Thread: 1/4" roundover bit burns

Good morning, OP,
As a regular user of cheap bits I've found that burning can be minimised by keeping your router speed high, never dwelling on the work, and ensuring that the bit is clean and sharp. Actually, that goes for all router bits (obviously not big ones that should be run more slowly), so you'll know all that stuff. Make sure the bearing runs freely, my cheapies get gunked up pretty easily.

I don't know if roundovers are inherently more prone to burning than straight bits, but there could be something in it...

A touch-up with one of those little diamond plates works a treat- about $15 from Bunnings if you don't have one, or pick one up at the WWWS.

Good luck,
Rusty.

One majr factor could be that the bit's carbide cutters are not high quality and not sharp. The old adage " You get what you pay for", I have noticed, is particularly true with carbide tipped tools. As Rusty suggested, try to give the bit a quick sharpen and see if that makes a difference.

Technique can also be a factor with a number of variables needed to be taken into consideration. Take some of the following into account:

1. Feed rate........................perhaps go through your cut slightly quicker
2. Depth of cut....................make it a habit to take several smaller passes, this can dramatically reduce burn.
3. Backroute on your final pass....................that is being very careful go in the opposite direction...................you'll be presently surprised with the results

............Hope this helps

REgards Lou

Feed speed is very important, particularly with any bit on end grain!
As has been said, keep the feed rate high and within the limits of the bit size keep the speed high.
We all tend to be impatient but sometimes it's better to make two small fast cuts than try and do it all with one cut.

Hi

Generally speaking burning occurs because you are moving the router bit too slowly. The burning does not really occur because the bit is not sharp, however if the bit is NOT sharp then you tend to move it more slowly (because it's not cutting properly) therefore it burns.

My guess is that the burning you are receiving is due to a change in direction of the router eg inside or outside corners. BTDT (Been There Done That)

If the above is the case, then I suggest one of two methods...

Do the corners first so that you can concentrate on them, then you can *whizz* through the straight parts.

OR

Do the round over in two passes. Set your (stepped?)depth gauge to the final depth (check on scrap piece) then raise the fist pass height by .5mm. Go around once then set the final height and finish the job with a light cut.

My Exp with burning bits is vast!
I found it stopped occuring considerably when I started to use a variable speed router. Whenever I am a bit ginger with a cut I go slow so I slow it down a bit and the burning is less if at all. The other technique I use is to take less of a cut and when down to the last millimeter of cut go smoothly and dont stop/hesitate this will remove any burning that may have already occurred
One more thing - never hog out hard timber with a cheepie bit your asking for all sorts of drama... and make sure your bits are clean of resin and gum.

In general a smooth action with the router and no pauses when cutting gives the best results with all but the bluntest bits.