News – Page 11 – Stewart Raceway

Quick SR3 Update

Sorry for not spamming you all for so long. I’ve been slammed with this SR3 project, among other things…

Anyway, yesterday I abandoned my hardware/software solution after not being able to fix one of the two problems I’m encountering with the use of Phidget cards for primary lap counting.

Instead, I installed a Trackmate SCL3 USB card for the primary lap counting gantry (finish line/lap trigger). I’m not a big fan of this card but it does the job and seems to detect my fastest cars both individually and simultaneously, where the 0/16/16 Phidget card clearly did not.

And, Race Coordinator (RC) also supports this card. Because SlotTrak doesn’t support the much more desirable Arduino cards, I’m using the 0/16/16 Phidget card to handle the pit-in gantry sensors (much slower car speeds there), and two Phidget 0/0/4 cards to handle individual lane power.

I’m going to do more testing today and will begin to prepare for a coming track day to really flush things out. I’m going to need five drivers and the fastest, noisiest cars we have to run things through the paces and make sure everything works properly with SlotTrak. I’ll configure and test RC once I have SlotTrak rock solid.

If you have T-Jets and/or L10 cars, please let me know. I’d like to test a few this coming week and maybe do a track day on SR3 next Saturday. T-Jets and most “pancake” cars are very noisy electrically, which can generate phantom laps if track circuitry is not adequately shielded.

Okay, shut-up and drive!

SR3 Construction Update: March 11, 2022

A generic Arduino Mega 2560 card works beautifully!

Well, I was on target to have SR3 ready to go last Sunday but unfortunately ran into an interesting technical issue. It’s a much longer story but essentially the timing hardware I decided to go with doesn’t detect faster cars due to SR3’s gantry position and the speed the cars are getting to as they pass under the lap sensors.

“Steve, just change hardware and open the damn track!” Easier said than done. The issue is dual gantry, six-lane tracks, require a timing card that can sense up to 12 lane sensors: six for counting laps and pit exits, and six for pit-entry. Not to mention two more 4-relay cards to handle individual lane power control.

This limits the number of options out there. I’ve been able to get everything to work with Race Coordinator using an Arduino Mega card but SlotTrak does not support Arduino cards and the prolific Trackmate SCL3 card can’t support six-lane dual gantry tracks.

So, I’m stuck with the Phidget 0/16/16 card, which SlotTrak supports but does not detect fast cars on SR3. Further, this card also does not detect two cars passing under the gantry sensors at the same time. Yea, big issues. I guess most tracks use Trackmate, Arduino, or do not employ dual gantries.

I’ve sorted out a solution to this problem courtesy of “Madman” Steve Medanic. Steve was an engineer and has built numerous slot car tracks. He ran into this problem on his last track build, which was only a three-lane track but quite a nice build and circuit.

Steve may not have seen the single-car detection issue I’m seeing because his lap timing gantry is only 18 inches from the final corner (SR3’s final corner is nearly six feet from the lap timing gantry). However, he did encounter the simultaneous car detection problem, which I duplicated on my track tonight.

Steve’s fix was building three “signal pulse delay” circuits to install between the gantry IR sensors and the Phidget card. These circuits basically keep each lane trigger signal active long enough for the Phidget card to register it. Problem solved!

SR3 has twice the lane count and will require six of these circuits instead of three. I’m thinking the pit-entry sensors won’t need this logic since the speeds going into the pits are way, way slower.

Another option for solving this would be to add a 1.5-in long piece of black tape to the back of each car. Not sure if everyone would go for that but it is way cheaper and quicker. And, just think…you could paint or otherwise detail the tape for concourse consideration!

Anyway, that’s the current situation. I’m trying to find a “canned”(integrated) time delay circuit that could be used instead of discrete components. There are plenty of cards out there for timed relay control that may work. If not, I’ll have to source the individual parts required to build six of these little devices and then wire them up and test them.

So, as I wait for parts–again, I’ll stay busy installing the crash barriers, display monitors, speakers, etc. No idea yet when I’ll complete this beast but not likely to start a new series for at least two more weeks.

SR3 Construction Update: March 1, 2022

Progress continues on Stewart Raceway III but it has been slowed by all those pesky things that seem more important at the time.

So, where are things? Well, the table and track roadway placement has been completed. The track power distribution system is complete and tested. While there are still technical hurdles to overcome, the goal of supporting different voltage levels for each lane–by the driver–has been achieved. It’s not completely ready, but drivers can select any voltage they’d like to run when testing or practicing. This means you can practice/test any car, at any voltage, at any time racing is not underway. Think about that…you no longer have to restrict yourself to 15v, 12v, 20v, or whatever. You can go to any open lane, set the “lane” voltage (at the driver station), and run your car.

This is significant and very important for maximizing track/testing time. You no longer have to find out what the track voltage is set at to decide what car you're going to run. You simply set the lane voltage to whatever you want.

