Bonanza "Bulldozer" Dual PhaseRunner AWD

Since I removed the front suspension fork and went to a solid steel Surly unit to handle the BMC's torque the ride has stiffened a bit, and the extra traction and power makes me think of a Bulldozer - rides a bit rough but with AWD traction goes just about wherever you point it.

So I think I will call this the "Bonanza Bulldozer" 2WD eMTB.

I don't plan to put a blade on it, but perhaps a magnet and a leaf blower to clean the bike lane would be fun. :)
 
I was doing some calculations for my various ebikes and looking at motor choices for the Bonanza to get a bit more efficiency and possibly a bit more thrust in the rear motor, perhaps one of the new cassette type models for better gear selections.

In the case of the Bonanza we are limited to about 50 amps of motor current due to the PhaseRunner. You can push up to 70 with a heatsink, and possibly 80 or even 96 amps temporarily, but to be conservative I've chosen 50 amps for this comparison. So if you are current limited then motors with more turns provide more torque. The existing 9C rear motor is a 10 turn motor, so it has low Kv and high thrust per amp. Most of the available motors do not have such high turns ratios because it drives the voltage requirement up. Here I have 72 volts and it only produces about 30 mph, not too many folks want such motors. To match the BMC and the 10 turn 9C I need motors with a Kv of 5 to 6. I don't see much in that area aside from the torque type geared motors.

Also computed is the thrust for the CroBorg and the RidgeRunner. The Bonanza actually exceeds both of those bikes in thrust (if I did the calculations right):


ebike thrust chart.PNG


Note that these are initial thrust values, the thrust will fall off starting at some speed, where the power limitation takes over. This is where the Borg shines, as it has the highest power available due to the no-BMS Lipo battery pack. The other bikes have 18650 packs with BMS's that cannot handle current levels above 50 amps continuous. The Borg's Multistars can handle 96 amps at 3C.
 
dualCA20160909_183348.jpg


I readjusted the PhaseRunner parameters using the new software and did another test drive. I reduced the BMC thrust and power a bit and increased the recommended PLL loop bandwidth from 0.39 to 0.7, which appears to be successful since no trips were noted. With the slightly lower power settings on the 14% grade the speed dropped from 25 to 21. The front motor doesn't seem to be working as hard.

I received two Cycle Analysts to get more data so I can read out both motors at once. I have to modify them (remove speed sensors) and install them to get those readings.
 
Not sure what the difference is between the BMC 4TT and the 3TT.

My invoice says 4TT but the motor label says 3TT.

Anybody know?

I received an email response back from ilia at ebikessf.com, a long time BMC dealer, and he said that 3TT and 4TT were the same. I don't believe he sells BMC these days, something changed. He still has parts, and he still has MAC geared motors as I recall.


BMCmotor20160909_125024.jpg
 
Test Ride meets Hill

A couple of us revisited the hill in Marin today, on exactly the day 6 years after the day I joined ES, the same dirt road that almost melted the 9C rear hubmotor a little over 5 years ago. Same bike, same hill, with a few changes:

  • changed from 66V to 72V
  • changed from 12 FET Lyen controller to 6 FET Ebikes.ca PhaseRunner controller
  • changed from Schwalbe Marathon to Schwalbe Smart Sam tires
  • added BMC 3TT front motor with PhaseRunner controller
  • changed from 40A? to 30 rear, 16 front
  • changed from Zokes suspension forks to Surly non-suspension forks
  • no beer in the panniers this trip
  • weather was cooler, overcast

What a difference. Where before it was a struggle to keep the bike moving and stay on the bike with the rough conditions and inadequate traction (with the rear wheel slipping when pedal strokes combined with motor power), and it was necessary to pedal and ultimately to keep the motor from melting (with all the heat from a nearly stalled motor situation), this time the struggle was to keep the front wheel from slipping under the BMC's torque, (and the rear 9C still slips when pedals are added to motor torque), but the motors and controller didn't get much above ambient as the velocity was well above stall speed (and there was no real need to pedal). It was not hard to get to 15 mph on the steep uphill where it was smooth enough. The lack of front/rear suspension was noticeable as speed increased, and it makes this more of a tractor than a racer.

