Sunday 22 October 2017

How I Machine Without Holding Tabs - episode 165

There are times when I find it desirable to machine a piece without using holding tabs to keep all the parts in place. I started doing this 5 years ago and over time have refined the technique and defined the rules that I observe when doing this. 

Click to view this video.

The Rules!
  • You must use a 1/8 or 3mm down cutting spiral router bit.
  • Do not use this techniue on material thinner than 1/2" or 12mm.
  • Use only on wood.
  • If available use a dust shoe. If you find that the vacuum is pulling too much chipout of the slots then turn the vacuum off but leave the dust shoe in place.
  • Do not do this on anything you cannot afford to remake should it suffer damage.
  • If things are not cutting as expected then stop and sort it out before continuing.
  • This is not a standard machining technique so use at your own risk.

I have found that following these simple rules have worked well for me over the years.

Where did I get the cutters for this project?
The cutter I used were purchased from this supplier on Ebay

Other ebay suppliers of 1/8" down cutting bits.

They are 1/8" in diameter single flute down cutting spiral bits.
The length of the cutting edger is 10mm ( 3/8") but anything similar eg 12mm(1/2") cutting edge would work just as well. There is little point having a longer cutting edge unless you are looking to cut your material in one pass. The flute area is weaker than the main shaft so a longer flute just weakens the cutter in my opinion. In fact since I do not cut more than 1/8th per pass any flute longer than 1/4" is a waste.



  1. Peter, do you use single flute down cutting bits or double flute bits? I tend to use double flute bits but I note your link is to single flute bits so I an interested in your experience.

  2. The 1/8" down cut bits I use are single flute while the 1/4" bits are 2 flute.
    The single flute ones were the only ones I could find when I was looking for 1/8 and I haven't broken enought of them to warrent getting more. Not yet anyway. I haven't really got anything to compare it to so it's probably not much help. The only difference I cansee is the single flute feedrate is half a doubles and I suspect it is a little stronger than the 2 flute as it only has single gullet instead of 2. Just my thoughts.