Feigao 6xl?

[Jeff P]

Going to be starting my E-Revo conversion. Going with the Tekno mount, MMM, MaxAmps 8000 11.1. Just wondering if any of you have any experience with this set-up and using a 6xl. There's a local guy that is using a 6xl, but with a pinion and not a clutch set-up like the Tekno one will use. And his is crazy nutso. Good for bashing, but I am building a racer, just wondering if it will be too much. I guess I could tune down the esc if I have to, but was just looking for some feedback.

Thanks.

[BrianG]

The 6XL is a hot motor and will tend to heat up more unless you gear down enough. Not to mention the current required to move the truck like you want. It takes power to move these things, and it is more efficient (and better for the batteries) to go with higher voltage along with the proper motor. Generally, it's better to go with as high a voltage as the ESC will allow (5s-6s with the MMM) and then use a 9XL (for 5s) or 10XL (for 6s). Current draw will be less, and so will motor heat.

6XL can work, it's just not "ideal".

[Bondonutz]

I have mixed feelings with my experiences with the XL motors. I had a 9xl that totally let me down, a majority was user error several years ago. One day I decided to try a 7xl, I had difficulty getting it to run decent temps(as Brian mentioned) but I succeeded and was real content . Yesterday at the BMX track I was running some laps having a fabulous time enjoy the traction on the moist clay and landed a perfect huge jump. When the truck landed it rolled to a stop and nothing ? I waddled over to it and removed the body and discovered this (see picture). It never would have happened with a motor that is bolted together like a NEU or Novak HV etc. These XL cans are glued together and I'm not sure if mine is even salvageable, The front bearing has disintergrated either befor the jump and I didn't noticed or during the 14-15 foot drop from the jump ? RC Monster sells heatsink motor clamps that I would STRONGLY reccomend investing in if you go with the XL mill.

[Bondonutz]

Bottom line, If your serious about building a racer ; Wait until you have the extra money and purchase a NEU or consider possibly a Novak HV befor the XL.
My 0.02

[Jeff P]

I hear what you're saying Brian, but that will make the batts too pricey.
Bondo, I have been toying with going with a Neu http://www.impaktrc.com/product_info.php?cPath=186_292&products_id=2283&osCsid=d5e22ae
but for the price, i thought i could just buy a 6xl and 7xl and see which one i like and just buy a spare or 2.

[BrianG]

Bondo: No matter what, the XL motors will run hot. They are lower efficiency so more of the power is being wasted as heat. But really, that kind of thing is to be expected; after all, there is a reason why they are fairly cheap. I have found that running them for ~15-20 minutes, then letting them cool for about 30 minutes helps a lot. So basically, don't expect to run pack after pack.

And the end cap coming off is a pretty common occurance, which is why rc-monster sells those heatsink/motor clamp units (http://www.rc-monster.com/proddetail.php?prod=RCM01). Helps keep them cooler and keeps them together.

However, by the time you get the motor, and any heatsink solution (and fans if that's your thing), you are at around $100, and a Medusa 60mm motor is just a few $$$ more. They work quite well and are pretty efficient too. A happy medium between an XL and a Neu, although I personally would wait until they come out with their 70mm models first...

Jeff: Actually, the battery is about the same price when you think about it. A typical MT uses about 300w average power (bursts are higher). At 3s, this translates to 27A average. Well, an 8Ah pack will last around 17.8 minutes depending on gearing, drive style, weight, etc. However, you can get the same runtime using 6s 4Ah pack. And you reduce the inefficiency of running at high current (produces more voltage drop). Same number of cells; 3s @ 8Ah pack is actually 3s2p for 6 cells total, and the 6s @ 4Ah is 6s1p for 6 cells total.

And yeah, it is a little more, but I personally like the 5Ah packs. Running 6s @ 5Ah with the same ~300w will get you a solid 20+ minutes of runtime.

