Most outrunners are capable of around 20,000 RPM. That is true for most Orbit outrunners as well as AXIs. That is due to magnetic saturation. Beyond that heat tends to build up and efficiency goes way down.

Much depends on each individual motor, though.

EMF is "Electro-magnetic-fequency". Back EMF is the back pulse the motor creates as it rotates. A motor requires voltage to run, but it also creates voltage as it spins. This voltage is read by the ESC to give a rough calculation of the motor's RPM thus eliminating the need for position sensing. Software is EXTREMELY important in eliminating cogging as is high torque capability of the motor. High voltage normally reduces cogging as well.

Matt

Hey Modman Was that the AXI 4120/18 that you were running?

It's the only one that I see with a 515kv rating.

I thought I would show you the difference in the Outrunner used in the E maxx 40mph setup (direct drive to transmission) and the AXI 4130/20 that is going in the Revo. Big Difference!
http://i160.photobucket.com/albums/t...m/DSC06635.jpg
http://i160.photobucket.com/albums/t...m/DSC06636.jpg

I believe so. I will check it and get back to you. It is not here at the house.

That motor has alot of use on it. It started in a twin rotor helicopter, then it proceeded to run my truck, now it is running the head of my Taig CNC. :)

I love outrunners.

Matt

Made some Progress tonight.
 

Here's a few pics of the progress. Still in it's rough form. I plan to line the lower part of the battery tray with the "loop" side of some velcro. This will cover up the counter sunk screw heads and help protect those precious Lipo's.

http://i160.photobucket.com/albums/t...m/DSC06637.jpg
http://i160.photobucket.com/albums/t...m/DSC06639.jpg

Very Nice Sikeston... I like, very much...

Sweet!

Matt

i look forward to a vid!

sikeston34m, keep it up!

You are doing exactly what I have wanted to do... looks great so far! :yes:

Ooh, now that is rather interesting, I like.

:gasp:thats insane

that's awesome! i love how low the engine is... makes me want to do something like it...

imitation is the best form of flattery, right? =P

Made some more progress tonight. I took it all back apart and used blue loctite on everything. Now all I have to do is figure out how I'm going to mount the receiver and the Quark Esc.

I have a Servo Tester. Little box with a dial on it that will control an ESC also. It duplicates the PWM that normally comes from the receiver.

Anyway, I couldn't resist hooking it up to 6S A123's and seeing the tires swell. They really do swell too. LOL These tires are REALLY out of balance.
I think this one is going to get the Phaltline tires with the Blast wheels that I've been saving. I originally bought these for my E maxx, got the aluminum wheel hub adapter kit along with them. Are the Revo and E maxx hubs the same? Will they work?

It's a good torque monster, I think the high gearing just might work without cogging issues.

Does anyone have suggestions on mounting the esc and the receiver? Perhaps some mounts that extent over the shock in the front and rear. I would like to keep these in the center of the truck. This will save battery compartment room for some high voltage setups.

Just make a little plate on to mount the ESC on top of the motor. Receiver can go on top of the ESC, or on top of the steerings servo (or opposite the steering servo).

Looks good - I look forward to seeing a vid.

Excellant Idea BP!!!!

I can use 4 PCB standoff's just tall enough to give me good clearance directly over the motor. Then I can mount an aluminum plate on that. The plate can be up to 2" wide and 6" long! I'll put them both there!

What would really be nice is to find a heat sink of the right size. Use it for a plate. Turn it upside down and let the motor fan blow on it. On the top side, attach the ESC to it with some thermal compound.

During my test run, I let it run at full throttle for about 5 minutes. The Motor was cool as a cucumber.

Hmmmm..........the possibilities.

PS..........let me get it perfected and I'll get some vids. This should be good.

Here's a few pics. The Motor only stick up about 1/2" out of the frame. I think there is enough head room there.
http://i160.photobucket.com/albums/t...m/DSC06643.jpg
http://i160.photobucket.com/albums/t...m/DSC06641.jpg

Dang man, that looks soo bad ass. That thing would be SO quiet... but then again, it's kinda nice to have gear noise as well! :wink::neutral: THere would still be diff noise, and tire noise as well...