Back on the pavement we did a few acceleration comparisons between the AWD Bonanza Bulldozer and a RWD Cromotored 26" Fat Tire machine, and the Bonanza slightly out-accelerated the Cromotor in those big wheels. Not by a huge margin, but by a consistent and noticeable amount. This with 72V 60A to the 24 FET Lyen driving the Cromotor and 72V 16/30A to the BMC/9C via a pair of 6 FET PhaseRunners.

The Bonanza Bulldozer works pretty much as expected, and these little dual PhaseRunners are smooth powerhouses when coupled with higher voltage "torque" motors to keep the current down. While not a "rocket" like Luke's "deathbike", this bike has lots of thrust and traction and will handle about as much gradient as the traction will allow, and it seems to be a bit faster on the steep stuff than the RidgeRunner, but with more available power that's also an expected result.

It would be nice to have a fast/easy way to adjust max torque "on the fly" for front and rear motors to suit the conditions. I'll have to work on that. :)
 
I have a small "Mighty Mini" 52V 14S 6AH pack with BMS from Luna that makes a nice short trip and range extension pack for the 52V setups. I plan to use it with the Xootr Swift folding bike too. It is a great size. I might get a second one, they are so handy. But it is not enough voltage for a 72V system.

I was wondering about a short trip / range extension pack for the 72V 20S Bonanza, and it occurred to me that we can series a 6S brick to this "Mighty Mini" pack and increase it to 20S. So how would we do this?

Choose a lipo brick that is 6S, more than 6AH and can deliver 50A without problems. It could be an 8AH brick. If it was, then the load current of 50A divided by 8AH would be a 6.25C discharge ratio. If we want to insure good life for the lipo it should be C rated for 3 or 4 times this, so a 20C or 25C rating should be fine. Zippy 8AH packs are rated 25C so that should work, and I have a few of those. Multistars are not suitable here. Turnigy 20C or 25C would work, say a pair of 25C 5AH 6S bricks in parallel, and I have a few of those. But paralleling the balance wires should be done as well, though a commercial cable for that is easily purchased. So it is fairly easy but not as easy as the single brick approach.

So how does this work? You make sure the lipo brick is fully charged, and the Mighty Mini is fully charged, and make a wiring setup to series them. Since you have chosen the lipo brick(s) to have more amp hour capacity than the Mighty Mini does, it will run down first, and its BMS will shut off first. The voltage drop will shut off the controller if it is set up right (make sure the LVC is higher than the 25V of the 6S lipo to insure this). So the lipo brick is in effect protected by the smaller pack shutting off well before it is exhausted. So it is a little bigger and heavier than it needs to be, but it represents a small fraction of the total pack, so the extra weight is minor, especially since this is a small pack already.

If you really want to be safe, put a reverse biased diode in the harness across the BMS to avoid the lipo brick(s) pushing any current into the BMS when it trips. This is generally recommended when series connecting BMS protected packs, which is often done to get 72V packs from a pair of 36V BMS protected sub-packs. Some BMS systems don't need this diode or are already protected, but it is cheap insurance to put into the harness (and won't do any harm to have a duplicate). Any BMS rated for series connections is already protected.

I haven't tried this yet, but series connected 36V BMS protected packs are in common use without problems, so it is worth considering.
 
BonanzaFillUp20160911_090326.jpg


Heading out to the Assault on the Hill

Front Brake Upgrade

I'm going to move this Hayes front brake to the Canyon Express, and upgrade this bike to a Shimano XT hydraulic front brake to match, more or less, the rear rim brake which is an XTR. There are no disc brake mounts on the frame, hence the rim rear brake. The Surly front fork has the usual 51mm IS disc mounts. I'm looking at the XT M8000 front disc brake, the XTR 9000's appear to be a bit over the top for this bike, I don't need carbon fiber levers. In most product lines, dropping back a level from the top often yields a good product without some of the costly fluff. In bicycle components the highest grade is often optimized for low weight, which is not such an important feature on an electric bike.

