This is for the Alien Racing 1/12 Scale Pan Car. Feel free to try it out in other rc cars.
The holes from shapeways don't come with threaded. You will need to tap it using a M7 x 1 Flat end Tap.
Once Tapped you will be able to use CRC Pillow Ball end caps
https://www.amainhobbies.com/crc-steering-block-set-cln3251/p33107
https://www.amazon.com/BIDE-Handle-Wrench-Metric-Plastic/dp/B07G2ZFQBW/ref=sr_1_5?s=hi&ie=UTF8&qid=1547675510&sr=1-5&keywords=m7+x+1+tap
To be used with the following pillow ball
https://www.tqrcracing.com/shop/product_view.asp?p_id=5946