I've always liked mini and micro RC cars. The problem is that they usually have a... Well, sane amount of power and speed. I wanted more. I wanted insane. So I thought: RC cars this size never run more than a 2 cell Lipo battery, or 8.4 volts at their peak. Then I looked at some old slot cars I had. Slot cars run 12 volts. What if there was a way to convert a quality slot car chassis to RC in an easy, reversible way? I looked around and found that it hasn't really been done. So I bought an adjustable slot car chassis and started designing, and this is what I came up with.

This here is a conversion kit to convert an H&R Adjustable slot car chassis to RC, in an easily reversible manner. 4 3D printed parts make up a new front subframe that replaces the guide and solid front axle with steering spindles and a servo mount for a nano servo.

Non-printed parts required include:
H&R Racing Adjustable Slot Car
3mm axle
3mm set screw axle collars
2 M2x5mm screws
Nano servo
Brushed ESC
2s/3s Lithium battery
Radio system

To assemble the front axle, you press the 3mm axles into the 3d printed spindle, install the front wheels without a set screw and then install a set screw collar along with the axle spacers included in the kit. Assemble the 3D printed parts along with a nano servo with two M2x5mm screws and make a steering linkage from a piece of wire. I used a paper clip. Install the front subframe onto the main frame of the slot car and install your electronics. I would recommend a 5V external BEC from the ESC to the receiver because a 6V internal BEC will overheat the nano servo.

Battery mount is still not fully figured out. I currently have mine taped to the top of the motor.

Links to parts I used:
Ultra-nano Servo - $12.59 - Pair - Requires 5V BEC, will overheat at 6V
https://www.amazon.com/gp/product/B09SGZ6Z7F/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

ESC(Full Power, 3S Lipo) - $18.99 - Pair - Internal 6V BEC, requires external 5V BEC
https://www.amazon.com/gp/product/B0B7JD22TL/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

5V External BEC - $7.98 - Required for ESC with >5V Internal BEC - Need to solder between ESC and receiver
https://www.amazon.com/ShareGoo-Converter-Module-Quadcopter-Holder/dp/B075QJDW3Q/ref=sr_1_13?crid=18DD9DWZFW2VY&keywords=5v+bec&qid=1673828626&sprefix=5v+bec%2Caps%2C92&sr=8-13

3S Lipo Battery - $14.99
https://www.amazon.com/gp/product/B09V9MFMZQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Chassis: H&R Racing Adjustable Wheelbase Slot Car Chassis - $50.90 - Choice of tires and motor
https://www.ebay.com/str/midamericaracewayandhobbies - Seller eBay store - Many options for HRCH models
https://www.ebay.com/itm/372395919202?hash=item56b486c762:g:oCMAAOSwT4lWROgb - Version my build is based on - Fish Rubber rear/Foam front tires - 40K RPM Motor

Hardware:
3mm Axle
2x 3mm Locking collars - https://www.amazon.com/gp/product/B01EA912P8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
4x M2*5mm Hex Screws - https://www.amazon.com/uxcell-M2x5mm-Thread-Stainless-Socket/dp/B06XW8MMQW/ref=sr_1_4?keywords=m2x5mm+screws&qid=1673828509&sr=8-4
thin steel wire(can use a paper clip)

I would highly recommend PETG for this build for added durability with thin parts but PLA may work.