Following is how I make my tyres as round as I can get them. After cutting the tyre with a band saw and sanding the outside of the tyre on disc sander using a jig to hold the tyre against the disc sander so it can be rotated to get it nice and round. The next step is to bore out the the rim size, I like to use a forstner bit for this however the two circle are very hard to get exactly concentric. So I made this jig above that is clamped on to a clear Perspex top on my router base. For clarity I have only shown one tyre here, but for safety I stuck 2 tyres together using carpet tape (thank you Dutchy for sharing this carpet tape idea). With the two tyres the bottom one can be turned by holding the top one very firmly and keeping your fingers away from the cutter.
This is a clearer view without a tyre in the jig. With this method I made all three tyres exactly the same size. PLEASE NOTE THE DANGER ELEMENT in using a router this way. The user must always turn the tyre against the direction of the router cutter. Any one using a router in this manner must do so at their own risk
At the speed I type it takes to long to explain how I do things. Fortunately I made time on this occasion to share some Christmas spirit. Maybe I should rephrase that otherwise people will think the drinks are on me.
RyanGi commented about 1 hour ago Thanks for posting this! I agree, we need more explanative posts for specific parts of a project. Really helps me learn the skills.
Well said R'Gi... to complement a Well done PJ!
If your first cut is too short... Take the second cut from the longer end... LBD