I've ordered a 2.5mm spacer for the 6 speed freewheel, I measured 5.3mm available and split the difference. Right now the derailleur would scrape the motor to shift into the lowest gear if I allowed it, so hopefully this will fix that. Received the new Park FR-1.3 freewheel tool for removal, this variant of the tool has clearance for the thick 14mm ebike axles.
 
Progress

Today I experienced a flat tire from a tube failure, possibly caused by converting a rim from Presta to Schrader. I did that several years ago, but I'm wondering if I left the edges a bit sharp as the thick Slime tube failed right there. Most of the tubes I've used had metal valves so perhaps this snake has been hiding in the grass for awhile. I chamfered the hole better and installed a new Sunlite thorn proof tube.

While I had things apart I removed the freewheel and installed a 2.5mm bottom bracket spacer and realigned the derailleur. Now I can reach the Megarange gear as well as the other 5, so it really is a six speed. It is shifting smoothly but there is one problem - it can overshoot a little and dump the chain into the space beyond the first gear. The overtravel adjustment on the 8 speed SRAM X.4 derailleur can't fix this without also locking out the smallest sprocket. If I made a delrin spacer ring I could shift from the beyond first back into first, perhaps. :)

I might add a bumper on the derailleur so it touches the hubmotor before moving far enough to shift off the Megarange gear. If done right it might solve the problem.

Those freewheels sure are tight, a wrench didn't seem to work when loosening it, so I grabbed a deep impact socket and used an impact driver which spun it off instantly. I lightly greased the threads and surfaces for installing the new spacer but I think those threads always get very tight. Impact tools are amazing, though I would not use one to install the freewheel. The Park freewheel tool FR-1.3 which is made for hubmotor axles fits and works perfectly on the Megarange freewheel.

As mentioned in the last posting, a new hydraulic front brake was ordered, and it arrived today. A Shimano Deore XT M8000 front disc system. The install is only partial at this time, I left the Hayes adapter and disc on as the new adapter has not arrived, and some short screws for mounting the ICE disc are due in later. But the lever, hose and caliper were installed. The lever has a much narrower band to hold it to the handlebar, and this drastically improves the position of the shifter and the minor interference between the shifting trigger with the Magura grip flange. I'll add some pics later, but this is a good combination for my crowded handlebars. I wonder if they have a narrow mount lever for the rear XTR cable brake... If so that would likely help the right hand trigger shifter as well.

The static feel of the Shimano XT lever is very good, but I've a few more things to update before the bike will be ready for a test ride with the new front brake. This lever has adjustments, so it can be fine tuned. With mineral oil I don't have to worry about the finish being attacked by brake fluid. The Hayes brakes were fine, but recently the brake fluid was attacking the lever's own finish, and now they seem to be needing bleeding which may make things worse in terms of the finish. You'd think the manufacturer would use brake fluid resistant finish on a brake handle, at least for the fluid they use.

I was researching bicycle mineral based brake oil, and it looks like Shimano and Tektro may be compatible. The Shimano mineral brake oil is available in a larger and more cost effective container than the Tektro. Any comments on that?
 
With all the rain here, and other distractions I haven't finished the rewiring job on the Bonanza. It is an amazing machine, with an amazing amount of wiring. The dual PhaseRunner controllers are small and help minimize the wiring with their simplified cabling, but there is still a lot there. I hope to get back onto it very soon. Come to think of it, this would be a good bike to take on a camping trip to Pismo we have planned, but there may not be time to get it finished.
 
Seven years on ES today, I just noticed. I think this was my first thread, or at least the first of any consequence.

Thanks for all the input here!

This has been a very busy summer so I haven't finished the wiring cleanup on this upgrade to dual PhaseRunners. With the new dual motor simulation on ebikes.ca, I will be able to fine tune the PhaseRunner settings for even better balance.
 
Easy way for me to remove freewheels is to put the tool in a vise and rotate the wheel. I had the same problem with a Slime "thick" tube. The presta valve separated from the tube on the first ride. May be poor QC, but there are aluminum inserts (Problem Solvers) for presta valves in schrader "holes" that I'm trying next.
 
Alan B said:
Seven years on ES today, I just noticed. I think this was my first thread, or at least the first of any consequence.

Thanks for all the input here!

