DMSBD Tech Tips

DMSBD Alignment & Crossbind Clinic 
Written by- Ian Carsten

MSX International, 1426 Pacific Drive, Auburn Hills, MI, Saturday, March 30, 2002

The alignment and crossbind clinic began with Detroit Metro Director, Joe Flynn, announcing that he has nearly finalized plans for the standard dealer sponsorship package he has been negotiating with the Detroit Auto Dealers Association. He also said the DMSBD posters are being printed and should be at the dealerships within two weeks. Next, he said the plans for the fall rally are almost complete. Then he commented on the spring rally scheduled for Saturday, May 18, and Sunday, May 19. It will be an open rally and we hope to attract racers from all over Michigan, Ohio, Indiana, Illinois, and Wisconsin. Also, Joe mentioned that Detroit Metro will award trophies for 1st through 8th place finishes in each division at the May rally. He suggested that racing against some of the fastest racers from this part of the country is a good experience for our racers and allows them to see what kind of competition they would be up against at Akron this July. He stated that this would be a great way to “tune up” for our local derby in June. The first place winners in our local derby get to race in the national championship races in Akron on July 27.

Joe said that we will have to schedule a track “patch up” day soon and that we need as many volunteers as we can muster to help us to repair the track surface for the 2002 racing season. The date of the track preparation will be announced shortly.

Next, Joe began a review of last week’s car building advice. He said that he prefers to use the small, gold “N” washers to contact the axles in the kingpin washer stack when installing the axles. Additionally, he mentioned that our race teams could acquire a suitable aluminum beam for a triangulation trammel from Factory Steel in Highland Park. The required size is 3/8-inch x 3/4-inch x 72-inch. With the addition of a set of trammel points the set is ready for use. The ones made by the General Hardware Company are well made and reasonably priced. Further, Joe suggested Production Tool Company as a good source of tools useful for a derby builder, such as inch-pound torque wrenches, and micrometers. Also, Sears stores sell an excellent inch-pound torque wrench, the #44593 Microtork© wrench, which sells for about $70.

Joe also showed a custom alignment bar made of 1 x 3 oak. It has 1/2-inch diameter holes drilled through the 3-inch width near each end. The holes are spaced such that placing the holes over the spindles of a car holds the axles parallel to each other. This makes setting up and adjusting the steering cables with the steering wheel in the straight-ahead position easy. He cautioned that you must have a different size for each division since they have different wheelbases. Then he stressed that getting the car correctly aligned and removing crossbind is very important. It has to be as perfect as possible.

Then Joe demonstrated removing crossbind from the stock car he has been building at these clinics so that our racers and their crews could see the process. Joe lifted the rear of the stock car until the wheels were off the floor. Then he gave both rear wheels a good spin. By slowly lowering the car, it was easy to see that one wheel touched the floor and stopped spinning before the other one, indicating crossbind. He then placed a .015-inch feeler in the low side of the washer stack of our demonstration stock car and then re-torqued the kingpin. This time when the spinning wheels were lowered, both wheels stopped simultaneously, indicating the crossbind had been removed. He cautioned the teams to be sure to get out the crossbind, as it will definitely slow their cars.

Next, showed how to snug the steering cables. Since the steering turnbuckles were already closed for minimum drag, he used the nuts on the eyebolts to fine-tune cable tension. He talked about different cabling options and commented on the new AASBD-supplied awning pulley and support bushing. Several attendees said this seemed to work more smoothly than the older, standard floor mounted pulley, which allows the brake cable to rub the flange of the pulley rather forcefully. One of the builders asked whether we still had to use the cable-keeper block. Joe said that even though it serves no purpose, the AASBD still mandates it be in place. In fact, he said, he saw a number of crews at Akron in July of 2001 scramble to install them. And that required quite a few of them to rent oxygen-acetylene welding rigs to cut out the necessary clearance in their steel weights.

