new engine frame and rim

Here are new 6x_ motor_arm1, 6x_ motor_arm2 and a new rim. The rim has a diameter of 88mm. The motor_arms have been extended by 4mm and the appearance has been changed so that they are easier to print. The caps of the axles are printed individually and glued on, so you can also design them in a different color. Matching tire https://de.aliexpress.com/item/32814715047.html which I also use.