Project: Low 'n Speedy

sessiz · Post by **sessiz** » Fri Jan 07, 2005 10:18 pm

You got the idea on motorised steering nas. You could prolly find a cheap motorworks car at wallmarts with motorised steering to chop up. I'ld say it's the best and easiest work around.

Nasphere · Post by **Nasphere** » Fri Jan 07, 2005 10:36 pm

got some more cool pics for yall to druel over.

http://img93.exs.cx/img93/6098/13030413lm.jpg
http://img22.exs.cx/img22/681/13030447gl.jpg
http://img22.exs.cx/img22/7571/susptravel2zu.jpg

ball bearings and this suspension are seriously fukin smooth!!!

Nasphere · Post by **Nasphere** » Sat Jan 08, 2005 6:14 am

ok, betty.k, i need some help. The suspension is soft, the wires are so thick, they mess with the spring rate. im using the thin wires which are the same that they use in a controller (thinner than the motor wires inside the bit). Its got me stumped. I could probably strip out some headphone wires, use the enameled threads in em... im not sure if they'll handle the amps, eh, im good at over amping things, i could probably put em through adequate testing. *POP!!* yup, 3A...

No but really, I was wondering what wires do you use?

Oh god! I did a throw test on the chassis!!! Yeah, a throw test. It's like 10x a drop test from 4 feet. I wanna make sure if i loose control it wont break if it hits a wall at 20mph... Everything is still perfect on it, i didnt have the pcb in it, the board probably woulda cracked after that much abuse... i guess the next parts to do are battery straps and a pcb cover cause thats probably what parts would fly out on impact.

SESSIZ!!!!!! how do those motorized steer things work? i know its got a gear set, but do the cheaper ones have a return spring? How does it center itself?

Has anyone seen or heard from Ph2t recently??? he is my bit idol... i wanna ask him a few questions.

betty.k · Post by **betty.k** » Sat Jan 08, 2005 6:27 am

i had the same problem with thick wires. i found some really thin (but not too thin) and flexy wire inside an old hard disk. old busted computer shit is a great source of micro electronics.

i've definately never seen a design like yours, but i'm thinking it will work really well

Nasphere · Post by **Nasphere** » Sat Jan 08, 2005 11:53 am

Has anyone ever taken apart one of those motorworks or superslicks cars with the motor steering? I need to know how they center. Im thinking of changing the setup a bit if its possible.

sessiz · Post by **sessiz** » Sat Jan 08, 2005 4:53 pm

The motorised steering cars have a pot that centers the front. (I could be wrong on this) I think all motorworks cars are set up this way. The only problem is that the front motor is not parallel to the rear drive motor.

crazydave · Post by **crazydave** » Sat Jan 08, 2005 7:32 pm

Damn, that is a nice project.

I've been daydreaming of building a frame like that for a car. Shit, I've been daydreaming about that kind of stuff since before I ever knew of a bit.

Good luck beating me though, Project Prostocker is already too light and fast, and I've already got plans for a bigger motor, faster gears, more speed.

I'm not worried about getting the front end on bearings, but I've been looking for some cheap ones for the back. You got something in mind? The only ones that most people around here post about that are the right size, are some from Boca bearings, and they are $16 a pair. I wanted to put the idler gear on a axle, so it can spin on bearings, but that's starting to get pricey. I thought, maybe direct drive, or maybe some teflon slot car bushings, I don't know....

backdrift · Post by **backdrift** » Sat Jan 08, 2005 8:46 pm

hmm.. i think some slot car bushings lubed with graphite powder could be almost as good as bearings..

Nasphere · Post by **Nasphere** » Sat Jan 08, 2005 10:27 pm

soooo..... CrazyDave. Will the pcb run a quad cell stock

I know it has that inductor on it for a dc to dc converter. if i take that off, im curious if the thing would run right. Replace it with like a 500 ohm resistor and you should be able to run 6 cells, but thats if you dont already need to remove it. I heard that its to increase the voltage so the chip can run, most chips run on 2V minimum.

