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Designer interview: Billy Easton about the Spyder SRX4 buggy 1/10 4wd (15/09/2015)


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Spyder SRX4 buggy 4wd 1/10, Spyder SRX4 buggy 4wd 1/10 alu.

Designer interview  Spyder SRX-4 buggy 1/10

Hello Billy

I like to ask you some questions on the new Spyder 4wd buggy that is released last week .

Q: You have been creating a really nice line of 1/8 and 1/10 offroad cars in just a few years time, and even a GT car in 4 versions in the process too; how many cars did you design for Serpent till now ?

A:Although this seems like a simple question, I have to really think about that one. I have done somewhere in the range of 15-30 different models. This would include the originals nitro and electric updated versions, and RTR variants. I actually also helped design our original link 1.12 car as well as the 1.10 GT version.. I would like to consider myself a jack of all trades for Serpent.

Q: Which of these cars was the most challenging ?

A: Honestly, I donít think that any car is easier than another. The end goals are all equally difficult to achieve. Since we are in a very competitive industry where racing at a high level is considered the standard, itís always very challenging to make a car, which out of the box is competitive. I think, if we had to pick a class, in which the design has the most challenges, I would actually say 1/10 2wd buggies. 2wd buggies seem to be extremely critical of things that you would otherwise consider un-important. In all fairness though anything 1/10 scale seems to carry more challenges, due to the competitive nature of the industry in that scale size.

Q: Which software do you use to design ?

A: I actually use a variety of software. The main software for Serpent would be Pro-e. However, I use Solidworks for bodies and misc. items, Gear trax for making most drivetrain components and MathCAD for all the calculating. Aside from those programs/software, we use a lot of Microsoft products to keep things in order and for other smaller calculations.  

Q: When did you start on the 1/10 4wd Buggy design ?

A: I started working on the concept, if I remember correctly sometime in  April of 2014.

Q: What were the key goals to achieve ?

A: Well the primary goal was to create a car that I felt would potentially be competitive out of the box. I had to do a ton of research for that. Aside from that goal, I wanted to innovate the class. So many companies talk about innovating things, but they really fall short when it comes down to it. I wanted to give the customers a car that could produce more grip than anything they had ever had before. More rear grip and steering to match, along with having a perfect balance. In the highest grip condition would be extremely stable, easy to drive and fast. So far it has proven to achieve most of those goals.

Q: What are the 5 main specific elements why a driver should consider the Spyder SRX-4 1/10 buggy ?

A: If I were to sell you 5 good ideas:
        1) It shares over 50% of the parts from your existing mm Buggy
        2) The drivetrain weight is significantly reduced over what is on the               market. This translates into more acceleration and lap time.
        3) The car comes out of the box with every tuning tool you need to win your local race and save your wallet
        4) The rear grip, steering and overall driving feel is the same as a 2wd, only with the ability to handle more power and brake later and simply go a whole lot faster.
        5) The body is devilishly sexy. Your friends will not even know you are driving a 4wd.:)

Q: Why did you decide to use the belt-drive system ?

A:   With the belt system, itís actually smoother, and you do not need to make as many steel, heavy parts to make it effective. In the case of our design, the weight of the car is distributed perfectly left to right as well as the overall weight of the drivetrain is significantly reduced over a shaft driven variant. Balance is the key to any winning race car.

Q: When using belts drivers may pop the questions: do they last ?  how much time to replace ?  what about belt tension ?  What about debris inside the car ?  What is your reply to that ?

A:Its really funny, people seem to have this perception that belt driven cars will skip belts. In some case, they are correct, that is if you are using the wrong pulleys , too little belt tension or the wrong pitch belts. The width of the belt also plays into that. Offroad cars are not onroad cars and you can not have the same super free transmission. You have to have tension on the belts, and there can not be as much deflection as you would use in eptc. With the jumps, uneven terrain and all the other variables, picking the right pulleys, pitch and belt width are extremely critical. In the case of our car, our smallest pulley is 20t, the belt is 3mm pitch and they are 4 plus mm wide. I have been running the same belts now for 3 months and they are still in remarkable shape. As for the debris, that also is not an issue. When I design the bodies for the cars, they are a perfect fit so that you can use the clips and no additional debris will get in the car than necessary. Any of our current customers will attest to that. Aside from that, the front belt is 100% enclosed and the rear belt is elevated off the chassis and partly covered. Even if you did have an issue with the rear belt, you can actually change that in less than 2 minutes time. I did not actually time it, you probably can do it in less than a minute if you are really in a bind. Its that simple.. In my opinion, being belt, or the worry of wearing out belts, itís a past time.

Q: Which batteries fit the SRX-4 ?

