I think your idea of a ring would work well. I would use a zip tie to hold it all and solder, then take the zip tie off and epoxy the winds tight.

E maxx Video's
 

I got some video's of the E maxx with the custom Wye wind.

Let me know what you guys think. :yes:

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<object width="425" height="355"><param name="movie" value="http://www.youtube.com/v/9TJ446Pa2Tk&rel=1"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/9TJ446Pa2Tk&rel=1" type="application/x-shockwave-flash" wmode="transparent" width="425" height="355"></embed></object>

In, my opinion, your Maxx is very cool :mdr: It has a lot of torque and is accelerating really fast. :yes:
But i would use other tires, it looks like they are not the best ones for this type of surface....

I hope you understand my poor school english :whistle: :lol:

Way cool!
 

Looks great. The Maxx always was fun to drive, not too stable, but drive-over anything (almost). Check out my truggy wheels with Bowties if you want some better grip. It looks like you've got the acceleration nailed and really good control. I am so jealous of all that nice dry, snow-free ground you've got there. We have another storm on the way.

I ran my Maxx last night at an indoor track. Kept it in 1st gear and it was still too fast for the track. Really nice and driveable, smooth power, good brakes (The sound the ESC makes under braking makes me kind of nervous). No problems at all, just fun to drive. Hard to control in a small space with lots of jumps though, I had to pull it off the track after I ran over a couple 1/10ths.

From what I've seen so far, I would not hesitate to order whatever new toys Sikeston34m comes up with. When there's a direct drive that works, sign me up!!

How do you link the video to YouTube like that...
I like the Video bro.... is that a stockie E-Maxx?...
http://www.youtube.com/watch?v=kXG1bYLe4H8

True Direct Drive
 

Now here's a project that's going to take some Engineering. :lol:

All I need is 3 more motors and figure out how to attach them to the A Arms.

This is a regular E maxx tire that is 5.75" tall. :surprised:
http://i160.photobucket.com/albums/t...m/DSC06694.jpg
http://i160.photobucket.com/albums/t...m/DSC06696.jpg

THAT IS SO EFFIN COOL!!!!!!! steering will be an issue tho....

LOL, is that the same motor I have Sikes?..... LOL... too bad it wouldn't work in reality.... but man.. it would be Real awesome..
you really gotta test the torque of that motor... it's cray powerful...

How about 2 motors, sideways between the bulkheads? Then you could attach the driveshafts to the motors. It would cause a lot less headaches design wise I think. With 4 motors being in the tires you have to worry about durability, mad unsprung weight, gyro effect, much too difficult. Maybe for a large scale onroad though.

Yes I believe it is the same one you have. I had to get me one too. :whistle:

I'm not so sure this wouldn't work. It would be a very heavy and expensive setup though. Not to mention that it would use 14 pounds of motors. :lol:

But a cumulative Wattage output of 28,000 watts should be enough to justify some of that weight. LMAO

I have test ran it in my hand on 4S Lipo. It was all I could do just to hang onto it, and that's spinning it really slow.

What have you tried it on so far? I'm thinking an Electric Bicycle that will carry me around. :yes:

Two words
 

Unsprung weight.

have one in my BlackJack 55" Cat boat (Currently Being Re-Painted)... planning to put another one on another GST 7.7 Roller... I almost have enough parts to build 2 more GST Rollers... but I'll need to get my hands on another 40.160WK.. I'd rather wait until Lutach over there get's that Custom HV ESC made...

I have a feeling what you will run into on the GST conversion is issues with building diffs that will hold up to that kind of power. :surprised::oh:

Get us some vids of the boat and the GST if you can. Can you actually get a prop for the boat large enough to make use of the torque this thing can make?

Unsprung weight. Let's talk about that. A Motor in each wheel setup would have a center of gravity that would be unbeatable. The bearings in this motor are HUGE and appear to be up to a good amount of abuse. Not only that, the power isn't even being transferred through the output shaft anymore. The output shafts new job would be to just hold everything and keep it spinning true. It's now an "axle shaft" more or less.

With advanced Electronics and programming, we will have independant traction control. A slipperential would be a matter of programming. So would "diff slip".

Diff slip would be a matter of limiting amp draw based on steering angle. An ESC controlling this would become more of a PLC.

I really look for this to become a reality with full scale on road Electric Cars in the future.

The drive motors will be sensor based to smooth things out and completely eliminate cogging and erratic behavior.

No drive train! Can there be a more efficient way? How about one that's going to hold up longer? About the only "wear item" in this is the bearings in the motor.

Unsprung weight
 

For a crawler, you're absolutely right, keep the cg low. For speed though, your suspension can't keep that much weight on the ground going over bumps, too much momentum. Could work well on a totally smooth surface.

