Jeff Hoy, American » hop-ups

Did you get a new R/C car or truck for Christmas?

Jeff Hoy — Fri, 25 Dec 2009 23:00:08 +0000

Christmas has come and gone. The presents have been unwrapped with joyous glee. If you’re one of the lucky ones, then hopefully you unwrapped a nice, new radio controlled car or truck. Here’s some of my older articles about how to upgrade and hop-up your new R/C car.

Did you get a Losi Highroller for Christmas? Then you might want to check out a couple of my articles about it. I have written about mine a few times, highlighting some of the ways to make it faster and stronger. Check out my first article about upgrading the speed control to make your Losi Highroller ready to use LiPo batteries. I have also written about upgrading the motor to make your Highroller faster. And finally I’ve shown you three hop-ups to make your Highroller ready for a brushless motor.

If you got yourself a Tamiya Baja King then I’ve got you covered there, too. I’ve suggested some ways to make the Baja King handle better and more durable. I’ve written about how to make your Baja King faster by installing a better motor. And I’ve demonstrated some cheap or free upgrades to the Baja King that you can do with some common house-hold materials and tools.

I’ve also offered Highroller troubleshooting tips and suggestions in the comments to my Highroller review.

Now get out there and have fun.

Finally!

Jeff Hoy — Sat, 15 Aug 2009 06:19:24 +0000

I just noticed that Losi has released a ball differential for the Highroller. If you’ve read some of my previous articles about my Highroller you’ll know that the stock gear differential is probably the biggest issue with the truck. So if you have a Highroller then get over to your local hobby shop and buy one right now. You’ll see a major improvement in your Highroller’s performance. I guarantee it.

Losi’s new preassembled Ball Differential comes fully prebuilt from the factory and is ready to be dropped into Losi’s 1/10 Slider, 1/10 HIGHroller and 1/10 Strike SCT. This differential was designed to withstand high-powered motor and battery setups, and allows the user to make adjustments for enhanced steering and traction.

Click for more: Losi: Ball Diff: SL, HRL, SCT: Losi (LOSB3594)

There’s also another new product that caught my eye: CV Drive Shafts. These drive shafts are a little more efficient at delivering power to the wheels than the stock dog-bone drive shafts. I’m going to assume that they are a little tougher too. Weak drive shafts and axles were another issue I had with my Highroller.

These CV-driveshafts will also improve rear traction since they allow the rear end of the vehicle to work more efficiently.

All parts are made from precision machined high quality steel to prevent the parts from bending and breaking, and come completely assembled and greased for easy installation

Click for more: Losi: CV-Driveshaft Set: HRL, SCT: Losi (LOSB3589)

These two products immediately jumped to the top of my r/c must buy list. After I get them I’ll give a full report.

More Highroller changes…

Jeff Hoy — Mon, 16 Mar 2009 18:01:00 +0000

I’ve dumped the weak-sauce motor that comes with the Highroller. That motor is seriously underpowered for a 12-turn. So I dropped in a Team Orion Formula Pro BB 10-turn double modified and stepped up to a 15 tooth pinion gear from the stock 12 tooth. With the much more powerful motor, even geared more aggressively, the Highroller accelerates a lot faster and has a much higher top speed. I decided against making the jump to brushless due to the cost factor. I had already installed a very high quality brushed motor ESC in the truck and I didn’t want to just throw that out.

Another important change is the steering servo. I removed the stock Losi (Chinese knock-off) servo, which only has 45 oz-in of torque and does 60° at a glacial 0.17 of a second. I upgraded to a much beefier 100 oz-in and bullet-like 60° at 0.11 of a second. The servo I chose is a Futaba S9405. Not only does it have strength and speed, it also features ball-bearings and metal gears providing a greater amount of durability over the standard servo. This beast swings the wheels much easier and faster than was possible with the old servo. Steering response has been improved dramatically.

My main complaints about the Highroller still stand. It absolutely NEEDS a sealed gear diff or ball diff to improve performance. The Highroller also needs stronger (titanium anyone?) outer drive axles to improve durability, I’m getting tired of having to bend them back straight after a rollover or rough landing.

Three must have upgrades for your new Baja King…

Jeff Hoy — Tue, 23 Dec 2008 06:01:00 +0000

So you got a Tamiya Baja King for Christmas or you just bought one for yourself. Congratulations, it’s a great car. Welcome to the Baja King Owner’s Club. You may have assembled it already or you could be waiting until you have a little more free time. But if you’re anything like me you’re spending all your waking moments away from your new Baja King thinking about it. Thinking about how fast it’ll go, or how high it’ll jump, how good it will be at chasing away your neighbor’s dog, you just can’t wait to start driving it. And maybe start upgrading it.

