Cheap and easy speed controllers

[aliboy]

Cheap and easy speed controllers

that is really weired i mention it and then it appers hmmmmmmm....gold plated toilet :P

[aliboy]

Cheap and easy speed controllers

while searching i came across these http://www.robot-electronics.co.uk/shop/Motor_Controllers2008.htmhttp://www.robot-electronics.co.uk/s...ollers2008.htm are they any good for a FW ?and is that a good price to pay for it? has anyone else used them before?

[ewan]

Cheap and easy speed controllers

Those are the ones technobots has started selling, so youll probably want to buy from http://www.technobots.co.ukwww.technobots.co.uk

That price doesnt include heat sink I dont think and a 2 Channel heatsinked version will set you back at least 70 pounds probably. Itll probably do about 15A with heatsinking so youll want to keep away from any bigger motors. Current limiting at 20A on the single h-bridge controller is probably too low for most decent featherweight motors.

[m2xt]

Cheap and easy speed controllers

Ewan, I would have thought that 20A @ 24V i.e 500W per motor should be adequate for most feathers. I have yet to make a heatsink for the 2-channel version but I expect it to be suitable for the 8 motor / 8 wheel drive Zeobot but as you say, keep it away from larger motors.

[RogueTwoRobots]

Cheap and easy speed controllers

Ive just read one of the entries into the featherweight database (Kang) and it says it uses drill triggers to control the speed of the motors. I thought about using these as speed controllers but I wasnt sure how to connect both the speed and direction switches. Assuming that the drill controls have the trigger for speed and the slide switch for either forwards or backwards, whats the best way to connect them up so as to have both speed and direction control? Is there a way to modify them so that you dont have to slide the switch across (which would be murder to remember in the heat of a battle) or do you have to connect them both upto servos or something? I know they arent the most practical speed controllers around but it would be handy to have them fully operating.

Many regards,
Jamie

[glen]

Cheap and easy speed controllers

yes you use 2 microswitches that actuate before pushing in the trigger in place of the mechanical switch. one micro for foward direction one for reverse

the drill triggers current limit at ~15amps and are full variable speed. BUT they are very fiddly to make.

the work well and even if you do blow out the fet which is unlikely you can still use it as a full on off power switch.

ill let aaron chide in here on how to make them and post a photo because my versions are only half built but be warned they are damn tricky to make

[glen]

Cheap and easy speed controllers

yes you use 2 microswitches that actuate before pushing in the trigger in place of the mechanical switch. one micro for foward direction one for reverse

the drill triggers current limit at ~15amps and are full variable speed. BUT they are very fiddly to make.

they work well and even if you do blow out the fet which is unlikely you can still use it as a full on off power switch.

ill let aaron chide in here on how to make them and post a photo because my versions are only half built but be warned they are damn tricky to make

[knightrous]

Cheap and easy speed controllers

My team mate Andrew was the genius behind using the XU1 variable speed drill triggers for controllers. We didnt actually realise that they were 15amp current limited till we stall tested a set and noticed it wouldnt feed ore then 15-17amps at most.

Something inside the little trigger cuts back the postive voltage to limit current, was quite interesting to play with. Andrew now builds them to fit inside the drill battery case for easy of mounting

[RogueTwoRobots]

Cheap and easy speed controllers

Cool, thanx for the replies, Ill see what I can do with mine then (probably melt them into oblivion or something )

Regards
Jamie

[trig]

Cheap and easy speed controllers

ive just made my own speedcontroller cost bout £90 (bout 3xs the amount u wanted to spend lenny) and that was with some of the bits already owned. building speed controllers are hard and very time consuming mine was all surface mount tests ya patence tho :P. i now probably have the most complicated speed controller ever in my featherbot :P gotta big up somthing bout me feather.

triggy