OutRunner brushless motors?

[WRXronald]

yep

I'd watch out for the 2.3mm shaft. They're fine for aircraft, but aircraft don't get their tires wedged in rocks ;-)

exactly my thought. minute that tire is wedged and you tell that motor to BUST out the power... its going to snap a small shaft like that on short order. thus the 'hardened steel 3.17mm shaft's' of the AXIs.

and from what i've read. the only difference of the Silvers to the Golds is that the Silvers are approx 2% less efficient. so all other variables being equal--- theoretically you can get the same power, but the run time will be 2% less.

that's good to hear about the torquey part-- that's what we need! :mrgreen:

and for the gearing--- i'll be considerably lower than my current setup so that will help as well. 300+ kv lower, and 3teeth lower in pinion size. NICE!!!


the real problem that i have with the MP JET is not that it stalls AT ALL at its current gearing--- but i get to a point where the tire will be hung up on something, and i'll have to gun the throttle a bit to get it to break free--- and it always does (or it strips the plastic spur gear right to shreads first :roll: ). but once it breaks free i have this rig that just wants to SHOOT OFF out of control and it instantly gains alot of wheel speed. as you can guess-- this nature of the setup really SUCKS on the rocks. especially the daunting terrain at Nelson's Ledges. i need UTMOST precision and slowness at certain points--- or the truck will go plummeting to its death :shock: . i don't seem to have so much probs with the Clod cuz its SO slow it easier to control in these 'sticky' situations. if i can get the PTI slow like this--- i think i can crawl much more effectively on the 2.2 level.

so anyways thanks for the advice, i went ahead with the order for the AXI 2212/34 (690 Kv ) and a 10t / .5 modules pinion. Reports just as soon as i recieve it and get it on the rocks!

anyone interested in my MP JET outrunner? HUGE torque! 5mm shaft though. sell it pretty cheap-- it only cost $58 in the first place.

 

[JohnRobHolmes]

My only concern with using a low kv outrunner is follows- Just like any motor it will like to be run at a certain wattage. It is wound slower for 3-4 cell lipo use. If you use it on 2 cells the performance will be less than impressive, and it is possible that it would suck. The amp draw wont be there for power, and the voltage wouldnt be there either. I have run into this problem with inrunners many times. If you undervolt them to try and slow down the rig, you get sucky power too. It is always best in my experience to get your motor and battery voltage mached up first, and then adjust gearing for speed. It sounds like you need a smidge more reduction Ronald. A 3.2mm shaft would allow you better reduction, but I dont know if it will be as much as you are wanting.

How fast would you say the PTI goes right now? I know how frustrating it can be to have the wheelspeed bite you in the *** and send you flying off a rock.

 

[WRXronald]

hmmm

My only concern with using a low kv outrunner is follows- Just like any motor it will like to be run at a certain wattage. It is wound slower for 3-4 cell lipo use. If you use it on 2 cells the performance will be less than impressive, and it is possible that it would suck. The amp draw wont be there for power, and the voltage wouldnt be there either. I have run into this problem with inrunners many times. If you undervolt them to try and slow down the rig, you get sucky power too. It is always best in my experience to get your motor and battery voltage mached up first, and then adjust gearing for speed. It sounds like you need a smidge more reduction Ronald. A 3.2mm shaft would allow you better reduction, but I dont know if it will be as much as you are wanting.

How fast would you say the PTI goes right now? I know how frustrating it can be to have the wheelspeed bite you in the *** and send you flying off a rock.

well that's actually good news for me... i run the PTI on 3 cell right now. so if 3 cell is what it takes to make the motor power up acceptably--- i'm spot on. i've tried 2 cell in the rig to slow it down a bit--- still has plenty of climbing and crawling power, and is of course somewhat slower--- but just not enough slower. you could be correct--- maybe i just need to gear down with a smaller shaft but stick to the 1000kv spot--- it would still be a 3 tooth drop with a 10t pinion on a 3.17mm shaft.

i would say it goes almost double the top speed of a clod with 55 lathes and 8t pinions. 5 maybe 7mph, tops?

maybe i'm approaching this the wrong way? perhaps i have a slow enough rig-- once its moving it WILL crawl at a snails pace. its just that when i'm stuck or have a tire locked up in a rock--- sometimes i have to punch it TOO much to get the motor turning over-- and then i have that truck that jumps out of hand. i thought if i gear it down and further reduce RPM/Volt.... punching it will give the tire more torque, and less speed-- and would therefore require less of a punch to get unlocked--- AND when it comes unlocked maybe it will also not have so much energy built up to 'take off' like it has been doing. the Clod with Lathes definately does not 'JUMP' once breaking free like the PTI does. but of course it doesn't really seem to have as much 'tire' breaking power that the PTI does. i figure if i can get the PTI as slow as the CLOD--- it will be much more controllable.

well all i can do is try out different setups and go with whatever works best. i'll try the AXI... and JRB i'll gladly take you on the offer you sent me in PM. i'd like to try out one of your new motors as well. ;-)

thanks all

 

[JohnRobHolmes]

One of the issues you are dealing with is the shafty loading. The drivetrain will store and hold a good amount of torque, and when the tires break free it unloads all at once (mostly through the rear tires if you are climbing).

