Rustler Addiction- Mid engine and more (lots of pictures)

[Doom!]

Nice job, and good skills to share.

 

[JCsRCcar]

Some more progress pictures. This thing has evolved slowly over the past week but progress has been steady. Its a bit more work than I thought it would be as almost everything on this thing is custom or a miss mash of parts from others cars. Its almost ready for a first test run though so thats exciting. We decided to install the ESC tucked tightly down low between the battery and steering servo because it weights about .5 lbs, which is kind of heavy, and I wanted to keep the center of gravity as low as possible. The custom made battery tray will fit our 4s or two 3s batteries snug. I just have to make some battery stops on the ends of the battery tray for it in case the straps aren’t strong enough to hold the battery down during spirited runs. I should probably mount a fan for that motor and we would like to mount those Polo Creations lights too. The wiring is a mess right now and we will clean that up. I had to make extensions for the brushless motor leads from the ESC because the wires were not long enough.

 

[Doom!]

Sometimes it gets crowded real quick. Looks good.

 

[olds97_lss]

That thing on 6S is going to be a nightmare to drive! Very cool!

Do you think the transmission will hold up though? I'm not sure what's in the nitro trans on those things.

When I converted my 2.5 jato to brushless, I replaced the 2 speed with a steel hot racing single speed conversion. The plastic single speed conversion lasted about 2 minutes. Which was about 6 seconds longer than the plastic axles lasted me... lol! That was on 2S!

I run 3S in it now and it's tough to drive at full tilt. Likes to lift the front. I tried 4S, it was super twitchy. The 1/4" thick chassis should help some with that. I run a max10 sct and hobbystar 3670 3100kv in it with the mod.8 gears the jato started with, but 25/58 gearing. Mine doesn't look nearly as nice as yours, but it's just a basher. Took a bit of effort to get it to hold up to launching it off jumps at the bmx track I run at, but it does pretty good.

 

[JCsRCcar]

That thing on 6S is going to be a nightmare to drive! Very cool!

Do you think the transmission will hold up though? I'm not sure what's in the nitro trans on those things.

When I converted my 2.5 jato to brushless, I replaced the 2 speed with a steel hot racing single speed conversion. The plastic single speed conversion lasted about 2 minutes. Which was about 6 seconds longer than the plastic axles lasted me... lol! That was on 2S!

I run 3S in it now and it's tough to drive at full tilt. Likes to lift the front. I tried 4S, it was super twitchy. The 1/4" thick chassis should help some with that. I run a max10 sct and hobbystar 3670 3100kv in it with the mod.8 gears the jato started with, but 25/58 gearing. Mine doesn't look nearly as nice as yours, but it's just a basher. Took a bit of effort to get it to hold up to launching it off jumps at the bmx track I run at, but it does pretty good.

It has the Hot racing metal transmission and Tekno metal axles, so it is about as bulletproof as I can make it. That transmission and Tekno axles have been used in my original Rustler and it held up well under 3S and many crashes and jumps without issue.

As far as the instability due to the short wheelbase and somewhat lightness of the car. I incorporated another set of holes into that custom built chassis so if I wanted to I can mount the transmission a couple inches further back to help with that issue.

Because of the ¼” aluminum chassis and other components like the metal transmission this car weights about 6.5 lbs without the battery so I guess we’ll see how it does. I also pushed as much of the heaviest components towards the front of the car as possible to try and prevent the likely front end lift I know Rustlers typically experience. I also have a nice wheeler bar ready, and I can add a 200 oz servo weight to the front too if I have to.

 

[JCsRCcar]

Update 3/13/22:

The car is 98% finished and we took it for a first run today on a modest 4S battery at the local college parking lot. Its only equipped with Pro-Line street tires that are not belted and it was a chilly 30 degrees out so we didn't want to end up crashing it on its first run. To my surprise it handles fantastic, doesn't do out of control wheelies, and it doesn't have a tendency to flip over like a stock rustler can sometimes do on 3S power. It also wasn't as quick as I thought it might be but it was still fast, about as quick as my sons 2WD Bandit Rustler geared for speed on 2S power. That makes sense though because 7.4 volts x 3800 kv = 28,120 RPM and 14.8 volts x 2050 kv = 30,340 RPM so they should be about equal in terms of motor speed. The Bandit Rustler is also much lighter than this custom Nitro/eletric conversion Rustler is. Here are some pictures of the finished product.

Here is another pic of my sons custom Rustler with Bandit body and a few other bandit parts using a Castle Copperhead/3800 combo for propulsion.

One cool thing was he got lucky and went into the local hobby shop and was given these old but still working Dodge drift car and RC boat for free. He was pretty excited about that. One of the two 7.2 volt Ni-Cad batteries still worked well too and the 9.6 volt battery for the boat took a charge. The drift car came with all kinds of extra tires too.

 

[Doom!]

Good to hear she handled well.

 

[JCsRCcar]

Update 3/19/22:

So I realized something real quickly while my son was bashing his Slash with the stock brushless Spectrum 3150 KV motor and 130A ESC combo I gave him to put in that car. It seemed very slow and every time he went to hit the brake, it would go into reverse instead with authority. Then I realized when we installed that combo that the motor rotation was backwards so we just switched it in the transmitter. The problem with this solution is the ESC still behaves like its reversed so it is sending 25% power when going forward, and when you try and use the brake it thinks its forward so instead of the car braking, it quickly goes into reverse. I realized that this was the wrong thing to do and we should have reversed the motor rotation in the ESC programing instead. We fixed this today and now it works correctly and it is way faster going forward (100% power now).

