Experience Wanted Only Please. Bashing...

[Jahay]

Hi everyone, i have been waiting to be activated for 3 days! But in those 3 days i have been reading as many posts as possible to get an idea of what people like to use when racing and when bashing.

I always originally thought that racers would like a high KV motor on less cells... But this is obviously not the case. People with their truggys and buggys are running crazy low kV motors in their lightweight racers! I thought these motors would have only been used on much heavier applications...???

Anyway, i am an EX nitro user and have seen the light with my Brushless Savage Flux.
Just a quick pic as this is not a build up thread.


Running Stock Torq2200kv motor 20/44 gearing only on 6s.
Desertboy17 chassis XXL

Anyway... i stupidly let my friend have a go considering i want some company when running this thing... So first thing he does is a WOT Run, and IMMEDIATELY hits the only lamp post in the car park! The damage is below:



So this is obviously why im here... Im trying to get advice from experienced users as to what motor i should be looking for. Obviously the motor i run depends on what i am looking for from the truck.

I only bash and only run on 5-6s.
weighing 13lbs fully loaded
maintain my 60mph top speeds but still having crazy low end torque on demand.

Now... i was very happy with my stock torq2200 but i was worried about trying any gearing as i didnt want it to over heat... I will be running a 39t High Speed Idler, keeping my stock 44Spur and flexible on the pinion.

I know its better to gear a lower kV motor higher than gear a higher kV motor Lower... So I ask you this... What is the ideal motor for my uses and what can i use with my stock mounts? or are there any after market mounts out there (i havent seen any, maybe i could utilise the buggy and truggy mounts)?

I was looking at the following Neu Motors
Neu-Castle 1518 1Y 1800kv motor
Neu-Castle 1520 1Y 1600kv motor

If i go for a too lower kV motor, wouldnt i have to gear extremely high to reach my desired speeds?

I forgot to mention that i would be running this with my Stock MMM than i was using with my torq2200.

Hope thats all the info you need? I want to get this up and running asap!!!

[thzero]

None of the Neu-Castle motors will work with the stock mounts without modifing the stock mount.

Check out Brian-G's scriptasylum.com to run through the numbers and see what you get.

Dropping from a 2200 to a 1800kV on 5S (44/25 to get ~60mph) using the same 44t spur equates to 32t pinion using the standard Flux gearbox.

If you are running different gears in the gearbox, you'll need to figure out your transmission gear ratio to use.

[Jahay]

I dont mind grinding down the stock mount a couple of mm to get the motor to fit...

How accurate is that speed calc? what do people usually punch in for how many inches does your tire balloon? I have Strapped HPI Dirt Claws with proline inserts. Maybe 1"?

What is more important for me is... Can i run this sort of gearing 44/25 with the 1800kv motor and not worry about temp issues and drawing too many amps from the ESC?

"using the same 44t spur equates to 32t pinion using the standard Flux gearbox. "

Im sorry i dont understand what you are saying? forgive my ignorance when it comes to gearing.
Yes i am currently running a standard flux gearbox... but i am hoping to replace the highspeed idler gear. I will quickly try and work out my new ratio... But how would i input the new ratio into the speed calc?

Also where do they stock the 1518 and what are peoples views on it as a motor to bash and do a few high speed runs? Should my temps be ok with this high gearing?

[thzero]

The speed calc does simple equations, so its only approx. It doesn't do anything with weight, aero, loses due to friction, etc.

Probably .5". I haven't been using much as my strapped ProLine Badlands (gorrilla tape) seem to not balloon hardly at all.

What I meant was that if you setup a standard Flux with 5S, 2200kv motor, 44t spur, wheels (I used Dirt Bonz), 0" balloon and 25t pinion you get just ~60mph. If you swap out the 2200kv for say a 1800kv motor, you'd need a 32t pinion (which I'm not sure they make) to get the same ~60mph.

As far as new gearbox ratio, you'd just enter it manually.

Well tower has them, but not til middle of the month... http://www3.towerhobbies.com/cgi-bin...?&I=LXZGP9&P=7

[bruce750i]

The 1518-1520 should fit your bigger application better than the 1515(2200) and that should keep the MMM happy. Just finding the gearing to do 60, If the High Speed Idler has 39t. How many teeth does or did the low speed idler have?

[Jahay]

THanks for the responses... i see what you are saying now.

I used the speed calc, and these are my results.

Differential Ratio: 3.3076923076923075
Transmission Ratio: 2.215277777777778
Other Ratio: 1
Spur Tooth Count: 44
Pinion Tooth Count: 25
Total Voltage: 22.2
Motor KV: 1800
Tire Diameter (inches): 5.91
Tire Ballooning (inches): 0.5
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 1.76 : 1
Total Ratio: 12.89632 : 1
Tire Circumference (inches): 21.71 inches (551.39 mm)
Rollout: 1.68:1
Total Motor Speed: 39960 RPM
Vehicle Speed: 63.7 mph (102.32 km/h)
Effective KV Value: 1800
KT constant: 0.75 oz-in/A

As you can see on a 6s running 44/25 and accounting for tire ballooning at 0.5" i can hit 63mph supposedly... This setup doesnt include the 39t Idler which would probably give me up to 10mph more. Does this sound correct?

