After a close battle at the end of Saturday, I tore off a new fast time on Sunday's second run.  Jason kept the gap close, still only about 0.4 seconds behind.  My third run was 0.2 seconds slower because I had trouble keeping the tail in line.  Jason continued to close the gap, ending his third run at only 0.143 seconds behind!  With the last run of the day, I was going to go all out.

As I went up the hill, at the last instant I decided to swing wide going into turn 3, rather than hug the inside like I had been doing all weekend.  This threw me off a bit and I got on the gas too early.  The tail stepped out a bit, but I caught it.  Rather than give up, this helped me focus on putting together a clean run the rest of the way up the hill.  I figured all was not lost with this minor delay.  I went flat through turn 5 and carried my speed very well.  The tires started to chirp and the car began dancing.  Great, I was at the limit, but didn't run out of room on turn 5's exit onto the mountain "straight."  Screaming down the straight, I tapped the brakes and got back on the gas turn turn 6, also known as 'oh shit.'  I was flying into the braking zone for turn 7, got the car slowed down, and managed a snappy 4th-2nd downshift.  So far so good.  I ripped through 7, 8, and 9, and hit 10 (the Pagoda) fairly well.  I kept my foot flat over the kicker into turn 11, and the tires were chirping again as I COOKED through 11.  The car held on and I kept it flat through the final uphill straight.  I tried to straighten out the lines as much as possible to cut off any unnecessary distance.  In doing so, I hit a big dip next to the timing relay tower.  As I screamed through the finish, I began shutting down.  It was only then that I noticed an unusual noise.  Hmm ....

Checked the brakes, no problems there ... steering is good, the car isn't that noisy.  Any louder than usual, that is!  Still shutting down, I check the oil pressure & temp.  Everything is good.  Hmm.  If the exhaust was dragging, wouldn't it make more noise?  Ignorance is bliss!  I drive down to the turnaround, still making noise.  I bring it back and get a look from the other drivers when I get to the grid at the top.  "I know!" I shout.  Jump out and look underneath.  Sure enough, I'm dragging my muffler, but it's still attached!  Thanks to some leather gloves, I hook the muffler back onto the exhaust donut.  Looks like when I hit that dip, the muffler jumped out of the donut!  Wow!  


When I finally get to the bottom at the end of my group, I heard the good news about my time.  Surprising how much faster I was.  I'm now less than 2 seconds behind the class record, set in 2000!   I picked up 7 seconds over last year.  Not too shabby!  Amazing what a new set of tires and a chip will do!  Practice doesn't hurt either.  I think the car has the final 2 seconds in it, I just need to drive it better.  Jason and I are now 2 and 2 in every event we've gone head to head.  Both Fall Jefferson and Fall Weatherly should prove interesting.  I'm optimistic because I only lost by 0.110 at Spring Weatherly and didn't yet have new tires and a chip.  Jefferson should also go well because the car is in its element on flat tracks.  I can't wait!  I expect both records to fall with a crash!

As of Saturday night, I am holding first place of six entries in the ITS class by a meager 0.333 seconds!  The first run this morning was quite damp after Friday's thunderstorms.  The second run was substantially better, but still a bit damp.  Even so, I turned a time several seconds faster than last year's best.  After several incidents delayed the action, the tires were stone cold.  I went for my third run, and managed to turn a 134.207.  Jason followed up with a 134.540, only 0.333 seconds behind.  I am currently less than 4 seconds behind the record, which was set in 2000.  I doubt we will bring it down this weekend, but I have made huge strides from last year, already 5.8 seconds faster than last year's best!

Unfortunately, three of the other entrants had car trouble.  One lost a motor mount on his GTI and retired for the weekend.  Though he had never run that car at a hill before, he has successfully campaigned his Audi S4 and turned amazingly fast times.  Regretfully he wasn't able to continue and raise the bar for ITS competition.  Also, the brothers' RX-7 was out of the action after an exhaust bung broke off, leaving a large hole in the exhaust header.  The brothers brought it home, welded it back on, and actually got it back in time to run the last run of the day.  Dale turned an excellent time, and should get within striking distance tomorrow once he's had a few more runs!  With any luck, we'll have at a three way battle for first through tomorrow afternoon!

