Single flute carbide cutters

[Jonathan]

I was wondering if anyone has used these single flute carbide cutters:

http://www.ebay.co.uk/itm/5x-6mm-Car...#ht_2706wt_905

They're a lot cheaper than anything I can find in England ... but will they be any good quality?

I've chosen single flute for the obvious reason - more space to clear the swarf.

I'm intending to use them with 18mm plywood and probably aluminium. I've been using the 6mm router bits from Toolstation recently but not having much luck. It's quite a lot to spend if they turn out to be no good ... can get 19 of the 6mm carbide tipped cutters from tool-station for that price so it's only worth it if they last at least 4 times as long.

[AdCNC]

Ive also been looking at these, i have used some similar before and have had good results. for what its worth i think i might give these ago. if you are wanting to cut ply then i would suggest you use a straight fluted cutter, there are a few on the market.. but having used a fair few i have found that the geometry on the cheaper ones like the ryobi and silverline to be really poor and this is shown with the cutting, they seem to resonate more so than cut, now swap to a trend, freud or titman and you will have alot better results.. thats if your cutting woods anyway.

[Jonathan]

I heard that straight flutes are better for ply as it's less likely to lift. Or even better apparently are compression cutters since they squash the material together on both sides... expensive though.

The finish I was getting with the silverline 6mm, 6mm per pass, was fine ... Problem was it snapped (twice). I'm hoping it's just a matter of getting the feedrate etc correct for them to last... the good brands you mention do cost a lot more.

Shall I buy them and we can share? (annoying that's it's an odd number)

[AdCNC]

Shall I buy them and we can share? (annoying that's it's an odd number)

Sure if you want to.. how do you want to do it tho. you have 3 and ill have 2?

[John S]

The finish I was getting with the silverline 6mm, 6mm per pass, was fine ...

If it snapped twice, back off a bit on cut, 100% of depth per diameter is a bit much on 6mm.

[Jonathan]

Sure if you want to.. how do you want to do it tho. you have 3 and ill have 2?

Sounds good to me. I was going to say I'll have 3 but didn't want to sound greedy :lol: I can buy them today - no doubt they will take forever to arrive. They shouldn't cost much to post. There's also 25mm long for £4 more ... not sure which to get as the 22mm will be stronger, but 25mm might be useful...

If it snapped twice, back off a bit on cut, 100% of depth per diameter is a bit much on 6mm.

Ok then, I've just checked the Gcode and it was actually 5mm per pass, not 6mm as I thought. I'll try less next time.
I was using 2500mm/min and 18,000rpm ... that makes the chip load very low which I suspect was what caused it to break. It broke when I lowered the feedrate to 2000mm/min. I think I'll try something like lower rpm but keep the same feed next time to reduce the heat.

[AdCNC]

Another thing that i you need to pay attention to is the resonance, these cutters can give off a "screaming sound" this is bad as what you are hearing is the cutter resonating. this will almost definitely cause the cutter to fail. Id experiment like you say keep you feed the same 2.5M/M and reduce or increase you RPM until the screaming goes, you should hear a nice cutting sound, I if get 5 mins ill do a vid for you.

[Jonathan]

I think I would describe the sound as 'screaming' ... not the normal sort of 'hissing' sound. I'll experiment tomorrow and do a vid...I bought a heap of cutters from toolstation yesterday, 3 each of 6mm, 1/4", 8mm and 10mm so plenty to experiment with though I'd prefer not to break them all! Before I made the recent changes to the router I can't remember ever breaking a cutter ... it was just too slow. I can use much more than 2.5m/min if neccecary - I tried a 1/2" cutter yesterday cutting 1/2" deep and it was fine at 6m/min.

[Robin Hewitt]

I bought a couple of these cutters in 2 and 3mm from J & L to try with aluminium. Haven't spun one up yet, but I reckoned that half fishtail point should be good for a fine horizontal finish. Wonder how it copes with a vertical plunge, I always prefer to add some horizontal movement when I sink a fishtail, but that might just be my poor old brain seeing problems that do not exist :whistling:

[blackburn mark]

iv bought 30 of the 3.175mm version... iv only managed to wear one out in alli, they seem to last for ever in acetal though (snapped one or two)

im lazy with my g-code and plunge straight in... if they costed more and i was wearing lots of them out id consider ramping