So I made the exact same mistake for the Nitro/electric Rustler conversion because that also runs a Spectrum 6S 150A ESC and 2050 KV motor combo. I reversed the motor rotation in the transmitter when I should have reversed motor rotation with the ESC programming instead. It also would quickly go into reverse, making the car spin out of control instead of braking, and this also explains the lack of wheelie power and disappointment with forward power I experienced. The ESC was only giving the motor 25% power because the ESC thought forward was reverse! So I instead reversed the motor rotation in the ESC programming and now the brake works properly and the forward power is now 100%, not 25% as it was before. I’m going to test this thing out on the next good weather day we get and I bet it will be way faster now.

Lesson learned for anyone who uses a Spectrum ESC and motor combo in a different car then it was designed for. If the motor is not rotating in the right direction making the car go backwards, then do not reverse motor rotation with the transmitter programming. Instead either reprogram the ESC, or reverse the two outer brushless wires to correct the issue. If you reverse the rotation with the transmitter then the ESC will send reduced power when your car goes forward and the brake wont work, and instead it will reverse when the brake is applied.

 

[Doom!]

At least you've solved the problem, good to know.

 

[JCsRCcar]

Added a Traxxas 5624 receiver box with integrated antenna holder and fixed the missing wheelie bar wheel. I also got the Polo Creations lights installed with some custom fabrication to make them fit.

 

[Doom!]

Lookin' good! I really like the Polo Light kits.

 

[olds97_lss]

@JCsRCcar FYI, with unsensored brushless motors, you can also just switch 2 of the motor wires and it will reverse it's direction. Only sensored motors have to be wired A->A, B->B, C->C. Then your forced to change the direction in the esc setup.

 

[JCsRCcar]

Last weekend we got the ESC backward thing resolved and took the car out with two 3s fully charged packs (6s for those that are learning). Sooo TBH the car was just too fast and too powerful for the way it is configured right now. It is scary fast. In our local college parking lot I couldn't get on the throttle with more than 33% throttle without the front end lifting (even at 50-60 MPH) and then running out of asphalt (need braking distance). Its just insane how powerful it is. In the end I ended up rolling the car and broke the front wheel off. I also cooked the stock slipper clutch before I realized it was slipping. It slipped so bad that it melted the aluminum backing plate and turned the metal disc blue.

So now we are going with the extended wheelbase option and doing a few other modifications to make the car more stable under that immense power. The LHS also gave my son a free roll cage from another car so he wants to integrate that into the car.

 

[Doom!]

Well, I think I spotted the flipping problem, I think it's having an allergic reaction to the Arrma 6s sticker.

Glad your getting things sorted out. Sounds like an adventure in the making.

 

[JCsRCcar]

We added a separate Kyosho drift gyro to help with the high speed runs and we have a nice ProModeler servo because the cheap Eco Power servo wouldn't play nice with the new gyro. I have several ProModeler servos from their Brushed DS series to their DS845LHV brushless servo. Their brushless servos are just insainly nice for what you pay for them, or at any price really. Nothing really compares to how nice these servos are.

 

[JCsRCcar]

On the last run I lost drive power and could hear gears grinding. After inspection we discovered that the spider gears lost their teeth. A quick spider gear replacement with new gears and 500k diff fluid and of course we cleaned out the differential fluid and all the metal pieces and it is ready for another run. Because the tires we were running were not belted and they ballooned like crazy under the intense centrifugal force from this Frankenstein Rustler we got some new belted drag race tires to help cure that issue. I purchased my son a DuBro Tru Spin wheel balancer from Amain Hobbies and my son got right to work balancing all the tires for all the cars we own. Its actually surprising how out of balance tires actually are. I got the AKA wheel balancing clay and my son used up almost the whole bar . The belted drag tire you see in the picture with clay was one of the better easier tires to balance that didn’t need much clay. I bet these cars will run a lot smoother now and probably crash less often too. Some pictures to tell the story.

 

[Doom!]

Looks like an MMA contestant with that many missing teeth!

 

[JCsRCcar]

My son and I are getting back into this and he wants to start a YouTube channel making some videos of RC cars, so we decided to start with the Nitro 6S electrified Rustler pictured in the thread above. We are going to do some speed runs with this car and purchased a Sky RC GNS GPS to measure the speed runs accurately. Unfortunately we had a failure and I “think” it resulted in a low speed captured by the GPS. We want to be honest however so we recored the low speed run anyway. I purchased a 45 tooth pinion to get ever closer to that 100 mph mark, so if we ever get close to that then we would have accomplished our goal. Well anyway, here is the link to his video that he edited himself. I narrated it for now because he’s a little she with that part but I’m sure that will change some day.

Enjoy:

 

[Doom!]

Nice job with the video, we want your son to narrate the next one, it's the best way to get used to it, he can always edit out mistakes.

 

[JCsRCcar]

I will tell him that. The best way to learn something is to do it which means making mistakes.