I have designed a new buggy. The STL's can be purchased here: https://cults3d.com/en/various/mkultra-3d-printable-1-10-4wd-buggy
Lynx will remain free. I appreciate donations if you want me to continue uploading free things. I appreciate it if you use my affiliate links to the parts below.
News - 12.11.2017
Added one piece chassis parts.
News - 21.08.2017
Added new wheels with countersunk holes on the inside for locking the printed tires with countersunk screws. The file is wheels03.stl
News - 16.08.2017
Changed the rear suspension arm and spindles to move the wheels farther away from the body and chassis. Also beefed up the front spindle in the upgrade set.
News - 05.08.2017
I made new lower suspension arms. They are stronger and don't rub on the wheels. The new parts are:
NEWS - 22.07.2017
I made upgrade kits for the front and rear drive shafts that use the Quanum Vandal CV shafts. This gives more suspension travel and steering lock than the stock plastic axles, and also doesn't wear every other run. I attached an exploded view of the assembly and some photos of the parts installed on the car. The set screw can be made by cutting a regular M4 screw, and the 2 mm pin can be made from piano wire or nylon filament if you don't want to buy them.
The new files are:
NEWS - 30.06.2017
Updated the diff gears with stronger version. Gears01 and Gears-belt01 have been updated, and Gears-update contains the updated gears by themselves.
NEWS - 29.06.2017:
I uploaded solid shock towers for higher strength.
This is my take on a high performance 3D-printable 4WD buggy. It's comparable to a late 80's to early 90's buggy really, with a cab forward look to it. My next buggy will be modern and better. It can be built with belt drive connecting the forward and rear gearboxes or using separate motors for the forward and rear gearboxes. It can also be built as a front wheel drive or rear wheel drive car off course, but that's not the intention. Parts that are required for the belt drive version are marked "belt".
Wheelbase: ~278 mm
Total width outside tires: 256 mm
Rear toe: +2° (toe in)
Front toe: Approximately neutral to -1° (optionally adjustable)
Front caster: 3°
Rear caster: 0°
Ackerman compensation: Yes
Bump steer is eliminated.
Kingpin hinge line goes through the front tire contact patch.
The dual motor version fits standard length lipos or six cell ni-mh packs or smaller.
Belt drive chassis has longitudinal and transversal battery mounting options for weight distribution adjustment and fits standard length lipos and six cell or smaller ni-mh packs.
I have uploaded some exploded views of the more complicated parts. It's hard to assemble it incorrectly but they should help explain some parts. If it doesn't want to go together one way check to see what's wrong. I have printed and tested everything.
The car has a few optional suspension mounting points. It does not have a million options like most cars do. This is pointless as 99.99% of the users don't know what to do with them. ;) I don't expect any pros to use this car.
The knuckle drive joints require grease to work reliably and not melt. This is very important. They are a tight fit when new and this makes them last longer. It is important that the car is not raised to far off the ground or set up with too much suspension travel so that it extends the universal joints beyond their limit. I might add adapters to fit aftermarket steel CV and dogbones some time, but it will be weeks until I can get some. The current iteration of knucles have proven to be remarkably wear resistant, even with a crazy 4000 kv motor (not recommended).
The eccentric belt idlers are eccentric so that they can be rotated and locked in position to tension the belt that connects the front and rear gearbox. Use a short piece of filament between the idler pieces to align them before installing.
Lubricate all the gears in the gearboxes with grease. I use a cheap lithium grease for bicycles because that's what I have readily available. Do NOT lubricate the belt pulleys!
The bevel gears and the belt drive intermetiate gears have support rings built into the parts. Remove this ring from the gears before installation.
The small bevel gears in the differentials can use 9mm long pieces of 1,75 mm filament as axles. If the hole is too tight you can drill it out with a max 2 mm diameter drill. Other shaft materials can be used off course, and 2mm metal will be stronger, but filament is easiest to cut.
I use pieces of 3x22 mm brass tube or steel tube in the center of the diffs to keep them aligned. 3mm piano wire can be used but is harder to work with.
Cover the opening in the unused gearbox housing with aluminum tape to prevent dirt from entering it.
-Minimum 2 channel transmitter and receiver. This is the cheapest i can recommend:
This is better:
-Up to 3000 kv brushless 540 motor and ESC recommended (or down to 21t brushed 540 motor):
-A good servo:
-2S hard body lipo: https://www.banggood.com/Giant-Power-11_1V-6000mAh-3S-65C-Lipo-Battery-T-Plug-Hardcase-Pack-p-1080404.html?p=HD240528697332015103
-250 tooth 6mm wide 2mm pitch GT/gt2/gt3 belt - https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575353675&campid=5338226872&mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2F152413083472
-20 pcs 12x18x4 ball bearings - https://rover.ebay.com/rover/1/711-53200-19255-0/1?icep_id=114&ipn=icep&toolid=20004&campid=5338226872&mpre=http%3A%2F%2Fwww.ebay.com%2Fitm%2F20pcs-6701-2RS-6701-RS-12x18x4mm-Rubber-Sealed-Ball-Bearing-Miniature-Bearing-%2F120901748928
-Oil shocks are recommended:
-M3x30 mm turnbuckles are optional for adjustable tie rods and upper suspension
-2 mm piano wire to make hinges for the lower suspension arms. Cut to length.