Oh, and what voltage, batts, esc are you using? Specs! :yes:

At first I'm going to play around with 6S2P A123. Although I'll probably be doing some testing on different Lipo configurations too.

I'm thinking the 6S2P A123 will take me to about 40mph with some insane acceleration. Gonna start the play sessions with the Quark 80B ESC, but this baby needs some HV!!!!

I've been looking at the Kontronik Jazz 55-10-32. Then I could run 2 packs of 5 Series Lipo's. Maybe the 5000mah versions for a 10 Series setup.

On HV, maybe the best thing to do would be to get the RCM buggy diffs. Get both the 4:1 AND the 4.3:1 ratio's. The motor would be spinning so much faster on 10 Series, I could trade some top end for more acceleration.

I'm gonna test it first on the lower voltage. All that HV stuff means shelling out some bucks. I wanna do a little more research on the HV ESC's first. I would love a Car ESC with reverse that will do 10 Series and get along with outrunners.

I think I have alot of power here. Some testing is in order to find the perfect balance of acceleration and top end.:yes:

It just about got away from me when I was running it. Now I look like I have a serious rug burn on my arm! LOL

Looks awesome DUDE!!... More voltage.. more more more... :) J/K

Go for the 10S.. it would kick butt..

VERY nice.
I like it a lot. Can you shoot a pic from the bottom?

You can see it up in there, but the front and rear skids plates are lower than it is. The Aluminum Underside of the brace should serve to protect it.

Here ya go.
http://i160.photobucket.com/albums/t...m/DSC06645.jpg
http://i160.photobucket.com/albums/t...m/DSC06646.jpg

you need to get that thing runnin, thats amazing

I got some more time to work on the Revo.

I installed the plate that I will mount the Electronics on. I also did a Cap upgrade to my ESC. I installed 6 - 820uf caps rated at 50 volts. They are low ESR rated at 105C.

The second picture shows where I'm headed with placement on the mount. I will put my receiver in front of the ESC. The only thing I'm worried about is, having them so close to each other, with I get RF interference? I hope not.
http://i160.photobucket.com/albums/t...m/DSC06648.jpg
http://i160.photobucket.com/albums/t...m/DSC06649.jpg

i love it! i mey steal your idea and make myself one of these! get-r done. now.

Looking good Sike! I do not think that you will have problems, but just to be safe, braid your esc to motor wires and keep the antenna wire on the opposite side as far away as possible. I have mounted my esc and rec close before and not had any issues. Definately need to see this thing run and hear your thoughts on it. I have another revo sitting here without a tranny, so this would be an interesting project for me. I also need to find a good motor for my redcat. I have a 833kv motor at the moment and would like to go to a 650kv or so motor. This would let me put larger wheels and tires on it. Any ideas what motor would be good? Maybe a smaller axi motor like yours?

Thanks Guys.

Hey Linc, give me the dimensions of your motor and I'll try to recommend. I need can diameter, can length and shaft diameter.

that caps looks so sexy...!

I think this Cap setup would work for 10S Lipo too! :yes:

This looks great Sike! :yes:

If I may state MHO, I would think of moving the esc around right in front of the cap bank to take advantage of such a massive cap.

BTW, those caps look awfully small for being 820uF/50v, they seem like they should be bigger than that?

She's still in rough form, got some tidying up to do. But I couldn't resist seeing it run. I strapped in 4S Lipo setup (2S2P each at 10,000mah) and took it outside.

She runs pretty good, but there is much tweaking to be done. It will cog on startup if I am too quick with the throttle. If I ease into it, it starts fine. After I let it roll up to about 10mph or so, I can stab the throttle and it slings gravel and tops out quickly. Top end on this configuration is about 30 to 35mph. She needs more voltage! It's pulling a really high gear. More voltage will increase the motor torque dramatically and broaden the rpm range. It will also raise the top end speed alot.

I'm having a programming issue with the Quark also. I can't seem to get it to go into Advanced programming mode! I feel like I need to set it to "outrunner" mode. This will increase torque and make it start much better.

