[brucew268]

I'm going to do some circle cutting in 40mm oak and had planned to use a spiral upcut bit with a 50mm(2") cut length and 1/4" shank. In this video

, the speaker says he is using a 2" bit but then in the early comments says that he had to use a 1" bit, assumably with a long shank, and adjust the router depth a bit more. Of course bits with this much cutting length are not so accessible and 1" bits are easy to come by in the £20-30 range.

I can see that a 1/4 bit 2" cuts less wood and so works/heats less and 2" seems more appropriate for the application. I never considered that a 1" long shank bit would work here and the video maker doesn't say much about what he encountered when doing it this way.

What do I need to consider or plan to surmount if using a longer 1" bit instead?

 

[brucew268]

G'day @brucew268 , and welcome to the forum.

What is the diameter of the cutter?
A 2" cut on a 1/4" shank would be stretching its limits, I feel...
Are you able to use a 1/2" shank cutter?

Thank you, I haven't touched a router in years, so been doing lots of re-acquainting myself with routing.

The cutter is also 1/4". I thought that 2" was likely a bit long on a 1/4" since hardly anyone had them. Yes, I can find some 1/2" x 2" CL that aren't eye-wateringly dear, so maybe need to go that route. They all have cutter and shaft both 1/2". I wonder if heat will be a problem with a 1/2" cutter in oak doing all the stock removal (as I don't have a bandsaw).

I'm still curious about the use of a 1" CL for a 1.6" thick application, would have thought it not possible or maybe some burning long the shank?

 

[brucew268]

I've been planning to use the plunge router in steps, but will have a think about a template and guide bearing as an option.

 

[brucew268]

Turns out my max Overall Length in my plunge router is 96mm without bottoming out in the collet. Most are 100-102mm OL, so that rather limits my options for a direct plunge cut without a template 3x the cost of a straight bit with bearing and template.

 

[brucew268]

But then if I added a universal base plate, which appears to bolt right over the existing base plate, that would add 8mm to the overall collet distance off the workpiece... which would relax my options a little. Right?