The Baja King is a decent performer out of the box. It could use some help though, and boy is there a lot of help out there for it. Tamiya is well known for supporting all of their vehicles with tons of hop-ups and the Baja King is no different. Being based on the TL01 sedan chassis, pretty much every accessory made for that chassis is compatible with the TL01B chassis that the Baja King is built on. Not all of them mind you, but most. Everything from carbon fiber drive train components to titanium screw sets is out in the wild. You aren’t going to need all those upgrades, but there are a few out there that are, in my opinion, must haves for the Baja King. So without further ado, here’s my top three must have hop-ups for your new Tamiya Baja King.

1. Oil filled shocks
The stock bouncers do not provide any type of real suspension dampening at all. They are pretty much useless on anything but the most smooth surfaces out there. If you want to run on a gravel driveway or unprepped dirt surface you are going to need a set of oil filled shocks to help smooth out those bumps and ruts. The performance difference will shock you (haha, I made a pun!). On my Baja King I went with Tamiya’s top of the line Super Low Friction Dampeners, you can find those online for around $60 for a set of four. They are machined out of metal and coated with Teflon to make them super smooth. The set doesn’t come with shock fluid, so you’ll need to buy a bottle or three of that which will set you back another $12 or so. I recommend starting with the medium weight set and going up or down from there depending on your surface conditions. But if you don’t have the money to spend on those fancy pants super duper shocks you can go for the slightly cheaper CVA Mini Shock set. They’re priced at about $20 for a set of two, so $40 for all four corners, they also include shock fluid in the pack. I would actually buy this hop-up before anything else. The difference they make is just astounding.
2. Ball bearings
Ball bearings will make your Baja King run faster and longer. They are also a key ingredient to cutting down on maintenance and parts replacement in the long run. The Baja King comes stock with plastic and bronze bushings all over the place. Plastic bushings in particular aren’t very durable and wear out quickly, creating slop in your drive train that reduces efficiency. When it comes to driving with electricity, efficiency is the key. The easier it is for your electric motor to turn all the gears and drive shafts and axles the faster your car will go and the longer it will run. Bushings create a lot of friction between parts, even when they are greased and oiled. But bearings, they just roll with the flow, like a fat dog on ice. Ball bearings help all your pieces and parts break lose of that friction more easily making the job of running it all easier on your motor. You can pick up a full set on the internet for about $30 if you buy the kit by DuraTrax, that’s what I’ve been using and they’ve been great so far. The official Tamiya kit is more expensive and a little hard to come by. I HIGHLY suggest buying these before you assemble your kit for the first time, and put them in where ever the instructions call for bushings, it’s just easier that way.
3. Hardened diff cups
This is another one of those “in the long run” maintenance items. The stock diff cups are very soft and the dog bone axles will start to make divots in them very quickly, reducing drive train efficiency. Unless you’re wrecking a lot or still using bushings these will probably be the parts you replace the most. The hardened cups will resist the wear and tear and last a lot longer than the stock pieces. They’ll run you about $10 a set so $20 total for both ends of the car. Just make sure you don’t lose the o-rings in the front cups when you go to swap these in for the stock pieces, you need them to keep the front axles in their proper place.

There you have it. Three must have upgrades that you should be shopping for right now. But be warned, Baja King ownership becomes a sort of illness after a while. Once you’re bitten by the bug there’s no turning back and you’ll be spending every last cent you have buying new toys for your baby. If you haven’t already, go back and read my posts on my Baja King here, here, and here.

All the links I’ve provided are for illustrative purposes. I have no affiliation with Tower Hobbies. Buy your hop-ups from where ever you’d like, you might want to consider shopping at your local hobby shop first.

Hacking my Baja King

Jeff Hoy — Wed, 12 Nov 2008 05:32:33 +0000

I spent some time today looking at my Baja King and trying to find ways to improve it. I’m not at all dissatisfied with it’s performance right now, it’s fast, somewhat agile, and a blast to drive. But I wanted more. But other than putting in a faster motor what else could I do to improve it? How about a weight-loss program and patching up some of the intentionally made holes?

The Baja King is based on Tamiya’s old TL01 sedan chassis. Basically all they did was swap out the short suspension arms and drive shafts for long ones. They also took out some extraneous parts that weren’t conducive to off-road driving. They left all the mounting holes and whatnot though. The first thing I did was take my dremel (I use a craftsman rotary tool, but it’s the same thing) to all those mounting positions for sedan body posts and electronics trays that I don’t need. I didn’t take any measurements but I shaved at least a few grams from the chassis. I also got some acrylic glue and used it to seal up empty screw holes from the missing parts.