Anyways I think I got the batteries an pcb packed in there nice.
http://img102.exs.cx/img102/715/1303091copy2af.gif
I changed a few pads since the pic so they hold in the pcb, it just pops out with a little pull now and the batteries slide out after that.

Im not sure if a motor steering is ok for my car cause you can see how much space im workin with....
http://img102.exs.cx/img102/8972/13030963wt.jpg
If i get one of those cars, i think maybe i can pack the gears and motor over the steering bar... In the zzse the front end is almost empty, all thats there is the steering bar and drive gear, waist of space to me, so maybe theres a way to pack it all in with almost no space left.

Thanx Sessiz, im gonna try n pick one of those cars up tonite.

Betty.K, I found a bunch of old computer cable, when stripped out, they have a ton of flexible strands in em.

Nasphere · Post by **Nasphere** » Sun Jan 09, 2005 6:28 am

I came up with a better steering solution. I say screw propo motor steering. Takes up WAY too much space, and all that weight... wow!

How about a coil steering set up on a rotary hub, just have the pot on the shaft of the hub. That way you save lots o space, theres still the propo there, you can even build it without a return spring!!!

I still need to come up with the gate/driver board... I have an idea, except it draws too much power on idle. Basically it calls for a dual op amp, input 1 from amp 1 coupled with input 2 of amp 2 goes to the steering pot. Inputs 2 and 1 from amps 1 and 2 go to the smoothed input pulse. The output doesnt need an H-bridge cause the amps go plus and minus, so outputs from 1 n' 2 go to the steering wires... Simple single chip set up, although it would be extremely jittery cause theres no play in the elecrtronics, its all digi plus er minus, no analog... Oh well, ill come up with a solution... Maybe I can have a timer on the propo like the zzse's do, when a command comes through it enables it for around 3 seconds, same basic concept as the charger on the controller.

Hey! does anyone wanna donate some FET's?

I have no idea where the hell i can get some at this scale except from the manufacturer in bulk...

crazydave · Post by **crazydave** » Sun Jan 09, 2005 7:17 am

I believe you can run quad cells with a stock bit board, Iknow several people have done it. I haven't done anything special to mine other than upgrade the trannies to FETs.

I get my FETs at digikey.com. They're about 50 cents a piece, and there is a $5 sur-charge on orders under $25. Just type irlml2502 into the part search. (irlml6401 for the p-channels, but I use the flipped N-channel method on bit boards)

Superslicks and Muscle Machines both have a spring return to their motorized steering. Personally I'd think motorized steering would be too much extra weight for a drag car. Since the idea is to keep a straight line, and not really hang corners, I've been thinking I should limit the steering on my car, so it barely turns. Maybe do it in a way so it can be easily removed to return fill steering.

hue35 · Post by **hue35** » Mon Jan 10, 2005 1:23 pm

crazydave wrote:I've been thinking I should limit the steering on my car, so it barely turns. Maybe do it in a way so it can be easily removed to return fill steering.

The simple way I've done that is to just double up the steering magnets, so you have less steering travel... works great, easy to undo.

codesuidae · Post by **codesuidae** » Tue Jan 11, 2005 11:49 pm

I've got a big pile of magnets that work well for that if ya need some.

Bit boy · Post by **Bit boy** » Wed Jan 12, 2005 10:03 pm

i built a chassis for my monster bit but it isnt near as cool as that.

Nasphere · Post by **Nasphere** » Thu Jan 13, 2005 12:43 am

Boiz n Girrz... It's Hammuh time.

Actually its called slow progress.
My pcb plug http://img73.exs.cx/img73/5595/pcbplug1gc.jpg
And again http://img73.exs.cx/img73/8089/pcbplug28vf.jpg
Im kinda debating if i wanna use an 85 tercel sr5 er an 85 vette body...

Cant forget the front end... http://img73.exs.cx/img73/4452/frontskidplate29fk.jpg