I’ve done a couple of posts about the posts…in other words, discussing the principal weakness of the T-jet platform, the screw posts, and some ways to mitigate damage when dealing with cracked or stripped posts. There is, however, another aspect of the T-jet setup which is less than ideal: the guide pin.
Because of its design, it is not economically feasible for T-jet pins to be made from metal; later chassis redesigns by Aurora (Magna-traction) and Tyco allowed for the use of thicker, more robust plastic pins or metal pins, but with our old-skool TJ’s we’re stuck with an easily breakable thin plastic pin. Of course replacing them is easy and cheap, but have you considered the performance effects of which guide pin you choose to use? I’ve found from experience that in some circumstances and on some cars, it can make quite a bit of difference. As with the screws that hold the cars together (see my post appropriately titled “Screw This”, isn’t that punny?), I have discovered 3 distinct types of pins, all which have their strengths and weaknesses…in some ways, literally.
The stock pins that come on Auto World Ultra-G chassis are fragile and easily broken. Though the bases of the pins fit nice and snug into the recess on the chassis, they don’t last long, especially if your track has X-over pieces as many do; a crash with another car at such an X-crossing is almost guaranteed to break them. AW has recently redesigned these pins with a new, horizontal brace molded into the top part of the pin which has improved their strength, but not their resiliency; the main issue is that the plastic they are made from is inflexible.
A more durable option is the aftermarket pins made from Delrin, the DuPont brand name for polyoxymethylene plastic. These are of a slightly altered design from the stock pins, as they set slightly further back from the front of the car and they are also slightly longer, which can give you a road holding advantage. Most importantly, these pins are slightly flexible and thus far more resilient, and they also produce less friction and thus have a tendency to reduce drag, which may fractionally increase speed in the turns.
FRONT
But, beware: the Delrin pins are more durable, but I have found that when it comes to performance they are not always better; although they are less prone to break they are also thinner than the stock pins, and thus the car has a tendency to “wander” a bit more in the slot. Obviously we’re talking about an amount of drift too miniscule to be detected by eye, but it stands to reason that such drifting may take nanoseconds off straight-line time and may reduce holding in the corners. Precisely because they are more durable, the Delrin pins also have a tendency to wear down over time (usually on the right side due to the frequency of left turns), and thus can become even thinner, having even more effect on performance; too thin a pin will also make your car more likely to deslot on a turn. Check your pins from time to time; if this wear is setting in you will notice that the pin will appear noticably “sharper” than when it was new; I have seen a few so worn that they resemble push pins and are sharp enough to pierce a cork board. Your regular tune-up and cleaning procedure is an ideal time to check this to see if your pin might benefit from replacement.
Another observation I’ll make is that I’ve had some Delrin pins that fit too loosely into the chassis recess, requiring an extra turn on the screw to tighten them enough to keep from wobbling. This is obviously not good, as you never want to put more torque on the screw than is necessary to barely hold the car together due to the risk of stripping or cracking the post. The stock pins always fit the chassis very tightly which keeps them in a fixed position even on hard cornering, an obvious advantage. There are enough production variances in the chassis and the pins that if you find a Delrin pin is too loose in the recess you may be able to just try another pin that will fit more closely, but I often find myself just accepting the use of the weaker stock pins-knowing I will have to replace them more often-for those chassis where the fit of a Delrin pin is never snug enough for my liking; better to replace the pin than risk over-tightening the screw!
RIGHT: the OS3 Lightning Rod
The above comments apply to the 3rd type of pin, the “Lightning Rods.” Brought to us by the fine folks @ One Stop Slot Shop, aka OS3 (who also gave us the awesome White Dragon and Black Dragon motor magnets, which I love and use extensively), these pins are also made of Delrin but are significantly longer than the standard T-jet pins. Whether or not it is beneficial to use these depends greatly on the configuration of your particular car, but it also may depend on the brand of track you are using. I cannot use the Lightning Rod pins on my Tyco track; the slot on the Tyco track is not as deep as on AFX, and the Lightning Rods will bottom out before the front wheels contact the surface of the track, even on cars with full size tires. On my AFX track I can-and do-use the Lighting Rods on my cars with Road Race Replicas or Vincent wheels that have the “full size” Road Race Replicas silicone tires; they are perfect for this configuration. However, they are again too long to use on those cars running on the RRR or Vincent low profile tires.
One thing I have done with some of my cars is mounted a Lightning Rod pin and then used my Dremel to grind down the pin until it is just right length; I test run after each hit with the Dremel waiting until I just barely hear the pin stop scraping the bottom of the slot, telling me the pin is now as long as it can be for that car on that track. The obvious advantage here is better road holding and less chance of de-slotting. The significant disadvantage is that, as of right now, I am racing between 2 tracks, one Tyco and one AFX which is currently still in the construction phase and will be for a while, but which I am testing and racing on when the track is not covered with the debris from the diorama construction going on around it. When using the longer pins on the AFX track, I have to swap the pins out for shorter ones if I want to race the same car on my Tyco track. This seems like it should be no big deal, and it really isn’t, but once again, I’m always leery of the constant unscrewing and re-screwing required to make this change due to the fragility of the screw posts.
Fortunately I now have so many cars that if I wanted too I could have one set for the AFX track and one set for the Tyco track, but many racers may not want to have over 100 cars, so if you have multiple tracks or are racing with friends who have a different brand of track from your own, these are differences you might want to be aware of.
As far as performance goes, it is obvious that you want your guide pin to be as long and to go as deep as possible into the track slot (you know how this works, guys), as any advantage that will allow faster cornering should be taken. It has been my experience that many cars will perform about equally with any of the 3 types of pins, and whether any noticeable gain in performance can be had in using one type over the other depends greatly on how your car is set up. Foremost this requires experimentation with what works best and, secondly, consideration of what type of conditions you’ll be racing under. Hopefully whatever you choose, you won’t get “pinned down.”
Ha. Ha. Get it?
Take it, Siouxsie!
(Great song, I LOVE The Creatures!)