Medusa 36-50-3300 Vs. Ammo 36-50-3300
 

I've been thinking about building a nice brushless Maxx for a few months but had been waiting for the Monster Maxx(like everyone else).

About three weeks ago I decided to just get a new 3905 to play with stock till the new ESC hit the streets. Thinking I would need 2000w to get the performance of my Big block T I didn't figure the MM would handle the power I desired.

After reading a few posts of others planed setups I decided to give the MM a try with some small high KV motors I had on hand.

I started out with a Hacker C40-8L on 4s A123 with a 15t pinion. The motor and ESC ran happily with this setup and it had great accelleration but just couldn't pull enough gear(19T) to reach the speeds I was looking for.

I had the Ammo in my converted NMT so I figured what the heck, turn the shaft down and use the 1/8" pinions I had and let the testing continue:party:

I started out with the Ammo on 4s and the 15t pinion and it was a dog, popped in the 19t and top speed was ok but it wasn't very quick out of the corners. Switched to a 5s2pA123 pack with a 13t pinion and the motor started coming to life, but was running a bit hot. Tried out a 15t pinion and speed and torque were awesome but the motor was getting HOT(no heatsink yet) went back to the 13t for a run and the motor siezed up the front bearing, and got very HOT. Replaced the bearings with some I had on hand I think they are ultra seals?? Ran it again temps still went real high and I was thinking I might have de-magged the rotor when it siezed up. So I started looking for an afforable quality motor as a replacement. Found a few threads about the Medusa V2. Being familiar with Medusa from helis I decided to try one out.

In the mean time I picked up a heat sink for the Ammo and seem to have the temps under control now, maybe. Needs some more testing yet.

Any way some pics of the test rig.
http://i287.photobucket.com/albums/l...6/DSC05049.jpg
http://i287.photobucket.com/albums/l...6/DSC05053.jpg
http://i287.photobucket.com/albums/l...6/DSC05055.jpg

I had porblems with my temp sensor on the first run with the Medusa on 13t today but temps never went above 100f. Felt less powerful than the Ammo with the same gears

http://i287.photobucket.com/albums/l...005s2pA123.jpg

Fixed the temp sensor for the 14t run. Temps rose to 114f after I powered down the ET(I have an MIP onboard on it right now also to keep an eye on the temps)Power was at or a bit better than the Ammo on 13t now.

http://i287.photobucket.com/albums/l...005s2pA123.jpg

I have a few logs from the Ammo before I put on the heat sink and installed the cooling duct so I want to retest that motor once I find the limits on the Medusa.

The next run will be with a 14t pinion and a 65t spur, followed by 15/68, and possibly 15/65 if it's not building up to much heat. Future testing will log the temps on both the ESC and Motor also but wont have RPM

In the end I'm almost happy with the power I'm getting on the 14/68 gears, wouldn't mind just a touch more top speed, so it seems I only needed half the power I thought I would to be happy.

As to what it takes to make me happy as a basher I like enough torque to pull wheelies at 10-15mph and enough top speed to jump the two lane gravel road in front of my house. These two goals were met with the 14t pinion, I still want just a touch more:yes:

Stay tuned to see how the $35 Ammo($50 with the new bearings:no:) stacks up against the $110 Medusa.

BTW, I seem to remember reading that 4 pole motors should have about 15deg timing on the ESC, I'm running the default 10deg on the MM and have noticed a few quirks running the Medusa at low speeds, couple times it sttutered a bit and once it seemed to hit reverse then buzzed, I let off the trigger almost instantly and it drove away fine so I'm not sure what happened??

You may want to turn the start power up with the medusa, and disable the punch control. I usually leave the timing to normal, as higher timing seems to cause extra heat. It does make more power with higher timing, but I am not usually looking for more power! Just trying to smooth out the power from a standstill,

Graphs look good, thanks for the info. I have a 1500kv 60mm medusa coming, and plan to run it in my hyper8 buggy on 6s lipo.

Cool, Thanks for the tips. I also dont think I'll need any extra power from the timing advance.

I did a little rearranging and harvested a small fan from a laptop for the ESC, it was getting up to ~140 yesterday with ambiant temps in the low 60's, so I turned it 90deg heatsink forward from the pics in the first post(hard to see with all the wires) and if that isn't enough I'll hook up the fan. I'd like to see it about 60deg above ambiant. Got bored waiting for the sun to come up this morning, LOL.

Ok graphs with the 14/65 gears, I split up the data so the graphs aren't so messy.

http://i287.photobucket.com/albums/l...avoltsamps.jpg

Temp1 is the motor temp2 the ESC.
http://i287.photobucket.com/albums/l...temp1temp2.jpg
http://i287.photobucket.com/albums/l...sawattsmAH.jpg

I could probably push it harder yet, but ambiant was 43f when I made this run so I think this is the limit. Speed was decent up a little from the 68t spur, darn near cleared the down slope on the far side of the road, wheelies up to maybe 10-12mph. Stuttered on one start up. I'll turn up the start power and see if it helps. Then back to the Ammo for the heads up portion of this thread.

How do you like these titanium beadlocks?

Ok turning up the start power seems to have helped, Thanks much Linc!! Drove off the last half of the pack.

http://i287.photobucket.com/albums/l...sthalfpack.jpg

Next graphs will be with the Ammo on the same gears.

Serum, I just got them about a week ago but so far I like them enough to want another set for the T.

Ok here is a graph with the Ammo on the same 14/65 gear set, only other change was I went back to low start power on the ESC.

http://i287.photobucket.com/albums/l.../14-65Ammo.jpg

Even though the motor is running well outside its comfort zone it was putting down big power, at least 5mph faster than the Medusa, more torque, it's like it's a much higher KV motor. I'm going to gear down till it feels close to the same speed as the Medusa and see how the temps are.

You got them from DUH engineering?

Wow I'm down to an 11t pinion the Ammo is still as fast as the Medusa on 14/65 maybe even a touch faster, torque is better, lifts the front end much easier at higher speeds, but the temps dont want to drop. Maybe a drop in timing advance would help at this point??

http://i287.photobucket.com/albums/l.../Ammo11-68.jpg

Serum, Yes, They are from Duh

Pic of the distance I've been launching it today.

http://i287.photobucket.com/albums/l...w46/Bigair.jpg

The red line is the first point of contact

Interesting. So essentially, the Medusa is a far more efficient motor, while the ammo is just freakishly powerful but runs like a heat pump.

Hey Buzz, I compared the 56/1800 ammo to a feigao 15l (1600kv or so). They had similar performance, even though I had to use a larger pinion with the feigao to get the same top speed. I could not get the temps on the ammo to go down. I tried really low gearing, and even geared it up. Higher gearing just made it hotter. The feigao could pull higher gearing and did not get as hot. I got rid of the ammo and stuck with the feigao.

You may be able to gear the medusa up more, and see how it does. Being 4 pole it should have more torque.

I plan to test the medusa 60/1500 and an align 600l, hacker b50 15l, and the feigao 15l in a 1/8 buggy on 6s lipo. All are similar kv, and I will gear for the same top speed and use my eagletree to get some data.

Great tests BTW, very interesting info!

I concur that you should try gearing up the medusa motor as 4 pole motors like to have quite tall gearing.

I'm almost wondering if I didn't de-mag the rotor when that bearing seized. I know it wasn't this fast on the 13/68 gears the first few times I ran it. Oh well, at least it was cheap.

I dropped the timing advance to 5deg just to see what effect that has, if it dosen't help I'm just going to bin the Ammo.

Well dropping the timing did help with temps slightly the Ammo is still running way hot! 2.5 min of running and the temp peaked higher than the Medusa after 8 min of bashing around in warmer weather.

Done with the Ammo in this App. I have a small boat I might try it in with water cooling??

I'll try some steeper gears with the Medusa also, looking at the graphs I see very few points over 75 amps. I also want to try increasing the timing slightly with the Medusa, I found in the literature that came with my motor an 8-15 degree timing reccomendation.

I kind of like the punch the Ammo has, the Medusa seems to be smoother, easier to control the power. The punchyness keeps you on your toes becuase you never know for sure if it's gonna slip out from under itself, so somewhere in between the two would probably be my ideal.

