Mitre lock bit

[Steve Maskery]

Has anyone here had good results with a mitre lock bit?

I have a couple, not used either in anger. I have renovated one of my garden planters. It needs new fake lega. They are made frome two pieces of 4x1 mitred along a long edge and stuck on over the corner of a posh crate.

I have anew mitre lock bit. It is a bit of a beast, so I've turned the speed down to minimum ( I think that might be about 8K rpm).

I understand the setup procedure, that is not a problem. But the actual cutting, feeding the workpiece in, it is a very scary and difficult-to-control operation. I am getting juddering on a massive scale. Does anyone have any good ideas as to what I am doing wrong? I have 10 digits and I'd like it to stay that way.

 

[porker]

I've got one I've used a couple of times. Sounds like you are OK with the setup so I'll ignore that. I was routing Medite MDF which is quite hard (for MDF) and put a packer of thin MDF against the fence and did the cut in 2 passes. It went a lot smoother that way and gave good results. The cut with the workpiece flat on the table went OK but I made a taller fence (with another piece of MDF probably about 8" high and featherboards to keep it at 90 degrees and my fingers well away from the action.

 

[Steve Maskery]

Thank you, but that info does not help me, well-intentioned though it was

I am wondering if I have reduced the spindle speed too much. It's down to minimum, but I can't imagine having a bigger bit in the machine, so I am reluctant to wind it up.

It's a brand new bit, so I can't see sharpness being a problem.

 

[Trevanion]

How big is the bit?

 

[Luke Barnard]

Hello,

I'm new here, but have used a lock-mitre bit to make a few boxes. I also initially had problems with a scary amount of juddering, particularly for the member that has to be held vertically against the fence. Similar to you, I had set the router speed to the lowest setting, 8000rpm.

Two things that helped me get acceptable results were; using 4 passes to get to the full depth of cut, and using feather boards. For the piece held vertically against the fence, I clamped it to a wide backing board to push it through the cut. All in all, it was a bit of a faff, even though I was happy with the results.

Cheers,
Luke

 

[Luke Barnard]

I typed this before I read Porkers response, and now realise I've added nothing new! Whoops, sorry.

 

[porker]

Hi Steve, I run mine probably a tab above 10,000 rpm. Mine is 52mm across (just measured it)

 

[porker]

Guessing a bit on the speed but on my big Triton its about half the max speed

 

[Steve Maskery]

Thank you all. Maybe I'll try upping the speed a bit and see if that helps, but so far I'm not happy. I like to feel safe and I don't.
If it doesn't get any better I shall just make a simple T&G joint.

 

[Steve Maskery]

T, I've not measured it but it is as big as my aperture will allow, so >2". It's a big bit.

 

[Trevanion]

If it's in the 2"- 2.5" range I'd probably run it at around 12,000 to 16,000rpm, The bit may be big in total but a lot of the cutting is happening at a sub 1.5" cutting circle.

 

[doctor Bob]

surely it's juddering because it can't cope with the volume you are trying to remove in one pass.
Some router bits are just to big for a single pass in a conventional router whatever it's power.

 

[Phil Pascoe]

<2" ?

 

[sunnybob]

online speed chart gives a 2" bit speed of up to 16,000.
Turn it up Steve.
I have one of these, brand new, waiting for me to finish a bathroom refurb so that I can go out and play with it.