tracked ROV

A couple of weeks ago Mike (SN96) asked me what I was building.
Here are some photographs of what I have so far, which is mostly mechanical.

The interior is large enough to hold a mini-ITX and 12V sub-C cell pack.
The ends are just pinned ATM but I’ll use screws and some neo magnets to hold them on when I’m done (works well with RC stuff.) The ends are 1/2" thick so I can hog out pockets with a mill to support irpd and ping sensors. Right now the top of the track is just riding on some long standoffs but eventually that’ll be some more plastic. I’ve also got some small omnivision camera samples and usb interface boards left from a work project so one or two of those will migrate in once I get the mini-ITX in place (since I need that to access them.)
Anyway, so far no major malfunctions.

:open_mouth: sick…

workmanship looks excellent eddie, very professinal, keep up the good work and keep us posted

btw, i dont think u have enough glue, u need more

This looks very nice! It will be great to be able to see this moving around. :slight_smile:

Which mini-ITX board are you going to use and what CPU/speed?


The cheapest one I can find that supports usb 2, preferably fanless, something like the via mii6000 which is 600mhz and fanless. basically I’ll surf for 'em once or twice a week for the next couple of months and wait until I find one that does what I want on sale somewhere… under $150 range. I can use the wiport in the interim but I don’t have a good way to get video back from that without a major project in and of itself… or spending a comparable amount of money so I figure I’ll just get the mini-ITX when an opportunity presents itself.

where did you get those 6mm rods (i believe 6mm) and ball bearings to hold the wheels on???

shafts (one actually, cut down) came from mcmaster (as did the Al tubing) and flanged bearings are from vxb. that part is really overbuilt by the way, easily could have used 4mm hubs / shaft / flange bearing. certainly not a problem to be 6mm but once I had it built up it was like wth did I use such big parts for. :slight_smile:

That is one nice looking machine Eddie. Bravo. You have a real talent. That thing looks very professional.

And I love the double foam airplane wheels for idlers. Ingenious. They will also act as shock absorbers.

I wish I had access to sheetmetal and 6mm rods and stuff. Ontario dosent seem to have any stores that stock this kind of stuff…

Very nice EddieB!

Are those motors Pittman gearmotors with built in controllers and encoders?

Thanks for the compliments guys. :smiley:

Nah, just the ghm-04 w/qme-01 motor and encoder that lynxmotion sells. I thought about trying to beg some samples out of them but… meh. I’m not sure the lm motors are going to have enough torque but I figure if they don’t I can buy a pair with higher gear ratio gear box and move the motor+encoder to that. Actually, even if that doesn’t work I intentionally left the idler axle shafts long so worst case I could just put encoders on them and use some beefy motors on the other end.

Joe, mcmaster and vxb are both internet orders. the idler axles and wheels are from tower hobbies. Of course you’d have to pay international shipping from those places I suppose but if you can wait for pony express (ie parcel post) it might not be that much more. The sheet metal I actually had a local guy with a digital readout on his mill do for me. I prototyped the thing full scale with light plywood and then made a drawing with datum style dimensions so it was real easy for him to just lock the piece down and index to each hole. the other thing he has that I really wish I had is a shear. My experiences cutting thick metal leave something to desire as most of my tool shop is geared to woodworking.

Just thougt I would stop by and congratulate you! nice job!

Ahh yes, shears… :slight_smile:
We had an 8 foot shearing machine for up to 1/4inch steel sheet at the Machine shop I used to work at. Man that made some nice cuts.

Keep us posted with lots of pics. We love pictures. :slight_smile:

Wow! That definately puts my rover to shame. :laughing: It looks awesome!

Evolution, yeah the guy has his own machine shop and is one of those people who like making 1, 2, maybe 10 of something but that’s about it. I would consider him a craftsman more than a machinist. Good guy to know IMO. :slight_smile:

Don’t put your stuff down man, the mechanicals are only a small part of the whole thing and in the end I think that 'bots that are actually doing something useful are the best ones going. An example, I built a BRAT/WiPort and got it to waddle around but I couldn’t think of anything it could DO with value to me. I think the rovers, especially all the tracked rovers folks are making, should be much more useful for doing stuff.

