Foell.org

Mmm.. Candy Canes

That day I discovered what it means to “candy cane” a CVD – there’s a groove in the inner shaft that allows it to telescope with the outer shaft. Abuse the axles too much and axle will twist, sometimes a full revolution before breaking. Making the groove create a candy-cane like appearance:

CVD Upgrade

Rather than looking for old 3906-spec CVDs, we opted to upgrade to the latest E-Maxx CVDs, which also require some supporting parts. We followed the recommendations from this excellent 3906 upgrade guide.

From that guide we ordered:

• Traxxas 5451X CVDs
• Traxxas 5143 & 5141 Turnbuckles (get them on eBay with ends and linkage balls included)
• Traxxas 5334 Axle Carriers and supporting parts (get them complete on eBay with bearings included)

Additions that were needed to complete the installation:

• Traxxas 5131R Upper Arms & 5132R Lower Arms (you can get them as a set on eBay)
• Traxxas 5134 Spacers/Shims
• Traxxas 2580 3x20mm Button Head Cap Screw

You can sometimes find parts bundled on eBay such as this set with arms, axle carriers, turnbuckles, and screws. Then you just need to add CVDs and shims.

Tiny Arms

After purchasing the first set of parts, I went to install everything and discovered the arms were way too short. There were apparently two arm-length options in the 3906 series alone, wide and narrow. If you don’t know what you’re running, here are the specs:

• 110mm Narrow Arms
• 127mm Wide Arm (no need to upgrade)

But that’s not the full story. I did some research using the E-Maxx 3903 front and rear exploded views to see what else is different. Notice how the longer arms have narrower hinges where they connect to the bulkhead? This is for adjustability, and that’s where the 5134 Spacers/Shims come in. Use the removable C-clips in front (so you can adjust the camber):

Install the circular spacers in back:

The shorter 5141 turnbuckles used for steering linkages come with offset ball mounts. Make sure the extra space faces up:

Attach the turnbuckle to the new style Axle carrier using the longer Traxxas 2580 screws. That’s it for assembly, time to adjust everything before putting it back on the road.

Set Toe & Camber

Camber is adjusted using the pivot ball screws that connect the axle carrier to the arms. According to the manual, the top screw is normally all the way in, meaning the camber adjustment is made primarily through the bottom screw. Stock camber angle is one degree of negative camber.

Toe is adjusted with the turnbuckles and stock adjustments are one degree of toe-in at the rear and zero degrees at the front. I adjusted the front to 1 degree out to soften the turn-in.

With the wider stance you can probably go a little nutty on your wheel/tire options. But mostly you have a more robust platform that will be easier to replace and repair with more widely-available parts.

I have a feeling something upstream in the drivetrain will fail next: driveshafts, slipper clutch, spur gear, etc. But until then, we’ll just enjoy the ride.

The post 3906 E-Maxx CVD Upgrades appeared first on Meatball Racing.

Batteries

I know the old NiMH batteries were going to suck and what really impressed me when I came back to RC was how awesome Lithium batteries were. But do we need to get everything that goes along with it – like the newer EVX-2 electronic speed control that has low voltage cut-off? Heck no, we’re just trying to get it running. A simple low voltage alarm will do just fine.

So we’re going to get only batteries, but the 3906 chassis is sort of particular about fitment. Each battery sits (snugly) in a tray, and there’s battery strap that goes directly across the center of the battery. I found these 2S lipos that have the power and balance leads coming off of opposite corners, so they can sit in the tray nicely and have the strap close them in without crimping any wires.

But when it came time to put them in, we needed to trim one more piece. The old NiMH battery packs have rounded edges, where LiPos are square and about 2mm taller. The edges of the battery were getting hung up on part of the gear cover. The solution was to remove the gear cover and cut off the wire routing slots using a side-cutter:

Re-install the gear cover and the batteries will now snap into place. They’ll be snug, but they’ll fit. You’ll need to loosen the metal battery clip screw & post a couple turns to accommodate the LiPos thicker profile. Then you can use the original battery strap to hold everything in.

Here they are installed. The low voltage alarm is just zip-tied to the rear shock tower:

That’s it! Now go have fun 

I will warn you that the 1st Generation 3906 E-Maxx is capable of doing a backflip with some backwards/forwards throttle – but the old drivetrain is not up to the task. Next time we’ll tackle CVD upgrades to the newer E-Maxx units for better durability.

The post E-Maxx 3906 LiPo Battery Upgrade appeared first on Meatball Racing.

Tips for recovery after a crash

My son, now age 9, is an excellent spotter. The only problem is getting him motivated to come with me to the flight line. He probably knows that a crash and a long “walk of shame” are inevitable when I’m the pilot. So he’s content to make friends his age and help locate the YouTube stars for selfies – more on that later.

