I got the Brushless Jato to the track yesterday. Here's the layout of the track. It's not exactly to scale, but it's a good representation made by one of the drivers.
http://www.goatman.com/johnpics/rce/INSIDE_TRACK.jpg
So you have an idea of the size, the back straight is 96ft.

When I first got the Brushless Jato going on the track it was apparent that there wasn't enough weight in the rear to get enough traction, so I added a 4-cell dry pack with 4AA batteries into the rear battery holder. Even with the extra weight it took a light throttle finger to keep the back end in check.
The owner likes technical tracks. Normally this means that there are jumps with specific timing, or they're located close to turns to force thoughtful driving. This is the first track that's technical due to the placement of turns rather than jumps. The jumps are actually very easy to land (overall), but I couldn't get over about 1/2 throttle due to the frequent turns. Even on the cleanest laps I ran I couldn't push the truck anywhere near it's limits.
The Brushless Jato was *extremely* stable in the air. I was very pleased to see that it was perfectly level and jumped more smoothly than any stadium truck I have driven. This includes XXX-T MF, T3, T4. I think it has to be the changes in the way Traxxas designed the Jato that allows it to be so stable even after such a radical reconfiguration. The only thing I expect to do in finishing up the suspension is to raise the ride height in the front and possibly add stiffer springs to the front. It sags more than my liking during braking.
Sorry, no video of the track runs yesterday.

One new configuration note: I hooked up my Nomadio Sensor to the Jato (since the MGT is in pieces right now). I really love the radio and telemetry information.

The Brushless Jato entered it's first race last night. It was a less-then-stellar performance....
2 qualifiers and the main.

Qualifier 1 - on the second lap my motor mount moved and disengaged the pinion from the spur...
Qualifier 2 - on the first lap the pinion actually fell off...I didn't find it until the end of the night. At least the shop had a few 32-pitch pinions that let me get it back up and running. I hadn't lost a pinion or even had one come loose in all the testing...go figure.
Main - about 3 minutes into the race the motor mount moved again...game over, man.:C:

The bonus is that I now know a few important things.

1. This battery (2s), motor (lehner basic xl4200), and speed controller (MGM12012) is a GREAT combination for racing the Brushless Jato. Controller temp never went over 108 and the motor stayed only slightly warm. It has too much power to hit full throttle on the 96' straight, so I have no need to make it go faster. This is the same setup I GPS'ed at 36.8MPH.

2. The problems I had are easily fixed (once I get to work on it, that is). I already put a drop of threadlock on the pinion. Now I just need to get the motor mount to stop moving.

3. I need to work on reducing weight overall, focusing on moving the weight that remains down and to the back. It's still about 1lb. heavier than a "normal" electric stadium truck.

I hope to get it back up and running reliably and see if I can actually race again next week.

Sounds good. Great update, Batfish. Thanks for sharing this with us.
Too bad about your bad luck with this pinion. Fortunately your problems are easy to fix. Can't wait to hear from your next race. Good Luck!

Do you race against Nitros or do you have a BL stadium class?

This Nomadio Sensor telemetry, what information can you get out of this??

And, what are jumps with specific timing?

Thanks
DAF

Sounds like you need some loctite!!!

;)

Is it always one screw that's get loose on the motormount?

Dafni, the Nomadio sensor can give you voltage readings and temp and can give you beeps and vibrations on the transmitter for pre-set high temps or presumably low voltage aswell.I think it comes complete with sensors and it sounds perfect for brushless.
Maybe could be used instead of LVC for Li-po.
There's a little video explaining it herehttp://www.rcuniverse.com/magazine/a...article_id=525

If Batfish reckons it's worth it I might get one.

i personally fancy the eagletree, (because of it's current and power reading)

Thanks Serum,
I hadn't heard of the Eagletree but that looks really cool.I like the G-meter.that would be lots of fun for measuring acceleration and for chassis set up.And to know how many Gs you just pulled in a crash.

It says the EU version is 433MHz.Do you know how many bands are on that frequency?I don't suppose you'd come across many others on that frequency anyway.

People say with the 2.4GHz the interference is less than 27 or 75 FM.