This has been a very busy summer so I haven't finished the wiring cleanup on this upgrade to dual PhaseRunners. With the new dual motor simulation on ebikes.ca, I will be able to fine tune the PhaseRunner settings for even better balance.

A great read beginning to end! Any finished project pics?
 
Alan B said:
When I finish it, I'll post a picture.

At the moment it is waiting for the rewiring to be completed, and other projects have taken priority.
HAH I know how that is. 3 bikes are in limbo in the basement shop here...
 
Recently we took a couple of ebikes to Quartzfest for a week in the Arizona desert. While there I did some work on the Bonanza AWD's wiring and programmed the new front PhaseRunner so it is working in all wheel drive mode again, now with two identical PhaseRunners (prior it had two different generations of units onboard). Now that they've changed the PhaseRunner again, these are no longer the current production units. These are the units that have pushbuttons on them for on/off as well as cables for power coming out. The only connector embedded in these is the programming connector.

I did a presentation on DIY ebikes while at Quartzfest, and there was lots of interest in this two wheel drive ebike as well as the process of bicycle conversions to electric. A few of those folks may even show up here on ES. This is the second time I've done this, the first was two years ago, also at Quartzfest.

Quartzfest is a week long Ham Radio event that takes place in the Quartzsite area near the end of January each year. Attendees and speakers either dry camp there in the desert or travel from elsewhere to participate. There is a full schedule of events for the week and you can read about it on their website.

The other ebike I brought was the two speed Luna Xiongda front hubmotor on the Xootr Swift. I need to start a separate thread on that motor and bike, it worked fine in the desert but it had the wrong tires on it for this use-case.

The Bonanza 2WD worked nicely in the desert, riding on the so called "desert pavement" there, which forms when the desert wind blows away the sand and finely ground rock until the bigger rocks form a flat surface that protects the finer particles from that wind. It is rough with the varying sizes of rock, but the dual drive helps keep the bike moving without a lot of speed or power needed. The Schwalbe Smart Sam tires took the rough "pavement" in stride. The distances were relatively short, and the large numbers of people necessitated keeping speeds low, so this wasn't a high speed test.

I didn't take photos but other folks did, perhaps if anyone has photos from Quartzfest they can contact me and we can arrange to post them here and give credit. Right now the bikes are still in storage in the toy hauler, but soon I will dig them out and can get some photos. There's still a lot of work to do on the wiring cleanup, but at least it is running again. The weather at Quartzfest was excellent, and here at home it has been dry and warm as well, so ebike season may be upon us (though we need a lot more rain yet this year).

It took a couple of tries to get the PhaseRunner to autotune, but it did work pretty easily with the BMC front gearmotor. I think they have improved the default values because I didn't have to change much to get it working. Previously I had to change more.

With the individual on/off pushbuttons on the PhaseRunners I can turn either one on or off independently. This works nicely to turn the front one off and run on just the rear, but running on the front only doesn't work, probably because bias to the throttle is lost when the rear PhaseRunner is off.
 
Here we are one day shy of 9 years on ES. I need to update this thread with the promised photos of the bike after I do a couple of things. I see some of the images now have bad links, need to fix that as well.

Was just looking at the switch I got for drive control. I think others have done this before, but it is a good (and a bit unusual) setup and I will document the way I use it. The switch is a somewhat special ON-ON-ON toggle switch. This particular one is an NKK M2024SS1W03 that Mouser carries for about $6.50.

The goal is to have a toggle switch that will route the throttle signal to both controllers such that UP is front wheel drive, CENTER is 2WD/AWD, and DOWN is rear wheel drive. A 3 wire cable will do the trick, and for this an independent shield connected to throttle ground would be good to minimize noise or RF pickup into the PhaseRunner throttle inputs. The throttle signal passes through pins 2-3 to the rear controller and 4-5 for the front controller.

To mount this switch on the handlebar I plan to design and 3D print a mounting bracket for the switch.

Another thing I need to document is the new mounting setup for the dual Cycle Analysts. I designed and 3D printed a bar to join them in a stack. I may need to do something about the mount too, the stock mount seems weak for the rotational moment of the dual displays.
 
What about having two throttles for both controllers?

