My HV Outrunner REVO

[BL-Power]

I'm still waiting for my parts from liquidrc and i'm looking for someone who is interested in my CrimeFighters that i can order the Phaltlines. According to Brians calculator my total ratio is 4,9!? I think my setup would also work well with higher gearing. Is your motor cogging only when it is under load in your vehicle or is it also cogging if you let it spin freely?

I can only recommend you buying a Kontronik ESC, you won't be disappointed.

[sikeston34m]

Originally Posted by BL-Power

I'm still waiting for my parts from liquidrc and i'm looking for someone who is interested in my CrimeFighters that i can order the Phaltlines. According to Brians calculator my total ratio is 4,9!? I think my setup would also work well with higher gearing. Is your motor cogging only when it is under load in your vehicle or is it also cogging if you let it spin freely?

I can only recommend you buying a Kontronik ESC, you won't be disappointed.

The stock Revo diffs are 2.85:1 ratio. The E maxx tranny in second gear provides a 1.72:1 reduction ratio. These added together comes to 4.57:1 overall reduction.

Let me start at the beginning with my build. It has changed and evolved alot since the start of it.

I set my Revo up Direct Drive to Diff. It doesn't have a transmission. I installed a AXI 4130/20 outrunner. It's a pretty big one. Using a Quark 125amp Monster Pro. I noticed it would cog about 50% of the time on startup from a standing stop. If it was rolling at any speed, there was no cogging. I was using the stock diffs with a ratio of 2.85:1.

This is when things began to change. I replaced the stock diffs with a pair of RCM's Revo diffs and went with the truggy gear ratio of 4.3:1

The cogging went away and things were looking great. I then rewound my 4130. Factory wind was 20 turns with a Delta Termination. The custom wind that I chose is a 4 turn Wye termination using 6 parrallel strands of 22awg wire.

I dropped so many turns because I wanted a higher kv rating. It is now in the 550 to 600kv range. The factory Delta wind was 305kv. I went with the Wye Termination because 8 poles are energized at any given time instead of 4 as with the Delta termination.

Wye has 1.73 times less kv, BUT makes 1.73 times more torque. This is the reasoning for the drastic change in the number of turns. I also raised it's amp capacity by using such large winding wire.

By adding AXI's motor fan to the endbell, it runs VERY cool and makes tons of power! I have some vids posted if you would like to check it out.

The Wye wind starts better. There is no cogging. but here's where the problem sets in.

The 4.3:1 truggy gears are spiral cut gears. The pinion tends to load the bearings as if they were thrust bearings. They can't hold this load since it isn't a side load.

In less than 2 packs, it will punch the inside race right through the pinion bearing. I know my shimming is correct.

I'm going to go back to the regular cut gears. They are 3.3:1 ratio. Still lower than stock, but my fear is startup cogging will come back with the Quark.

This is where I will probably go with the Kontronik ESC that you are using. It looks like it has a better startup routine than the Quark for this application.

I also like the fact that I can bump on up to 8S Lipo if I want to.

[BL-Power]

Ok, now i understand your problem. I've already seen your Revo, the motor is really large. I don't think that you should get much more cogging if you go up to the 3.3:1 ratio. Have you already added some caps to your Quark? I think that they would help to reduce cogging.

[sikeston34m]

Originally Posted by BL-Power

Ok, now i understand your problem. I've already seen your Revo, the motor is really large. I don't think that you should get much more cogging if you go up to the 3.3:1 ratio. Have you already added some caps to your Quark? I think that they would help to reduce cogging.

In the beginning, I added a huge bank of Capacitors. LOL Now I just have 1 additional Novak 2700uf cap. It seems to work great as the Quark 125 runs very cool.

[BL-Power]

You are using the stock Traxxas radio!? Don't you have range issues or something like that?

[sikeston34m]

Originally Posted by BL-Power

You are using the stock Traxxas radio!? Don't you have range issues or something like that?

Yes I'm using the stock radio system. No range issues or any issues at all.

It's been working great for me.