Monday, February 18, 2019

The American Formula: CRC WTF1-FC16 Build Tips



    Besides it having the best chassis designation in the game (WTF?!), the Calandra Racing Concepts WTF1-FC16 is arguably one of the best formula car kits on the market for a variety of reasons. Ease of adustability, parts availability, simplicity, a strong racing pedigree, and a modest price tag all make this a chassis that's hard to beat. While it's designed for all types of racing surfaces, it shines brightest on carpet. And why wouldn't it? CRC sells the very carpet that this car competes on.

Best name in RC, end of story.


As with any car though, there's a certain amount of massaging needed to extract the full potential out of the WTF1. Below is a step-by-step guide that I've come up with based on my own build. Now, on to the car!

Ony tighten the center pivot enough so that there is minimal play,
but the pivot ball is still free.

Bag 1: Center Pivot

    This is the first step in the build, and it's a simple one. The instructions do a good job of describing how to esure the pivot stays free. I tightened the ceneter pivot and used a wrench through the ball stud, moving it around in all directions until I was satisfied with the movement. This is a critical pivot point to the car, so take your time, and make sure it's a free as possible.



It's extremely important to make sure
that the rear pivot assembly is free of any binding.
Take extra time to make sure the links feel smooth and free.



Bag 2: Setting the One Piece Links

    This step was admittedly time consuming, and I took the better part of an hour making sure the links were free, but only because this is probably the single most "pivot"al (pun intended) step in the entire build. Again, CRC does a good job of describing things. No need to tighten the link screws, just having them threaded into the link is enough to keep the link from popping off. Take your time and double check the alignment of the motor plate relative to the main chassis, as this will cause binding and clicking if it's not correct. It will also bind up otherwise free-moving links. Adjust this through the slots in the center pivot assembly.




From here, you can see the side spring resting just at the chassis plate.
Make sure this is even on both sides.



Bag 4: Tweak Plate

    This step is fairly straightforward, but there's a couple tips here out of convenience. With regards to the side springs, the manual doesn't mention it, but when threading the set screw/spring assembly into the tweak plate, make sure that the side spring just barely touches the chassis when layed flat on a table. Make this adjustment equal to both sides, much like you would on a 12th scale car.

Note: Before you install the tweak plate, go ahead and install your body mounts to the plate itself. The mounts are located in Bag 10. The mounts are nearly impossible to screw in if you wait until the end of the build per the instructions.



You can see the o-rings on each ballstud. This reduces slop.
Also, I used the rearmost hole on the motor plate to mount the shock.
This reduced the amount of rear droop.

Bag 7: Center Shock

    This is probably one of the smoothest shocks I've ever built, but as with other parts of the car, I did massage it a bit. On step 2, it shows the o-ring going into the shock body, followed by a plastic shock plug. When installed, I found the plug to be a bit long on the o-ring side, which squeezed the o-ring around the shock shaft too much, causing a lot of drag. a couple swipes on an emery board and a cleanup with a hobby knife, and all was well. Note: Take off small amounts as needed, just enough so the o-ring will still seal, but doesn't drag excessively. Add a little green slime or 1UP "blue" grease to the o-ring during install. Also, when I mounted the shock, I added a soft o-ring to both ball studs. This takes up any slop from the ball cup to the stud.




In this picture, you can see the steering stop,
which takes the place of the inside mounting screw.

Bag F: Front End

    On the various parts in this bag, I came across some flashing and mold lines that needed a quick cleanup with the hobby knife before assembly. With the front arm mount (1543) in particular, make sure the bottom surface that mates to the carbon lower arm is as flat as possible and free of any flashing. This will give you a more accurate/consistent reading for your ride height, etc. I also took some time making sure the lower arm ball socket (1547) and pivot ball (1546) were as free as possible. There isn't a ton of movement in these parts, so as long as they move easily and are equal side-to-side, you should be good here. Instead of the kit plastic caster shims (1550), I opted for 3x1mm aluminum spacers instead. These weren't as tight as the stock shims, which freed up the upper arms quite a bit, albiet with a very small amount of play.

Note: This is one of the few cars that does not include a steering stop, which in the event of a crash, saves the knuckle from being ripped from the car. CRC does now sell a stop kit, but I decided to make my own from some parts I had laying around. I used a 7mm spacer, a wide washer at the base of the arm moulding, and a 3x16mm screw that threads into the kit-supplied 3mm locknut on the bottom side. 



Bag F: Servo Mounting

There's three different ways to mount a servo in the WTF1: 
Vertical (Standard/mini servos)
Horizontal (Low-Pro servos)
Flat (Airtronics/Sanwa 94761)

    For those of you like me who run standard or low-pro servos, there's an infinite amount of ackerman adjustment, but the mounting is a bit unorthadox. Unless you're using a super narrow servo, a standard-width servo will not fit in between the facory mounts and carbon plates. What I did was mount my low-pro servo horizontally with tape directly to the chassis, then use 4 screws threaded into each mount to center the servo inbetween the mounts and secure it against side-to-side movement. It's certainly a different way of doing things, but no less effective. 

With a standard-width servo, you won't be able to use the carbon plates.
Instead, secure with servo tape and screws.
It's unorthadox, but it works. It also makes adusting ackerman easy.


From here, you can see the 10g weight,
nestled in the center against the battery.

Battery Mounting

    The WTF1-FC16 will accept both inline and cross-ways battery mounting. For most surfaces, mounting the battery cross-ways will work best to start, and the chassis allows a wide range of movement fore and aft. I ran my battery all the way forward against the upper plate standoffs, then added a 10g weight behind the bettery to keep it in place. Not only does it keep the pack secure, but it adds a bit of ballast at a good spot in the chassis.



Conclusion

    Well, there you have it. My build tips for the CRC WTF1-FC16 chassis kit. While some might feel the fit and finish isn't quite up to par with other cars on the market, the modest $249.00 price tag more than makes up for it. To me, performace is the most important aspect, and this car has that in spades. None of these tricks are anything out of the ordinary for me with any other build. Take your time, test fit your parts, massage and trim where needed, and you'll have a race winner in no time.

She looks so good in my pit.

Setup

The box setup is absolute money for this car, but for the sake of info, here's my current setup:

Front:

Ride Height: 4.5mm
Spring: .045 kit, 20k lube on kingpin
Camber: 1.5deg
Toe: .5 out each side
Caster: Kit (one spacer on each side of upper arm)
Droop: .5mm over ride height

Center:

Shock: 35wt, zero rebound, kit red spring, rear ballstud mount on motor plate
Damper Tubes: 10K
Side Springs: .045 kit
Droop: .5mm over rear ride height

Rear:

Ride Height: 5.5mm
Diff: XRAY gear, 30K

Tires (carpet)

Front: Rush medium-soft, glued sidewalls, inside 1/3 sauce, 5 mins soak, wiped
Rear: Rush carpet soft, full sauce, 10 mins soak, wiped

Thanks for reading, and see you at the track!

-JRoy