Search found 105 matches

by Max
Sun Apr 05, 2015 6:27 am
Forum: Antweights
Topic: Team MedBots
Replies: 127
Views: 88931

Re: Team MedBots

Ok, thanks Rory.
Does anyone know of the lemon rx provided direct access to the ppm stream?
by Max
Fri Apr 03, 2015 3:38 pm
Forum: Antweights
Topic: Team MedBots
Replies: 127
Views: 88931

Re: Team MedBots

Thanks for all your help so far. If I were to stick with mosfets and diodes and used a configuration like this: http://i1261.photobucket.com/albums/ii593/maxmedhurst/rOBOTS/10165AF1-003E-4785-9E23-0779FF370A30.jpg Would I get a problem with the motor braking between pwm pulses and would I get motor ...
by Max
Fri Apr 03, 2015 1:42 pm
Forum: Antweights
Topic: Team MedBots
Replies: 127
Views: 88931

Re: Team MedBots

So something like this:
http://www.ti.com/lit/ds/symlink/sn754410.pdf

I guess that doesn't have built in braking but it's not the end of the world if the motors don't need brake. Would I still need a fly back diode?
by Max
Fri Apr 03, 2015 1:13 pm
Forum: Antweights
Topic: Team MedBots
Replies: 127
Views: 88931

Re: Team MedBots

Melty brain spinner! I only need to drive each motor in 1 direction so no real point using a motor driver. So plan is to have a mosfet driving each motor then a fly back diode across the MOSFET so that when the MOSFET is off you get braking of sorts. As in writing this I'm realising that the diode w...
by Max
Fri Apr 03, 2015 12:53 pm
Forum: Antweights
Topic: Team MedBots
Replies: 127
Views: 88931

Re: Team MedBots

Ok cool. So something like this should work fine: http://pages.ebay.com/link/?nav=item.view&alt=web&id=321712256525 Not sure what the 4th pin is for, I guess it's just connected to the drain. Then a fly back diode like this: http://pages.ebay.com/link/?nav=item.view&alt=web&id=350964...
by Max
Fri Apr 03, 2015 12:14 pm
Forum: Antweights
Topic: Team MedBots
Replies: 127
Views: 88931

Re: Team MedBots

I thought when using PWM you need a mosfet rated substantially higher than the stall current of the motor as when driving not at 100% duty cycle the midget can see much more current (for shorter times) than the motor is seeing? ie if say the motor was drawing 1a but is running at 50% duty cycle the ...
by Max
Fri Apr 03, 2015 11:35 am
Forum: Antweights
Topic: Team MedBots
Replies: 127
Views: 88931

Re: Team MedBots

What size mosfet would people recommend to drive one of the high power any weight gear motors with PWM? And what current capacity diode would I need to protect the MOSFET from induced emf flowing the wrong way (which will also act as an electronic break)?
by Max
Wed Apr 01, 2015 1:53 pm
Forum: Antweights
Topic: Peter Wallers Robot Ramblings
Replies: 755
Views: 633137

Re: Peter Wallers Robot Ramblings

Did you just cut those titanium teeth by hand? I'm looking at titanium teeth for the next incarnation of 50/50 but got a quote of £70 for 8 small teeth from laser master with me supplying the material which I feel is pretty unreasonable.
by Max
Mon Mar 30, 2015 10:31 pm
Forum: Antweights
Topic: Team MedBots
Replies: 127
Views: 88931

Re: Team MedBots

Hmm do you have any pictures of the underside/ from the side of the motor? I wonder how hard it would be to rebuild the base to provide better mounting points.
by Max
Mon Mar 30, 2015 6:07 pm
Forum: Antweights
Topic: Team MedBots
Replies: 127
Views: 88931

Re: Team MedBots

Thanks, that's helpful but I'm not sure what constitutes powerful in an antweight?

Has anyone used this motor:
http://hobbyking.com/hobbyking/store/uh ... duct=14554

Is it any good?