If you can make it, I highly encourage you to come out and watch the action.  Thrills are guaranteed!

If you like machinery, tractors, trains, equipment, and all things mechanical, the 2012 Thresherman's Reunion is going on now through this Saturday the 18th of August at the Rough and Tumble Engineer's Museum in Kinzers, PA (Lancaster County)!  Tonight's activities feature an antique tractor pull along with exhibits of working antique engines and other machinery.  More information at their website, http://www.roughandtumble.org/reunions/2012/2012_promo.asp!

This coming weekend I will be running the #762 ITS BMW in the Duryea Hillclimb.  For those who aren't familiar with the Duryea Hillclimb, it is held in Reading, PA.  The course begins above Reading's City Park, follows the Pagoda Hillclimb route, and continues past the Pagoda up to the top of the mountain.  The final straight follows the ridge line, with the finish line in front of William Penn Tower.  The fastest cars will achieve speeds in excess of 140 MPH at the finish.

It promises to be another exciting weekend, with at least 6 entrants in the ITS class.  I will be gunning for first place, and the record.  It's roughly 8.4 seconds faster than my best run from last year, but based on my improvements at the Pagoda Hillclimb, I anticipate substantial reductions in my time.  I expect another heated battle, but Jason may be a bit more cautious to avoid a repeat of last year.

For those who are interested, directions and more information are available at http://pahillclimb.net/about/the-courses/duryea-pagoda/

I've included a video from 0-60 Magazine, done in 2007, that features some of the cars from the event.

I had long wanted to do a retrofit on my Bridgeport BOSS 5 CNC mill.  This, along with the BOSS 3, 4, and 6, were late 70's through 80's mills which were purpose built CNC knee mills from Bridgeport.  They were not simply manual mill retrofits, but much of the iron was the same.  Key differences included a heavier knee and table, and limited X travels so that the center of gravity of the table would never exceed the boundaries of the knee.  The iron was well made, but the controls are now quite antiquated.  Mine still worked, but had a number of shortcomings.  For instance, it could only do coordinated moves in 2 of the 3 axes and had a program size limit of 8kb.  8kb is practically nothing if you're looking to do 3d machining.  There was no sense in purchasing CAM software for such a limited program capacity.  When I did my first production run of BMW wheel bearing installers, I managed without the improved control, but found many of the shortcomings in the control problematic.  I finally decided to pull the trigger on a retrofit.

So what did I choose?  Well, the primary options for those of us retrofitting machines with PC based controls are Mach3 (Windows XP based and requiring a paid license -- don't ask me how much, I never bothered to find out) and LinuxCNC (formerly EMC2).  As a MythTV user, I already had some Linux exposure, and liked the Ubuntu distribution for its ease of use.  When I found out that LinuxCNC ran on a real time version of Ubuntu, I was already sold!  Plus it's free!  I've now had a version of MythTV running on Ubuntu 10.04 for over 2 years and have not had a hiccup, so gave me confidence that I could get it working without too many headaches.

I researched parts selection for some time, ultimately deciding to make every effort to use the existing spindle speed control, spindle brake, and other external inputs from the machine rather than exclusively use the pc interface.  This required figuring out which wires did what.  Ultimately, the machine schematics were very helpful, but some probing was still required.  With all this in mind, it was clear that I needed stepper motor drivers to run the mammoth NEMA 42 steppers, a power supply for the steppers and the interface board, power for the 24V DC solenoid valves, and power for the lubrication pump and spray mister (120V AC).  I also required an interface board to connect all these signals to the computer and a Variable Frequency Drive (VFD) to turn my single phase power to three phase power.