This means without my expert spotter by my side, I recruited some random passersby to help. They weren’t as adept at helping with crash location, but luckily I had a trick up my sleeve.

Even if your plane is bright pink, it’s easy to get lost in the bean field at Flite Fest in Malvern. The beans aren’t as thick as you’d think from the photographs. Planes tend to slip past the top cover of leaves and find their way to the ground. Now they’re covered by a canopy of bean leaves AND if you have a plane made of water-resistant foam board like this:

It’s likely sitting on the dirt that is approximately the same color 

You could buy a beeper for your model, but I suggest a simpler solution: add a streamer. The streamers are more likely to stay above the leaves. If you choose a color that is not green, it will make spotting your downed plane much easier:

YouTube Stars

So while Jules didn’t accompany me often to the flight line, he was keen at finding several of our favorite YouTube personalities so we could snap a pic.

 

 

 

FT STEM build

I did manage to get Jules to do the FT STEM build. It was a free-form challenge to build and test a plane design using a pizza delivery box.

Our guys decided to go with a tried-and-true Nutball design they dubbed “The Pepperoni Plane.” As a coincidence I had built a Nutball just weeks before so the build details were fresh in my brain. I was able to give them tips – at least how the Flite Test guys do it – and let them do all of the labor.

Out of the entire class only two planes actually flew and this was one of them. Here’s Jules (blue hat) buddy boxed with an expert pilot/volunteer during the maiden flight:

Take a break from flying

Also, Flite Fest doesn’t have just flying enthusiasts. We brought our Slash trucks to drive if the flying (or crashing) was getting frustrating. These kids made the best of a giant Nutball carcass by turning it into a jump:

I think Flite Fest fully embraces the RC mantra: JUST SEND IT!

The post Flite Fest Ohio 2018 appeared first on Meatball Racing.

Safety First

When I’m marshalling, I follow a few of safety precautions:

Watch for traffic – be aware of what is heading in your direction, especially when you’re about to jump out onto the track. Some of the more spry marshals will literally jump over cars to help someone. If you’re feeling your oats, go for it. But if you have to wait for some traffic to pass, wait. Better to have helped one driver recover than to have caused an additional 6-car pile-up. Watch for traffic as you return to your corner position – there’s zero need to do any athletic moves at this time.

Be careful of hot motors – many R/C cars have their motors exposed to keep them cool from the passing air. You don’t want to touch these parts. I find it best to grab the cars with two hands somewhere around the body. Be careful of stuff you can’t see – there might be something hot waiting to burn your fingers underneath. Try to just grab what you can see that’s safe.

Don’t grab moving parts – wheels, avoid them. There are way too many overzealous drivers (see below) out there willing to pull the trigger before you get their car fully righted. You don’t want your hands to be a fresh recipients of road rash.

Marshal with your ears and eyes

When I’m marshalling, I play zone defense. Keep an eye on the parts of the track that you can get to quickly. Don’t pay attention to the race, it will be dizzying from where you’re at.

You want to be paying attention to what’s going on in your zone – the area you’re responsible for. If you’d like, you can study the cars lines through your area and learn something. How are the fastest drivers getting through the corners?

But you don’t necessarily need to watch every car come through your area…

I allow myself to unfocus my eyes without checking out mentally. I don’t watch every car come through, but I’m looking generally at my area. This is where using your ears helps a lot. Especially in electric on-road, any driving drama is going to be accompanied by some noise. A car hitting the boards or crashing into another car. The sound of a brand new lexan body sliding across the asphalt. Off-road gets a little noisier with all the jumps, but you’ll come to recognise the sound of a buggy wing hitting the ground first when the wheels should have. Nitro adds even more noise, but once you do it a few times you’ll begin to recognize the sounds that are clear signs of trouble. This is when your marshalling duty calls. Once you’ve got your ears tuned to the right sounds, you can use them to locate their position (which might be behind you) for your nest assist.

At the ready

Sometimes tracks will provide a chair or a bucket to sit on at the marshalling points. You’re welcome to use them and sometimes sitting is compulsory to provide a better view for the drivers.

But you should always be ready. Some marshalls on the outside of the track will opt to stand – especially for the mains. If you’re in the infield, you can sit but should be ready at any time. You can even play shortstop by almost sitting if the action is particularly hot that day.

Marshalling tips for Drivers

The single worst thing you can do as a driver is yell at a corner marshal from the driver’s stand.

