A new toy for me!

[lincpimp]

Yes, I ran all of those numbers, but figured that you would use the existing tranny gears for your setup. If the 2 speed is an auto shifter via the servo and some sort of rpm sensor, then your 920 kv motor will most likely get it over 60 mph without much of a heat issue. It would be killer cause 1st gear would let the outrunner startup easier and not put as much load for light bashing, and then when you really get on it 2nd gear will allow for some killer top speed. Or gear it for 45mph in 2nd and have some killer torque in 1st gear!

I have noticed this with my teckno converted revo. I still have the 2 speed tranny and it will run fine with a small aveox motor (l can size). Plus you can go low speed with it, just don't go fast enough to engage 2nd gear. It will almost pull a wheely when shifting at full throttle!

Is the 920kv good for 6s? That is 20k rpm which should be fine.

[lincpimp]

Also for the different gears to fit correctly in the tranny a different size idler will have to be used. The input and output shafts are a set distance away from each other and the 18 / 21 setup will have to have a larger than 20t idler to fit and mesh correctly. Wonder how they will do this?

Both the 21/18 and the 26/13 would fit in the tranny as 1st and 2nd gear respectively and could use the same size idler for both, as the radius of both sets of gears added together is the same.

EG. 21t=23mm/2=11.5
18t=20mm/2=10
___________+___
21.5mm

26t=28mm/2=14
13t=15mm/2=7.5
___________+___
21.5mm

So I guess that when installing the 2 speed the original single speed gears will be discarded. Sounds cool, can't wait.

[sikeston34m]

Let me take a few minutes and show you my favorite setup with the Direct Drive to Transmission outrunner setup. The Motor is a Century 600. It's stator is a 3530 and at 5 turns is rated for 715kv.

In first gear, there is NO cogging at all. It will blast off the line at WOT with the front wheels in the air every time. Without a wheelie bar, it will flip onto it's lid.

Differential Ratio: 2.8461538461538462
Transmission Ratio: 2.769230769230769
Other Ratio: 1
Spur Tooth Count: 1
Pinion Tooth Count: 1
Total Voltage: 14.8
Motor KV: 715
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 1 : 1
Total Ratio: 7.88166 : 1
Tire Circumference (inches): 18.06 inches (458.83mm)
Total Motor Speed: 10582 RPM
Vehicle Speed: 22.97 MPH (36.89km/h)
Effective Speed Rate: 1.55mph/V (2.49kmh/V)
Effective KV Value: 715

Here's 2nd gear on 4S.

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.7222222222222223
Other Ratio: 1
Spur Tooth Count: 1
Pinion Tooth Count: 1
Total Voltage: 14.8
Motor KV: 715
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 1 : 1
Total Ratio: 4.90171 : 1
Tire Circumference (inches): 18.06 inches (458.83mm)
Total Motor Speed: 10582 RPM
Vehicle Speed: 36.93 MPH (59.32km/h)
Effective Speed Rate: 2.5mph/V (4.01kmh/V)
Effective KV Value: 715

Starting in 2nd gear, it would cog about 10% of the time if I grabbed WOT off the line. If WOT was grabbed at anything above 5mph, it would raise the front end and really haul! VERY good acceleration with this setup.

On 6S, this setup would blow the transmission! It would either rip the teeth off the output gear or the output shaft would strip the drive dog hole.

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.7222222222222223
Other Ratio: 1
Spur Tooth Count: 1
Pinion Tooth Count: 1
Total Voltage: 22.2
Motor KV: 715
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 1 : 1
Total Ratio: 4.90171 : 1
Tire Circumference (inches): 18.06 inches (458.83mm)
Total Motor Speed: 15873 RPM
Vehicle Speed: 55.39 MPH (88.98km/h)
Effective Speed Rate: 2.5mph/V (4.01kmh/V)
Effective KV Value: 715

I love how this is going to come together. Finally I can put together an outrunner setup with a slipper and the kind of gearing it needs to show what it can do.

I'm going to go with the two speed transmission kit. Motor choice will be the AXI 2826/10.