Batfish,have you noticed less interference?

You don't have to use the Eagletree in telemetric mode. You can also read out the data via cable, I believe. Please correct me when I'm wrong. No submission, no interference.

I had a close look at this Eagletree, and I would love to get one. Would be a perfect gadget to share between two buddies, and share the costs. Unfortunately most RCer's here in my area don't care about the temps of their nitros.:C:

Daf i'll share it with you :eek: .

Okay, I'll take it first, but whenever you want it, just come and get it, not a problem :)

But I hear you, mate.

Sorry for the hijack, batfish.

Yeah, i am in desperate need for one too.. Can anyone explain it to Isabel how it enriches my life?

You are right Dafni, it is some kind of black box, read afterwards.

I have the feeling Isabel and Sandra would have a lot of interesting topics of discussion.

Batfish, another question: Do you read the temp on the motor and/or ESC / batt ??

Whew! A few questions since my last post, heh :)

First - I did loctite the pinion after losing the first one :)

Second - it's not really a specific screw/bolt that comes loose, it's really my poor design skills that do it. Once I have a better-designed mount it'll do fine. I'm going to be buying another Jato chassis from ebay soon so I have a backup when I drill the current one to death.

Third - the Nomadio Sensor is, for lack of a better description, freakin' awesome :D
Price difference is pretty interesting when you consider everything you get, too. I did a price comparison on rcuniverse in the Sensor thread a while ago. A similar high-end radio with add-ons to make it nearly as feature-rich as the Sensor would run about $700, while the Sensor will sell for $520.
In comparison to the Eagletree system, you'd need the Seagull system to get live data like the Sensor and even then it doesn't give you tactile feedback like the Sensor. The Sensor can vibrate and/or play sound files when an alert is triggered.
The one thing the Eagletree has over the current Sensor configuration is recording of data for later viewing on a computer. A future software update from Nomadio will allow the Sensor to record live to a computer via USB. Granted, carrying a computer with you while driving would be a pain, but it would only be used during practice to gather data and adjust for actual racing.
Sensor can work with up to 4 temperature sensors. There are two ports for temp sensors and each is capable of two sensors. Still waiting for Nomadio to explain how to wire them (and, for that matter, actually sell them seperately) to work on the two ports. I currently have the temp sensor held onto my ESC via ziptie. I figured I'd keep it on the more expensive component while I only have one :)
I love the feel of the Sensor and have become very accustomed to being able to see my battery voltage and temperatures at any time. The only thing I'd change at this point is the springs in the trigger and steering. I'm used to the steering one, but the trigger is still stiff for me. I'll get used to it, I'm sure.
The Sensor is a software-based PC peripheral, which means you should never have to send it back to Nomadio for updates. You just download them to your PC and install through the USB port. You update both the radio and the transceiver this way.

Fourth - I have had zero interference with the Sensor. Since it's DSS I can also turn it on in the pits with no worry about affecting anyone else. At my local track it means I can practice on another track while racing is going on (if I want to).

You can see Nomadio's Sensor support forum here: http://support.nomadio.net
and their regular website at
http://www.nomadio.net

Lastly, I think it will end up being worthwhile for me to have purchased the Sensor since all of my vehicles at this point are "project" vehicles, which means I never know if what I've done is going to work right until I try it. That means that if I gear my vehicle wrong and my speed controller jumps right to 150F I'll know the second it happens and I can stop throttle right then and there. This can definitely save on equipment. I'm sure everyone who already has a $300 radio setup and has fried a $200 (or more) speed controller wishes they had a way to know it was going to fry before it happened. That's how I feel it'll help pay for itself in the long run. Now Nomadio needs to come out with their second-gen transceiver so I can get them in all of my vehicles.

Sidenote to Mike - if we had the Sensor reading the temps on the E-Revo motor we might not have blown up that 10L at Monster Madness :D

There's a nice long post for you to digest. Let me know if you have any questions :)

Hey Batfish. did you think about making a motor plate off the gearbox? thats how i'm doing mine. the only problem i had was the pinion wouldn't reach, so i took an old associated slipper clutch and ground out the center and the bushing to fit the shaft and used the traxxas spring and nut. Now i can run any 32 pitch gear for the rc10gt, even 48 pitch.