Power Supplies:
For the stepper motor power supply, I chose an Antek 70V 20A (1500 Watt) power supply.  This is the biggest wattage they make, and 70V leaves a reasonable margin for the Gecko Stepper Drivers' max voltage (80V).  More on them in a bit.  I chose 20A so that I could run up to 5 stepper motors quasi-simultaneously without overload.  See the Gecko manuals & documentation for calculations on this.  You may need less if you only ever run 3 or 4 motors.  I chose a version that also had a 2A unregulated 24V DC output, perfect for operating the solenoid valves (that each take roughly 6 Watts, or 0.25A at 24V) and a 12V regulated output, also perfect for supplying an interface board.  The interface board would need an on-board regulator to bring that 12V input to 5V, but many boards have that functionality or I could easily build my own.  After playing with electronics for a while you tend to have 5V regulators in your 'inventory.'  It's a very handy voltage!

I also needed 120V (nominal) and I only had single phase 240V wired to the machine.  Incidentally, the machine runs on 30A, 240V.  This is plenty of power for our needs, but 120 is not available directly from the mains.  So I chose another Antek toroid which would transform the 240V input into 120V output, allowing me to run some relatively low power devices like the lubrication pump and the spray mister.  This version also had 18V AC and 12V AC windings, but I didn't need them and just tied them to terminals on a terminal strip to secure them.


Stepper Motor Drivers:
I chose the Gecko G203V's for ease of use, low price, and acceptable performance ratings.  They will operate the steppers at up to 7A, 80V.  The original Bridgeport motors were wired in series configuration, with 8A and 55V.  Thus, the low speed torque is marginally reduced (because it's current limited, not voltage limited -- see the Gecko manuals for a fuller explanation) when the motors are run in series, but the high speed operation is slightly improved due to the higher voltage.  In parallel, the low speed torque is substantially reduced due to the lower impedance of the wiring.  However, the Geckos are simple to use, cheap, and readily available.  I could find numerous affirmations that they ran the Bridgeport steppers just fine.  If we wanted absolute maximum speed and power we'd be using servos but that would cost substantially more, and is out of scope for this project!  Although the standard NEMA 42's are relatively torquey, should we ever need better performance, we can always retrofit NEMA 34's which have far lower inertia and generate superior torque as compared with the original steppers.  A true win-win, and only ~ $120 each plus shipping.

These also have 10 micro steps by default.  Initially I was concerned because I knew that these motors would not respond well to microstepping, as there is a high detent torque between motor steps.  However, I realized that if the machine would only move accurately between one step and the next, it won't be any less accurate than having whole step drivers.  At present, 1 step = 0.001" so any distance less than 0.001" is not considered reliable.  Certainly no worse than the original control!


Interface Board:
Here's the million dollar question:  Do we use a simple 'breakout board' and rely on software stepping of the parallel port, or use a hardware solution?  I chose to use a hardware based solution from Pico Systems called the Universal Stepper Controller (USC) board.  The USC board offers a number of advantages.  First, if your computer has a lot of variation in its timing (often from video card drivers, etc), there is a risk that the machine will lose steps because it can't give the next step before the inertia of the table pushes past the stepper's holding torque (when moving).  If you set the pulse speed slow enough that this is unlikely, then you may not be able to go as fast as the machine is capable of moving.  Further, a single parallel port (though you can add more) is limited in the number of inputs and outputs it can provide.  I like to have total control, so I didn't want to compromise on I/O.  It is also possible to add a second USC board through the same parallel port connection, further expanding the available I/O.  Just the ticket!  I must also add that Jon Elson of Pico Systems was extremely helpful throughout the process.  His customer service is excellent and he is very knowledgeable.  You can't go wrong.

I also purchased his 60V 15mA Solid State Relays (SSR's) for control of the VFD's direction inputs.  Finally, I sprung for the Pico Systems DAC board to (ultimately) enable frequency control of the VFD, which will enable total speed control!  This outputs an analog signal from 0-10 volts upon command from LinuxCNC.  The VFD, when properly configured, will read this voltage and adjust its output frequency.  This is one easy way to adjust speed, and can be used if you don't have the air powered spindle speed option.  I plan to mount an encoder on the spindle and use a hybrid method to achieve spindle speed control, using the solenoid valves and the VFD to achieve automatic speed adjustment.  This is a bit more difficult than the standard closed loop spindle speed control examples shown on the LinuxCNC wiki, and may require that I program my own LinuxCNC component.  We'll see, I haven't gotten there yet!