I just spent the last few hours putting the Medusa back in and doing some quick runs in the yard just to see what kind of peaks I could pull on taller gear ratios. Started with a 15/68, pulled about 80amps. Went to a 15/62 and pulled 91a. I figured what the hey and tried 19/68 and pulled 106a and it still dosent have that kick the Ammo does.

I honestly dont need any more than I was getting with the 14/65 gears so I put it back to 15/68 and I want to run straight through a full pack, right down to the LVC to chrck for temp issues. If I can make it through a full pack with out temp issues I'll start tweaking the timing. Cold, windy, and snowing this morning:(

Water cooling will make a huge differenc in temps. I tried a sv27 6 pole motor in a few different vehicles, and it ran too hot with just air cooling. With water cooling, pushing the sv27 at 42mph it does not even get warm. Something about having a billion gallon radiator seems to drop temps!?

hi there everyone...
i had originally registered to this forum just to post a comment on lutach`s thread, but since i registered, i thought i could chime in and drop my 0.02... :)
since i am new to this forum, i am completely unaware of each individual`s tempos,ideas,likings and such... so in case anyone already knows the stuff being typed below [or disagrees with it], please don`t take it personally... :lol:

i think your ammo is partially demagnetized. 'higher than before' rpm [as you put it] and elevated temps [low efficiency along with quite high currents] is a clear,solid indication of this... so essentially, you can say it`s not a 3300kv anymore... a round speculation about the 'revised' kv rating wouldn`t be much difficult to guess/estimate either; if that`s a question troubling you that is... so let`s just say that this isn`t a sharp head-to-head comparison between those two motors... :wink:
try contacting tower; they might get you a replacement...

as medusa motors are 4pole motors, it is necessary that the timing is set above 10degrees... the slotted stator design makes it even more necessary... if i were you, i would be running a medium to high timing setting on the MM, and would definately avoid 'low' or 'lowest' settings... 15 degrees is a mediocre setting for a 4pole motor [unless if it is high-kv compared to it`s physical size], and typical settings for the particular genre of motors usually float between 15-20degrees; meaning that even the stock '10 degrees advance' of the MM is quite low for the particular motor...

btw, 3300kv is a bit high for the emaxx imo... that poor ammo would stand a chance if it was a 36-56-2700 or even better the 1800...
*ammo motors on the other hand are rather touchy with the timing... lowest timing on MM should be considered mandatory when running an ammo...

The ammo you're thinking of is a 2600, 36-56-2600. It's much better suited for an emaxx, but still has a tendency to get hot. Anything smaller in an ammo and it would not be enough. I've never ran the 36-50-3300, so I can't comment on it in particular, but I wouldn't have thought to try it either. I have been through 2 of the 56-2600 motors though. I liked them well enough. Not quite feigao, but very similar. I'd place the 36-56-2600 right alongside a 9L. About the same power, heat, and durability.

J.

Interesting input Kostaktinos. Valuable information for running these motors I would think. I'll keep all that in mind for when I get home to run my Medusa.:mdr:

i missed 100 points worth of rpm/v :lol:

That wasn't the point i was trying to make, really. I know you're familiar with the motor. Just wanted to make sure the OP was ;).

J.

i know what you meant man... :wink:
i am just teasing up things, to make the atmosphere 'lightweight' [familiar] to me... :lol:

LIGHT WEIGHT!!! LIGHT WEIGHT!!! WOOOO! (anyone know who Ronnie Coleman is? Hehehe! :mdr:)

yeah, i know 'ronnie' [not personally though :na:], and i also know that my english sometimes sucks big time :lol:

Yep that fact that the temps have gone up, speed has gone up, amp draw has gone up. I think it safe to assume I have demagged the rotor to some extent. So this thread will be more of a Medusa reveiw.

As to the timing setting the Medusa liturature says to run between 8-15 degrees advance.

The fact that so many are running ~1800Kv's led me to try the short can 3300's on lower gearing, basicly I traded motor toque for gear torque. These motors are really for a converted HPI NMT, I just wanted to try them out in my Maxx too see how they would perform.

Both motors blow the stock power system out of the water, unfortunatly the Ammo siezed a bearing and overheated, causing the demagnitization of it's rotor and ending the head to head portion of this thread.

Even before the Ammo was damaged it was running much hotter then the Medusa but did give better punch(could be timing related) and possibly slightly higher top speeds, hard to tell just by sight.

The Medusa is much smoother in it's power delivery, more predictable, and just easier to drive.

In the end this setup is only temporary till the MMM becomes available and I buy the motor I reallly want for the Maxx.

Why do you think the 3300Kv is too high for a Maxx? The Ammo is rated for up to 18.5v(61k RPM) The Medusa is rated at 60k RPM. I'm running them in the 45k range, I have an Aveox powered heli that only sees less then 41k spooling it up and when I shut it down after a flight.

The fact that no one would think to try a setup like this is as good a reason as any if you ask me. Ya sure I destroyed a $35 motor but who's to say the bearing wouldn't have siezed in the NMT causing the same damage? The Medusa is performing well at this point, will it continue too is what I want to find out now. No it's not a super high power rig that will run 60mph doing wheelies at 40mph, it will however do mid 30's with 10-12mph wheelies. I can easily jump the road in front of my house(my favorite big air jump). If this power setup continues to perform like this I might not even buy a differant motor but I do still want the MMM to allow for future performance increases.

well, based on my personal point of view and experience, motor bearings have a really hard time at such high rpms... it`s a matter of time for the bearing to bit the dust at either 50 or 60k rpm; unless if it`s top notch [but then again, we are talking about a 35$ motor here- the bearings can`t be top notch]. some years ago, i had to have a motor spinning at 70k, and what i came up with, is two bearings put into each other, so each was spinning roughly at 35k. there wasn`t any other way around it; single bearings failed no matter the brand. what i am trying to say is that you can`t really expect a motor of this cost to withstand 60k rpms... yes the ratings can tell otherwise, but it`s tough to happen in real life. 50k has eventually seized bearings in one of my feigaos [8l], so even 50k is too much imo -especially with cheap motors. the rotor might take it, and the bearings might take it, but for how long is the question...
aveox is a different story allright... and my plett maxx has gone up to 58k rpm, with no side-effects... i wouldn`t do it continiously even if the motor/bearings are top notch though... experimental reasons however, deserve some credit :)

from what i see from the graphs, it seems that you are running with 4s [correct me if i am wrong]. thats about 48-52k rpms... don`t get me wrong, i am not saying that it`s your fault that the bearing on the ammo failed; i am just saying that it`s to be expected [kinda un-avoidable] with a 35$ motor. could have been just a bad/deffective bearing however...
imo,it would probably have survived with a 3s lipo in the nmt, since the nmt is lighter than the emaxx and thus doesn`t require 4s to perform efficiently. at 3s, the rpms would be much more reasonable and safer. the same setup however, would be either underpowered [geared down] or inefficient [geared up] if used in the emaxx.
bearings failing is one reason not to choose high rpms... the other is efficiency, but that`s a long story to be discussed within a couple of lines...

i have a medusa 36-50-2200v2 and a 36-60-2000v2... you can safely gear up with the 50mm one that you have, although 3300kv shouldn`t need much gearing-up. assuming stock emaxx wheels/tires [or similar in weight and dimensions], i think you could run with the 15t without problems.
i currently run mine [36-50-2200v2] with a 22t pinion in my esavage, and i am quite happy [top speed is about 40mph, and everything runs quite cool]...
the same motor made my lgt [about 11,maybe 12lbs] on 5s lipo to pull wheelies all day [with a semi-locked 500k center diff]... :yes:

i hadn`t tried the 36-60-2000v2 till today [5s,lgt]... :surprised: and that`s all i am gonna say! :yes:

Very handy info. I just bought a 36-60-1500 to run on 6s in my hyper8 buggy. What is a lgt? some sort of truggy? Maybe a lightning truggy from hotbodies?

yes, its a lightning gt
http://www.hbeurope.com/kit.php?partNo=hb55007&lang=en

essentially a lightning truggy with large wheels,and without a center diff [i added one however to compensate for the luck of slipper clutch and tame down the wheelies since i electrified it :intello:].

Ok, one of those! That thing is badass! Can't belive the 60 motor moved that thing around, what was your gearing? And we need pics, forum requirement!

gearing was 12/50 with the medusa, and previously 13/50 with a kb45 8xl...
i use the stock mechanical brakes, and thus running the thing with an airplane 80amp esc with extra input caps and a small/old cpu heatsink :lol:
stock rims/tires, 7inch [178mm height roughly]...

i was running 14 nimh cells with the kb45 [too violent for any reasonable bashing with the 5s/flightpower_evo3700].

members at e-savage.com [i am one of the founding members there] hate me because i broke my camera last year and haven`t bought one since :lol:
i will be picking one by the end of this month hopefully, otherwise i see myself banned from both forums :lol:


those medusa motors seem to carry twice the torque and efficiency you would expect... :yes:
i just love 4 and 6 pole motors...

kostaktinos: Have you used the 50mm medusa motor in a 1/10 scale stadium truck or touring car at all? If you have, I'd like to hear what gearing you're able to get away with in a lighter application (1/10 Stadium vs. "1/10" Monster Truck).

nope...haven`t used any medusa in any other truck...
but you can rely on the neu-like specs of the medusa, and therefore gear up somewhat -contrasted to most 2pole motors...

Gotcha. Thanks.

Got my medusa 36/60/1500 today. Motor looks nicely made, and the windings look good too. Packaging and labels are a bit cheap, but that is the place to save a few bucks IMO! I do not care for the color, but I will try the motor in my hyper8. Performance is what I am looking for!

you got the v1 or the v2 version?

i think medusas are somewhat 'neu rip-offs'... the rotor is 4pole,segmented, and housed inside a carbon shell [instead of kevlar; i guess that saves some bucks,but it`s a lot better than nothing], and the stator is slotted [don`t recall if it`s 8 or 12 slots though -it`s been almost a month since i teared my 36-50-2200v2 apart to check the insides]. the construction seems solid, even though the motors are designed in usa but made in china i believe [that also helps keeping the costs down].

nonetheless, i think they are a good option for those average bashers out there, who [at most cases] are between a cheap feigao [or ammos and similar -disposable- motors] and an expensive neu [or lehner].
now what we want, is 70-75mm medusas for our heavy trucks :yes:

A longer can usually means more torque right?

Yup, usually. More poles also equates to more torque, usually.

kostaktinos_mt, Thanks for the quick education on the in's and out's of surface brushless systems. You gave me some good info to consider. It certainly makes sence that the bearings will have much more dirt and crud to deal with in a truck than in my helis, and planes. Unfortunatly I'm having a hard time accepting this. I basicly need to throw all my ingrained experiance from aircraft out the door and accept what you guys have learned through trial and error.

But as an experiment I think this was worth the time, just from the respect that I now know I dont need 2000+watts to match the performance of my FLM EXT Big block T. Since nothing has been purchased specificly for the E-maxx yet I learned a cheap lesson with the Ammo!!

Weather has been cold and wet all week so I haven't had a chance to drive since Sunday night. But I have been thinking hard. With trying to keep the motor RPM's down around 30k, how do outrunner motors do in surface vehicles?? I know most larger helis(See I cant let it go) use outrunners because they tend to produce the best power at around 30k which lets the heli guys run a larger pinion with more teeth contacting the main gear, it's very rare in helis to see inrunners geared for less than high 30k rpm's.

http://www.innov8tivedesigns.com/ind...cPath=21_25_65 I'm thinking the 1400kv on 8s A123 or the 1900kv on 6s A123.

I could also drop to a 4s A123 pack with the Medusa to get the RPM below 40k, I think the drop in available watts would be too much though, unless the medusa can stand 110+a bursts. I did plan to try it on 4s and still will, 19t/65t combo looks decent for top speeds

I believe Medusa was up and running before Neu, so the V1's were probably more Aveox copies, the V2's could be influanced by the Neu design. Since Neu took over the Aveox model motors it makes sence that all these motors would resemble each other.

I agree with the 70-75mm Medusa, I had almost discounted them because of their lack of size. When I siezed the bearing in the Ammo I ordered the Medusa as a replacement before I even checked the Ammo out to see what happened, figured the rotor let loose.

Would the 35-60-2000V2-5 be a good replacement for a Feigao 8XL? Running 5S in a LST2 with Hydra 120.

