speed controllers
 

I need help! does anybody know if speed controllers switch from froward to reverse instantly? I have one and need it to rapidly switch from forward to reverse being I designed a truck that uses a motor to control steering instead of a servo. The problem is I have a delay between steering from left to right which is unacceptable. What could I be doing wrong or do not understand, and if I just have the wrong speed controller what kind do I need?

thanks for any help


john

RE: speed controllers
 

The duratrax mini-quake will do it. Ask around in the "rock crawling" thread because that's good for crawling.

RE: speed controllers
 

I called duratrax and they informed me that all speed controllers have a built in delay to prevent DC motors from being polarity switched when they are still rotating. Plan B would be for me to design my own speed controller - does anybody have the receiver output specifications so I can decode it myself and discretely assembly my own power switch?

thanks for any info

john

RE: speed controllers
 

Umm, this may sound budget, but I brought a RC car off an auction site, that used a motor to steer (not an actual servo)... it wasn't proportional though, which sucked. Perhaps go budget?

RE: speed controllers
 

Novak crawler ESC's

RE: speed controllers
 

Older LRP Runners, they go forward, brake then reverse, but its just as quick as you move the stick, you wont even notice it brakes, it will revese really quick.

Not to insult your project. But it sounds same steering design as Tyco and Nikko rc. They are non proportional, and the motor just keeps pushing the sterring rods when you hold the stick on either direction. Also you will need some kind of spring to hold and bring back the wheels in the straight forward position.

Have you considered or tried using a High Speed Servo?

Can you share photos of your project. Someone here might be able to assist you more with the help of some visual aid.

RE: speed controllers
 

My truck is totally hydraulically controlled - no electrical motors. I have a small desiel engine turning a hydrostatic pump which drives two hydrostatic drive motors along with two hydraulic cylinders that drive the tie rods. I need to control the solenoids that I use to pull and push on the spool which allows hydraulic flow to push another spool that opens and closes the hyd circuit that moves the steering cylinders. A speed controller works well because the two solenoids that move the steering circuits L and R need about 2 amps each to open and close. With the delay however steering doesn't work so well. However, it looks like the Novak Crawler ESC's can go from forward to reverse without delay. I ordered one to give it a try - anybody know if they wouldn't work?

john

RE: speed controllers
 

Many ESCs are programmable, where you can adjust the delay and brake time prior to reverse. From what I've foundhe Tekin Rebel is among the easiest to program this way.