Now that sounds promising. Do you have any pictures you can share?

Sorry i don't. I'm not sure i can post if i had them(still new to computers) but i noticed a potentia problem with this idea, the pia on the shaft is exposed on the sidesbut the clutch nut and spring should keep it on

I think I know what you're getting at, though. Did you use the mount holes from the clutch guard to attach your motor mount? I went and took a look at mine and I think that may be workable as long as there's more support for the rear of the motor somewhere.

Yes i did. It feels really good, but i'm going to brace it to the upper plate where the guard mountedfor extra support. I was also thinking that you could grind the groove that the pin fits into to move the gear closer to the motor. I may try this today. I may also try to get a cheap camera and take some pictures of what i've done so far.

Version 2 is now ready. :)

Here are the changes:
1. Tranny has had first gear removed and second gear locked (similar to my MGT tranny). This allows for the motor to be used for the braking, and for reverse.

2. Throttle/brake servo (and components) have been removed.

3. Most of the upper plastic tray has been removed. The only part that remains is the part that the steering servo mounts to.

4. Associated battery cups attached to rock guards to mount battery sideways in front of motor.

5. Removed the battery compartment rear bumper and replaced with the optional Jato rear bumper.

You can see the comparisons here in these pictures. The first two pictures are the overhead view comparisons from V1 and V2. the second two pictures are the side view comparisons from V1 and V2. These changes have moved weight to the rear and lowered the center of gravity, the two things the Brushless Jato needed most.

<img src="http://i20.photobucket.com/albums/b239/1joeyoung/Jato%20-%20Brushless/Jato_top_right.jpg" alt="Image hosted by Photobucket.com">
<img src="http://i20.photobucket.com/albums/b239/1joeyoung/Jato%20-%20Brushless/V2_Top_right.jpg" alt="Image hosted by Photobucket.com">

<img src="http://i20.photobucket.com/albums/b239/1joeyoung/Jato%20-%20Brushless/Jato_side_right.jpg" alt="Image hosted by Photobucket.com">
<img src="http://i20.photobucket.com/albums/b239/1joeyoung/Jato%20-%20Brushless/V2_Side_right.jpg" alt="Image hosted by Photobucket.com">

Here's to hoping for a better turnout this coming Thursday at the club races :)

Almost forgot to add the little video that shows forward/brake/reverse.
http://www.rcpics.net/view_single.php?medid=63835

omg me want
you gonna start sellin this conver with Mike??
if you are man i might get a jato jus to use that conver
wish i have money tho =(

I decided to go back to nitro on my jato. I couldn't get the batteries to fit to my satisfaction, but don't worry i've still got a revo to convertto electric

Take your time fitting the batteries, with converting, the batteries are a struggle to begin with. Perhaps you can do something with the tub from emaxx..?

the emaxx tubs won't work (not enough room between the servo and gearbox) there is only enough room for about 5 1/2 cells. I was going to try to use the steering servo vertical but the linkage binds too much so the only 4 options i see are lipo's, smaller batteries (2200's), new gearbox with relocated upper gears (nobody makes one yet) or going back to nitro untill i can afford one of the other options,so that is what i am going to do. Don't worry, i've still got two ele stadium trucks to play withso it's ok for now

I decided to skip racing last night in favor of spending some time practicing tonight.
The Brushless Jato V2 is a HUGE improvement. Getting the weight distributed more appropriately definitely made the truck more driveable.

One problem remains now...the truck is just too powerful for the track. I'm going to have to spend a bunch of time setting my radio up to dial out the power. There isn't a single spot, including the 96' straight, that I can get over 1/2 throttle. The truck is just too darn fast for a technical racetrack.

I'm learning to drive it all over again since V1, but at least it's controllable as V2 and I don't have the moving motor mount problem anymore. When I race next Thursday night I expect to actually finish both qualifiers and the main. So far I'm 1 for 6, which is a pretty dismal record, heh.

that is a cool truck, You are a true inovator and really know what you are doing in this hobby, Props to you man

You working the kinks out there batfish. I am glad to here it. Should bring home the trophy thrusday. Good luck.