This motor is similiar in size and KV to the Feigao 12L but it is double the max amps.

Looking at nothing but the specs I would suspect the Medusa to be better than either of the Feigaos, lower resistance and no load draw. Weather it can comfortably replace an XL motor is not known for sure. It's a bit smaller than a Neu 1512 but longer than a 1509, from what I've seen the 1515 and 1521 seem to be the Neu's to have in big heavy trucks.

The 36-50-3300 is doing well in my light(stock) Emaxx, not crazy powerful but enough to make it more fun than the titans.

The weather here this week was a washout so I haven't been able to get any more run time all week, tomarrow looks nice, finally, haven't seen the sun in a week!

buzzsaw,
sorry for the delayed response, i was kinda busy the past two days.
i agree, cars and aircraft have quite some differences in both theory and real-world.

besides dirt, bearings in cars [not just motor bearings; all bearings] suffer severe mechanical shocks. for example when landing after a jump, hub bearings [those that support the wheels] take a serious hit; and if the quality and size aren`t up to par [weight of the vehicle], they fail. for example, if you do a quick search on the old traxxas stampede you will find that people were killing 5x8 bearings in no time, and then replaced the stock carriers in favor of aftermarket ones that could hold larger bearings. same applies [in a lesser extend] to all car bearings, even motor ones and transmission bearings too. when a truck lands after a jump, the wheels stall momentarily, thus causing a massive mechanical shock/wave beating from the wheels to the motor. if this shock isn`t absorbed [slipper clutch], something will break throughout the chain. if there is nothing to bend [tranny or diff case] or break [axles,cvds,shafts,diffs,gears], then the bearings take the impact; usually leading to grindy bearings that spit a tone of heat once they see high rpm again.
some years ago, we were beefing up our emaxxes to handle bl power, and i remember that everytime something was 'steel-ed',something else failed. first it was universals, so we used steel cvds, then it was the stock diffs so we used RR ones, then it was tranny gears, so we used steel gears, then it was the tranny case, so we came up with alloy ones, and then the motor shafts started breaking [feigao 's' and aveox was popular back then], so we used 5mm shafts, and then finally, rims were getting cracked. all these problems went away when the slipper clutch was upgraded and carefully tuned.
so i have come to believe that there isn`t a thing such as 'bulletproof drivetrain'. ultimately, the heavier a vehicle is and the higher the power that 'feeds' it, the higher the necessity of a slipper clutch is.
finishing my thoughts about this matter, i recall some hardcore rock-crawling guys running their trucks with bushings instead of bearings. reason is, that bearings break under the massive torque being produced between counter shafts and counter gears in the transmission, whereas bushings survive this effect without serious efficiency losses [since it`s low rpm, bushings vs bearings doesn`t make any considerable difference,nor efficiency is a primary goal of rock-crawling].


outrunners do well in cars and trucks, and some people are running their vehicles with the 'no center tranny, but an outrunner' concept. it works well, but removes the slipper clutch [which is bad imo].
outrunner + tranny also works well, but mostly for rock-crawling it is being used [where torque is half the world].
another aspect that i am sure many will debate and argue, is that most [not all] outrunners don`t easily put their efficiency above the 90% mark... which is already a reality for good inrunners [eg: plettenberg,neu]. that said, i personally still like outrunners at some applications, but i won`t agree in blind with the 'outrunner is always better than inrunner' idea.


i think your current medusa on 4s [lipo] should do fine [with proper gearing; i would personally start with a 16t and stock spur], although a 36-60-2000v2 on 5s would be perfect in terms of efficiency,reliability, and performance potential. 6s and 36-60-1500v2 would be close to 'as good as it can be'.


as for the feigao 8xl vs 36-60-2000v2:
i had a kb45 8xl [1700kv] in my lgt, and i am seeing similar performance [and temps] between the kb45/14cells nimh and the 36-60-2000v2 on 5s lipo. so i think the feigao 8xl is close to the 36-60-2000v2 [performance wise], but still not as efficient.

in a heavy lst2 conversion, i think the medusa still has the upper hand when compared with the feigao, but still it`s quite small to run ideally; and thus a kb45 would be a better fit in that application. hence my comment about a 75mm long medusa...:yes: