Wednesday, January 28, 2009

Post week #2

I received the 3 4200 mAh batteries I bought off the rctech.net forums on Saturday - they were certainly very used, hence the $10 each price tag! I set out to reconfigured the packs to be saddle packs and get them cycled to see how they rate. They were exactly as pictured, and I ranked and labelled them on appearance alone before charging them : A, B & C.

As I had guessed, B was better than C, but A acted extemely unusual. It peak charged at 9.75v with an average discharge voltage of 6.67v - other than runtime of 574, this was worse than my 2000 mAh's. I spent an evening cycling each cell individually and found cell #5 to be bad - it would charge up completely showing a peak voltage pretty high, but would then on the discharge side would drop out after a few seconds. I'll probably pick up a cell or two just so I can make a decent practice pack out of it.

I didn't get much else done during the week - I had planned to cut the motor and put new brushes in it, but that never happened. Luckily I did find out that the battery hold down was broken, and got the holders out of there so I could run tape through to hold the batteries down instead.

I also spent a bit of time with a set of calipers measuring the rear arms of the car to see what could be a match - the TC5 rear arms look pretty similar and have about the same length, so I'm hoping they'll be a match.

Monday, January 26, 2009

Race week #2!

The next friday I went racing - it was the start of a points series, and I fretted making five minutes with my packs as I hadn't received the 4200's I ordered yet. When the drivers meeting starts, they announce that races will be six minutes!

I charge up the 4200's for the first qualifier and get out there on a new layout and run a fairly good qualifier, holding back on the throttle being worried about run time. The car is oversteering pretty fiercly with the new tire and spring combination with the TC pattern applied. The 4200 still has full power and plenty of runtime left at the end of th race.

I swap out the rear springs for a softer Kawada spring and get my best 2000 mAh pack ready to go. I run a good qualifier for the first 4.5 minutes when I finally board the car and need marshalling - I lost a good 10-15 seconds, which is a full lap and then some on this track. It didn't really matter, I completely dumped on the last lap and had worse overall numbers than the first qualifier, but my lap times were improved and the car felt better.

I get the 4200 charged for qualifier three, and disable the current limiter on the speed controller when I'm offered someone's spare LiPo battery to run! I get the wiring redone with some help from Terry, get the pack taped down (it's a standard stick type 2s LiPo), and make sure the car runs with it, which is seems to do. I don't get a chance to get any test laps until my qualifier starts... Unfortunately, switching from NiMH saddle pack to LiPo stick pack causes three changes that in combination spell disaster:
1. The car is lighter
2. The car has a higher center of gravity
3. The weight is now on the outside of the chassis

Needless to say, I was flipping the car coming out of any high speed corners unless I drove slowly. I drove slowly, and the lap times showed it, and I also had a weird steering glitch - that blue wire = FET servo = Powered directly off the battery. The servo was getting too much voltage and freaking out under high current draw (i.e. full throttle). I wound up flipping the car four or five times, one time right off the track, breaking a rear body post in the process, using my last spare to fix it.

The main came, and the 4200 was charged and ready to go. I qualified third for the B main based on my first qualifier. The race was fairly uneventful, I finished where I started, but improved on my qualifiying time by almost a full lap. I won't find out until late next week that I've broken the battery hold down piece on the left side of the car...

Thursday, January 22, 2009

What to do between races?

Having four days til the next race day gives me an opportunity to spend some time fiddling with my car and gear...

During the week from Monday through thursday, I cycle my four "best" 2000 mAh packs and cycle individual cells on a few weaker packs, and swap out a couple bad cells for cells that more closely match the rest of the cells in the pack just to improve my chances of making a 5 minute race. I document all the stats of every pack every time I cycle one to see which ones I should be using.

On Wednesday, I stop by the hobby shop to pick up an 87 tooth spur gear to help fill in the slight gap in gear ratios I have due to not owning a 23T pinion. No 87 to be had. Just a 78 and an off brand 86 tooth I'm told may not fit. The guy at the hobby shop is an off road racer, sponsored by Orion, so we get to talking, and I tell him what I'm racing and what gear I've got and my battery/charger dilemma. He shows me a charger, it's a tiny thing, DC only, but it will charge anything - NiCad, NiMH, LiPo, LiFE, etc... It would fit neatly in my pit box but for the huge power supply I would still have to lug around - until I mention that and he shows me a DuraTraxk Onyx 230, which is barely any bigger, and has an AC input already. I decide to bring it home to be my new charger to take to races because it eliminates the HPI box from what I have to carry! Hopefully the Turbo 30 TF won't be jealous.