Look at the 1st gear total reduction ratio. It's less than the century setup. It won't cog at all being so much less.
Differential Ratio: 2.8461538461538462
Transmission Ratio: 2
Other Ratio: 1
Spur Tooth Count: 40
Pinion Tooth Count: 25
Total Voltage: 14.8
Motor KV: 920
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 1.6 : 1
Total Ratio: 9.10769 : 1
Tire Circumference (inches): 18.06 inches (458.83mm)
Total Motor Speed: 13616 RPM
Vehicle Speed: 25.57 MPH (41.08km/h)
Effective Speed Rate: 1.73mph/V (2.78kmh/V)
Effective KV Value: 920

Now check out 2nd gear. A Respectable 44 mph.

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.16
Other Ratio: 1
Spur Tooth Count: 40
Pinion Tooth Count: 25
Total Voltage: 14.8
Motor KV: 920
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 1.6 : 1
Total Ratio: 5.28246 : 1
Tire Circumference (inches): 18.06 inches (458.83mm)
Total Motor Speed: 13616 RPM
Vehicle Speed: 44.09 MPH (70.83km/h)
Effective Speed Rate: 2.98mph/V (4.79kmh/V)
Effective KV Value: 920

I'm going to order a 25 tooth mod 1 pinion AND a 22 tooth pinion from Mike. Combine this with all 3 Revo Spur gears, the 36, 38, and 40 tooth, and I have should have all the adjustibility I need to make a SWEET 4S setup.

If I feel the need for more speed, I'll go 5S or 6S if motor temps and startups remain good.

A Quark 125amp Monster Pro with a Novak Cap and a heat sink. And all this with a TOUGH slipper like so much discussion has been about concerning the outrunner setups.

I'm gonna love this!

[lincpimp]

Hey Sike, your 2826/10 setup looks good. I would say to do with a higher voltage setup, but the stock chassis setup really lends itself to 4s, either 2 larger 2s packs in series, or 2 smaller 4s packs in parallel. I have some ployquest 12c 3600 cells (8 of them) and as long as they fit I will make up a pair of 3600 4s packs. It will be nice to have a sturdy tranny and slipper! Lets see how this proposed setup works and I may have to give it a try!

Any idea what you think average and max current draw with this motor would be? Mainly cause I have a mgm 90amp 4 cell esc that needs a home, and the mgm escs will run an outrunner IIRC.

[sikeston34m]

Originally Posted by lincpimp

Hey Sike, your 2826/10 setup looks good. I would say to do with a higher voltage setup, but the stock chassis setup really lends itself to 4s, either 2 larger 2s packs in series, or 2 smaller 4s packs in parallel. I have some ployquest 12c 3600 cells (8 of them) and as long as they fit I will make up a pair of 3600 4s packs. It will be nice to have a sturdy tranny and slipper! Lets see how this proposed setup works and I may have to give it a try!

Any idea what you think average and max current draw with this motor would be? Mainly cause I have a mgm 90amp 4 cell esc that needs a home, and the mgm escs will run an outrunner IIRC.

Soon, I will have a quantity of Lipo packs made from 5000mah 20C cells that have the 45mm x 145mm footprint. I plan on keeping 2 - 2S packs and 2 - 3S packs.

They will all fit the stock battery compartment.

This will allow me to run 4S, 5S, or 6S configurations. Motor temps will show me the way. I might play around with this. I believe optional battery hold downs are going to be available for this to allow for larger packs. Have you heard anything on this?

Your battery setup should work well. 86 amps continous and 7200mah should make for some nice runtime.

About the amp draw, I'm not sure on this one yet. Actually, you have a better idea of how the 2826 performs with the Redcat. Tell me, how does it do? How many watts do you think it's capable of? You don't have the cooler though right? Here's this same setup with your AXI motor. It would perform pretty good too IMO. Using a motor of less kv, just means it's going to accelerate that much harder.

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.16
Other Ratio: 1
Spur Tooth Count: 40
Pinion Tooth Count: 25
Total Voltage: 14.8
Motor KV: 760
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 1.6 : 1
Total Ratio: 5.28246 : 1
Tire Circumference (inches): 18.06 inches (458.83mm)
Total Motor Speed: 11248 RPM
Vehicle Speed: 36.42 MPH (58.51km/h)
Effective Speed Rate: 2.46mph/V (3.95kmh/V)
Effective KV Value: 760

It's tricky business with Direct Drive trying to match the "power band" of the motor to the diff gearing and tire size.