[redshift]

Any sentence that begins with "I let my friend" can't end well...

Funny how they never seem to pay for damage incurred either

Welcome to the only forum that matters!

[Semi Pro]

Originally Posted by Jahay

THanks for the responses... i see what you are saying now.

I used the speed calc, and these are my results.

Differential Ratio: 3.3076923076923075
Transmission Ratio: 2.215277777777778
Other Ratio: 1
Spur Tooth Count: 44
Pinion Tooth Count: 25
Total Voltage: 22.2
Motor KV: 1800
Tire Diameter (inches): 5.91
Tire Ballooning (inches): 0.5
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 1.76 : 1
Total Ratio: 12.89632 : 1
Tire Circumference (inches): 21.71 inches (551.39 mm)
Rollout: 1.68:1
Total Motor Speed: 39960 RPM
Vehicle Speed: 63.7 mph (102.32 km/h)
Effective KV Value: 1800
KT constant: 0.75 oz-in/A

As you can see on a 6s running 44/25 and accounting for tire ballooning at 0.5" i can hit 63mph supposedly... This setup doesnt include the 39t Idler which would probably give me up to 10mph more. Does this sound correct?

looks right, i can tell you this, if you want to be doing of 60mph you need to find a lighter vehicle, it puts alot of strain on your truck always being geared for 60+

if i were you i would gear it for around 45, thats still very fast for off road and when you get the speed bug then drop in the big pinion and let it rip onroad

[suicideneil]

60mph with a 13lb truck, thats either extreme bravery or reckless abandon

I like 40mph as a top speed in my 13lb truck on 5s lipo, using a medusa 36-80-2000kv motor, roughly equal in power to the castleneu 1515 1y. 60mph is just a bit too fast for my liking in a truck that size, and using a lower kv motor means having to gear rather high to maintain that high speed. 12:1 overall reduction ratio is more like you'd see in a lightweight 1/8 buggy rather than a heavyweight MT.

I think something like a the 1518 if you can get it to fit would be more suited, but only with a max speed of about 45-50mph; the extra torque from the longer rotor combined with 6s lipo would make some serious power without overheating too quickly, but I reckon you'll still have to watch your temps closely.

Dont let your 'friend' drive it again though, get him to buy a cheap 1/8 buggy or truggy which has cheap spares available locally or on t'internet.. If he breaks his own truck, he can pay to fix it- people rarely care about treating someone else's vehicle carefully, especially if they dont think they'll have to pay for any damage they cause; I know that from experience.

Castle should be able to replace your motor for you, though it may be out of warrenty due to the nature of the crash; remind your friend of the cost if you decide to get it replaced...

[Jahay]

Very true redshift! BUT he will be reimbursing me for this motor! I had only run this motor 3 times before he broke it.

Suicide neil... this is a savage... its all about being reckless!

Considering the stock flux can do 60mph with a torq2200 on 44/25 gearing... I dont see why these larger motors wouldnt be up to the task?#

I am not going to be running or pushing the truck to these speeds all the time... Its more of a "Hey watch my truck do 60mph" sort of thing. I am just trying to find a motor which could potentially run at these speeds comfortably... If the 2200 can do it, i am sure this def can with a tiny bit of gearing.

I would probably run the stock gearing 44/20 when bashing and when i decide to run on asphalt (which is not often) i will just drop in the 25T pinion.

Ive been speaking to mike from this site... and he says that for my needs, the 1518 should easily handle what i am asking for... So i think 1518 it is!!! Just need to find one and get some extra gearing options...

[maneba]

Originally Posted by Jahay

I only bash and only run on 5-6s.
weighing 13lbs fully loaded
maintain my 60mph top speeds but still having crazy low end torque on demand.

In my opinion 60 mph is not bashing. If you want to go so fast you have to prepare your truck with an adequate setup.
60 mph and crazy low end torque is an oxymoron.

[Jahay]

i have just bought a 25t pinion for my high speed asphalt runs... 21 pinion for grass bashing and an 18 pinion for jumps.

I just want to make sure this motor can handle the variety of gearing i throw at it...

[suicideneil]

If you read the official blurb on the HPI website, you'll notice that they say the 60mph gearing with 6s lipo is for use onroad only, with suitable tyres ( HPI Phaltlines ). Offroading on grass or over uneven terrain, dirt or gravel etc places a high load on the electronics which results in overheated and toasted escs. Onroad speed runs are just high speed passes, you can limit yourself to how many you do and take a cooling down break inbetween as needed; bashing offroad tends to be a continual/ non-stop run that doesnt end until the LVC kicks in- by then it could be too late if you dont stop to monitor temps during.

Once you max out the throttle at 40mph in a truck this size it feels and looks alot faster- you'd need an airport to reach max throttle at 60mph on 6s lipo without the front end taking off.

Its fun to experiment, and fun to go fast, but you have to be a bit more savy ( no pun intended ) and realistic about what possible and whats too much for the truck to handle