At home that night, I play with the charger a bit, make some leads to be able to charge packs, and then I take the plunge. I still have my Tekin G9 speed controller, but I didn't use it in the TC because I didn't have the urge to desolder the G12c III and set up the G9. I take the plunge and swap out the speed controller and get it set up, remembering what the blue wire leading to my steering servo was for and making sure that's re-connected. I dial down the current limiter to about half and set the brake at about three quarters. While I'm in there, I clean the motor comm, and the brushes, and run some comm drops through the motor.

On Thursday, I get a small little padded envelope in the mail from Competition Electronics and get that little chip installed, and verify that I'm now on version 4.6 on my Turbo 30 TF, and proceed to cycle my only 4200. The numbers on it are vastly improved and I'm liking my chances of making five minutes with it.

The Plan For Friday : New Charger, New Tires, Tekin G9, 22/81 gearing, HPI Black springs in the rear (down from HP Purple)

Parts ordered

The Monday after the race I start trying to figure out what I want to do about batteries as the 2000's are a dicey proposition, and running one 4200 NiMH four times in one night just didn't sound like a good idea... Oh, and there is that little problem of the Turbo 30 TF as my charger.

Monday morning, I make the call to Competition Electronics and spend the $25 to get the firmware update to let the Turbo 30 TF charge hi capacity NiMH's. In my mind, it's a worthwhile purchase regardless of what I wind up doing.

I shop ebay, I shop the rectech.net for sale forums, I'm rather undecided about what I want to do - there's cheap LiPo's on ebay straight from Hong Kong, there's cheap balance chargers too... I make up my mind when I find an ad on rctech.net selling 3 4200 NiMH side-by-side packs for $10 each plus shipping. I commit to buying those and running NiMH for now.

Tuesday, January 20, 2009

My first raceday in eight years!

The day finally came, I was prepared for it - I made my way into the building the scope out pit spaces ahead of lugging my gear around - I spotted one right in the first row all the way against the wall, then brought the Crafts man-o-saur, HPI box and car to the pit spot. After getting set down, I realized I was pitted next to Barry - someone I knew! Then after talking to the guy across from me, Terry, I knew him by name from back in the day as well, and behind him was John, someone I knew really well from back in the day. All told, there were four people I knew there that night and all of them within shouting distance!

The night was going well after getting registered and finding out that I was one of maybe five people in the building not using a spektrum radio, I got a few laps of practice in. The car handled about how I remembered, it couldn't carry much speed into and through the corner, but it squirted out of the corner like no other. I chose not to change anything for the first qualifier and ran the new 4200 mAh NiMH battery with a 26/84 gear ratio.

The first qualifier and I'm on the stand waiting for the start, getting jokes about "going fishing" and the anouncer comes on and asks me if I even remember what tires I have on the car. Apparently noone runs Kawada 20 or 25's with blue inserts anymore - go figure! The run was fairly uneventful, I was able to keep it clean and avoid needing marshalling - however, at about the 4 minute mark, my car starts slowing down big time! Here I am, with a brand new 4200 NiMH pack and dumping after 4 minutes! I thought my Turbo 30 was partially to blame as it doesn't have the NiMH update - I was thinking it wasn't providing a full charge. Barry says that NiMH's need a few cycles on them to "wake them up".

The second qualifier, I gear down a tooth to 25/84 to try and increase runtime on older batteries as I've got 2000's in, trying to make five minutes. I'm off like a herd of flying turtles and manage to keep it clean again, avoiding needing marshalling a second time, and trying to conserve the 2000's. I do manage to keep full power for about 4:45 and squeek out the last lap on a flattening pack! I turned a 24/5:01 or something along those lines and felt good for qualifier #3.