My 'bots destiny in life is to crawl around in my attic where I can’t get to and let me see what’s up there. Seems trivial but my house was built by a gadget head 45 years ago and there is stuff in the walls and ceilings that no body has any idea what the heck they are, and the only access is through a hole in the roof of a closet that my 3-yo niece can fit through. (in the words of my wife, “not gonna happen”) Once that mission is done I’ll take him to work and have fun with people there with it. :wink:

I’m happy with what I built, with the tools I have. It’s fairly stout, but I will probably end up rebuilding it once I learn the electronics aspect. Pics should be up pretty soon (in the Rover forum).

I found this one which looks nice:

VIA EPIA-CN10000EG Mini-ITX Motherboard with VIA C7 1GHz Fanless Processor

It’s a bit more expensive than you want, and it has stuff you probably won’t use (but one never knows with robotics). It’s also a bit faster. :slight_smile: This is the least expensive fanless board I could find with USB 2.0 ports (8). I think this is a board I might consider myself for a small Linux powered robot controller. :slight_smile:


so far this is the cheapest one I’ve found, although it needs (?) a fan.
the only thing I don’t like is no apparent access to the smbus, which would be a plus if it were there but isn’t necessarily a show stopper either.

Is fanless really that important? :confused: Would it be because of dust? There seems to be lots more option if you go with a board with a fan.

You probably want a VIA EPIA 5000. It has basically zero computational power it’s 533 Mhz but think PII 266 in terms of performance. The advantage is it is dirt cheap, x86, ITX, and with the exception of some of the pricey Nano ITX boards (unless they released something better) the lowest power consumption around.

Here is an e-Bay (comes with 192MB RAM), you could probably win for < $50. Link

If you want to buy retail, here is the same thing for $90.

Considering we’re talking about ITX motherboards, let me show you the other end of the spectrum I’m looking at:

Essentially it’s a Pentium 4/ Core Duo 2 ITX board which supports DDR2 800, 2 Gigabit ethernet, 4 serial ports, PCIe x16 and has 6 SATA ports. It goes for $400.

I’m a little upset I can’t get accurate thermal specifications for Conroe Core Duo 2s. I’d assume a Conroe at 2Ghz takes the same amount of power as a Memron at 2 Ghz. However, everywhere lists Conroe at 65W and Memron at 35W. I know from my PIIIs I can run a 35W processor fanless (with only a mid-sized heat sink). Even though I have Core Duos, I can’t get good data because the machines also have Radeon X850s in them. At normal use my machines pull 130W (Kill-A-Watt) which assuming an 80% efficiency PSU means the machine is using about 100W. It runs a fast SATA drive which takes up about 10W. It also has a number of drives (DVD-RW, floppy, Zip) which even when not in use pull some current. Now that leaves say 75W between the CPU and GPU. The X850 can pull over 125W itself under load, since I’ve seen reviews that show system usage going from 144-300W when gaming. I’ve also seen forum posters saying the X850 will draw 20-30 more watts at idle than other cards. If the GPU pulls 40W when idle, that would mean my Conroe only uses 35W. One of the biggest things is my power meter shows 130W despite whether I’m typing an e-mail or running two numerical simulations (i.e. 100% CPU usage). Since this is a Linux system, it is very possible my kernel can’t use Conroe’s throttling ability properly. The only time power usage shoots up is when I use the GPU. Now you might suggest dropping in another video card and seeing the result, but unfortunately I don’t have any other PCI x16 cards that are free to test.

I also can’t get access to the temp sensors while the machine is running as lm-sensors (the linux equivalent to Motherboard Monitor) doesn’t work with my kernel yet. If I had reliable temp sensors, I could just put on a passive sink and monitor the temp carefully. If it never went over 60 even under full load, I’d know a passive sink could cool it. Perhaps I should schedule some time to play around with the sensors package.

Anyway… I went way off topic there. Sorry. :blush: