********* 9XL test

[mbeatle]

I got my 9XL today and hooked it up to the MMM. As there is no flat spot on the motor, I had to grind one myself. With the the RC-Monster heatsink clamp, I am not able to position the pinion onto the motor such that it will make full contact with the spur. The flat side of the pinion is towards the front of the truck. If I flip it around, the grub screw does not make contact with the shaft. Without the heatsink I don't think this would be an issue.

I have it geared 24/56 right now and I ran through my *****-K 3000 2s packs without any major damage. I did flip it backwards and had it slide down my street for 30 feet, grinding a hole in the roof, however. I also lost two body clips in the rear. Other than that the truck held the power well... oh the power.

It was difficult to use full throttle with the truck now. Even in the grass, where I did most of my running, it was blisteringly fast. Wheelies are a quick pull of the trigger at all but the fastest speeds. Without a good safe place to run, I was unable to top it out. You people running 40-50 mph are nuts. I'll have to add some punch control as it's currently zero. Start power is medium, timing is normal.

Temps were a mixed bag. ESC was 120, batteries were 125, motor was 205! The heatsink is not doing a very good job, as it was 75. I spread a very thin layer of thermal grease onto the motor and heatsink, but I may have used too much. I'll wipe off even more and see if I can get it to make better contact. At this point the heatsink is acting as an insulator.

Overall I'm very pleased with the truck, and that's just with a pair of 3000 mah 20C packs! The 4300 20Cs are up later.

[asheck]

Boy thats geared pretty high imo.That could be why your batts and motor were so hot.But good to hear that motor will do a descent job.

[Garbage_Man]

That's only about 15f degrees headway on your batteries.

[kulangflow]

I agree with asheck on the gearing. I have my Feigao 9XL geared at 24/62 right now and it seems to be great gearing for it.

Try lower gearing and let us know how the temps react to it.

Thanks for testing, btw!

[stumblin]

Not so sure about the gearing.. usually if the motor is hot and everything else is cool the gearing is too low. You need to gear up as in a bigger pinion or a smaller spur (54t jato spur is available). The temps should be equally hot, or at least close.. I'm thinking that is pretty darn cool for an esc. Again having run a 8XL on 24/58 I'd have to say it makes sense that it would be undergeared a touch with your 24/56 on a 9xl. Make sure you have a few air vents in your body as well to help with some fresh air flow How were the battery temps? anyway... Enjoy it!!

[brushlessman]

so you got it hooked up, they are insane! i love my 9xl! and put a fan on that heatsink

[asheck]

His battery was hot ,too though,and he's running a mmm.I'm not sure that you could really heat up that esc with that motor.

[stumblin]

His battery was hot ,too though,and he's running a mmm.I'm not sure that you could really heat up that esc with that motor.

Ya that is up there but expected on those batteries... with the active cooling on the MMM it does throw a wrench into that though as everything is not being cooled equally. With that taken into consideration.. maybe he should try the 62 or 68 and see what impact he gets, maybe it will be the right way to go in this case.

[mbeatle]

A fan on the heatsink won't do any good if it's not getting hot. I need better contact with the motor. It's difficult to see whether it's making good contact or not. If it's making contact without the grease (as it should, good fit) then I may have too much grease. Grease is better than air, but not better than metal to metal contact. If it's a poor fitting heatsink, I'll need to load up with grease so that I have SOME kind of contact, or I'll ditch the heatsink altogether.

I may install a NACA duct ahead of the motor if temps just won't settle down.

[mbeatle]

Stock 68 tooth spur would not fit, at least the way I had it mounted originally. The low CG mount did not work with the big shaft and pinion - the grub screw would hit the mount every time. The high CG mount puts the shaft directly in the center so there is room. If the motor had a longer shaft or I remove the heatsink, I'd be able to flip the pinion around and use the low CG mount.

[Suicideneil]

I was getting 160-180*f with similar gearing- I dont think these motors are terribly efficient </massive understatement> regardless of having the heatsink or not to aid cooling. I was suprised by the speed on just 4s lipo though with 58/24 & 62/24. 5s lipo was nuts, but certainly fun. I think I may have to stop recommending the 8XL to people, and suggest the 9XL instead in future....

[larrydino]

. You people running 40-50 mph are nuts. .

yep...nuts is correct...

[mbeatle]

I'm fiddling with the heatsink and thermal grease. I have the motor cleaned off and I'm applying different amounts of grease to the heatsink to see how much I need before they're actually mated together. As it turns out, you need gobs of the stuff before they are actually touching. That's just poor. The heatsink will act as a big aluminum sleeve, trapping hot air against the motor and not allowing it to dissipate. Thermal grease shouldn't be used to mate dissimilar surfaces, just to fill in microscopic pores in the metal. Has anyone else noticed a difference in motor temps when they added the RC-Monster heatsink? The clamp is nice, but my $1 tube of red loctite may serve a better purpose. I'll try running the truck again tomorrow without the heatsink and see if temps improve. I'll also send RC-Monster an email asking about mating the surfaces.

[nitrostarter]

I saw a 15-20 degree drop when I added the heatsink to my 7xl. It fits nice and snuggly on there!! The clamp is an added bonus.

[mbeatle]

Another bonus I forgot to mention earlier. The 9XL, even with the RCM heatsink and 24t RCM pinion on it, weighs approx 70g LESS than the stock titans w/their 19t pinions. Sweet!

Late last night I was able to mount the 9XL in the low CG position without the RCM heatsink. I was also able to orient the pinion on the shaft such that it now makes full contact with the spur.

[mbeatle]

I just finished running the 3000 packs again in the grass. It was about 75 yesterday evening, but it's 90 outside right now and sunny. That said, here are the temps:

ESC: 135
Batteries: 135
Motor: 248!!!

