Funny thing about having relatively infinite spare parts (not counting printer time) - it makes you drive much more aggressively.
16-20 crashes later, the car looks like this, a little heavier, better balanced and much faster than when it started. Original set of tires - and I haven’t been gentle with them. NinjaFlex may not be as grippy as rubber but it sure wears better - and as you scuff the tires they deliver better grip. NinjaFlex also provides impressive grip in rain, very surprising.
Crash Parts Stats: 9 front wings, 2 rear ones, 7 noses, 6 suspensions (upper or lower) 6 front axles (though haven’t broken one in a while since I went all solid, they strip the screw area to fail now), 7 axle holders (note the latest anti-over rotation mod on the axle holder), 1 front suspension block and 2 front chassis plates, about 12 rear axles, 5 pinion gears and 3 spur gears, 3 engine/axle mounts, and two pair (4) of each front and rear rims later, oh and about a half dozen hub caps, about a dozen rear view mirrors, and four cameras.
The last crash instead of snapping suspension bits, wheels or axles, scuffed the nose and munged the servo saver, it doesn’t lock in any more and the steering is nonresponsive as the servo saver free rotates - and I’m fine with that, it’s a pain to replace requiring a lot of disassembly, but the fact that it was the sacrificial component is ok by me. Means the wheels, steering, nose, and front at 100% infill is tough enough now (wing probably excepted) and if it’s the servo saver going instead of the servo that means the scrappy little metal gear heli tail servo I’m using (SPMSH3650) is tough enough. I’m going to keep printing those servo savers so they are weak, they print fast.
The Castle Sidewinder SCT motor/controller combo I’m using just barely fits in the car and is way too much power especially with the 50c 3s 2200mAh batteries plentiful current, haven’t ever really gotten above 50% throttle under any reasonable control of the car, and I had a hard time not shredding gears and axles at first. Eventually went with 100% infill with the drivetrain (gears, axle) too, and that’s strong enough now (in ABS). Super over powered is a blast of fun, but requires much more careful throttle control. Recommended.
Some hints and recommendations from what I’ve learned so far:
Recommendation 1: need to mod the axle holders to include counter over rotation stops (or the upper and lower suspension, if you want to keep the axle holders symmetrical and interchangeable) I improvised at first with a 2mm x 20mm cap bolt and a hole drilled in the upper at just past the maximum wheel rotation (remember to up your servo travel to max 150%, use a 24mm bolt if you want to drill through both lower and upper but that seemed fiddly to align so I only used the upper, seems to hold for the first while, but that mod had a tendency to rip the suspension in harder crashes). It stops the steering/wheels from over rotating on one side or the other while under hard maneuvering - leaving the steering locked, and the car dead. Another option is to put a stop 2mm bolt in the axle holder which was the second solution I went with after a crash that smashed my suspension and I think I like it better than the stop bolt in the suspension - seems to damage suspensions less in crashes and be tougher. See picture - zoom in on the front wheels.
Recommendation 2: put a drop of medium CA (it’s not as permanent on metal to plastic as it is on metal to metal) on the end of all six non linkage front suspension bolts to stop them from being shaken out under the rigors of being yanked around under hard driving.
Recommendation 3: Put a stack of dimes or other metal weight in the nose (US pennies fit perfectly, but we gave up pennies here in Canada sadly), as ballast, to bring the center of gravity to the front of the camera deck for more speed and better handling. Mount the battery as far forward as you can. The CG should be somewhere in the range of the area of the camera deck - out side of this it is a little tail happy. Use as much infill as you can for the wing, nose, front wheels, suspension and chassis plate. Not only does this make these, the most vulnerable of all the pieces, tougher, it will also help the balance and require less ballast. My second to last crash was an at speed nose in donk into a curb (oops, heh) and in earlier iterations of the front bits they would have disintegrated but at 100% infill it just dented. The car handling and stability, esp over bumps, improves, top speed and acceleration the car can tolerate increases, and the amount of stabilizer “wiggle” the AVC stabilizer in the Spektrum 4210 receiver I’m using adds as steering corrections goes noticeably down - all very dramatically as you improve the balance of the car.
Recommendation 4: use a stabilizer, either a receiver with one built in like the surface Spektrum receiver I’m using, or a airplane receiver with stabilization built in, or a helicopter tail gyro or one axis of a three axis flying thing stabilizer. The car’s stiff suspension is very squirrelly over road bumps and computer gyros make it much more fun to drive when they correct and smooth out the little hiccups - your top controllable speed will go up a lot.
F1 car print tips for ABS:
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increase raft margin to 16mm for the wing so that it builds one big raft for all three sections and one won’t break loose without losing grip on all the sections as well and they don’t move in relation to each other.
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when printing at 100% infill, using linear fill pattern will shake the print less and help adhesion as well as being faster.