A: You have to use saddle pack batteries with the SRX-4. A variety of brands fit in there, if not most.  A shorty can be fitted, but requires some mods by the driver.

Q: Why did you choose to use a carbon chassis and will there be other options ?

A: I actually like the Carbon chassis as it allows me more options with weight. Its lighter, so if I wanted to add weight it opens up freedoms for me. Other than that we will offer an aluminum light weight chassis that customers can use.

Q: how do the slipper, clicker and diffs work together ?

A: The slipper,clicker and diffs are actually all three different entities all together. We have a couple of different slipper options..1 you have a thrust driven slipper, which basically is an improved gear diff concept in my opinion. With the thrust driven slipper, you can control the amount of power to the front wheels with a spring and slipper pads. It does not change during the run or if it gets hot or cold. Its an extremely consistent concept. A gear diff center for instance, will start off thick, and by the end of your run will be thin, so you have to account for that. Having your fluid viscosity change through your run is never a good thing. The second slipper choice would be our full time 4wd option, where the front and rear wheels are connected. The slipper then works like a normal 2wd. The slipper controls both wheels. The clicker, now, that is more like an adjustable front one way. The idea behind it is you can control the breaking bias as well as it allows the drivetrain to be separated during cornering. It actually can serve two purposes there. We have 3 spring options and we also have a locker to lock it out. Finally the diffs in the SRX-4 are both gear diff, but we also have ball diffs too. I think gear diffs are more suited for higher grip whereas I like ball diffs in lower grip. Everyone though has their opinions of that. We have some other options as well, that include overdrive and a front one way differential. Either way, all the parts are the same as the Srx-2 rm and mm. So you can reuse and share most if not all the parts. We have pretty much every base you could cover, coveredÖ

Q: are the wheels industry standard in offset and size ?

A:  The rear wheels are industry offset and size. They are also the same ones you would use from your Srx-2 rm or mm buggies. As for the front, when I redesigned all the front end geometry, which is very unique and different than the other cars, I wanted to have the wheels look the same as the rear. There is something about having a car that is uniform that is very appealing to me. In doing this, it also will allow us if we ever had to(etc. world championships) we can adapt any other brand of wheel to our car. The spindle design and offset are in our favor. So, our front wheels are specific to our car,but with a couple optional parts, anything other brands wheels can be made to fit.  We are also making 61mm wheels for our 1/10 buggies.

Q: Will the car come with a ball differential or gear differential ?

A: The car is slated to come with Gear differentials as standard equipment.

Q: What is the approx ready to race weight when using saddle packs ?

A: The car ready to race is in the high 1700ís. I would say the weight is comparable to some of the other cars even using a shorty.

Q: The low, narrow body makes it look like a 2wd almost , is that intentional, and what about fitting a fan and electronics ?

A: One of the main ideas when I was designing the car was to make them look almost identical. So many of the cars these days look like shoe boxís.. When you go from your 2wd to your 4wd, the appearance is quite different. I wanted to eliminate that for all the Serpent customers. Give them something that was or seemed like the same car. I think that goal was achieve quite nicely and it really sets our cars appearance apart from the rest of the cars. I have added scoops for ducting air into the motor and also I have improved the area around the speed control to allow most if not all speedos to have a fan installed.

Q:  Did you try to run the car as 2wd as well, and if yes whats the feeling and performance?

A: I actually have not tried it yet. When I designed this car, I had a plan to spin the design off a few different ways. I designed many of the parts to be able to attach to different chassis so that making more cars out of this design would be really easy for me to do. The design is very modular capable. I simply have not had as much time as I would have like to start tinkering with ideas on this project.

Q: Does the 4wd buggy share many parts with the 2wd car ?

A: I would say about 50% or more of the parts are carried over from the 2wd. This car is probably one of the cheapest entirely new cars we have actually ever made. Thanks to being able to carry over so many parts.

Q: Will you run the 4wd at some bigger events in near future ?

A: I plan to attend as many races as I can. I have other responsibilities though at work that can make that really tough on me. I try my best to prioritize work and racing. I will most likely attend the nationals, an EOS race and the world championships later this year. I am sure there are other events in between, but those are the major ones I would like to be at.

Q: Now that the 4wd design is finished, what is your next project ?

A: Right now, I am working on a new 1.8th Nitro buggy for release early 2016. I have only had the chance to update our old car a couple times. However, I have never had the chance to take everything I have learned the last 6 or more years and apply it to something I could call new. I really want to turn the market upside down, with something that every customer would want to race. I also want to make a product that can bear the Serpent brand name, and have the respect of all the other industry partners. I am very excited about what I have so far, and I think all of our racers, future racers and customers will be overjoyed with what Iím going to bring to the table. Its going to be a contender straight out of the box..:)

Thanks for the answers !

Team Serpent