This was running without the RCM heatsink, same gearing as before. I wonder how long the motor will last at this rate... Who wants to take bets?

Also, I changed the punch control to 20% which seems like a good setting. I may try 30% but at 20% you get a bit of warning before the front end pulls up slightly. It'll continue to wheelie until you back off on the throttle.

I'm going to try running the 4300 packs with the motor at the lowest timing. I found that when I had the MM5700 in my Stampede that the lowest timing was still ridiculously fast, but temps were lower.

[mbeatle]

Just tested it with the timing set to lowest and the 4300s. Mind you, this is the first time I've run this motor with the 4300 packs. I only got about 12-13 minutes before the truck started to cut out. I then found that my premade series adapter had failed and lost one of the wires. I got it a year ago with my Stampede. Looks like the 14awg wiring won't cut it. Here were some temps when I was done:

ESC: 135
Batteries: 130
Motor: 358!!!!

Yes, I smell burnt electronics. I'm not sure if the motor is beginning to fail or if it's my MMM. When I get the batts recharged and a new series adapter made with 12awg wire, I'll give it another shot, this time with the heatsink back on.

[jcm-maxx]

Geez dude.. grill a steak for the 4th on that thing! That can't be good.

[BL-Bob]

You should of cooked some brownies under the body while testing.

[asheck]

I bet the motor is done.IMO you should have geared it down.I would think that with this cheaper version it would have to be lower then the fiegao.But I have to hand it to you,thats the hottest I've ever heard of a motor getting. And maybe checked temps more frequently.

[mbeatle]

Yep, it's shot. I put it back together and heard it growling and barking like a sick dog. I'd let it rip @ WOT and I could get it to move, but poorly. Now it'll barely move. After about 15-20 seconds I took its temperature - 225F.

Looks like these motors are indeed part of the axiom that you get what you pay for. Neil, are you running the RCM heatsink clamp as well? Are your 160-180F temperatures taken on the motor itself or the heatsink?

A Neu isn't in my future, but I'd pay $100-$120 for a good, low kv motor that'll run cooler than this. When are the 74mm Medusa motors supposed to be out again?

[Suicideneil]

Medusa at the end of August I believe, so not too much longer now. I dont have the heatsink or fans or anything else- just a wing & a prayer...

Temps were taken on the motor- it does seem to heat up quickly, but then doesnt get much hotter. I found a 5-10 minute cooling down break half way through the run helped to keep temps under control, but I need to do more testing with different gearing; I have more A123 cells coming so I have more run time to test in. Shame about your motor cooking, but at least you have a nice $30 paper weight...

[mbeatle]

What batteries are you running, Neil? I wonder why mine was so absurdly hot... We are talking about the same 9XL from *********, right?

[Suicideneil]

That lovely deep-red colored motor, no mistaking it!
First I ran on 4s2p of lipos (2x 4s 10c 4000mah), then on 6s2p of A123 cells (= to 5s lipo). My truck is also 13lb, with 4lb of that being the tyres, so it put a hefty load on the motor too. Gearing was 58/24 and 62/24, though I do have the 1/8 scale buggy ratio diffs that lowers the overall gearing a touch (equal to 1 tooth less on the pinion compared to stock diffs).

Seems like they are a bit hit & miss really, some people get good-ish temps, others get a spinning toaster of death....

[alangsam]

dont wast money on the fiagos + heatclamps plus fans plus gearing fiasco.
i know people make it work but its just not a good setup

[kulangflow]

Feigaos are a fantastic set-up for the budget minded when compared to the $250+ motors.

Now that the Medusas 74s and the CC version Neus are coming out though, you'd be crazy not to spend the extra money to get them.

[asheck]

I had to say it 1 more time. I love my 60 Medusa.It's not broke 150 since I geared it down a little,hits about 44-45 on 4s and likes 5s even more.They are way better then the xl motors at a much lower price then Neu.

[kulangflow]

I had to say it 1 more time. I love my 60 Medusa.It's not broke 150 since I geared it down a little,hits about 44-45 on 4s and likes 5s even more.They are way better then the xl motors at a much lower price then Neu.

Imagine how much better the 74's will be!

I bought a 60 size Medusa as well (the 1600kV one), but I haven't ran it yet. I'm hoping it performs as well as yours has, although it will obviously be slower on the same gearing/cell count since yours is the 2000kV.

[asheck]

Imagine how much better the 74's will be!

Thats what I'm afraid of.

[mbeatle]

Sounds good then. Hopefully the Medusa 74 will come out on time. I guess it's back to brushed power for now.

[Suicideneil]

Oh god, anything but that!

They might be a little on the small side, but the ******* 56mm motors are worth looking at maybe, or an L can feigao (10L).

[mbeatle]

Hmm, guess I may have to figure out another plan. I just got this email:

Matt,

We expect the 36x70mm and 36x80mm motors to be available sometime in September.

Regards,

Jeff Little

Medusa Research, Inc.

Engineered Products for the RC Enthusiast

I don't think I can go until September with these brushed motors. How about the CC Neu? I'm guessing it will be about the same price point. I'm just wondering how it will perform, being a 2200kv motor. I'll need a smaller pinion for sure.

[Suicideneil]

CC neu would be more than fine. I would probably gear down a couple teeth on the pinion, and think about the larger spurs too. Motor and esc will handle the taller gearing though as CC tested it out alot- 24/65 is about the biggest you can fit.

[Carbonmaxx]

I saw a 15-20 degree drop when I added the heatsink to my 7xl. It fits nice and snuggly on there!! The clamp is an added bonus.

What size pinion and spur your are using with the 7XL in the E-Revo ? I just got a 7xl and dont know what to use. Thanks