Scimitar Wide Pan
Finally, I have a fully Scimitar Spec Wide pan for my own use.
Attached are a few photos. I am still trying to get some duplicates cut, but am having much trouble. This chassis was machine cut, but not without errors. I had to hand sand it in four spots with the Dremmel. The countersinks were terrible. They were shallow and had tearouts from a dull bit. I recountersunk all the holes but there were still some minor flaws making the chassis unsaleable. The nerf wings had deep notches that I sanded out. Both suitable for my personal car though. I thought I would go through some pan car ills that I have tried to correct with the car. These were experienced starting in August 2006 in the
I tried a very wide variety of pan cars. These included
The CRC Pantoura which is the subject of the above thread. (Center pivot side link)
A Powell Racing Products, Wide Pantoura (graciously loaned to me) (center pivot side link)
An Associated RC10L2O converted to road use (T bar with viscous disk roll control) graciously donated.
Several converted oval cars (Rear Pivot short T-bar)
The main differences in the cars were how the pod was joined to the chassis. I can rate a couple of important qualities fromt the test.
Best throught the bumps, the Center pivot side link like on CRC cars and now on the Associated 1-10 pan.
Best acceleration (the Rear pivot T-bar car). This car is much like the Center pivot car, in effect, but it has a pivot that is at the rear edge of the T-plate. The CRC pivot is slightly forward of this. This gives the Rear pivot T-Plate car better Antisquat and more forward grip.
Best front turn in was the T-bar car with viscous disk roll control. This is probably the roll control with lightest action.
Now here are some problems shared by all when using powerful motors on a large outdoor track.
Sluggish acceleration on the second part of the straight
. All the cars tended to bounce and touch only the tops of the bumps. The Center pivot side link car was best here but a full 4 mph slower by radar than my 3-link rear end car
Steering is imprecise
.- I probably can give you the best example on the oval. If you do not turn in the sliding kingpin car just right midway in the straights you can forget running a tight line. You have to aim the car rather than steer it. This is corrected by my dual A-arm front end. You can steer and manouver all the way to the apex.
Going Airborne on the Straight (Blowovers)
This was the most vexing problem and was the hardest to solve. I tried many forms of the strut front end. I added shocks, I added a sway bar. The sliding kingpin was just unsuited to resolve the this problem. It had too much friction and not enough travel. I finally cured the problem with a dampened dual A-arm front end. It also helped a lot to add a diffuser just under the front lip of the body. The car is really sucked down now and does not bounce up in the air at all.
All of these trials and experiments are recorded in the Pantoura thread followed by this thread.
Some Good Scimitar Features
- There is a 3-link rear end, and Dual A-arm front end, fully dampened on all four corners. This addresses all the problems above.
- The front end has droop control screws. The roll center can be adjusted by reshimming at the kingpins.
- The rear end has bump stops that prevent the chassis from bottoming on the high speed bumps. This allows you to use the best rear springs for cornering rather than overly heavy springs to prevent chassis rub on the pavement. The pod can be run 1-2 mm lower than the chassis for a low center of gravity with no tendency to rub the ground. The front edge of the pod is no longer "hinged" to the chassis so the pod plate stays almost level through full suspension travel.
- The chassis is drilled for only two servos and servos of similar size. This avoids holes too close together and ajustment hardware that still wont let you put on the full strength servos. I really like the PDS 2413 ICS. This is a half height servo. It can be mounted farther back for good weight distribution. The steering links can be driven off the front of the servo horn. I am using the large white Kimbrough servo saver as it has a hole position for the ballstuds which is midway between the lower and upper holes on the small servo. This gives me proper bump steer. The wheels do not steer as you push them up. The other set of holes farther forward is for the small Hitec Mighty Mini Servo. A small servo saver with ballstuds on the back side will be required.
- The battery is a quick install from the top. A CRC Oring and posts secure it. The LOSI JRXS battery tray is retained for the lowest possible Center of gravity.
- The pod is the old Associated L3T/CRC carpet knife type. It has a full width curved blade top plate (Hence Scimitar). and a full length left side pod metal. This gives a rigid pod and chatter free performance.
- The chassis is very solid in the front for good performance in the high speed crashes.
- The new 3 point front top plate and through bolts make the front end very rugged.
- The Nerf wings provide axle protection and freedom to mount electronics back for more forward traction with an inline battery.
As this is the first fully equiped Scimitar 1-10 pan, that I have shown, I thought I would list the equipment
LRP SPX8 speed control (this speed control is most like the old LRP TC edition that also worked well in the car)
LRP X12 3.5 motor
Thunderpower 4200 mAH, 50C pack. This brand is the most heat tolerant that we have found. This prevents puffing up with use.
KO PDS2413ICS, This servo is half height but full strength and speed.
Test to come in a couple of weeks.
That first pic can be blown up with a second double click and you can scroll around the car.