Then Joe discussed airfoil mounting. He suggested sanding the airfoils until they were the same thickness as the axles or, perhaps a bit thinner. He said the missing thickness could be made up in multiple layers of sealer and paint. The idea is to get the airfoils exactly the same thickness as the axles to promote smooth airflow and thereby minimize drag. He said he didn’t like the idea of sanding the ends of the airfoils to smooth them since the process shortens them somewhat. He likes to leave them long to smooth as much of the airflow over the axles as possible. To smooth the ends, he recommended building up sealer to fill up the rough cut and finishing over them when they are painted. It was pointed out that superstock front airfoils need to be trimmed to clear the body. Joe said that scrap lumber or rough 1 x 2’s could be mounted and used as stand-ins to determine where to cut them. Once this has been done, the layout can be transferred to the airfoils and they can be cut to match. The benefit is, if a mistake is made, you won’t have to order a new set of airfoils. You simply cut another piece of 1 x 2 and start over until you have the proper fit. Also, an easy way was suggested to get the eyebolt clearance properly located into the front airfoils. You first screw them in position, then transfer the eyebolt hole into the airfoil by placing a 3/16-inch drill through the eyebolt hole in the axle then drill about 1/2-inch into the airfoil. Now remove the airfoil and open up the hole with a 1/2-inch drill to a depth of 1/2-inch to 3/4- inch. Then, after the eyebolt is installed, the hole in the airfoil should clear it perfectly when the airfoil is screwed back in place. Joe also said the rear airfoils could be notched out to clear the stabilizer on a stock car if necessary.

Jim Scotti suggested using a piece of 2 x 6 lumber standing up from the floorboard and braced against the front edge of the base plate of the brake/steering assembly and against the front of the steering wheel, c-clamped to the brake plunger to immobilize the steering wheel in the straight-ahead position for steering cable setup. He said you have to remove the spring from the plunger in order to do this. Joe commented on the wide disparity in steering cable tension he witnessed while traveling to rally race at various tracks in several different states. He likes the cables to have no slack but said he doesn’t want them too tight either. However, Jim Scotti countered that he believed the cables and stabilizer bars of a stock car should be quite tight. He said he thought the bars should be tight enough to ring audibly when struck with a screwdriver handle. Joe observed that derby racing generates many opinions, sometimes disparate, from equally successful teams.

Then we broke up into independent work groups. Several teams laid out and prick punched triangulation dimples into their rear axles, installed them, torqued the kingpins, and used the 6 foot trammel to triangulate the rear axle 90 degrees to the car’s centerline. One builder used our custom-made ballpoint trammel to lay out the triangulation marks in the rear axle of her superstock car. Other teams continued with various phases of construction. At least two teams said they didn’t care for the rough action of the standard floor-mounted pulley and were going to reconfigure their brake system to the awning pulley option since the ones they have observed in other cars work so much smoother.

Several builders traded tips on how to get the most satisfactory finish using tung oil varnish. It was suggested that rubbing the board moderately with 000 steel wool between applications helps produce a smother surface. Another idea was to use a fine abrasive polishing compound intended for painted automobile bodywork, such as Mother’s California Gold Auto Polish to smooth out the final coat. One of the key ideas to using tung oil successfully is to apply a number of really thin coats, well rubbed in. As always, we answered a number of construction and rules questions that had come up since last week’s clinic.

Theresa Young conducted a drawing for all Detroit Metro drivers in attendance. The lucky winners and their prizes were:

  1. Sally Guimond—Millenium Mug

  2. Alexa Johr—Derby Luggage Tag

  3. Justyn O’Green—Twix Bar

  4.  Kelsea Klein—derby License Plate Bracket

  5. Tori Balough—Derby Luggage Tag

  6. Tillie Bergmeier—Twix Bar

  7. Kyle Scotti—Bobble Head El Jeffie

  8. Zach Balough—Lucky Monkey

  9. Jeffery Lukacs—SBD Keychain

  10. David Barnowsky—twix bar

  11. Maddie Klein

  12. Harrison Woods—Red Ring Cap

 
Next week’s clinic at MSX will focus on final assembly,
wheels, and tuning.

Back to Tech Tips
______________________________________


Copyright©  2001 - 2007 DMSBD
All Rights Reserved