The Brushless Jato V2 had it's best outing so far tonight.
3 qualifiers and the B main all finished. There were 5 drivers in my group.
I was 3rd in the first qualifier, 4th in the second, and TQ'd my group in the 3rd. I came in 3rd in the B main.

To control some of the power, I adjusted my radio's throttle end point at 40 (the Sensor goes from 0-100). That seemed to do the trick, but once I have better traction in the rear I'll probably have it up to 50 or 60.

Interesting development tonight - I put some white Revo springs on the front of the Jato and lowered the rear about 1cm (threaded shock/spring adjustment) and TQ'd the next qualifier. The front is very stiff now and the rear tires got a little more grip. Overall, I was suprised that this drastic of a change came out so positive.

I hate to add weight to it, but I think my next tuning test will be to re-add the 4-cell pack rear bumper. The last thing I'm missing for stable running is a little more traction in the rear.

Next electronic steps are to upgrade the stock Traxxas 2055 steering servo with a BMS 620MG I already have, and trade the 12012 for the 8012 I got from Mike. The 12012 will be transplanted into my 1/8th buggy.

We'll see how next week goes. With just a little more traction and quicker steering, I'll be in the A mains again in no time :)

Hey Batfish. You could add lead weightused in model airplanes. I can get it at my ihs pre cut in 7gram squares.

maybe you can find it near you. Beats adding too much weight with all those batteries. Sorry for double post, too late for edit

Actually, the 4-cell dry pack is pretty good for tunability. If I find out that I only need to add a little weight, I can just put one battery in it...all the way up to 4. It's a quick adjustment to pop a AA into or out of the pack, too.

Heck, I gotta find SOMEthing to do with all these dry cell holders laying around.

:)

Few more notes to add tonight.

- I got the BMS 621MG servo in for steering and swapped the stock bushings out for bearings in the steering
- I put the rear bumper/battery holder back on
- I changed the gearing from 20/54 to 15/58 hoping to have smoother starts and better low-speed running
- I got the MGM 8012 (new version) ready and will be installing it tomorrow when I get more heatshrink tubing for the wires/connectors

Hopefully another good Thursday night of racing around the corner :)

Brushless Jato V3
 

It's been a while since I made an update here. I hadn't even realized that I forgot to post about my motor mount finally giving up. The design I came up with to mount it to the chassis ended up failing in the end.
I stopped running the Brushless Jato and decided not to run it again until I got a new motor mount worked out.
People at the track ask me no fewer than 3 times each week where the Jato is, heh :)
Well, I got inspired to get it running again and spent the last few days working out a new motor mount. It came from an idea that crazyjr posted about earlier in this thread. I bolted the mount to the holes in the tranny where the clutch guard comes out of. I made the mount angle upwards to the front so that I could move the battery holders further back on the chassis. End result is that I moved the motor slightly back and up, and also moved the battery holders back almost an inch.
I actually expect the mount to fail at some point since it's still the cheap aluminum I got at Home Depot, but I'm hoping to get in enough races to prove that the design works before it breaks. Once I know if the design is good, I can look at getting one machined.
Here are 3 pictures from V3:

<img src="http://i20.photobucket.com/albums/b239/1joeyoung/Jato%20-%20Brushless/Jato_v3_side.jpg" alt="Image hosted by Photobucket.com">
<img src="http://i20.photobucket.com/albums/b239/1joeyoung/Jato%20-%20Brushless/Jato_v3_top.jpg" alt="Image hosted by Photobucket.com">
<img src="http://i20.photobucket.com/albums/b239/1joeyoung/Jato%20-%20Brushless/jato_v3_motormount.jpg" alt="Image hosted by Photobucket.com">

the edges look very "sharp" on your desing:P

It's a trap...I want anyone that thinks of messing with it to think twice, heh :)

Now where did I put those band-aids?

:)

That is exactly how i did it. I still have mine, but i'm saving it till i can put more money into the project. Thanks for the credit, but you actually made it work. As far as the motor mount failing, i don't think so. The clutch guard mount will probably fail before then