up-shear or down-shear router cutter?

[Woodmonkey]

Both are available on Wealden website for the same rebate cutter...Whats the difference? Which would be the best to cut a rebate around the inside rim of a circle?
Thanks.

 

[Stu_2]

Upcut bits are better at removing waste material when cutting mortices etc. Not sure what the benefit of a downcut spiral would be, apart from in a router table maybe?

 

[Mark-numbers]

a down cut stops break out on the top face

 

[Woodmonkey]

Can't see what difference it makes cutting a rebate?

Edit: just saw above post, that makes sense thanks

 

[dejaa]

Hi new to this site but been cabinetmaking for last 10 years and just going through the questions.

Upcut or right spiral are used to limit burning when plunge routing. Downcut or left spiral will allow waste to be ejected at the bottom of the cut assuming for non plunge cuts. Both will give cleaner finish than straight cutters. Downward will help to keep work pressed against table if using a vacuum clamp.

David Abbott

 

[Mike.S]

As an aside to your question - which has been answered - and fwiw, when I was cutting a rebate (6mm wide - 10mm deep) in MDF I contacted Wealden's about buying an upcut router versus a straight edge cutter (to help clear the waste) and was advised not to bother. It was good advice and much appreciated. Of course, your materials/project may differ but I'd certainly recommend speaking to Wealden's - free and friendly advice.

 

[Woodmonkey]

Thanks everyone. Down cut ordered from wealden yesterday, arrived today, just the job for what I wanted.