Sometimes I wish I could have two when my thumb gets sore. Then I just use the the bottom of the thumb, on the hand. Other times I will use my index finger. I guess I should really just hook up the cruise control wires.
 
I use a high quality Domino twist throttle on most of my bikes. The thumb throttles are cheap and easy but hard on the thumb.

Pedal sensing is one way to rest your thumb.

If you want to use more than one throttle some low forward voltage drop diodes should work for tying them together. Then either throttle can be used.

Putting a separate throttle on each controller is often done with simple dual motor setups but synchronizing the motors adds workload to the pilot.
 
Alan B said:
The more I think about this, do I really need the "front drive only" option?

Perhaps KISS and just do REAR / ALL (wheel drive), which is simpler to implement. Only takes a SPST toggle switch and 2 conductors for that.

I'm sure you want to remain able to easily shutdown either drive in case of failure. But think you have the push buttons on the Phaserunner for that. And probably several other possibilities.

Have you done any testing on flat terrain at say 10-15-20 mph comparing the load on the battery with the front motor off to both motors on? I'm curious how close the sim is to reality?

The Grin simulator using 2 9C212 for a quick check at 72V with dual PR's, showed 6A total drain at 20.1-20.2 mph in both 1 and 2 motor operation. This is 50/50, a different split than you targeted. It's different motors too. But unless one motor is significantly more efficient, this would probably hold if you modeled your setup more precisely.

Unless you got down to <10 mph? And doesn't reflect any penalty for stop and start situation if that's a factor? So KISS, might be AWD all the time ala Subaru?

I still haven't fully explored all the CA3 options...especially those that can switch on the fly, but since you have 2, maybe you could essentially turn off a motor there?
 
Of course at the moment it is AWD all the time, though I can turn off a PhaseRunner with it's pushbutton. But that only works for turning off the front drive, the rear drive is providing 5V for the throttle. To turn that one off I have to swap the throttle plugs around.

One situation where I might want to turn off the front drive is in the rain. Even then it might be better to have it on. But if the front slips it can be bad.

In general the motivation for turning off a motor is not very strong. I have stopped working on that for now.

9/23/2019 uploaded images on this page to ES for more reliable viewing
 
The motivation for a handlebar mounted AWD control isn't failure, that would be handled by turning the PhaseRunner off and possibly re-configuring the throttle plug if the DD subsystem failed. In any case reliability has not been an issue. Having fingertip control is more about changing the configuration on the fly. I suppose the overall reliability of the gearmotor is likely less than the DD, those gears are the main liability. Turning off the front GM is a single button push, but it is not convenient to do while riding.

In terms of efficiency I haven't looked closely but I have struggled to get the torque balance, the gearmotor is really good at making torque from current. I have to direct quite a bit more current to the rear 9C to get more torque. The front tire makes scrubbing sounds like it is getting ready to slip probably due to the gearmotor torque and the weight transfer away from the front, so you may not want 50/50 torque unless you like dancing with instability and slip. I have never experienced a loss of control from the front slipping even in the dirt, and would rather not go there.

If starting a design from scratch one could make arguments for dual gearmotors or a DD in front and GM in the rear, this design was constrained by starting with a DD rear system that was working well but in need of low speed torque so adding the front GM was the reasonable option. However, that said, I prefer to have regen in the rear, and to have lower weight in the front. Losing the suspension front forks is annoying, but the cheap ones are just not well suited for a high torque gearmotor, and having high quality steel forks is a much better choice.
 
Whatever happened to the Throttle Manager project? (it looks like it was abandoned when the Phaserunners were used?)

I ask because I'm working on some changes to the 2WD SB Cruiser trike, (delta, drive by both rear wheels with separate hubmotors), and part of the changes include:

--switches to go from individual left/right throttle control to each motor separately, to either throttle controlling both motors simultaneously, while:

--a sensor (undefined as yet) on the steering will apportion power to the left and right motors in turns to help push it into the turn harder.

--The Cycle Analyst can be switched in or out of the circuit to accomplish speed limiting whenever it's presets are used for that.


I'm wondering if the Throttle Manager could be adapted to this type of usage?
 
You have a good memory Amber. Or you have been re-reading threads. Perhaps both. :)

You pretty much hit the nail on the head there, the PhaseRunners eliminate the need for the complexity. Plus my transportation situation totally shifted after I retired and then bought the Leaf EV and my ebike use plummeted.

I did make some throttle manager circuit boards but I stopped before building it up. I have a pile of circuit boards that I designed that are still bare. One thing I really like about 3D printing is once I design something the printer makes it for me. With electronics I do the CAD for the schematic, then the CAD for the board, then the fab makes the PCB. Then there is still a ton of work left with parts procurement, parts installation, and then there's the testing and programming. Getting to the end is a long process.

I've started using ebikes again but nowhere near the daily level that ended when I stopped commuting. Of course the Bonanza wasn't a commuter any more, but it was my original ebike and an improvement project had been started with the purchase of a front gearmotor, the challenge of the Marin hill was calling and the Quartzfest presentation provided a deadline. Once that had been completed the Bonanza project was set aside. Now I'm divided over Bonanza AWD vs Diamondback mid drive upgrades as well as too many other projects.

As to whether the Throttle Manager would do what you are wanting, perhaps. The software I was planning would not, but the hardware might. But as I recall software wasn't something you really wanted to delve into, so you might want to find a more hardware oriented solution. It is interesting how our interests shape our solutions. Lately I'm more interested in 3D printing and CAD design than PCB design, I haven't designed a board in several years. Software I do whenever I have a reason to. I have a backlog of CNC and kit projects, and the wife has a long list of house upgrades we need to do.

Taking a KISS (keep it simple...) approach is often best. For example, a normally closed pushbutton on each handlebar that drops out the throttle signal to the motor on that side to aid in turning. Or perhaps put both buttons on the left thumb and throttle with the right hand/thumb. Rather than make grand plans, try something simple (maybe you already have) that gives you ability to instantly drop power on the inside wheel. A simple switch dropping the CA throttle limiting signal would allow overriding that. See how that works and then make additional small improvements, one step at a time.

I did that here with the PhaseRunners, and they just work fine with one throttle signal sent to both. No fighting, none of the issues commonly experienced with PWM based throttle controllers. The only real question is should I bother with some kind of front/rear/both switching, mostly for fun as it really isn't needed. Between the PhaseRunner and the CA3 programming things are already very well "managed". :)

I have a trip so I'll be partially off net for a few days.
 
Alan B said:
You have a good memory Amber. Or you have been re-reading threads. Perhaps both. :)
Actually I was searching for posts about bidirectional throttles (one way for regen, other for accel) to help another member, and ran across the throttle manager post by accident in the results...since it was by you I read it anyway even though it didn't have anything to do with what I was after, since it was pretty sure to be interesting one way or another. ;) Then I searched and skimmed the rest of the thread for further info on it.



As to whether the Throttle Manager would do what you are wanting, perhaps. The software I was planning would not, but the hardware might. But as I recall software wasn't something you really wanted to delve into, so you might want to find a more hardware oriented solution.
ATM I'm probably just going to do a bunch of op-amps to mix the signals together and isolate them from each other (so a failure in one can't take the system down from a cabling short, etc). Adjustments can be made by making some of the input or feedback resistors potentiometers instead. (so for instance, the "range" of a throttle input scaling could be altered to match a second different throttle, or whatever).

An MCU solution would be more flexible, in that it could be reprogrammed to alter behavior whenever desired, but is more complex to design to start with (especialy since I'm not much of a programmer, and I know no one that can help with that, or at least no one that is willing to, especially since they'd have to do almost all the work of that part, and I don't know anyone else that wants the same kind of system either).




It is interesting how our interests shape our solutions. Lately I'm more interested in 3D printing and CAD design than PCB design, I haven't designed a board in several years. Software I do whenever I have a reason to. I have a backlog of CNC and kit projects, and the wife has a long list of house upgrades we need to do.
I'm more of a hack than anything else, more of some sort of "sculptor" than designer, etc. I know enough of many disciplines to get by in making or fixing stuff I need, but most of it is hacking other things to do what I want. I don't really know enough to do most things "from scratch" that I want or need to do. Some of it I've figured out over the years...but my mind doesn't work like most people's, so I have quite a bit of trouble learning certain kinds of things, while others come perfectly naturally to me without "learning" them in any normal sort of way.

But still, you're right, our interests do shape our solutions (as do our capabilities).... Most of my interests I can't do much to accomodate, as there just isn't enough time (or money...if there was more money there would be more time as I could work less and/or pay others to do things I don't really want to be doing).




Taking a KISS (keep it simple...) approach is often best. For example, a normally closed pushbutton on each handlebar that drops out the throttle signal to the motor on that side to aid in turning.

Or perhaps put both buttons on the left thumb and throttle with the right hand/thumb. Rather than make grand plans, try something simple (maybe you already have) that gives you ability to instantly drop power on the inside wheel.

For either of those, I'd rather just keep the present one-throttle-per-motor system; it's even simpler. ;)

But I would still prefer an automated solution, whcih is why I want to put something on the steerer to sense steering position, and control power to the motors based on that. (with an override switch to disable it for the situations in which it might be unhelpful, if one should arise).

And I want to have a both-on-1 / both-on-2 system available, because my hands randomly go numb, not usually at the same time, so I can't feel what I doing with them very well when it happens, and it's difficult to control the throttle correctly then. If the system will take either input to control both motors, then I simply use the other hand to control it instead, until feeling returns (which usually happens in a minute or two; or less).

I can also use TorquePAS to control both motors this way, via the CA3, but first I have to find out why the CA is sometimes allowing a touch on the pedals with no actual rotation, while trike is just sitting there, to gun the motor to full power, and why the CA forces a delay in throttle response if PAS is enabled/connected, and why it forces motor speed to drop so far below the set speed limit before reengaging it, etc...for now, PAS is disabled in the CA and the sensor is disconnected (and none of these happen if PAS is disabled / not connected).


A simple switch dropping the CA throttle limiting signal would allow overriding that.
ATM I have presets for the CA so it will limit (or not limit) to various speeds. Unfortunately ther'es only three presets, so for now it's 5, 10, and 20MPH, and it only applies to the right side motor system. If I had the system setup for "both on 1" / "both on 2" (aircraft terminology) rather than independent throttles, I might instead have a 5MPH and 20MPH preset, and the third would be unlimited. I don't need the unlimited often, only when a traffic issue presents itself that makes it safer to accelerate out of the way rather than braking, to avoid the problem. Once every few months, perhaps.

So perhaps as you suggest a switch on the throttle, or even better a detent at the top of the throttle that if pushed beyond that point clicks the switch automatically, which would be even more "natural" to use, with no thougth needed so much better reaction time, especially since it happens so infrequently.





I did that here with the PhaseRunners, and they just work fine with one throttle signal sent to both. No fighting, none of the issues commonly experienced with PWM based throttle controllers. The only real question is should I bother with some kind of front/rear/both switching, mostly for fun as it really isn't needed. Between the PhaseRunner and the CA3 programming things are already very well "managed". :)

I don't really experience any particular problem using just one throttle for both, just that with the trike configuration with both rear wheels powered, I can force turns to be sharper by powering one wheel harder than the other.

I could do even sharper turns by forcing (proportional) regen on the inside wheel while having full power on the outside wheel, but that's a more complex system I woudl have to work out carefully.

Sharp turns are sometimes very important, because I sometimes can't slow as much as I would like, becuase of traffic behind me that isn't slowing down becuase they're going straight thru in the same lane I have to turn in. (rarely, these types of drivers do clip or fully hit from behind cars that slow for turns, and I don't want that to happen to me). But becuase of road conditions (slickness and/or wavy bumps up to several inches high and several yards or more in extent) at intersections, I don't always have enough grip on the front to steer the trike via the front wheel, without slowing to a few MPH. Using the rear wheels (at the heavy end of the trike) I have plenty of grip, and can force a much sharper turn with power to just the outside wheel, and if I had braking setup as independent (dont' right now) it could be even sharper.


It would also help turning around in narrow spaces, but most of that only needs to happen at speeds where I can do it with my feet on the ground, like a parking space.
 
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