Thread: Using a solid carbide bit with the Leigh D4

I have looked at the Leigh site for dimensions etc and the 170C would appear to be a true spiral replacement for the 140-8 carbide tip bit, i.e the critical dimensions match.

I would expext the solid carbide to be more rigid and less prone to chatter than the brazed tip bit because there is always a a greater solid metal cross section in the cutting area than there would be for the brazed bit, and there is significantly less interuption to the cut as the bit rotates.

Assuming that both bits are genuine Leigh and not 1/4in shank knockoffs, I think the problem would probably come with the chattering issue, rather than the cutter type. If the tipped bit is chattering, there is a fair chance that the 8mm adaptor is not true, or not mounting true in the collet, or there is a lot of the bit hanging out of the collet/adaptor assembly.

Leigh went with the oddball 8mm shank size because it offers a lot more shank cross section and rigidity than a 1/4in shank while still allowing the bit to pass through the guide bush.

As a first step, I would chuck up a either (or both) bits in the router and check the shanks for runout to ensure that they are mounting truely. Obviously any runout will result in inaccuracy and a rougher cut caused by regular interuption of the cut. Could arrange a loan of a dial guage and mounting hardware if required.

Thanks Malb. I also checked the dimensions with the Leigh site however that was as far as I got. I am seating both the collet and spiral cutter as deeply as possible and after having the bit work loose a couple of times I am tightening it as far as I can (which goes against my better judgement). It still produces a little error though. I will check for runout and recheck how the bit and collet are sitting in the router. FWIW I am using a Triton MOF001 with US style chuck.

I know that this is late but for what it is worth.....
I have got the older version the 1258? and I had the problem of chattering when using a single speed Makita 3600B. when i changed to a Variable speed dewalt router and turned the speed down I did not notice the chatter and I did not have any chip out to speak of. I was doing through dovetails and I was only using pine.

Regards