ~1000mA.
>
>All in all, looks pretty good for my first project, using "free" AOL
>CDROMs for the body, and running off a couple of L293D H-bridges
>and 3-4 AA's. Got enough info now to go ahead and design my new SBC.
>
>Ever get your car to run "slow" enough?
>
>best regards,
>- Dan Michaels
>Oricom Technologies
>http://www.oricomtech.com
>=========================

> Tom Handley wrote:
> >
> >>>   I'm using multiprocessing with a 16F876 for testing, 12C508 for the IR
> >>>detector, 12C671 as a dual RC servo controller (I needed the TMR0
> >>>interrupt), and a 16F84 as a dual H-Bridge controller. I plan on another
> >>>12C508 for the Ultrasonic detector. They all talk over a serial interface.
> >>
>
> Do you have specs or good xmtr ckts for any ultrasonic transducers?
> I got some from Jameco, but specs are minimal.
> ==========
>

>>   I could use polling but I wanted to know immediately if there was a
>>bumper switch hit. I had intended on 4 switches. The 74x30 was a simple hack
>>to expand the RB0/INT capability. I want an event-driven system so the
>>processor (16F877) can spend it's time on the AI responding to sensory
>>inputs as needed. I'm also adding external SRAM.
>>
>Did you think about using the RB4-7 interrupt on change for the
>bumpers? I am wavering between 4 bumper switches to RB4-7 IRQ or
>feeding same to 4-way R-ladder for sampling by 1 A/D channel. It
>would be polled, but I think my bot will have minimal real-time
>tasks due to using the L293 chips plus hw PWM for motor control,
>and not driving servos/steppers in real-time. OTOH, I did plan to
>have servo capability available, so ?????????  [lotsa possibles]

>Hi Tom,
>
>I found only one Tamiya twin-motor, but if there is another stronger
>one, would be good to know about. The one I bought is seen here:
>
>http://www.sinerobotics.com/twinmotor.html --> P/N 70097
>http://www.hvwtech.com/gearsets.htm --> bottom of page
>
>Just remember, Steve is apparently using the same one I got, and said
>it does have minimal power for his 1# dozer. Still I think it will do
>ok for my minibot.
>
>The shafts stick out 1.125" [28mm] on each side of the box, total
>4.25" [107mm] end to end. They are hexagonal and accept a std model
>airplane wheel with .125" [3mm] diam hole with a bit of slop.
>
>best regards,
>- Dan Michaels
>Oricom Technologies
>http://www.oricomtech.com

>Well that's perfect - it'll give you 1ft/second of movement - If you use
>.72 inch diameter wheels... ;-)
>
>-Adam
>
>Tom Handley wrote:
>> Well, after fumbling through all the junk
>> gears the best I could do was a 10:1 ratio which ended up at 320 RPM with
>> great torque. At 9V, good torque but still too fast. The assembly did turn
>> out fairly nice though. The bottom line, I'm buying a gear box...
>