capri-boy Posted September 7, 2016 Share Posted September 7, 2016 Hi all, showing some gaps in my skill set here but could use some advice. I've a Kyosho half eight (mini inferno) that I've just brought back to life. With no motor in it free wheels lovely, though with a motor in you cannot get the drivetrain to turn the motor. If you spin the pinion on the motor all works as expected, try to spin one of the transfer gears, the centre diff or all 4 wheels together and it's locked tight. When the truck moves though as soon as power is off this results in a braking force like it has a drag brake set to near full. There's a quick vid below where you can see/hear the issue. I'm sure i'm overlooking the obvious here (inc this is just how this set up should operate) so would really appreciate people's thoughts. Thoughts appreciated. Quote Link to comment Share on other sites More sharing options...
turok007 Posted September 7, 2016 Share Posted September 7, 2016 some ESC's build up a resistance so when the power is cut it just locks up also have you tried unplugging the motor then try to freewheel the truck. as this will show if that is happening Quote Link to comment Share on other sites More sharing options...
capri-boy Posted September 8, 2016 Author Share Posted September 8, 2016 10 hours ago, turok007 said: some ESC's build up a resistance so when the power is cut it just locks up also have you tried unplugging the motor then try to freewheel the truck. as this will show if that is happening Unless I'm having a senior moment I tried it when building, and without a motor it freewheels fine, though as soon as a motor/pinion are involved it 'locks' up if you try to 'power' the drivetrain from anything other than the pinion. Quote Link to comment Share on other sites More sharing options...
turok007 Posted September 8, 2016 Share Posted September 8, 2016 2 hours ago, capri-boy said: Unless I'm having a senior moment I tried it when building, and without a motor it freewheels fine, though as soon as a motor/pinion are involved it 'locks' up if you try to 'power' the drivetrain from anything other than the pinion. so if you unplug the motor wires it still won't turn when using the wheels. also some gearing cannot be easily turned i can turn the wheels on a slash vey easy but on a crawler it is not so easy so that suggests the gearing is the reason. Quote Link to comment Share on other sites More sharing options...
capri-boy Posted September 8, 2016 Author Share Posted September 8, 2016 7 hours ago, turok007 said: so if you unplug the motor wires it still won't turn when using the wheels. also some gearing cannot be easily turned i can turn the wheels on a slash vey easy but on a crawler it is not so easy so that suggests the gearing is the reason. Nope. The motor turns very easily out of the chassis, and if you spin the pinion the whole drivetrain turns very easily. If you try to turn anything else (the transfer gear(?) from pinon to centre spur / the centre spur / all four wheels) the whole thing locks up - hence when your running and come off the power it's just the same and acting like a full on drag brake. It's got to be a function of the design but as in OP it's lost on me. Quote Link to comment Share on other sites More sharing options...
turok007 Posted September 8, 2016 Share Posted September 8, 2016 45 minutes ago, capri-boy said: Nope. The motor turns very easily out of the chassis, and if you spin the pinion the whole drivetrain turns very easily. If you try to turn anything else (the transfer gear(?) from pinon to centre spur / the centre spur / all four wheels) the whole thing locks up - hence when your running and come off the power it's just the same and acting like a full on drag brake. It's got to be a function of the design but as in OP it's lost on me. My sidewinder 25 combo acted the same. But when the motor wires were disconnected it would all turn by hand. Quote Link to comment Share on other sites More sharing options...
capri-boy Posted September 10, 2016 Author Share Posted September 10, 2016 On 9/8/2016 at 18:29, turok007 said: My sidewinder 25 combo acted the same. But when the motor wires were disconnected it would all turn by hand. Had another look today, vid below. No pinion meshed - spins freely. Pinion connected - will not spin unless the pinion provides the 'force'. As you can see from the vid as soon as a pinion is meshed the drivetrain locks up unless 'force' comes from the pinion - it's nothing to do with the motor though as I backed the grub off so the pinion can spin on the shaft freely. Odd, feels like a design thing, but is a killer for the chassis for me - insta brake as soon as throttle is removed does not make for fun driving and must surely kill the drive train. Quote Link to comment Share on other sites More sharing options...
turok007 Posted September 10, 2016 Share Posted September 10, 2016 that is very strange Quote Link to comment Share on other sites More sharing options...
capri-boy Posted November 13, 2016 Author Share Posted November 13, 2016 On 9/10/2016 at 20:01, turok007 said: that is very strange Finally got round to having another look at this, and result. Sourced a 12t 48DP pinion, as originally fitted a mod 0.6 as they allegedly mesh fine. Drivetrain is still a little stiff, it's barely turned a wheel in many many years since new, but she now runs as she should. Snapped a quick pic of the pinions side by side - as I knew at teh time, the 0.6mod one is physically bigger - swapping to the 48dp solved it so the 0.6mod must have been the issue - so for future reference for anyone else looking to swap 48dp with 0.6mod or vice versa it's neither perfect nor good enough. Quote Link to comment Share on other sites More sharing options...
turok007 Posted November 13, 2016 Share Posted November 13, 2016 25 minutes ago, capri-boy said: Finally got round to having another look at this, and result. Sourced a 12t 48DP pinion, as originally fitted a mod 0.6 as they allegedly mesh fine. Drivetrain is still a little stiff, it's barely turned a wheel in many many years since new, but she now runs as she should. Snapped a quick pic of the pinions side by side - as I knew at teh time, the 0.6mod one is physically bigger - swapping to the 48dp solved it so the 0.6mod must have been the issue - so for future reference for anyone else looking to swap 48dp with 0.6mod or vice versa it's neither perfect nor good enough. so if you turn the spur now it works Quote Link to comment Share on other sites More sharing options...
capri-boy Posted November 13, 2016 Author Share Posted November 13, 2016 2 hours ago, turok007 said: so if you turn the spur now it works Yup, nice and freely. Was going to give it a run out until the nasty servo horn popped off. Still searching an alloy replacement. Quote Link to comment Share on other sites More sharing options...
turok007 Posted November 13, 2016 Share Posted November 13, 2016 13 minutes ago, capri-boy said: Yup, nice and freely. Was going to give it a run out until the nasty servo horn popped off. Still searching an alloy replacement. glad you finally found out the issue. Quote Link to comment Share on other sites More sharing options...
brit_bulldog Posted November 20, 2018 Share Posted November 20, 2018 I have 2 of these sitting in loft doing nothing. got for my son but hes not into RC anymore. Quote Link to comment Share on other sites More sharing options...
capri-boy Posted November 20, 2018 Author Share Posted November 20, 2018 1 hour ago, brit_bulldog said: I have 2 of these sitting in loft doing nothing. got for my son but hes not into RC anymore. Sold mine - running a BL set up was just daft - and i've too many other micro's. Fetched reasonable £ and had a lot of interested buyers - mine was in vgc but not perfect and no box. Quote Link to comment Share on other sites More sharing options...
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