OK to extend PAS cable?

[johneb]

At long, long last I have started installing the kit on my recumbent trike. I want to position the controller in a spot where it is least likely to get splashed by water thrown up from the wheels whilst retaining a good airflow over (which I assume it needs, given the cooling fins). However, the PAS cable is too short to reach the ideal controller location. Is it OK to extend the PAS cable (soldered and heatshrinked), or does this have the potential to screw up the signals it is sending to the controller?

Alternatively, am I being too concerned about the cooling aspect? Could I mount the controller inside a waterproof box and locate it in a position which wouldn't require cable extension?

I'm using a Q128c 201 (260) rpm in a 20" wheel with a KT36 36/48v 17A controller. The trike will be used for ambling along on the flat most of the time, with the occasional hill which, I guess, will cause the controller to get warm.

 

[Woosh]

Is it OK to extend the PAS cable (soldered and heatshrinked)

yes. you need 3-core unshielded cables 20AWG or 22AWG.

 

[Nealh]

My KT's are in saddle bag or in under slung top tube bag, though I have added air holes and some extra heat sink.
No issues with heat.

Extending pas is no problem as long as you don't get wire order wrong, for insulation the self adhesive
heat shrink is another option for keeping the joint moisture free.

 

[anotherkiwi]

Please post a picture of your proposed layout.

I am at the stage of deciding too and I definitely need air flow because I have had overheating problems during testing on the upright - at peak load adding just 120 W more power. Here are my choices in preferred order:

1. under the boom in the air flow in a controller box with a PC CPU radiator attached to the controller. Very short cable runs except from battery. Battery in Ortlieb pannier(s) on low rider carrier under seat. Removable but not lockable...
2. in a bespoke battery box mounted to the low rider carrier - controller in bottom of box (so in the air flow) with external radiator as above. Longer cable run to motor and LCD, very short battery wires. LiPo battery in lockable, removable holder.

PAS option for n°2 is the possible inclusion of the 12 magnets in the chain idler under the seat.

LCD option for n°2 is the Eggrider V.2 display, for n°1 the normal KT LCD mounted up front on the light holder - extended cable back to handlebars for buttons.

I would also mount a Watt meter in a waterproof holder up front for option 1. For option 2 it will be in the battery box behind a window.

That is about where I am in designing the motor integration ATM, quite a bit of fabrication to do in both cases. On the riding front I am now strong enough to wonder if building a vélomobile shell for an un-powered trike is the way forward... Bad technique means I still have pedal steer when getting into the high cadences and over 60 km/h (yes it is scary - the pedal steer I mean) I wonder if it is just a gearing issue - higher gearing = lower cadence at that particular speed...

 

[johneb]

Please post a picture of your proposed layout.

I am at the stage of deciding too and I definitely need air flow because I have had overheating problems during testing on the upright - at peak load adding just 120 W more power. Here are my choices in preferred order:

1. under the boom in the air flow in a controller box with a PC CPU radiator attached to the controller. Very short cable runs except from battery. Battery in Ortlieb pannier(s) on low rider carrier under seat. Removable but not lockable...
2. in a bespoke battery box mounted to the low rider carrier - controller in bottom of box (so in the air flow) with external radiator as above. Longer cable run to motor and LCD, very short battery wires. LiPo battery in lockable, removable holder.

PAS option for n°2 is the possible inclusion of the 12 magnets in the chain idler under the seat.

LCD option for n°2 is the Eggrider V.2 display, for n°1 the normal KT LCD mounted up front on the light holder - extended cable back to handlebars for buttons.

I would also mount a Watt meter in a waterproof holder up front for option 1. For option 2 it will be in the battery box behind a window.

That is about where I am in designing the motor integration ATM, quite a bit of fabrication to do in both cases. On the riding front I am now strong enough to wonder if building a vélomobile shell for an un-powered trike is the way forward... Bad technique means I still have pedal steer when getting into the high cadences and over 60 km/h (yes it is scary - the pedal steer I mean) I wonder if it is just a gearing issue - higher gearing = lower cadence at that particular speed...

Following advice/reassurance from Woosh & Nealh, I intend to extend the PAS cable. I plan to cut an aluminium plate which I will bolt below the pannier rack (on the rails parallel to and below the top rail), ensuring there remains adequate clearance at full suspension deflection! The controller will be bolted to this plate, with a waterproof box immediately adjacent to it to contain the many connections emanating from the controller. The aluminium plate will double as a heat sink, should the controller get warm.

The battery will sit atop the pannier rack, immediately above the controller.

The display will probably be located on the front mech pillar, possibly utilising a handlebar stem and some sawn-off handlebar from my parts collection. I've yet to ponder that in detail - it may interfere with the front mech operation.

I'll post more detailed pics and the story of the build when it's complete.

 

[anotherkiwi]

I know you don't go fast but the battery up that high will seriously affect handling/cornering. Otherwise good plan.

 

[johneb]

I know you don't go fast but the battery up that high will seriously affect handling/cornering. Otherwise good plan.

Thanks AK. I'll see how it goes at my tame pace, but may end up relocating to below/alongside the seat.