HellTriX

iTrader: (1)

Thanks for all the replys.

I understand a prototype car wouldn't be classified as stock until it met all the specifications as stock and was in large scale production valued at a reasonable price. At this point I have no plans to start any RC business

The reason I'm trying to make one thats legal in the national level of racing is because if I magically find that I'm a great racer (probably not), or that I built a great car (somewhat unlikely on first design). It would be nice to advance to the next level without having to buy a race car that is legal.

joe of loath: Some nice work doing a scratch build with some simple tools. I've done a few projects in the past like that. The latest one was when I was looking around at home built motors and all I could find was those 2 pole coil winds with a battery. So I spent the weekend making a laminated 3 pole armature and built a rig for magnets. Had it running by Sunday. Told some friends and they didn't believe it would work. I literally had to record a video of it spinning with power applied before they believed me. Oh and I should mention I only used a saber saw, dremel, drill, and hammer. Looked really crude, over heated if you ran it too long, wasn't very balanced, and had all thread through a drilled hole as a bearing surface lol.

I started it just as a proof of concept to show them that yes you can really build a 3 pole motor from simple tools. I was designing a scaled up version with cad files because I was going to send off to a CNC buddy to make me a bunch of plates that I could laminate together. Basicly I was designing and building my own 10inch motor to convert my 1978 280z to electric drive. I have built my own 2000 amp 250v max pulse width modulated speed controller for the car already. Its basicly complete I just needed to make a second prototype PCB so that I can add the current limiter function that I was having problems with. I should mention a 2000A controller for an electric car is usually over $3000 while I have about $150 in parts into mine. I might have 50-80hrs into the prototype in design and building so I guess in engineering costs I've already spend way way more? lol But its fun making your own stuff.

Anyway thanks for all your feedback so far.
I'm still undecided weather or not to buy or build my own at this point. TBH I'm beginning to lean toward buying one, and building a prototype anyway. I'm gonna test the waters (if I can find the right forum spot) to see if someone would like my older nitro T-maxx 2.5 in trade for a touring 1:10. The wife might throw a fit if I bought more RC stuff since I have already bought an RC plane, stuff to fix up my T-maxx and some other fun stuff .

Tnx,
TriX

timmay70

iTrader: (5)

JimL is the ROAR region 1 director, so his vantage point is from a ROAR perspective (or he has a personal vendetta against development - I doubt)... For level 4 and 5 events, it would not be legal for Stock. For all other races that you would actually want to compete in stock, check with the race director or tech inspector, as they would have the final word on legality.

Good luck and keep us posted. The tech-heads here love to see new stuff.

charlie_b

iTrader: (1)

I say build it. Run it Locally and enjoy. If it starts doing very well, then worry about other sanctioned events. Club races are supposed to be fun. This hobby is supposed to be fun. Build it and race!

HzR

I also can't imagine you're not allowed to run prototypes at sanctioned events. For stock racing I see the point of this, but for modified?

There have been numerous IFMAR events where prototypes were raced, and not just pre-production cars, like the infamous Associated Stealth car for example.

Anyways, I'm just curious to see if I can beat my own lap time with a car I built myself compared to an off the shelf car. And enjoy the design and building process of course!

Dawn Sanchez

Interesting read....!!!!

NO to running this at any STOCK class. You do need to check with your local program and I would advise, if asked, to allow it, as we could all use more racers at the local level but as far as a ROAR sanctioned event outside of club racing, nope to stock. SS or Mod.. sure... go for it!!

Will this car be at the nats in Omaha in 2 weeks? I would love to see how far you are...

Dawn

imjonah

lets say your goal was either
1. The fastest possible ROAR legal 1/ 10 scale TC
or
2. The fastest possible 1/ 10 scale TC which looks something like a ROAR legal
car

Instead of re-tracing the trial and error incremental improvements which are represented by the high end kits from the major manufacturers, you would be far better of served working in the following areas.

1.Use real scientific research with instruments and methods out of you physics/engineering lab. Using telemetry and computer control systematically change variables/ record results. In the RC world there is a ton of subjectivity since conditions change and skill levels between drivers and between drivers own performance from one day to the next vary.
This or that battery, motor/ tire will be recommended over another with virtually no empirical data to back it up.
Motor A will be said to out accelerate Motor B without any real world test.
If I am not mistaken, scientific highly instrumented computerized testing of every variable is the way it is done in 1:1 scale racing.
I think I read some where that the budget for F1 motor R&D alone ran into the tens of millions per manufacturer per year.
2. Experimentation with on board advance electronics such as electronic traction control gyros, etc. Many improvements are specifically ruled out by ROAR rules but like brushless/lipo might be allowed if they proved successful on club level.

I am not an electronics expert but their are many aspects of RC that seam to be behind the curve when it comes to recent technology.
(the high tech i seems over priced when it does arrive) My $29 cell phone seems a whole lot more sophisticated than Futabas $399 2.4ghz transmitter. The electronics in a $149 ESC don't seem like much of a bargain.)

