Which cutter, straight flute or up cut spiral fluted?

[Maximus]

I am looking to buy some new cutters to create straight grooves in timber over my router table. Up until now I've always used a twin flute straight cutter and only in pine. I found that creating a 9.5mm wide groove by 5/6mm deep in two passes would dull the tip fairly quickly and the shoulders in the groove would become "flakey", although this may have been down to my feed speed, although I never tried to force it through, rather, find the speed that everything sounded right at i.e. not rough on the wood and not pulling down the rpm too much on the router. I am making my first batch of jewellery/keepsake boxes in Oak, English Walnut and Ash and need to make grooves for lids, floors and dividers in varying widths from 3mm to 12mm. Will spiral cutters be the better way to go? Having never used them before, I don't want to splash out on them only to have them sit in the drawers not getting used. Another point I would appreciate your experiences on are router collet extensions. I have a Ryobi cast iron router table with the sliding table and a Trend T9 or 10 mounted (can't remember which.....). These narrower width cutters tend to be shorter in overall length so I'll need to extend the length to reach the depth I need. Do these suffer from vibration? What makes do you folks use? I'm in unknown territory here so any advice would be much appreciated.

Cheers
M.

 

[Maximus]

My apologies mods. I've just realised I may have posted in the wrong section

 

[OPJ]

A spiral-fluted cutter might give you cleaner edges but, you'd still be restricted to completing the depth of cut in several shallow passes. Instead, I think you would be better off looking at a grooving or slot cutter set, if it's at all practical for your application. The main difference here is that you'd need to run the timber across your table on its edge, with the face up against the fence. Depending on the model of router your using, you may not be able to raise a cutter like this to much more than ½in above the table's surface (in most cases though, that's perfectly adequate).

You should find they give a clean cut and, also, because of the way in which they cut, you can remove more material in a single pass (do use featherboards, though!). I've had the Tornado set from Rutlands for several years and it's suited me very well.

 

[Maximus]

Instead, I think you would be better off looking at a grooving or slot cutter set, if it's at all practical for your application.

Great, hadn't thought of doing it that way.... It would certainly work well for the grooves needed at the edges of the face of each board. With just the one arbour and a selection of different thickness cutters, quite a flexible system.
What about housings going across the grain and higher up the faces of the boards with the grain? I don't plan on doing any grooves deeper than probably 5mm, with most being 3mm.

 

[Oryxdesign]

Like Olly says use a groover, cheaper than spiral bits too.

 

[Steve Blackdog]

I use a CMT collet extension in my table. About £30 from Screwfix.

 

[Maximus]

I use a CMT collet extension in my table. About £30 from Screwfix.

How do you get on with this Steve? Any problems with vibration or loss of accuracy?

 

[Steve Blackdog]

I use a CMT collet extension in my table. About £30 from Screwfix.

How do you get on with this Steve? Any problems with vibration or loss of accuracy?

To be honest I've not had the chance to use it much yet. I can say that it appears to be very well put together and very accurate. I guess it goes without saying that anything that extends your router shaft will exaggerate any existing vibrations and imperfections. But I don't think the CMT adds any new vibes of its own.

Cheers

Steve