It doesn't matter which trigger sequence I use, (min-Max......or Max-Min) it slips into Basic Programming mode. What am I doing wrong?

Here's a pic with the Lipo's in place. I'm going to try 6S2P A123 next. Gotta get the receiver pack out.

http://i160.photobucket.com/albums/t...m/DSC06652.jpg

They are stamped Nichicon 820uf @ 50 volts. You can see it in the picture there. There's another number on them, HO129 I couldn't find the spec sheets on them. I got them from a speed controller for a 36 volt forklift.

I considered using another Nichicon style that I have here. They are 1000uf @ 63 volts HO110 But in reading your discussions (many others were involvled too) about ESR values and Transient Response times. I opted for the 820's.

After a 10 minute test run, everything was cool. I could hardly tell the ESC had been ran and the motor was stone cold.

WOW! So does it run smooth and quiet besides the minor cogging? I agree that turning it to 'outrunner' will probably treat the cogging issue. I hope you get the programming figured out.. :smile:

Move throttle to 'min' position...
Turn 'on' esc switch...
Press and hold the esc program button and move the throttle to 'max' and hold..
Release the program button after 2-3 seconds...
Now move the throttle until you hear recognition beep...

You should have entered advanced programming mode... the LED pattern should be the two inside LED's (green and yellow), move the throttle to change, yada yada yada.

Yeah, that esc mount must suck a good amount of heat away from the esc.

It runs VERY smooth and VERY quiet. The tire noise is louder than the motor unless I slip off into the grass.

It needs programming and More voltage. I'm gonna be working on those two things next.

Are these good caps? Do you know where to find the spec sheets? I tried the HO number on the nichicon website with no luck.

With using Aluminum for the motor mount and the ESC mount. The whole thing is acting like a heat sink, even to the chassis.

I really think it's going to take some major voltage before heat becomes an issue.

Going up in voltage may cure the cogging too. I had that issue a while back. I almost bought a different ESC untill I tried higher voltage. :)

Looks good!

Matt

That thing is gonna really confuse a lot of people when they see it for the first time- no visable motor!

Can anyone say "perfect left-right balance"... if you lower this thing for stance a bit, it would murder at a race! :gasp:

Very good Point you brought out there Brian. I'm not sure what that equation is, but I think I'm over the line on the cogging side with this setup.

I just tried the 6S2P setup with a receiver pack. Cogging on startup is still there. It's not horrible to the point where it won't move. I just can't stab the throttle and explode off the line. Top End is alot faster on the 6S A123 setup with NO heat issues at all. Barely felt anything from the motor or ESC, even after top speed runs.

I tried the ESC in outrunner mode and inrunner mode. Inrunner mode works best. I adjusted the throttle trim on the controller, and it would then let me into advanced programming.

This is geared too high. I thought the AXI 4130 would make up the difference in torque to compensate for gearing, but it doesn't. I'm not getting the kind of acceleration I'm looking for.

In my mind, I am constantly comparing everything to the E maxx Direct drive to transmission setup. With it, I used up to 800kv outrunners. On the E maxx, Input shaft to Tire is a 4.57:1 gear ratio for 2nd gear. I will be ordering the 4.3:1 RCM Revo Hybrid diffs for this. This will almost duplicate the gearing of the E maxx and further multiply the torque to the wheels. All without a transmission and those wear items that tend to be weak and break.

I could see some GREAT results from the AXI 4130 with the lower gears IF I could put it on 10S Lipo. But for now, to stay within the voltage limitations of the Quark, I'm thinking about going with a different AXI motor.

The E maxx outrunner's stator is 35mm in diameter with a length of 20mm and has a kv rating of 650. The AXI 4120/14 has a stator the is 41mm in diameter (torque bonus) and is 20mm long with a kv rating of 660. The cooling fan attached to the back of the motor works with the 4120 also.

The 4120/14 is rated for 4 to 5 Series Lipo, but in this new setup, motor temps will determine how much voltage it can be fed. I think this setup dissapates heat very well, so 6 Series Lipo is possible.

Without batteries, the truck in it's current state weighs 9 pounds 8 ounces.