In other words I would be surprised you could improve on a high end TC kit like Xray T2, HB Cyclone, chassis but I would be equally surprised if through scientific study you could not improve on the adjustment and fine tunning of the whole package.

JustinLessard

listen to this fellow, he is well aware of rules regarding one-off parts

CarbonJoe

There a few flaws in this part of your argument. That cell phone you "paid" $29 for isn't $29. The cost is being subsidized by your cell phone company so that you will commit to a 2 year agreement. That's the shaving razor model.. give away the razor handle, make money on the blades.

Also, it comes down to economies of scale. The cell phone market is selling tens to hundreds of millions of phones per year worldwide, so the cost of production goes down as volumes go up. How many 4PKs does Futaba make each year? 10,000? 50,000? The R&D costs have to be paid for by relatively small production runs. Regulatory testing isn't cheap, either, and has to be done for each country that it is sold in.

I would imagine that a company like Tekin has very small production runs for their ESCs (like 500 or 1000 pieces at a time, or maybe even less). Thus, parts costs are higher than if they could afford to make 10,000 or 50,000 at a time. With each jump in quantity (above a certain threshold), all parts costs come down.

niznai

Yes, I understood it that way too.

But the way the rule is worded ("parts need to be comercially available etc,") still leaves a door open to building a custom unique car by mix and matching parts from whatever manufacturer you want. It further raises the question of what would happen if you used one minor parts that you made yourself (like a steering link for instance) ? This is probably where my cars would leave a scrutineer scratching their head since I have for instance my home made weight trays and battery straps and other bits and pieces as well as parts from various other cars (from different manufacturers, not after market hop-ups or the like).

But your idea (helltrix) is what I was hinting. Buy a car, race that and see what you could do better and perhaps what other manufacturers did better on their product. Even better, you will find things that no manufacturer has thought of and that's where real innovation comes in. Or at least great personal satisfaction. This is the most interesting part of the hobby for me.

DLS II

So,if I went to a ROAR race,joined and presented my car for tech, I would be told it is illegail for stock class? If so I will never go to ROAR event and will discourage others also! Don

CarbonJoe

Unfortunately, if your car isn't 100% readily available production parts, no, you couldn't run it in stock class at any ROAR Level 4 or 5 event. (Basically, any Regional Championships or National Championships). So, your custom chassis would be illegal.

What's not clear is if you "kit bash" and take parts from other vendor's kits. For example, running Tamiya shocks on an Xray, or Xray diffs on a Schumacher. Or even more esoteric, taking shock piston "blanks" and drilling your own holes in them. Where is the line drawn? What about sponsored drivers having access to not freely available ESC firmware? Would that make the ESC a prototype?

A current On-Road Carpet National Champion had one of his heats disallowed for using prototype parts in 1/12 scale.

snoopyrc

iTrader: (2)

Thats from the brass folks. If you arent going outside of club racing I wouldnt worry about it. Or I would go SuperStock since that seems to be OK.

DLS II

I disagree with the whole idea that my car would be "illegal" for stock class. Everything on the car is available at any well stocked hobby shop-including the 3/32 G-10 that the chassis is made of. Nowdays the only difference between stock and mod is the wind of the motor. The car I built is a kit-bash. As for the chassis-that was done using a drill and a Dremel. Any competent hobbiest could do the same. It's this kind of nonsensical baloney that keeps folks OUT of ROAR. This coupled with having to have a Wye wound motor and sensored speed control(in stock class) is just one more reason not to join ROAR and to discourage others from doing so. I've been playing with RC cars for as long as ROAR has been in existence and they still haven't realized who they really serve-the members-not the manufacturers! Don

Scott B

iTrader: (47)

Well from the photos you posted it looks like a FWD rubber tire car, so what ROAR class does that even fit in??? Like most have said you should't have a problem running it on a club racing level, but I would check with the race director first.

Edit... I just noticed, I believe you need to run a "sensored" motor and esc in a ROAR event. Your car has an approved motor but a sensorless esc. But again should be fine at a club level.

timmay70

iTrader: (5)

It's actually just the opposite. This rule was created because some resourceful teams (manufacturers) have the money to produce purpose engineered kits to win at one specific event. This rule cuts the costs of stock to parts and kits that are readily available to the public.

If you are that good an engineer that you can design a one-off car that can be competitive at the national level, you shouldn't be allowed to race it in a stock class. After all, none of the parts of a one off car are 'stock', the specialty parts aren't in stock anywhere, except maybe off the end of your dremel tool.

Rules are put in place to help control costs and make racing fair to everyone. If you choose to be a tool and not abide by rules that even the playing field at the regional and national levels, go race in your local ball park, and see how many people will be willing to join you. ROAR for years has set the rules that everyone else based their rules off of. They deserve a lot of credit.