The only thing you should be yelling about is if there’s a hazardous situation like a car stuck in a straightaway. If that’s the case you should be generally yelling to inform your fellow drivers on the stand. Something like “Back straight!” should be good enough. If you want, even add “Outside on the back straight!” to instruct them to take the outside line if the hazard is on the inside of the back straight.

Do not, I repeat, DO NOT yell at a corner marshal for doing what you might think is an unsatisfactory job. To illustrate this point here’s an anecdote.

Why So Serious?

At my first official off-road race as an adult, I found myself marshalling a section of that track that was rather quiet. In a 5-minute qualifier I didn’t have to help one car, but I noticed there was a section of the track that saw more action.

Not wanting to be a slouch, I chose the busy part of the track on my next stint, which was a qualifier for A-main stock buggy drivers. Stock buggy drivers are serious – perhaps too serious.

One driver flipped over a jump and when I went to turn his car over I wound up flipping his car too much so that it landed on the roof again. I could hear from the driver’s stand “Awwwww, COME ON!!!”

Did I do a bad job? It wasn’t my best, but I felt the feedback was unwarranted. So I confronted the driver after the heat. I told him

If you don’t like my marshalling, then you should work on your driving because you were all alone on that jump – and the only one responsible for the crash was you.

Tough stuff, but I’m glad I said something. He said that his comment was merely expressing disappointment in himself. So we were cool and went on with our races. If I had not said anything, I would have perceived it as a dig on me personally as a marshal.

Marshal Preference

At a big race there’s probably some sort of law regarding racing leaders getting marshal preference first if they’re caught in a tussle. But during club racing, I give everyone the same treatment. If you as a driver feel you’ve been treated unfairly, it would be better to talk to the driver that took you out, not the track marshal who is on your side trying to help you out.

The post How to marshall appeared first on Meatball Racing.

Experts are asking “Where has everyone gone?” and “How can the cost of tires be controlled?” I’d like to ask, how does “box-stock” sound? Everybody on the same tires, same motor, same ESC, same chassis. Low cost as well? Sign me up.

The Traxxas Slash undoubtedly started a short course revolution, and it’s far from over. While box-stock racing is the most important aspect that the Slash has brought to the table, there’s much more to Short Course than meets the eye…

Short Course Buggy

This is probably the deadest thing with the words “Short Course” attached to it, so let’s address it first. I don’t know if it never caught on or quickly flamed out. The Pro-Line conversions kits are hard to find nowadays, but it seemed like such a cool idea! I can only presume everyone that started with a Slash decided that the next graduation would be into the “real” 1/10 scale buggy class.

But is it dead? This recently popped up in my facebook feed:

Chuckworks RC has couple great buggy conversions. Also, there is the “Backslash” phenomenon – 4WD short course trucks converted to a 1/8 scale E-Buggy. It may not be a thriving racing class in your area, but if you’re wanting a new look, you’ve still got options.

Monster Truck

Not really for racing, but definitely for having fun. I would suggest this to anyone who is “in a rut” with their Slash and just need to smile when they pull the trigger.

Several Oval Classes

If you’ve ever been to a local dirt track for stock car racing, you’ll recognize some of these racers from their 1:1 scale classes.

All of these are based on the venerable short course chassis, and some specify stock parts to keep the playing field competitive. Click on the images under the headings to learn more about those specific oval classes. You might have an oval track near you!

Slash Spec/Street Stock

This is a street stock style class. Stock Slash underneath, with a standard car (or dirt oval truck) body on top.

SCT Modified

SCT Late Model

Slash Sprint

Drag Car

Want to go fast? Fastest to 132ft (a quarter mile at 1/10 scale) wins. There is a quick guide at the Traxxas site, but I prefer this sleek JConcepts design:

Speed Run

How about just all-out speed? Top speed. Insane speed. Check out this video of a speed run Slash that did 147 mph on 6S power.

Apocalyptic

While more of a style thing and not really racing, these creations are . With the popularity of short course trucks, it’s no surprise that they’re part of the scene:

More information on that build and another noteworthy one.

Crash-up Derby

There’s an event for this in my area. I’m floored – I didn’t even know this was a thing. People make their own bodies out of rain gutter aluminum for realistic damage.

Then they all get in the ring and have at it! I certainly didn’t watch this entire video, but it’s worth a peek just to check out the “Family Truckster” complete with luggage on top:

So if you think the Slash (and others) should be discontinued, think again. Sure there are a bunch of them out there, but there are also a bunch of people that are discovering R/C racing for the first time. Wouldn’t you want them to get started in a family-friendly, cost-controlled way? Short Course is here to stay and serve as the gateway into the greater world of R/C racing.

The post Short Course Trucks – decidedly not obsolete appeared first on Meatball Racing.