Direct Drive to Diff E Revo Build - RC-Monster Forums

johnrobholmes · 12.13.2007, 09:09 PM

That is great news! Looks like I should be testing my crawler motors to a Y termination too.

As for the wind resistance, each wind will have lower resistance because of the larger amount of copper and lower wind. The phase resistance in comparison to a D termination would be higher of course. The combination of changing wind count, termination, and copper netted you better startups, better acceleration, and a higher top speed? I would say either your efficiency went up or your amp draw did, maybe both. Got any old data logging from the previous setup?

aqwut · 12.13.2007, 10:04 PM

98% Efficiency is beautiful.... I want one... build me one...

ilpufxit · **Spin-up -** 12.13.2007, 10:46 PM

I've been following this thread as I continue to experiment with my e-maxx. I'm starting to think that a centrifugal clutch might be just the answer. If the outrunner's only real problem is startup, why not let it "idle" like a nitro (just set your throttle trim up a little) and then just grab all the throttle you want to take off. If you can't really use the ESC brakes on a direct drive anyway then it seems like a natural fit, no?

lincpimp · 12.14.2007, 01:23 AM

Actually the esc brakes work fine on my redcat/axi setup. But the clutch idea would be nice. I am going to do a twin outrunner, twin hv85 setup. We will se how well the castle air controllers work!

sikeston34m · 12.14.2007, 02:26 AM

Quote:

Originally Posted by lincpimp

Actually the esc brakes work fine on my redcat/axi setup. But the clutch idea would be nice. I am going to do a twin outrunner, twin hv85 setup. We will se how well the castle air controllers work!

Hi Linc,

I'm very interested in what you're getting ready to do. Please keep us posted. We need pics.

If you can swing it, go with the HV110's. I've often thought about the Castle Controllers, but the lack of reverse and suitable brakes steered me away from them.

I believe with the mechanical brake setup that you have, they will do great!

lincpimp · 12.14.2007, 02:34 AM

If you really wanted a clutch that could handle the torque load, a modified baja 5b clutch should be able to hand an outrunner, it seems to cope with a weedeater motor in a 20lb truck!

Any specific reason to go with the hv110 over the hv85? Do you think that I will be able to pull more than 85 amps out of those outrunner with only half the load? It will be setup for an road running, so the rear motor should not have to work as hard, less weight transfer due to lower cg and stiffer, short travel shocks.

sikeston34m · 12.14.2007, 02:39 AM

Quote:

Originally Posted by lincpimp

If you really wanted a clutch that could handle the torque load, a modified baja 5b clutch should be able to hand an outrunner, it seems to cope with a weedeater motor in a 20lb truck!

Any specific reason to go with the hv110 over the hv85? Do you think that I will be able to pull more than 85 amps out of those outrunner with only half the load? It will be setup for an road running, so the rear motor should not have to work as hard, less weight transfer due to lower cg and stiffer, short travel shocks.

Well I'm not sure, depends on the setup. I am sure my Revo is spiking up more than 85 amps on take off. It performs much better with batteries that can deliver more current.

I like to over size in the ESC department if possible. You can't have one too large as far as ratings go.

That's going to be an awesome setup.

sikeston34m · 12.14.2007, 02:23 AM

Quote:

Originally Posted by ilpufxit

I've been following this thread as I continue to experiment with my e-maxx. I'm starting to think that a centrifugal clutch might be just the answer. If the outrunner's only real problem is startup, why not let it "idle" like a nitro (just set your throttle trim up a little) and then just grab all the throttle you want to take off. If you can't really use the ESC brakes on a direct drive anyway then it seems like a natural fit, no?

The problem with a clutch and this setup is, current clutch designs are up on the factory drive train where torque levels are much lower. How do we design a clutch that is inline with the shaft to handle the higher torque?

ESC brakes work fine with this setup. I've never had a problem with that aspect.

sikeston34m · 12.14.2007, 02:20 AM

Quote:

Originally Posted by aqwut

98% Efficiency is beautiful.... I want one... build me one...

How do we figure or gauge efficiency of a motor?

Huh? What do you want? Build you what? LOL

sikeston34m · 12.14.2007, 02:18 AM

Quote:

Originally Posted by johnrobholmes

That is great news! Looks like I should be testing my crawler motors to a Y termination too.

As for the wind resistance, each wind will have lower resistance because of the larger amount of copper and lower wind. The phase resistance in comparison to a D termination would be higher of course. The combination of changing wind count, termination, and copper netted you better startups, better acceleration, and a higher top speed? I would say either your efficiency went up or your amp draw did, maybe both. Got any old data logging from the previous setup?

I have read on the Croco site and other sites, that you want the wind resistence to be as low as you can get it without resect to how many turns it is. That is a goal with motor winding.

Manufacturers make compromises at the cost of effeciency with motors. Small wire is used because it is easier to work with. The larger wire is harder to work with but produces a wind that has a greater Cross Sectional Area. Less Resistence.

This Raises the Power Handling ability and efficiency.

I also feel like they steer away from the Wye wind because of the added termination point that can create problems if not done correctly.

They settled on a Delta termination, because in their testing with a prop, they are only measuring thrust at top speed and total amp draw.

They don't start the motor under a load at all compared to a Monster Truck. The amp draw doesn't come up hardly at all until some rpm's come on to the prop and make the load.

This makes the Delta wind easier and more profitable for them.

I have reached a point where I need a data logger. I have a brand new factory delta wind in the 3530. It would be VERY interesting, to collect some data from several runs with this custom wind. Then put the factory motor back in and collect some more data. Comparing that data would tell alot of things I'm sure. The difference is enough to see for sure. It performs alot better.

I put the factory wind on 6S one time and blew the transmission on the first run. I'm tempted to bump up to 5S on the custom wind, but I think that would be enough to make the transmission go Poof. I'll try to get some video soon.

The new E maxx should be hitting the market anytime. One of them has my name on it. I'll do this conversion with it. A transmission that can handle 2 1/2 times the torque of the original? Let's make that thing dance! LOL