I like the idea of motors where the diffs go, 2 motors opens up a whole range of control options.

Aaaah, I see your point. On road would be alot different and would work much better.

I like the idea of putting motors where the diffs go also. Aside from redesigning the bulks to hold them, this is going to be like running locked diffs in the front and rear.

How do we use front and rear motors, and retain our diff slip?

We've talked about an inline with the shaft slipper clutch here several times. How about instead have a centrifigal clutch in the wheel hub? The hub would have to spin up some before it would gradually apply torque to the wheel rim. Let's make this run on a large one-way bearing so when we put on the brakes, it will stop.

This setup would only "cushion" in forward, but who runs races in reverse? :lol:

Diffs
 

Locked diffs would be a problem for sure. The whole concept of direct drive really gave my little brain a stretching but now that I've thought it through, I'm thinking maybe two outrunners back to back in the same center diff location could use a fully electronic system for optimal everything, ie traction control, stability, ABS, the works. It could be a quantum leap in controllability. Is there a software engineer in the house?

servo mixing could be used to drive the front motor harder when turning as the front wheels spin more rpm in a turn. Assuming a 3 channel remote is used. ch1=steering, ch2= rear esc, ch3= front esc.

I'm finding the limitations of the bearings in the truggy diffs.

With the spiral cut gears of the 4.3:1 ratio, the pinion not only side loads the bearing, but it also pushes or pulls against the bearings.

I've been using steel ball bearings and they aren't holding up to the increased torque levels of my setup.

I could hear the diff Pop occasionally in the rear under hard acceleration. I took the diff back apart, and found alot of slop in the bearing closest to the pinion. I swapped positions with the two bearings, reshimmed to take all the play out and it worked perfect.

Now about 4 runs later, it's doing it again. On 6S, it will do 60mph+ and top out very quickly. With NO slipper, the setup is able to transfer all the torque that the motor will make. Which is alot!

A needle bearing with thrust bearing type qualities would be ideal, but I can't find any in this size. 8x14x4mm.

Is Ceramic Nitride the toughest out there in a ball bearing? like this one:
http://www3.towerhobbies.com/cgi-bin...?&I=LXPVB1&P=7

I've heard they are.

@Lincpimp - You need to consider this on the setup you're looking at. Tough Diffs are a must. :yes:

Wow, that is deadly looking! Use that with a speed record! I have mentioned the wheel motor idea a few times on this forum, but yeah it won't really work with these monster trucks. MAYBE, smaller on road cars... but they would need a very high power density to keep the weight down in the wheels, like someone said "unsprung weight" is a killer.

A few companies are doing wheel motor for full scale cars however, with GREAT results, works much better than motor/tranny/driveshafts.


About the diffs Sike.... I think all pinions have thrust on them when loaded, these spiral cut gears may just have more pressure is all. I don't really know what the best bearing are in these sizes? Sorry.

What diffs are you running in your 7S1P A123 setup? Ever had problems?

I know that truck really runs! :yes:

Yes, I understand the need for a good diff! I have a feeling that your combo of larger (heavier) wheel/tire and higher (numerically) diff ratio put more strain on the pinion gear than my smaller (lighter) wheel/tire and lower (numerically) diff ratio. Your truggy pinion has fewer teeth than my buggy pinion (10 to 13) and that can cause mesh problems as well (not sure if it is?). Plus I will run on road which should offer less traction as my tires have much less contact patch than a mt tire.

The ceramic bearings are most likely a good idea, as they are built better and should last longer.

I recently got a Revo 3.3 (September), and am running 7s1p at the moment, with the emaxx tranny (GM single speed). I am using the stock diffs right now, as the truck is quite light (just over 10lbs) the diffs are holding up fine.

7s1p has pretty good power... 7s2p however, halls ass man!

You may want to reconsider running only 1P in that case. If you are getting significantly more power on 2P, then you are overdriving your 1P pack. You will always get a touch more power on 2P because of less voltage drop. However, if there is a huge difference, stick with the 2P. That will keep your 1P packs from prematurely dying.

Matt

Believe me, I have been running A123 packs since spring '06, I have had the most experience with them on this forum... a 7s1p pack can deliver 1300 watts solid, and only gets barely warm to the touch running a 1512/3D. This is probably because the truck is fairly light weight, so not much stress on the pack (plus it handles better with a 1p pack). I too usually recommend 2p packs (mostly with less than 7s though), but the combination of HV, the Neu's efficiency, and light weight truck, 1p is JUST enough to throw the truck around with authority.

As far as cycle life goes, the 1p pack is still delivering a little over 2300mah after >200 cycles at 4C average discharge (15 min runtime) and 4C/10 amp charging.

