[billcoke]

So I'm new to using a router w/ a bushing. Laugh if you must.
For a bit w/ a shank of 1/4", how big must the ID (inside diameter) of the bushing be?
I tried one w/ an ID of 1/4" and the bushing got hot and loose very quickly. So I think that I probably got that wrong.
Do I need a bushing w/ an ID of 9/32" at a minimum for a 1/4" shank?

 

[John Smith_]

welcome aboard, Bill.
it may help if we have more information about your equipment, tools and projects.
photos always help the most.

 

[old55]

Welcome to the forum.

 

[jdonhowe]

Short answer to your question: Yes, you need clearance between the bit shaft and the bushing.

 

[TenGees]

Sometimes there are bits that are poorly made and then there's the problem of metric bits in standard chucks or the opposite. Another common issue is that a bit shouldn't be bottomed out in the chuck. I typically insert the bit and pull it out about an 1/8" before tightening. A bottomed bit can cause a chuck to not tighten properly.

 

[jw2170]

G'day @billcoke and welcome to the forum.

The 1/4" shank is only part of the equation. What is the diameter of the cutter?

I would not use a guide bushing less than 1/8" larger than the cutter size....

As John said, more information on the tools and project would help us to better guide you.