Project: Low 'n Speedy

HirotoR34 · Post by **HirotoR34** » Thu Jan 20, 2005 12:31 pm

definitely. If you're gonna go through all that work and build a custom chassis, then that beast deserves propo speed and steering control

betty.k · Post by **betty.k** » Thu Jan 20, 2005 10:54 pm

lookin' great man.

if you want some ideas and you've never been there check out prof farnsworth's site:

http://members.surfeu.de/cyberjunky/mybits.html

lotsa great ideas there

Nasphere · Post by **Nasphere** » Thu Jan 20, 2005 11:01 pm

nice call there betty, never seen that site till now.

i like the buggy suspension, looks almost like spring loaded watch parts.

blankboy · Post by **blankboy** » Fri Jan 21, 2005 12:51 am

Nasphere wrote:nice call there betty, never seen that site till now.

i like the buggy suspension, looks almost like spring loaded watch parts.

hmm very much well wants to make me use my old guitar strings that are laing around

. I might do this if i can find some stuff !

Username · Post by **Username** » Fri Jan 21, 2005 9:18 am

betty.k wrote:lookin' great man.

if you want some ideas and you've never been there check out prof farnsworth's site:

http://members.surfeu.de/cyberjunky/mybits.html

lotsa great ideas there

Oh man, I saw that when I was lurking through the really old threads...it's awesome.

biohazard · Post by **biohazard** » Fri Jan 21, 2005 1:36 pm

I am glad to see someone who likes to solder. Great job on the chassis so far. By the way I am sure that you and solder aluminum paper clips to brass bar. I recently solder a brass bar to an aluminum cast car (see Toyota ZZMT bumpers http://bitpimps.lixlink.com/pages/phpFo ... um.php?f=7). I confirmed that is was aluminum by checking it with a strong magnet. If you really like soldering take a look at this

Nasphere · Post by **Nasphere** » Fri Jan 21, 2005 2:03 pm

soldering is like welding on a micro scale... you can build just about anything and the cool thing is if you screw up, unlike welding you can desolder it and solder it up again.

Nasphere · Post by **Nasphere** » Thu Mar 17, 2005 3:05 am

hey, i just wanted to update, sorry, i havnt been working on low speed much, lol, caught up with studying physics and doing other things more related to book knowledge.

so far ive got a sub micro steering motor in place, i want to do and optical sensor system for the wheel position and a worm gear driving the steering plate, sorta like a CD tray, but with optical detectors as a reference. if anyone knows anything about infrared please please please help me out. i want to know about different bands and interference factors ide have to worry about. im not sure if i need to seal it up like a camera in the front...

the car's controller board or brain is not near finishing, its still on the sketch pad. i need some sort of digital to analog converter, a surface mount 556 chip would be awesome but im sure i can find some other 'specialty' chip on a scrap computer board that does it all on its own. the comparator stage gets two inputs or reference voltages that it compares and moves the front wheels proportionatly by reference of the optical inputs. this idea would be better than a simple pot because everything would be stationary and none of the parts could possibly go bad. hehe, i bet none of you are keeping up with me on this. oh well, it will be finished so i can show more maybe in a month or so.

but like i said im just updating with new ideas and i hope i can find time and parts to finish it soon enough to put it into a bit pimps contest, just so all of you are amused, lol, jk.

codesuidae · Post by **codesuidae** » Thu Mar 17, 2005 9:33 am

Nasphere wrote: so far ive got a sub micro steering motor in place, i want to do and optical sensor system for the wheel position and a worm gear driving the steering plate, sorta like a CD tray, but with optical detectors as a reference. if anyone knows anything about infrared please please please help me out. i want to know about different bands and interference factors ide have to worry about. im not sure if i need to seal it up like a camera in the front...

You'd probably want a optical quadrature encoder so you get both step and direction encoded. Basicly the same thing as a mouse wheel encoder, although that would probably be way to big for a 1/64th car. I don't think I've ever seen optical encoders that small, but then I've never really looked either. If you can find a standard encoder that small you won't need any light shielding. If you modify a mouse wheel encoder you'll want to shield it. They will usually work open, but its possible to get bad input when you use them that way.

You might also consider using a miniature stepper motor instead of a servo. The MetlTech racers use a stepper and worm to drive the steering rack. That eliminates the need for steering feedback encoder. With a worm drive you're pretty unlikely to loose any steps, so you shouldn't even have to home it. Just provide an input to allow the user to set the center position and compensate in software for backlash in the rack and you should be good to go.

Nasphere wrote: the car's controller board or brain is not near finishing, its still on the sketch pad. i need some sort of digital to analog converter, a surface mount 556 chip would be awesome but im sure i can find some other 'specialty' chip on a scrap computer board that does it all on its own.

You really ought to consider using a microcontroller. Atmel has several that have a few 10 bit A->D channels, PWM outputs and internal clocks for under 10 bucks. Available in DIP and SMT to make prototyping easy. I'm sure you can do it with discrete parts, but you'd probably save a lot of space with a single microcontroller.

DarkTari · Post by **DarkTari** » Thu Mar 17, 2005 2:17 pm

Goddamn! You Pimps are INSANE !
You guys show so much dedication and that's what makes it worth while!
You Pimps are takin this Micro RC thing to a whole nother level !

JDM-R34 · Post by **JDM-R34** » Thu Mar 17, 2005 2:23 pm

DarkTari wrote:You guys show so much dedication and that's what makes it worth while! You Pimps are takin this Micro RC thing to a whole nother level !

True Dat'! Preach on DT, thats some hot stuff man, keep it coming.

Nasphere · Post by **Nasphere** » Sun May 01, 2005 11:14 pm

newest pictures

http://img234.echo.cx/img234/8951/14343661kr.jpg
http://img234.echo.cx/img234/1894/14343657dp.jpg

older picture showing the motor size
(theres one sitting on the front too)

http://img244.echo.cx/img244/9760/13535157kb.jpg

JDM-R34 · Post by **JDM-R34** » Mon May 02, 2005 5:06 pm

Hottness man, looks good, I can't wait to see the end results.

Post by **CaboWabo** » Fri May 06, 2005 9:50 pm

Me either - put em in the bitPimps Galleries holmes.

Nasphere · Post by **Nasphere** » Sun May 15, 2005 2:25 am

Well, you are all getting to see progress...

im working on a new design involving steering knuckles inside the rims, which are actually ball bearings, so handling will be no problem. The old front plastic skid plate broke anyways, plus this one goes along with the soldered metal theme... I still have to build the end caps with arms for it, and it all has to fit in the center of the bearing/rim. pain in the bootah cause its got maybe 1.5mm top and bottom, with no room on the sides... I have really thin bearings for it all, big inside diameter but really thin. it should all come out nicely.

I'm replacing the current steering motor with a smaller one!!! As if that wasnt possible, but I've got one smaller, fixes the pinion problem cause this ones got the same size shaft as a bit's motor. So now i get to use rear drive gears with the axles.

Im stumped on the circuit driver board... maybe SE? i dont like the SE boards though cause of the 50% duty cycle, codesuede offers a solution but im sure theres a better way. plus im not sure if an SE board can take 4.8V...