Variable Frequency Drive:
What better way to get rid of your noisy rotary phase converter than to use a VFD?  I could have gone cheaper, but Hitachi drives have an excellent reputation and the WJ200 series are fully featured.  They should enable virtually any function I could want, including analog speed input, and digital direction control.  Running a three phase motor on single phase power has never been easier!


Conclusion:
I've attached a spreadsheet in PDF form of all the purchases I made to complete the project.  I can say that I could have bought more cheaply in some areas, but I tend to try to do it right.  Of course, I included things like a full case of both cabinet filters, which certainly adds to the cost, but isn't strictly necessary.  Keep in mind that it's probably an item you wouldn't think of changing, so it doesn't hurt to factor it into the plan.  I suspect, for me at least, that 12 of each will be a lifetime supply!

Oh the memories ... I'm getting nostalgic already!  My first HPDE (and first NASA event) was at Summit Point in April of 2011.  I can say, it was a blast, but at times it proved rather frustrating.  For anyone looking to get started with HPDE's, I highly recommend it, but sometimes those new parts you put on just for the track may not work out so well ...

I was thrilled about the upcoming Polish Mountain Hillclimb.  I had everything packed.  I just had to take the truck, trailer, and race car for gas, ice, and go.  Just Gas and Ice.  I got to the Sunoco station, 3 miles away, and pulled in to fill up the race car and the spare fuel cans.  I was about an hour later than I meant to be, but still plenty of time to get there for the evening's festivities.  Until the truck won't start.  Damn.  So I spent Friday afternoon, from about 3:30 PM until 8:30 PM, stuck at the gas station 3 miles from home!  I managed to troubleshoot the problem to either a bad starter solenoid or a faulty wire from the neutral safety switch to the starter solenoid.  Sometimes the best laid plans ... but at least I was only 3 miles away from home, rather than stuck in the middle of nowhere.  Towed the truck to my friend's shop, and got another friend to tow the trailer/race car back home.

And I just replaced that starter in December!  The quality of rebuilt parts has been suspect for awhile now, as many of them are mass-rebuilt in China.  Blows the mind that it's cost effective to ship cores to China (which weigh a ton) and then rebuild them and ship them back.  And often the rebuilds are done poorly.  Can anyone recommend a local (southeast PA) starter and alternator rebuilder?  I need to get spares for the BMW's too.

I'll have to see how the results came through from the weekend.  I was only 0.8 seconds off the ITS class record.  With new Hoosier A6's and some extra horsepower, I was set to beat it.  I guess I'll have to wait till next year!  Hopefully Jason and Dale didn't raise the bar too much!

NASA's VIR event was another HPDE 2 event for me.  It was only my second time at the track, so it took a bit to get comfortable with all the turns.  I also had a style conflict with my instructor, who got a bit nervous with my aggressive use of the car!  Eventually he grew accustomed to it, and we had a great time.  On Sunday morning we were chasing down a modified Audi S4 (which passes me on the back straight at about 7:50 in).  Too bad the camera quit after only 10 minutes.  I spent the entire session dogging that S4.  It was quite a blast to chase down a much faster car.  Spec E30's sure hold their own in the corners!

Hyperfest 2012 at Summit Point Motorsports Park went well, I drove another High Performance Driving Event, this time in Group 2.  I also soloed at the end of Sunday, my first time driving on track with traffic by myself.  I was able to analyze traqmate data from the session and found that I was quite consistent.  I had a great time chasing down a Toyota Supra Turbo, with an E36 M3 chasing me.  I always managed to catch up to the Supra, but he wasn't really holding me up.  The M3 never really caught me, except at the end of the straights!  All in all, a great time!

The 2012 Pagoda Hillclimb was another tough fought battle for first.  Though I held the lead through the weekend, on the second to last run of the day, nearly a second behind, Jason fired off a fast run, beating me by 0.370 seconds.  I went all out on the final run, but missed a fourth to second downshift into turn 7, and could not get the car into gear.  Needless to say, I'm not posting the last run because it's not censored!

In other class action, check out the fire response from the PHA safety team ... Motorsport may be dangerous.  Videos below!