-3 mm x 22 mm long brass or steel rod to make the center shafts in the differentials:
-Tires if you don't want to print tires:
-Bicycle tubing for making rubber bands for the printable rubber band shocks:
13 pcs M2x8 screws - Gearbox housings and steering links
6 pcs M2x12 screws - Various suspension and steering
6 pcs M2x25 screws - Suspension arms installation
6 pcs M3x6 screws - Gearbox housing assembly
10 pcs M3x8 screws - Chassis joint, shockplates and wing mount
10 pcs m3x12 screws - Various shock and suspension attachment
4 pcs M3x20 screws - Motor installation
20 pcs M3x8 countersunk screws - Various chassis assembly
4 pcs M3x12 countersunk screws - Battery mounting posts
6 pcs M3x28 countersunk screws - Chassis bridge, belt idlers and belt pulleys
4 pcs M4x18 mm screws - Wheel attachment
Armfront01.stl - Lower front suspension arms
Armfront02.stl - Fixed upper front suspension arms
Armfront03.stl - Adjustable upper front suspension arms (requires m3x30mm turnbuckles)
Armrear01.stl - Lower rear suspension arms
Armrear02.stl - Fixed upper rear suspension arms
Armrear03.stl - Adjustable upper rear suspension arms (requires m3x30mm turnbuckles)
Battery01.STL - Battery hold down latch.
Battery02.STL - Posts for rubber band battery hold downs
Body01.STL - Forward body style01
Body02.STL - Rear body style01
Body03.STL - Forward body style02
Body04.STL - Rear body style02
Body05.STL - Forward body belt drive
Body06.STL - Rear body belt drive
Chassis01.STL - Forward chassis dual motor version
Chassis01-belt.STL - Forward chassis without motor cutouts
Chassis02.STL - Rear chassis dual motor version
Chassis02-belt.STL - Rear chassis for belt drive
Chassis03.STL - Chassis right center bridge
Chassis04-24mm.stl - Chassis left center bridge with 24mm wide servo mount
Chassis04-34mm.stl - Chassis left center bridge with 34mm wide servo mount
Chassis04-41mm.stl - Chassis left center bridge with 42mm wide (standard) servo mount
Chassis04-belt-24mm.STL - Chassis left center bridge with 24mm wide servo mount for belt drive
Chassis04-belt-34mm.STL - Chassis left center bridge with 34mm wide servo mount for belt drive
Chassis04-belt-41mm.STL - Chassis left center bridge with 41mm wide (standard) servo mount for belt drive
GBfront01.STL - Front gearbox housing for dual motor version
GBfront01-belt.STL - Front gearbox housing for belt drive version
GBrear01.STL - Rear gearbox housing for dual motor version
GBrear01-belt.STL - Rear gearbox housing for belt drive version
Gears01.STL - One gear set for dual motor version
Gears-Belt01.STL - One gear set for belt drive version
Idler01.stl - Eccentric belt idler for two 12x18x4 ball bearings
Shaft01.STL - Drive shafts
Pinion-16t.stl - 16 tooth 32dp pinion.
Pulley-belt01.stl - Pulley for front and rear belt version gearbox
Pulley-belt-overdrive01.STL - Optional smaller overdrive pulley for the front gearbox
Shock01.STL - Rubber band shocks
Shockplates01.STL - Shock mounting plates for rubber band shocks
Shockplates-aftermarket01.STL - Shock mounting plates for aftermarket shocks
Spindle01.STL - Axles for the wheel spindles and 12mm hex
Spindle02.STL - Front spindles
Spindle03.STL - Rear spindles
Steering01.STL - Parts for steering assembly
Steering02.STL - Tighter clevises in case original parts are too loose
Steering03.STL - Adjustable tie rods (requires m3x30mm turnbuckles)
Tirefront01.stl - Front tire with small knobs
Tirerear02.stl - Rear tire with large knobs
Tirefront01.stl - Front tire with small knobs
Tirerear02.stl - Rear tire with large knobs
Wheels01.STL - Wheels for standard 2.2" tires, or printable tires
Wing01.STL - Wing
Wingmount01.stl - Separate wing mounts
Print all parts at 100% infill (rectilinear) unless noted below. I used PLA for everything except the pinion (ABS for motor heat resistance) and tires (TPE 90A). The car is designed to be printed from PLA. All parts should be printed in the orientation they open. If you need to print a separate part in the part sets then separate them in your slicer (get a better slicer if you can't).
Print body parts with one perimeter and zero infill for reduced weight. For best result make the start/stop point on the inside of the body
Print with at least 10% infill and at least two perimeters. Print the bottom 1 mm solid to protect the battery tray.
Support is required under the ears on the ends.
I prefer to print tires with zero infill and three perimeters. I used a 90A hardness TPE.
Can be printed with 10-30% infill for reduced weight.