I'm really excited about this setup because we have the gearing to work with to keep the motor in that "sweet spot".

[lincpimp]

Actually, the redcat setup can't be pulling many amps, my battery is a 2500mah 18c 5s pack and it did not even get warm. The redcat is much lighter than an emaxx, but the final gearing (inc tires) will be very similar (slightly lower in the emaxx) so we will see how it does. Wondering if the 4120 would be a better motor? You have more outrunner experience than I so I will see how your experiments go. I will say that maybe 5s will be better with my lower kv motor. Seems to be the general feeling that lower kv and higher voltage yields better results. I do have the cooler now, just need to put it on!

Here is what I feel would be the best setup for my motor, but will need to be tested.

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.16
Spur Tooth Count: 40
Pinion Tooth Count: 20
Total Voltage: 18.5
Motor KV: 760
Tire Diameter (inches): 5.75
Spur/Pinion Ratio: 2 : 1
Total Ratio: 6.60308 : 1
Tire Circumference (inches): 18.06 inches (458.83mm)
Total Motor Speed: 14060 RPM
Vehicle Speed: 36.42 MPH (58.51km/h)

Maybe put a 22t pinion on it, and aim for around 40mph. Using a 2 speed will allow for higher gearing and top speed, and motor rpms look good too, it may work!

[sikeston34m]

Originally Posted by lincpimp

Actually, the redcat setup can't be pulling many amps, my battery is a 2500mah 18c 5s pack and it did not even get warm. The redcat is much lighter than an emaxx, but the final gearing (inc tires) will be very similar (slightly lower in the emaxx) so we will see how it does. Wondering if the 4120 would be a better motor? You have more outrunner experience than I so I will see how your experiments go. I will say that maybe 5s will be better with my lower kv motor. Seems to be the general feeling that lower kv and higher voltage yields better results. I do have the cooler now, just need to put it on!

Here is what I feel would be the best setup for my motor, but will need to be tested.

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.16
Spur Tooth Count: 40
Pinion Tooth Count: 20
Total Voltage: 18.5
Motor KV: 760
Tire Diameter (inches): 5.75
Spur/Pinion Ratio: 2 : 1
Total Ratio: 6.60308 : 1
Tire Circumference (inches): 18.06 inches (458.83mm)
Total Motor Speed: 14060 RPM
Vehicle Speed: 36.42 MPH (58.51km/h)

Maybe put a 22t pinion on it, and aim for around 40mph. Using a 2 speed will allow for higher gearing and top speed, and motor rpms look good too, it may work!

The 4120 is too fat. To get this mesh using the mod1 gears, the motor is going to be pulled down really close to the transmission. I'll take a look at possible mounts with the 4120.

The 4120 would make LOTS more torque than the 2826, but I don't think we'll be coming up short in the torque department.

It takes a really big outrunner that's loaded with gearing to pull big amps I think. I had some separation on the 80 amp Quark between the sticky and the heatsinking case. I believe that's why it was thermaling running the 4120 in the Direct Drive Revo.

With the Revo, we're talking an even heavier truck (about 11 pounds), plus some really tall gearing to pull.

The only thing I've ran so far in the Revo has been 10C packs. Think about that. But this does give me a better idea of how many amps the Revo is pulling.

The two cell types that I've ran the revo on are:

4000mah 10C(15C) 40 amps continous 60 amps Burst
5000mah 10C(15C) 50 amps continous 75 amps Burst

With the 5000mah packs, it worked GREAT. I could hardly tell the packs were warm at all.

With the 4000mah packs, I could tell I was pushing them. The 4S worked good, but I could tell voltage drop under the load was greater. They didn't have the punch the 5000's did. When I put it on 6S with the 4000's, They got pretty warm. I could tell this was a bit too much for them to handle.

The 4000's work well in the E maxx, but it's a lighter truck with a smaller motor. The Direct Drive to Tranny setup in the E maxx draws less than 40 amps continously, and that's a 3530 outrunner.

I believe the outrunners to be very effecient in their use of power and this helps keep the amp draw to a minimum.

The 20C packs should be GREAT compared to what I've been used to running.

"Psssst.......I've got 2 more of the New E maxx's on the way. I think I'll part them out and put them on Ebay"