Other than six lanes, and a much larger layout, SR3 is expected to support the same racing features that SR2 supports. One small difference will be a slight increase in pit spacing. SR3’s dual gantries will be spread slightly further apart to compensate for the higher pit entry speeds.

Lots of work remains but mostly tedious wiring, track section power connections, crash barriers, etc. After that, it’s all about software configuration and testing.

Power distribution under the main straight timing/pit gantries.

One huge difference between SR3 and SR2 is power taps. Brad Bowman insists that I can run just one power tap, at most two (SR2 has eight power taps). I’m not convinced just yet but I’ll start testing with just two to validate that. The track design of being able to convert sections and convert to an oval makes the usual power tap calculations more difficult. No biggy though, adding more power taps just costs more time and money.

So, SR3 is coming along nicely. My garage is a complete disaster but the new track is going to be quite cool. Yea, lots more work to do, but it’s getting close. Really only need to wire the gantries up and I can start testing things. The 6-lane, dual gantry setup adds some complexity and delay. I had planned to just use the usual RJ-45 twisted-pair cable to handle that but RJ-45 only provides 4-pair, which doesn’t quite handle a 6-lane dual gantry setup (need 6-pair x2). Yea, yea, I could make it work but decided to find some 6-pair cable to handle this. Sadly, it’ll take a week or so to arrive.

Then the challenge will be shielding the cable. Shielded 12-conductor cable is extremely expensive. In fact, way too expensive. Yes, some of the noisier cars can trigger false laps if the gantry wires are overly exposed to RF/EMI frequencies.

Can’t wait to get all the infrastructure completed and start running some laps on this beast.

SR3 Construction Update

Mostly doing research on power solutions and waiting on materials needed for the track elevations and banking. Not sure if you’ve noticed lately but FedEx and UPS really suck when you compare them to Amazon and USPS.

I try not to buy CCP products as much as possible but sadly there are simply too many things that are simply not made anywhere else these

days. That’s another subject entirely of course. But even products that are already in the States seem to take forever when shipped by the major players. And, no, it’s not related to the “supply-chain” hoax. In fact, these days you can expect at least three days where the item(s) just sit in some shipping hub location for a long, long time.

Anyway, waiting on spacers (standoffs), wire, wire sheathing, power components, and other items right now. The track is pretty much secure to the table just need to set the banking and overpass elevations but need the proper spacers and screws to do that. These pictures show the proposed overpass height and shape. I think it’ll be challenging for both L4 magnet cars and our other less stuck platforms.

The banking elevations and shapes will be different on each of the four corners. I’ll decide on that once I get the needed materials and start to shape the oval corners. The banking will likely be less than SR2’s banks but fairly close at the highest points. Of course, I’ll do my best to make each corner as different and challenging as possible.

Once I get this stage completed, it’ll be time to secure each track piece completely to the table and then start the basic track and power tap wiring. I’m planning a “Phase 1” power solution for the track opening, which will be at least the same power control setup we have on the SR2 VSR track. Phase 2 will be driver-selectable voltage levels for each lane, from 3v to ~28v, which will also be programmable from the track computer by the race director.

Two purposes for these features: one is so that we can test/practice different types of cars in the same practice/test session and not have to switch voltage levels; the second purpose is so the race director can reset each lane’s voltage to the proper levels prior to each race.

Don’t forget to register for Round 2 of the Formula “E” Series this coming Saturday, January 15, 2022!

Also, if you know somebody who you think would enjoy racing little cars with us, please invite them along. We always need new drivers to join the group and it’ll benefit all of us when we have a large enough “club” to always have more than enough racers to support our events.

Remember: SR3 is six-lanes! That means we’ll need at least eight (8) participants to have any hope of full utility of the track and enough turn marshals. Yea, we can run just four lanes, but that’s not cool!

Okay, shut up and drive!

With All The Recent Rainfall, SR3 Is Moving Right Along

With plenty of other tasks to do the rains have been keeping me indoors. When that happens, I usually play with slot car stuff or hack on computer stuff. This week has been all SR3 construction.

With the table completed, I started laying down the track and completed the oval course placement. Once you get that set, you can go ahead and lay down the road course pieces. While I didn’t achieve perfection with the oval pieces fitting together perfectly, it was good enough. So I decided to keep going and get the road course pieces fastened to the table.

It’s quite an interesting operation if you’ve not done it

before. Brad Bowman’s tracks are tongue and groove, which is really cool. However, you still have to fit the pieces together very precisely. Like a plastic sectional track, you don’t fasten any pieces until you’ve put it all together and made sure everything lines up–end-to-end.

In the case of a convertible oval-to-road course track, you have to get the oval layout dialed first. Then you have a fixed starting point for the rest of the puzzle. I didn’t get the oval to align together perfectly but it was extremely close and I didn’t have time to start over and get it perfect. These shots show the track in various stages of placement completion and the complete placement of the entire course.

The next steps are to set the banking angles of the oval and elevate the overpass section. I may also elevate or bank other sections of the road course as I evaluate the course complexity and funness.