I think you are on the right track. We will get you another motor, a smaller pinion, and run the sucker on 2 cell lipo. I bet that would get you the speed you want.

7mph is pretty fast for a crawler. I like the extra speed sometimes, but that could really be a problem on steep stuff.

 

[WRXronald]

yep

One of the issues you are dealing with is the shafty loading. The drivetrain will store and hold a good amount of torque, and when the tires break free it unloads all at once (mostly through the rear tires if you are climbing).

I think you are on the right track. We will get you another motor, a smaller pinion, and run the sucker on 2 cell lipo. I bet that would get you the speed you want.

7mph is pretty fast for a crawler. I like the extra speed sometimes, but that could really be a problem on steep stuff.

agree completely... just too fast for what i'm trying to be doing.

like i say i'll try the AXI and i'll try one of yours--- whichever works best and i'm all set. HOPEFULLY the AXI works well and then i can pick up a 2nd one of yours and turn my clod into a brushless setup as well. :lol:


i see what you're saying about loading up--- its like a little spring... when all that tension lets loose the truck jus unloads and 'shoots' forward obnoxiously. and its amplified by the motor engaging with TOO much rpm instantly after it springs loose... thus totally loosing control. i may not be able to do much for the spring-loading... but i think gearing down in some fashion or another is gonna make significant difference.

 

[James Luce]

thois is a long thread

 

[WRXronald]

now its one post longer....

the AXI is in.... it goes REAL slow now. and i like that alot. but seems like the AXI might just be a bit small for my taste..... has a tendency to stall out a bit.... and its no problem to pump up the throttle and keep it going though... and the great part is pumping up the throttle on this gearing does not send the rig flying when it breaks free--- which is nice.

however--- this may be more a function of my speed controller JAZZ.... but if i'm climbing a long steep rockhill...... and it stalls--- the rig will just roll back down the hill backwards.... ie i don't get any breaking unless i apply accordingly..... so if i want to climb a hill--- i have to fully dedicate to it and climb non-stop. which kinda sucks.... .

the NOVAK in my rockbull does not work like that. you can stop on a steep incline and no probs.

but with the JAZZ and the smaller outrunner.... if i don't keep heavy into the throttle and the motor stalls... its coming all the way back down (sometimes fast if its a steep climb) and i gotta start all over). bummer :|


i think i'll be happier with JRB's brushless once i get it... its a 28 and will have more power.... it will be geared a bit higher of course (680kv vs 1000kv)..... but should be no matter---- with a 10t pinion it will still be slow enough and with the extra power i don't see it being so willing to stall at lower throttle points--- which is what i need.

i may try 2 AXI's (hobby lobby accidentally sent me 2 of them) in a 2.2 scale clod rubicon-tuber i'm about to be working on. that could be REAL cool. a brushless Clod.... haven't seen too many brushless clods around ;-)


the idea is that the rig won't weigh much more than my PTI and will have 2 AXI's pushin' it instead of one--- and it will be with clod axles and 8t's and 3cell lipos. that should do the trick for power i hope.

 

[JohnRobHolmes]

And one more post to the gargantuan

I have experienced the "stall roll" a few times myself, but it is nowhere near as bad as what you describe. If I let the rig stop on a steep incline and the drag brake cant keep up, sometimes it keeps rolling backwards until i pump the throttle just right and the ESC catches back up. It is no biggie to keep on the throttle for me, and I imagine the 28mm outrunners exibit the stall less than the small guys. I would say it is a function of programming, because the motors are not weak by any means.

JRH

 

[Trac95ker]

I don't have any experience with the smaller brushless motors but I've been running the Novak 5800 for over two years and love it. I have mine hooked to 2 GD 600's. That gives it some drag which works very well. Also it's so powerful I so I needed to run the 2 GD's so it wouldn't strip gears so easily. It revs high so you can really play with the gearing and get it where you want. If it is geared to high it will cog when you are barely on the throttle. If its geared right you should have tons of power and top speed for those wheel spinning situations. Throttle application will be real smooth through the whole range. The main issue is that when flipping over you can't put it in reverse instantly, it pauses for a second and on a downhill it wont go into reverse if the truck is rolling. With the drag the GD's provide its usually not a problem. You could dial in some brake. That would solve the issue. The brakes are great, no problems there. It has to much power. I turned Kongs with 3 lbs. of bbs no problem. I had to gear it higher because it would snap axles. Hope this is useful.