Oh, geeze, sorry. I had no idea you were running A123 cells. I have always run flat lipo cells (mostly Flight Power and Thunder Power Extreme cells). I was assuming these were standard flat cells.

A123s are pretty much bulletproof.

Matt

bump??

Bump?

Where?

Matt

I had some good success with the custom wound 3530 that I put in the E maxx.

My Ceramic Nitride Bearings came in for the Revo, so I figured I would get this 4130 wound for it and install them all at the same time.

I wound the stator beautifully with 6 strands of 22 awg with 4 turns on each stator pole. I pulled each turn tight as I went and it all laid really well.

After completing the Wye termination, I checked for continuity between the winds and the stator. :surprised: Dead Short! :whistle::cry:

I removed the Wye termination thinking maybe it was the last set of winds that was shorted. After testing each leg of the 3 phase winding for continuity to case. I see EACH wind is shorted. :cry:

Now I get to start all over. I have decided to dress up this stator some and not pull the wires so hard. I'm gonna take a little more time next round.

When I was pulling it all back off the stator, the shorts are happening at the ends as the wire is being pulled tight.

A little sharp edge removal with a Dremel and several coats of fingernail polish should help. The fingernail polish is non-conductive and will help soften the edge.

Lesson learned. I won't be so rough this time. :whistle:

What color polish are you using, will you do your nails at the same time?

:oops:

It's actually Chrome Nail Polish. I hand picked it from this huge bag of little bottles that my daughter's have collected. :lol:

Naw, I won't be doing my nails. :whistle:

I prefer that "Manly" look. :lol:

Ahh, the "manly" look, when was the last time you took a shower? Dirty = manly! If that is true I am only manly when I come home from work!

That sucks man, all that time spent. I still haven't gotten a chance to finish mine up, only one phase left. Holidays has me slammed.

Finally! Whew!
 

I decided to cap each end of the stator with a plastic disk much like the Croco site uses fiber. This does help eliminate the shorting problem by giving the wire something smooth to slide against.

Much time was spent trimming and cutting them out, but it paid off. No Shorts! :yipi:
http://i160.photobucket.com/albums/t...m/DSC06735.jpg

It's a 4130 AXI Stator. I wound it to a 4 turn Wye using 6 strands of 22 awg. It is tight too.

That's the crimp/solder termination that I talked about earlier. It works good. :yes:

I got the custom wound motor installed. Even though it's dark outside, I had to go try it. MUCH Better! :yes:

Much better low speed driveability. Cogging is almost non-existent. I can make it cog by grabbing WOT from a stand still, But even then alot of the time it will blast off with the front end in the air. It will do 4 wheel burnouts on the concrete drive.

Torque is MUCH better. Top Speed seems a little lower on 4S than the 4120 660kv. I'm thinking this will be a GREAT 6S setup. I ran it for about 10 minutes and the motor was cool to the touch. It's 37 degrees outside, but I don't think temps are going to be a problem. I also put thermal heat sink compound between the motor and the mount.

Now that I have cogging under control, I'll start bumping up the voltage until I get the speed I'm looking for. :yes:

@Johnrob - Is there any way to estimate the KV rating of an AXI 4130 4 turn wye wind? 6 strands of 22awg?

Good to hear that this custom wind works better. The kv must be lower, if the spped is slower, maybe 280kv? That would be a wild guess!

No, it's alot higher than that. The factory wound 20 turn Delta was 305kv and that was using a really small ga. wire. The AXI 4130/16 Delta is 385kv.

Check this out:
http://www.rchotdeals.com/Products/r...or/A41308.html

It's a 4130 6 turn Delta rated at 510kv, but it doesn't show the Resistence values of the wind. Resistence means alot. Even if you have two motors with the same amount of turns, the one with the least resistence will make more power and more kv.

The Wye wind has 1.73 times the torque of a Delta but 1.73 times less kv for the same wind. That's why I dropped a few turns to make up for that.

I'm sure it's over 400kv, but I wonder if there's a way to figure this accurately.

Well you could radar both on the same number of cells and then fiqure it out backwards. I am sure that there is some mathmatical way of figuring it out. I see that my guess was a bit wild! I just thought you said it was slower on the same number of cells as the other motor.

The other motor I was referring to was the 4120/14. It's a 660kv motor.

I didn't really get a chance to top it out good even on 4S. It's pretty dark out there and they just graded the gravel road in front of my house. It doesn't take much to slip and slip on that stuff. :lol:

hats cool, thought that you were talking about the 4130 motor you had in there before, I need to re-read the thread, my memory sucks! How is the new emaxx coming along? Are you going to do a custom wind, or the motor we were discussing? I have to finish my other rc projects before I start on the new emaxx!