07.05.2022 Category: Site news
Episode 17: Electric on-road development 2008-2011
VRC v3.5 was the last release of the v3 based versions, 2006, but that didn’t mean that development had stopped. On the contrary. In fact, early 2006 I took a very important decision to start working on VRC v4, a completely new platform which we worked on till end of 2011 when it was released as VRC PRO. I will start writing about VRC PRO in a later episode as it was the beginning of a completely new adventure.
So, what did we work on? It was mainly new content development, in particular 2 new classes for the new VRC v4 platform: 1:10 electric Touringcars and 1:12 electric Sportscars, plus a number of specific indoor tracks for these cars. We felt these 2 classes would be great additions to our on-road offering as we would then cover the 4 most important and popular on-road racing classes.
1:10 Electric Touringcars
At Serpent we didn’t have a 1:10 electric chassis, so to continue the chassis development path we had followed with our nitro cars we needed the collaboration of a chassis manufacturer who could provide us with physical data of that type of a chassis. Xray had followed Serpent in using Pro Engineer to develop their chassis and when asked they were willing to collaborate with this development and in exchange, we would model their current 1:10 electric chassis. We had exactly the data Todd needed to build the physics for that new class. The geometry model was still 2D, and the suspension not animated, just the wheels, but suspension movement was so small that you would not see that, just like with 1:8 and 1:10 nitro.
Rubber tires
Todd had already collected tire tests data from the rubber tires, that data was very helpful, not to say critical to come up with good tires for the electric chassis. Finetuning of the rubber tires was very time consuming, Rene Cornella and Julius Kolff spent hours and hours testing different tires, providing feedback to Todd and then Todd came up with new tires to test. In fact, I think we spent a whole lot more time on the rubber tire testing than on the foam tires before they felt like what it should be. If I remember well, Todd’s tire model even had double parameters which would be used depending on asphalt surface or carpet surface!
Electronics
The electronics were straight forward. Electronic motors are not all that complex, nor are the batteries, more or less straight physics laws. The electronic speed controller (ESC) was the critical part, and kind of a mystery to Todd, especially with the arrival of ESC’s that were programmable. When we started with the electric chassis, they were still using brushed motors and NiCad batteries, remember those? Most time during races was spent cleaning up collectors, modifying brushes, experimenting with brush material and last but not least, charging methods of the NiCad batteries.
That all changed a few years later with the introduction of the brushless motors and a little later LiPo batteries, a true revolution and probably a lifesaver of all electric r/c classes! The ‘old’ technology was killing electric classes, too much expertise required. And with this massive motor technology shift also the speed controller technology shifted, of course everything computer and later smartphone programmable. We had to adapt to these changes immediately. LRP was a great help to us for developing a good understanding of this new technology and to implement it in our ‘virtual’ electric components. I remember I visited the 2006 Euro’s in Collegno, Italy (yes collected the reference material for that track then…). A few racers dared to use brushless motors and newly developed ESC’s, with massive overheating problems towards the end of their 5-minute heats. It was clear that this new technology was the way to go, I think it took the industry 2-3 years to sort it out!
I also visited the LRP Masters in Eppenheim one time, I believe it was 2012, together with Todd ‘Doc’ Wasson. During the lunchbreak I had arranged with Jürgen Lautenbach, President of LRP, that Todd could drive a 1:10 Touringcar around that track, it was his first real experience with an electric car. I am sure he then finally learned how an electric car should ‘feel’ like in terms of acceleration and handling!
The introduction of the LiPo batteries came a few years later, another massive breakthrough for the r/c market. And chassis manufacturers had to redesign their chassis to accommodate the new rectangular box design of the LiPo battery. And we had to follow of course. Technology wise (LiPo batteries have different electrical properties) and chassis wise with different dimensioned packs. Several chassis we had started with a NiCad version and then had to redesign it for LiPo. The LiPo cars were released in 2012 one year after VRC Pro was released. The NiCad and brushed motor chassis were introduced in 2010.
1:12 Electric Sportscars
For 1:12 we followed more or less the same route. We started with the Xray 1:12 chassis, got all the Pro-Engineer data Todd needed for his physics model, but of course suspension geometry wise it was completely different. The swiveling rear-end was a new challenge for Todd to write the physics model for but he succeeded, as always. The foam tire characteristics were very much the same as for the nitro on-road tires, so no new development required in that department! Once Todd had figured out the chassis dynamics of the 1:12 chassis he realized that the suspension movements and the masses he had to calculate with in the physics model were so tiny that the only way to make that little chassis work naturally was to increase the physics rate from 350 Hz to 500Hz, 500 calculations per second! This new knowledge led to canceling the Kyosho Mini-Z project as it was obvious that the physics rate would have to double again, just not feasible…
Anyway, the 1:10 and 1:12 electric chassis turned out to be very popular in VRC. Seeing these cars race on the carpet indoor tracks is quite incredible, the car control, the driving precision, the reflexes, it amazes me every time I watch a race. And it makes me proud that we have been able to achieve this! The video I posted with this episode is of the 2021 VRC Worlds 1:10 ISTC modified at the MB Models track in the UK, and the 2012 VRC Worlds 1:12 at the Heemstede indoor track, both with a voice-over of Mike ‘the r/c voice’ Garrison. These races give you a good impression of what we have been able to achieve with electric on-road!
With the 1:10 and 1:12 electric on-road classes done we could now focus on something completely different of which I wasn’t even sure we could actually pull it off: off-road, starting with 1:10 Short Course trucks which were very popular around that time.
That’s next…
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