[Bondonutz]

I hear what you're saying Brian, but that will make the batts too pricey.
Bondo, I have been toying with going with a Neu http://www.impaktrc.com/product_info.php?cPath=186_292&products_id=2283&osCsid=d5e22ae
but for the price, i thought i could just buy a 6xl and 7xl and see which one i like and just buy a spare or 2.

I've tried the XL's twice now and have had limited success not counting ruining my 7XL, My next motor purchase WILL DEFINITELY be a NEU. They cost more but no aggrevation with heat issues. You'll be hard pressed to make it thru a main without overheating and keep the speed decent.
Do yourself the favor and research more befor you commit to a XL.

[Bondonutz]

Brian, I'm fully aware of the RCM heatsink/clamps, I have one. But the Novak heatsink is far superior for cooling,I didn't need a fan with it. And you have seen the final results of my decision,Never again will I buy another XL.
I should have listened to you last year when we were chatting about a NEU for my ELST Prodject. I was researching NEU motors but got apprehensive about spending the $$$.
Nothing like learning a lesson the hard way,now It's gonna cost me more since I wasted my cheese on 2 XL's.:mad:

[Jeff P]

I like quality. So Neu's are the way to go. Now I will look into a higher cell and lower kv. I have decided to be in the 28000-30000 range. Like I said, this is my racer.
Can anyone comment on the Tekno kit?

[BrianG]

Gotta be careful about rpms. You don't want to go too high, but if you go too low, there will be greater chances of cogging at take-off and slow speeds. This is because the ESC doesn't have enough back-EMF feedback pulses to determine rotor position.

Generally, a Neu is good for 35k-40k rpm range. XL motors are good for the 30k-35k rpm range. You can then gear appropriately for racing (usually about 35ish mph). This would give good runtime and smooth operation.

[CrazyCooydog]

NEU ALL THE WAY!!!! I have just upgraded to NEU's and will never get anything else... in my e-revo 1515 2.5d on 5s 5000mha was awsome..finished 20 min main easly....thats on very large track and very hard driving. geared 20/58

then changed to a 1512 2.5d on twin 4s 4000mha and on very similer track but very easy controled driving I made 30 min main..Niether MM or the NEU even broke a sweat, with no fans, just holes cut in the body. I was gear very slow though 20/65..good enough to take second though.

I did try the 1515 2.5d on 4s but there was cogging....to the point of aggravation ...

I can't wait till the post ma comes with all the new toys....I have a new home for the 1515....look out truggy guys...:D

[CrazyCooydog]

Brian/Bondo will not steer you wrong!!
took me alot of thinking/$$$ to become a beleiver...I wish I would have listened from the start......I couldn't be happier...well that's not totaly true.. If only now some one could teach me how to be a better driver. I'd be exstatic..:)

[Jeff P]

I think i will go with this http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXVJN3&P=ML and a 11.1 8ah.
Any thoughts?

[Jeff P]

I think i will go with this http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXVJN3&P=ML and a 11.1 8ah.
Any thoughts?

Ok scratch that.
Man I change my mind a lot :D. I hate doing things more then once.
So, what do you guys think of this:
Medusa motor (http://www.impaktrc.com/product_info.php?cPath=186_292&products_id=3262) with a 14.8 5ah and the mmm? That will give me 29600rpm.

[The Dan]

I think i will go with this http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXVJN3&P=ML and a 11.1 8ah.
Any thoughts?

Just don't trust Tower to have it in stock before the second coming of Jesus.

But as a motor system, I would go with it.

[Bondonutz]

Ok scratch that.
Man I change my mind a lot :D. I hate doing things more then once.
So, what do you guys think of this:
Medusa motor (http://www.impaktrc.com/product_info.php?cPath=186_292&products_id=3262) with a 14.8 5ah and the mmm? That will give me 29600rpm.


A simple call to tower and a question will instantly let you know if it's availible.
The moderator Jason of MaxAmps has a Madusa motor in his 1/8 scale Fusion buggy and he seems happy with it,ask him a couple questions about it ?