Super Daves dual motor idea

[SuperDave420]

ok I am building a TXT Crawler, my firend is actually helping me quite a bit on the mechanical prep.

I'm running a E-maxx tranny with the shift servo.

This is not going to be a super comp truck so I am able to make some compromises. this is going to be a fun truck though

I will have a lathe motor in 1 mount with super low pinion 8,9,19 tooth.

in the second slot will be a Nice modified motor with a nice tall pinion.

I will be using my multi channel (9 channel EVO ) TX to control it.

I have seen electronic switches that plug into a free channel on a RX, I will use that to turn a relay on or off.

The relay will basically take the 2 wires form the ESC that go to the motor and switch them between the crawler motor and the bashing motor at the flip of a switch.

My thinking is that I could run the truck at high speed to get to the crawl spot and then instantly switch on the low geared lathe motor and Crawl.

the motor that is not connected will just freewheel on the spur. no big deal.

yes there is a slight drag on the unconneted motor but this is a compromise I am willing to make. with the new 3800 cells it should not make a difference.

I am also going to try it with 1 motor being the Novak Brushless setup and the Relay would then just switch ESC's that way the Novak would make my truck fly.

what do you guys think about that? the best of both worlds.

[moonbuggy]

You should look into multi speed trannys instead

[JohnRobHolmes]

it is a multi speed tranny.

i say do it do it!! use a brushless for your second motor. if you kept it in first gear you could use a short can 540 and get away with 6 cells (like the novak 5800). in second gear you could be careful of heat and still bash it, or use a longer can motor (like the novak maxx) and gear it high with just 6 cells.

also, if you used brushless for your second motor there would be no drag. added benifit.

you have an evo. why dont you mix the esc's into different channels? use your rate switch and program in which motor(channel) that your throttle stick mixes to. you should be able to do that. if not, then just put one throttle on the left and one on the right. you could install a spring kit in your left throttle (im assuming you fly in U.S. mode two in think). you could use a relay, but your transmitter should do your work for you.


i have been pondering this too. it would make for a very fun ride with the best of both worlds! with the lathe, you get long run times, with the brushless you get power.

[SuperDave420]

Originally Posted by johnrobholmes

it is a multi speed tranny.

i say do it do it!! use a brushless for your second motor. if you kept it in first gear you could use a short can 540 and get away with 6 cells (like the novak 5800). in second gear you could be careful of heat and still bash it, or use a longer can motor (like the novak maxx) and gear it high with just 6 cells.

also, if you used brushless for your second motor there would be no drag. added benifit.

you have an evo. why dont you mix the esc's into different channels? use your rate switch and program in which motor(channel) that your throttle stick mixes to. you should be able to do that. if not, then just put one throttle on the left and one on the right. you could install a spring kit in your left throttle (im assuming you fly in U.S. mode two in think). you could use a relay, but your transmitter should do your work for you.


i have been pondering this too. it would make for a very fun ride with the best of both worlds! with the lathe, you get long run times, with the brushless you get power.

cool feedback

I could look into utilising the mixes, I just know with the relay there would be no chance for both motors to be on at the same time. the brushles max motor is the way to go like you said.

I just don't know how the ESC's will behave if both are powered on, I need to have a deffinate line between off and on or barely on.

I think ifit were done with the sticks there would be too much error, I know I'd hit the stick midway and light off both motors.

[yodasands]

You could set the esc for the brushed motor up on the channel used for the flaps. If you have a flap knob or slider then it would give you proportional throttle on that channel. Use the standard throttle stick for the brushless motor.

Dan

[SuperDave420]

I'm also going to mix the rear stear servo with the throttle channel so the faster I go the less the rear wheels steer. basically at 100% throttle the rear steering would be electronically locked out and at low speed the rear would steer more.
with the Crawling motor engagded the rear steer would be controlled by a 3POS toggle switch, with the high speed motor on, the steering would be the same as a Y harness type but with the steering angle being electronicall reduced as the speed increases.

that way I can do fat 4wheel steering with the fast motor at low speeds and around turns or u-turns and has I peg the throttle the rear servo travel would electronically reduce..

[JohnRobHolmes]

that sounds like a good idea for the steering mixes. i really like the variable rear steering depending on speed. that is a kick *** idea for the speed mode. i think we have a full fledged rock racer with better slow speed control.

have you futzed around with the programming and mixing for the throtles yet? a relay might be the simplest solution after all. but, its extra weight, wires, and parts. i really think your radio can handle it though

second idea. use a switch at the motors for a brushless system. you would have to wait for the castle maxx to come out for the full effect, but you could change motors that way with one esc per your plan. it would run the novak motor too.

[fuzzhead]

or run the associated sphere esc. it can handle brushed and brushless. just switch a ground from one to another.

[JohnRobHolmes]

honestly, that esc is not worth the cash. sensored tech not only limits the motors you can use (to less than 5 weak *** sensored Roar motors in production instead of literally thousands of motors with a sensorless esc), but its programming and adjustability suck.

im a plane guy and im used to a different kind of esc i guess. not to knock your idea fuzzhead, i just dont like that esc for anything other than Roar legal racing. the ground switching idea should work unless it confuses the esc. no telling without a test or more knowledge on how it knows which leads are live.

i do see one problem with using a physical. the extra resistance would kill the performance of the motors when starting from dead stops.

[Arvin]

Nice plan buddy!Im actually running 2 motors on my emaxx tranny right now but I do have to disconnect the motor wires and reconnect it to the other motor(only have an mx3 for radio) I've notice that the motors are over heating too fast if both pinions are touching the spur gear. 1 motor is connected to a gd600(integy55turn)and the other is a havok 21turn. I'm guessing theres too much drag on the other motor. Taking off 1 of the pinions actually helped so If you have any more ideas lmk.

[SuperDave420]

Sweet ideas guys,

for my intial tests I will use 2 brushed motors, a Lathe and a racing modified.

if it works as good as I immagine it woud then I will move up the dollar scale and go brushless.

for now I am going to use a relay for the swithing as this will retain more of the normal feeling on the TX ( not that driving a truck with an airplane radio feels normal anyway...LOL)

I wuol dlove to get a non sensorless ESC for the wide range of 3 wire motors on the market, If I were to go with a Brushles smotor for the crawling mode alos I would want a sensored type purley for the low speed resolution.

"i think we have a full fledged rock racer with better slow speed control."

that is 100% my goal with this, here is a pic of my Rig soo far. no shocks on it in the pic. how about that BODY !!!. it's gonna be sweet.

[SuperDave420]

Originally Posted by Arvin

Nice plan buddy!Im actually running 2 motors on my emaxx tranny right now but I do have to disconnect the motor wires and reconnect it to the other motor(only have an mx3 for radio) I've notice that the motors are over heating too fast if both pinions are touching the spur gear. 1 motor is connected to a gd600(integy55turn)and the other is a havok 21turn. I'm guessing theres too much drag on the other motor. Taking off 1 of the pinions actually helped so If you have any more ideas lmk.

I think your GD600 is waaay too much drag for when your running your other motor. too much reduction there for keeping both motors geared to the spur.

one thing I though of doing at first but would be kind of scketchy was to have the motors pivot on 1 screw with a servo linked to the other mount screw, you just flip a switch and the servo drops the motor down onto the spur gear. this of course was gonna require some 160 Oz. servos and add a lot of weight.

that is how I worked my way into the relay switching method.

I figure the added weight of the relay I can offset with a smaller battery pack.