Starter moter

Perhaps these will answer some of your Qs Davd..

http://www.m.case.btinternet.co.uk/html/stater_motor_mods.htmlhttp://www.m.case.btinternet.co.uk/h...otor_mods.html
http://www.mgcars.org.uk/electrical/start_sol.htmlhttp://www.mgcars.org.uk/electrical/start_sol.html
http://www.mgcars.org.uk/electrical/start_motor.htmlhttp://www.mgcars.org.uk/electrical/start_motor.html

if you limited the curent i could get how low do you think you colld get the curent and still get a reasionabel amout of power and dose the selanoid move the gear on the shaft or the whole shaft

Forget limiting a startermotor, you will rob the only advantage those have. Torque for amps.
And only 1 brand of relay I know and trust,useable in RW and capable to switch startermotors or bigger on A. Albright. At least a SW 80B .Or when you want reversing, the SW 88B.

On the later pre-engaged type it moves the gear on the shaft.

If you would have read the link that I posted above, it would have answered all your questions!

But please, learn how to spell properly. Your posts are really difficult to read.

people assume there is only one type of starter motor on the planet. 4kg??? nope.

In case our friend hasnt read the links above, basically, you have to open the motor, disconnect almost everything, all armature brush wires and the feild coil wires, then take them all outside of the motor. Then you have the wonderful job of wiring them, which is a little tricky, especially at 3am when rushing for an event.

I havent bothered. It runs one way only, as the motors Ive rewired in the past havent been that great as drive motors. If you are considering them, Id say for weapons only. just a personal view though.

Is this still true for permanent magnet starter motors? I would have thought these would run in either direction without modification.

You still have to isolate the motor case from the chassis, though.

true, there was me thinking there was only one type of starter motor on the planet too.

never used one myself, but yep, theres lots of ways and means.

Current limiting any motor will always reduce the power it can deliver if it hits that limit. It does however conserve batter power and prevent damage to the motor and controller. The problem is most starter motors have very low resistance and when starting act like a short circuit. Without a really good current limit (for PWM controllers it needs cycle-by-cycle limiting for best performace) it will damage the MOSFETS over time. We only use 4.8Ah for our two 800W motors with a 70A limit and we have never run out of power in a 5 minute fight.

There are of course more than one type of start motor. But in general the ones Ive seen are usually alot heavier than other motors for the same power output and require big batteries. James, looking at your other robots if you say it will work then Im sure it will and I look forward to seeing it in action.

i did read the link it told me a lot but it did not ancer the question about the gear sliding on the shaft or the whole shaft sliding and limiting the curent is out of the question im tying to build on a very low budgit so is there any other motors that will work that i can pickup at a scrap yard thaks for the help one of you said wiper motors are good and you can wiper motors at a scrap yard to right thanks for the help