For Qualifier #3, I've asked Terry to charge my NiMH after running it on the discharge board until it was even, and he was happy to do it. On top of that, he had been rummaging through his pitbox and placed a well used set of Sorex 28's on my pit stall. I get them doped up and out for qualifier #3 and turn a couple laps on them when a familiar sound is heard. The sound of tires squeeling around turns as they gripped was like a little bit of music to my ears. The car doesn't slide through the corners like it did previously, and can carry a little more speed into the turns! I'm scheduled to start third this qualifier, so I park the car about halfway down the straight, waiting for the other drivers to get set to start. I'm watching a car zip around the track - I realize he's trying to turn a flying lap as he barrels down the straight away - straight through the back of my car, which goes flying down the track sideways and backwards. When it stops, facing the wrong direction, I can see from where I am that the rear-wheel steering option has been added to the car! Reflexively, I give the driver who did it a really natsy look and storm off the stand to go take a look. Oh yes, the left rear arm of the car is in three pieces. I throw the car into the pit box, take the transponder out and return it, and when I get back to my pit, Terry has taken the body off and is asking if I have any spares so we can get me back out to get a couple laps in! Long story short since I hadn't working on the car in so long, I had thought the arms were reversible, which they are, with the exception that the shock mouting hole is only on the wrong side, which was of course on the wrong side the first time! I do get back out, but with only 15 seconds left in the race - I turn a couple laps to get a better feel for the car. The driver who hit me came over afterward, and profusely apologized for what had happened and told me he was embarassed to have done that. That's class my friends, and I told him I truly appreciated that level of sportmasnship. That still left me without a really good qualifying run and I'm in 8th out of 10 cars, 5 in the A main, and 5 in the B main, with me right in the middle of the B...

For the main, I had Terry top off the NiMH and went back up to 26/84 because the 2000 made 5 minutes on 25/84 and I've got a good charge on the NiMH now! I've out-qualified two people in my class, my friend John, and my other friend Mark! Okay, neither of them completed a qualifier.... I'm qualified right behind Jeff, the driver who hit my car in qualified #3, so I have a goal to finish ahead of him :) The race goes well, and for the third time in the night I'm running clean and avoiding marshalling. John never made the race, and about halfway through Mark drops out of the race with some sort of problem. I'm running in second, ahead of Jeff and running well. At about the 4:15 point, the battery really starts dumping again! I keep it running around the track, and get passed back by Jeff, but I thought I had lapped him, so just keep trucking on and make 24/5:15 finishing in third. Coming off the track, Terry stops me with an infrared thermometer in hand and checks my motor temperature - 227 degrees I guess is a bit too high - whoops! I guess I was about 3 teeth too high on the pinion which testing after all the mains were completed showed.

All in all, not a bad night - I got a good feel for what was needed, where I was lacking, and I got wheel time.

$40 later, I now own my own set of unused Sorex 28's - which means I'll be back next week!

Thursday, January 15, 2009

Take a trip through the museum

So, let's get moving and stop and check out the relics from the past.

What a great picture! Captured on film here, we have several items found in few pits there days. In the far back right corner, we have the ubiquitous 12v power supply - not just any power supply, a HUGE power supply capable of 20 amps of output, and heavy! Up close in the bottom left corner of the picture, we have a battery, composed of six cells (6s!!!) putting out a hefty 7.2V for an incredible 2000 mAh... but wait, it's being balance discharged! Those LiPo guys aren't the only ones who get to have fun. Lastly we come to the feature attraction in this corner of the museum - an in-use Competition Electronics Turbo 30 Turbo FLEX! Yes, this behemoth does it all still, exept charge big NiMH batterys or any LiPo batteries, but it still outputs 5v to test your motor with... wait, does that work with brushless? Seen here, this Turbo 30 is busy cycling a NiCad 2000 mAh pack after it's cells have been re-"matched". Let's leave the old girl to her business, shall we?



What you see here is an FM transmitter, which uses an extendable "fishing pole" style metal antenna to deliver its signal on a frequency specified by insertable "crystals" that you put in the radio and the receiver. If we check our history books, we'll see that this is a Futaba T3PDF with a whopping 3 model memory. Also visible in this picture is the big red Crafts Man-o-saur tool chest - she's been my faithful pit box for thirteen years now. she's old, she's red, and she's HEAVY, but she can't hold the power supply and the Turbo 30, so those beasts get their own pit box, seen below trying to camoflague itself on top of the Crafts Man-o-saur...

It's not working terribly well is it? Hey, look who just pulled into the pits!


It's the Kawada SV-10 Alcyon himself! Look at that fine Honda Accord body and those super special chrome racing wheels! He must get all the girls! Does anyone recognize the paint scheme from anywhere? It may have been a world champion or something, but it was in a magazine in 1997 or 1998 on a buggy. This driver asked one of the local airbrush-masters to adapt it to a touring car body - he did an outstanding job, and this is actually the third iteration of that body, - the second and third being done by another airbrush-master who added his own touches of originality to the paint scheme. This is the last known survivor of the trio. If this brash little kid didn't wake the Turbo 30 beast, perhaps we can get under his shell for a closer look at what passed for a touring car over ten years ago!