The suspension arms are two pieces each, held together with screws. I took the suspension arms apart and used CA glue to stick them together and ditched the screws. Dropping eight screws from the unsprung weight of the car can’t hurt. I’m only doing this as a trial right now, to see how well it holds together. If it fails miserably then it’s back to the screws.

Next the dremel went into the battery compartment. I had to sand it out a little bit with the drum sander so that my LiPo batteries would fit easily. Once that was done, the open nature of the battery compartment had me a bit concerned that my expensive LiPos would be damaged by a stray rock or something else striking them at high speed. They’re hard cased racing LiPos, any damage would most likely be purely cosmetic, but sometimes you never know and it’s better to be safe than sorry. So I improvised a solution and made a underbody out of the plastic of some clamshell packaging I had in the trash. I cut, creased, and glued (again with CA glue, in hind sight I probably should have just used servo tape) the new underbody to the chassis. I may put some adhesive backed foam on the tray to further increase protection, but right now it’s sturdy enough and big enough to protect the batteries from most hard knocks, but at the same time it’s also flexible enough so that a good whack won’t break it or rip it off the chassis. It also tucks neatly under the body. I also used some of the extra plastic to make a cover for the drive shaft. More than once I’ve found pebbles and other debris stuck in the recess for the shaft, it’s marred my graphite shaft and I’m really suprised the shaft hasn’t broken. So I cut a narrow strip of the plastic long enough to run the length of the recess and again I CA glued it to the narrow lip above the recess. One last use for the trash bound plastic was to create a cover for the large hole on the right side of the chassis. Hopefully this will cut down on the amount of crud that builds up in the chassis during runs.

That’s the summary of my latest round of modifications for my Baja King. But in other r/c news my new Losi HighRoller (it’s a RTR, but it looks so cool) should be arriving in the next couple days, along with the parts to finish off my JRX-S and give my resurrected PureTen GP a test run. And my ThunderTech Pro-2 should be here in the next few weeks. I’m really looking forward to running all of them and will be writing full reviews of all the new ones after I’ve had time to break them in sufficiently.

The Baja King recrowned.

Jeff Hoy — Tue, 21 Nov 2006 08:58:33 +0000

I’ve been playing with my Tamiya Baja King for a little over a year now (read my old review here). It’s been in a mildly modified form since the very beginning with things such as ball bearings and light weight, carbon fiber parts. I’ve decided that it’s been long over due for some massive upgrades.

The first stock item to go was the friction dampened coil-over shocks. They’ve been replaced with Tamiya’s low friction, oil filled coil-over units filled with Tamiya’s medium weight (#600) shock oil. The performance difference is astounding, the car is much more drivable over my gravel driveway, and handles tight cornering at speed much better.

My second investment was to replace the Tamiya electronic speed control with an Associated/LRP A.I. Automatic Super Reverse speed control. This speed control is a huge upgrade over the Tamiya unit. Tamiya’s speed control is fine for being included in the kit, especially a kit that goes for less than $80, but it has issues and limitations that some people will more than likely outgrow. The biggest issue for me is in the way it handled dying batteries. It didn’t like low voltage and routinely flaked out near the end of the battery pack in an annoying way. There would still be juice in the battery and the car would still go, until you put too much throttle down, then it just stalled. If it handled low batteries a little more gracefully I probably wouldn’t have replaced it. A high point of this new ESC is that it allows me to use modified motors, which the Tamiya ESC didn’t. Which leads nicely to another upgrade worth mentioning.

Team Orion’s Formula SV2 Pro, in the 23 turn, double wind variety. It’s a mild modified motor, but it is a huge leap over the kit’s included generic Mabuchi 540 stock motor. I haven’t done an extensive break-in on this motor, so I haven’t yet pushed it to it’s limits. In stock form I estimated that this car did between 17 and 20 mph (RC Car Action clocked it at 20.2 mph in their review, page 3). With this new motor and speed control I’m hoping for 25+ mph.

Finally as an attempt to increase my battery run time I swapped out all of the Tamiya/Kyosho style battery connectors for Deans two pronged Ultra Plugs. These little connectors are a big improvement over the stock connectors in terms of electrical resistance, which allows more juice to flow through without being lost to heat and whatnot. I’m not an electrical engineer, so I can’t explain how it all works, it’s just better and that’s all I care about.

Overall I’m happy with this new round of upgrades, but I’m far from done. I still have plenty of options left to choose from, including some suspension component that will allow me to tune my setup even further. It’s not a full blown racer, but it’s definitely better than just a backyard basher now.