 

[K_B]

Anybody got any tips for reversing the shaft on these suckers? I've got a Park 370 and the shaft currently exits out the rotating end. I need it to exit out the stationary end, of course. So I removed the retaining clip and the little setscrew but the shaft will not budge...

Any tips?

 

[JohnRobHolmes]

a center punch and a hammer will do it. They can be hard to get out.

 

[K_B]

Yeah... I was afraid to really tug on it. Just about gave myself an aneurism pulling the thing out...

 

[K_B]

Well, I managed to shoehorn te 370 into my VMG. Even with a 12 tooth pinion, poor gear mesh and a driveline that's binding somwhere, I can notice a huge improvement over the stock motor. I was really surprised at how little it cogs with the bound up driveline. It might still have too much wheelspeed, but it's still slower than the stock motor with the 10 tooth pinion. And I was running it on 6 2/3a cells. I can't wait to get the bugs worked out.

 

[JohnRobHolmes]

In a vmg?? Thats pretty cool! What did you do about the pinion? That is one overpowered rig!

 

[WRXronald]

...

I have experienced the "stall roll" a few times myself, but it is nowhere near as bad as what you describe. If I let the rig stop on a steep incline and the drag brake cant keep up, sometimes it keeps rolling backwards until i pump the throttle just right and the ESC catches back up. It is no biggie to keep on the throttle for me, and I imagine the 28mm outrunners exibit the stall less than the small guys. I would say it is a function of programming, because the motors are not weak by any means.

JRH

Yep.. it pure ESC programming... nothing to do with power... although i will comment the breaking power of the Axi is not sufficient to FULL STOP the rig on steep inclines... and that is only part of the prob. if i could FULL STOP her... then i could get back to a fwd or rev drive option..... but w/out full stop and then back to neutral for 1 full second, then i can't engage a reverse (if previous moving forward).

its confusing.... the more powerful motor should better stop the rig i hope on the incline.... at least allowing me a moment or two to gather my 'finger's' and continue my driving in whatever direction is necessary.

 

[K_B]

In a vmg?? Thats pretty cool! What did you do about the pinion? That is one overpowered rig!

I just used a 12t pinion from my GD-600. And it even cleared the gear cover. The problem I have now is the Mamba's programming is messed up. It just sits there and cogs in reverse and when I let off the gas, the thing stops so abrubtly that the back end wants to flip over the front end. I think I can attribute that to the brake and the binding in the drivetrain.

I originally had a 400 but I figured I was gonna have fitment problems and it was probably gonna be more juice than I could use. Although I don't really see alot of difference between the 370 and the 400 size wise. And the 400 was 200Kv less...

 

[microgoat]

I'll be using a Park 400 920KV in the 3-speed 2.2 build. It should have a good combination of spped and torque, and the 3-speed will give me plenty of reduction. And since the motor will sit up so high, the lightweight outrunner will be perfect.

 

[EGRESSor]

Yep.. it pure ESC programming... nothing to do with power... although i will comment the breaking power of the Axi is not sufficient to FULL STOP the rig on steep inclines... and that is only part of the prob. if i could FULL STOP her... then i could get back to a fwd or rev drive option..... but w/out full stop and then back to neutral for 1 full second, then i can't engage a reverse (if previous moving forward).

its confusing.... the more powerful motor should better stop the rig i hope on the incline.... at least allowing me a moment or two to gather my 'finger's' and continue my driving in whatever direction is necessary.

thats the "free wheel" function of the JAZZ ;-)

i like the drag brake of my QUARK 33pro car esc
and the bec works fine with 94358 in front and 94161 rear

 

[WRXronald]

....

thats the "free wheel" function of the JAZZ ;-)

i like the drag brake of my QUARK 33pro car esc
and the bec works fine with 94358 in front and 94161 rear

where'd you find the quark car at? how much? i've seen a quark 33 for r/c electric helicopters... is it the same for ESC used for car/truck? fwd/rev and breaking and acceptable software to run a car application?

fairly affordable too if i remember correctly?

 

[EGRESSor]

i´ve got it from Japan $80 shipped

not sure if Hacker sells the esc only http://www.hackerbrushless.com/motors_e30.shtml

http://www.sky-technology.net/home.htm you can download the manuel