It's almost too easy to get this top off - I didn't even need beads! So whatcha got kid? Carbon Fiber chasis? check! Aluminum? check! Two-Belt driven? check! Stiff upper deck? check! CVD's? check! Super Front one-way diff? check! So, what's it missing? Droop stops. droop stops? ...so what? Ten years and the only thing you're missing is droop stops?


And here he is, proudly showing off his super-quiet 48 pitch gears along with those super grippy eight year-old Kawada tires, which have the writing "20 blue" on the inside of the rear wheels.



And now we move to the front of the chasis, where we can spot some more antique electronics. On the right, is a Tekin G12 III speed controller, for when you want to go fast with no limits (disclaimer : "no limits" does not include the use of LiPo batteries or brushless motors). On the left, we have a double stack of barely-out-of-the-tube-era electronics - a KO-Propo 2000 FET servo, which I guess, explains what the blue wire leading off from the speed controller is. On top of that, the always popular Futaba FM receiver, with a factory tuned antenna of the right length for channel.... 68 dude! Also pictured are the matching Kawada tires - these specimans containing the text "25 blue" on the inside!

That's all the time we have today for this trip around the museum! We're hoping to add a wing dedicated to NiMH in the near future!

How much could have changed? ...really?

I knew going into this that a few things had changed, and being the technical-minded persion I am, did a bit of digging to reacquaint myself with the sport - what had changed, what hadn't changed, what changed-and-then-changed-back?

what hadn't changed - was a pleasant surprise

  • there were still familiar faces present!
  • The smooth drivers are still the fastest
  • Everything is carbon-fibre and aluminum with a hint of titanium
  • The good guys are still out there - the ones who will lend you a hand or even a set of tires (how's that for foreshadowing?)

what had changed - technology at its finest

  • Brushless motors and speed controllers - more effecient motors and speed controls with fans on them!
  • LiPo batteries and small chargers - when is 3200 mAh not 3200 mAh? When it's a LiPo battery that runs 30% longer than a NiMH of the same mAh rating... someone explain that one to me?
  • 2.4 GHz Spektrum radios - I really love this! No! Really! I think I'm one of five guys there who uses a pair of crystals and the only one in the building on my frequency! No interference!
  • personal transponders - I guess everything gets smaller/faster/lighter or more personal eventually!
  • Car layouts - all the cars now are designed with the batteries on one side (a-la the TC3) either for single brick LiPo's or straight built packs.

What-had-changed-and-then-changed-back - everything old is new again

  • 2-belt touring cars! When I stopped racing, the TC3 "revolutionalized" touring cars by introducing a center shaft driven car. I guess there were too many problems with torsion from the motor affecting the roll of the car - the TC5 is a 2-belt design again! The XRay is a 2-belt design. The Tamiya is a 3-belt design (why?).
  • rubber tires - When Larry opened his new track he had gone to all foam racing because in the "tire-war" days, we had the-tire-of-the-week with the-insert-of-the-week and even the-rim-of-the-week... ya... Foam tires were to fix all that! Now, it seems there are spec tires that you buy pre-mounted on a common rim with a common insert - oh, and they last a while too! I never had the desire to use a lathe on tires, so kudos to the re-coming of the rubber tire.

Back in the Game?

I don't know where it came from.
I don't know where it will lead.
Some will say I don't know what I'm thinking.

but, what the hell, right?

Somehow, after being out of racing RC Touring Cars for quite some time, the urge struck me to do it again. I found my car, my radio, my power supply and Turbo 30 in multiple boxes - the car still with carpet fuzz from a track that no longer exists wrapped around its axle shafts, the 2000 MAH NiCad batteries still heavy in their cases, the bronzish colored Trinity P2k motor the only evidence of when it was last used.

Hello, my old friend! Hello Mr. Kawada!

I stopped at the track I used to race at on a Thursday night knowing that races used to be on Fridays. Larry's Performance RC's - they moved to a new facility shortly after I stopped racing, and it appears they've taken over the entire building, expanding the hobby shop - good for Larry! It turns out they still have a touring car class on rubber! brushless 13.5 or a 19 turn motor. After talking for a bit, it's an easy call - $20 for a 19 turn, oh and throw in one of those high capacity 4200 NiMHs - those should shame my 2000's!

At home that night it was like opening a time capsule of RC! Everything on the car was still set from the last race it ran, finishing 3rd in an A-Main just ahead of a brand new Associated TC3 - the RC Car Action Magazine Car of the Year... for 2001! The only changes I made were to put the new battery together, solder in the new motor, remove the carpet fibers from the last race and fix a mysteriously broken rear body post - only two of those left!