Now comes the fun part. Knives are not covered under preemption here in MI. Local governments are free to create and enforce ordinance on knives as they see fit. I would check out the ordinances of the city you will be spending time in. Here are the posted ordinances for Grand Rapids.
The Michigan Court of Appeals agreed with the defendant and held that under MCL 750.226 involving a knife, an element of the crime is that the knife’s blade be over three inches in length. The Court determined the prosecutor did not introduce adequate evidence to prove the knife’s blade length was over three inches, therefore, the Court vacated the defendant’s conviction for violation of MCL 750.226.
Officers investigating complaints regarding a violation of MCL 750.226 involving a knife must include evidence that the knife’s blade length was over three inches in order to obtain successful prosecution of the complaint. The Court also noted MCL 750.226 does not prohibit the carrying of any weapon (including a knife with a blade over three inches in length) for purposes of self-defense.