Burring on my work piece

Hello,

Can anyone help with a burring problem which I am experiencing?

I've used a 8mm left hand tool on my flycutter with both CCMT060 204 and CCGT060 204 tips. I'm cutting in a clockwise direction.  The tips are brand new.  I've used a range of speeds from 450 to 600 RPM.

The picture shows the cutting direction and the dash lines show the location of the bur. As the tool leaves the workpiece, it leaves a small bur on the edge.

I'm relatively new to Model Engineering and am at a loss as how to resolve this problem. Any help or suggestions would be appreciated.

Regards, Tom

Edited By Tom Gullan on 25/11/2016 23:01:47

Edited By Tom Gullan on 25/11/2016 23:04:40

Edited By Tom Gullan on 25/11/2016 23:06:58

It is not unusual to get a small burr on the trailing edge as indicated, the cutter has "nothing" to work against in that last instance. If you place and clamp a sacrificial piece of metal against that edge you will leave the burr on the added piece, alternatively you can use a fine file to remove the burr.

Edited By KWIL on 25/11/2016 23:15:11

You should expect a burr. The problem is resolved by the use of a small file.

Most drawings in engineering usually carry a comment like "remove all sharp edges". This should be done as a matter of course if only for your own safety. One thing that is not stated is how enthusiastic you should be with the file.

JA

Edited By JA on 25/11/2016 23:20:19

Hi Tom

You don't state the depth of cut but if you finish with a light finishing cut then your problem burrs will be much reduced and as stated already a Swiss file or carborundam stone will soon clean it up.

Emgee

Burrs are very easy to remove, fine file will do the job. Looks like your mill is "off tram". can tell by the finish on the workpiece. Some people like it slightly "off " to prevent the cross hatching that a perfectly trammed mill produces.

I prefer it to be "on tram " It is not so important on a small area workpiece, but the bigger the area the more "off " it will be. Just thought I'd mention that.

cheers

Some materials will bur even with the sharpest cutter.

You can clean up with a file, but the best value tool I have ever bought was investing in one of these:

www.arceurotrade.co.uk/Catalogue/Cutting-Tools/Deburring/Pocket-Deburring-Set-4pcs

Easy to use, and only £4.74!

They leave a small facet and I have used them for deburring holes down to 1/8".

Neil

Neil

What differences are there in the 4 deburrer blades ? I've had one deburring tool for years and use it on all materials for internal edge cleaning, I don't recall ever using it on an external edge, normally a small file for those jobs.

Emgee

The angles are different and the shape varies slightly so the cutting effect is different for different materials. They do work best if you use the right one on the right material, but I tend to forget the colour codes and just use the one I think is right and get a way with it!.

They work brilliantly on external edges, drawn towards your thumb as if you were peeling a potato, leaving a very narrow bevel.

Neil

+1 for deburring tools. Files tend to leave a hatched finish and knives are not very safe when used for deburring. I think mine is a Noga brand bought in Canada but there are a variety to choose from and the Arc ones look like good value.

Gentlemen,

Thank you for your words of wisdom. I decided to buy the debuting tool on Neil's link.

Tom

Edited By Tom Gullan on 26/11/2016 18:53:21

The Shaviv ones we gave away as a reader offer are very good as well.

Neil

Indeed, i found they even have regard among a few professional workshops i've been around.

Michael W

I too use those deburring tools. I have the Shaviv aluminum handle which look good and fits nicely in the hand. One word of warning: although they are easy to use, don't get too complacent. If you slip they can put a nasty gash in an otherwise nicely finished surface - ask me how I know. (They are fine if you keep your mind on it. Just don't use them in distracted-mode).

Another really kewl deburring tewl is this. I have several of these and use them a lot.

I like this little set from Tracy, handy for small work though I tend to prefer a file on external corners.

You can reduce the burrs being created by using a smaller cutter and have it with the cutting forces into the work piece edge. ie, a piece that is 20mm wide and 100 mm long, could be faced with a 25mm diameter cutter, but the larger cutter will most times leave a burr. If you use a 12mm cutter and approach with 2 axis till the cutter is just past the 1/2 way part of the work piece, ie 10.5 mm from 1 edge, it will cut clean mostly with little to no burr at all. In industry there are many times where a clean sharp edge is a requirement of the part being made.

Neil

And they obviously don't mind the concave surface this produces?

Regards Ian.

Sadly i don't think any technique can remove the burring that inevitably follows the cutting action, I stress that it may be managed, to a degree that it becomes insignificant,i.e using sharp tools. What insignificant is though is entirely down to the user, generally speaking, industries accept an .05 rad toleranced for deburring on most applications. 

but so far nobody has managed to come up with a method for totally eliminating burrs in a single cutting action, you just have to accept that this happens and you need to try and mitigate it with whatever you've got.

Burrs cost industry millions per year, the conundrum has never been solved. Thus huge amounts of money are both spent and generated in the art of finishing operations. 

Michael W

Edited By Michael Walters on 28/11/2016 11:50:31

I would like to emphasize the word "sharp". Switching to HSS tool bits will allow you to have a sharper tool and you can achieve more favorable rake angles. That will reduce the size of the burr. I also suggest a very light finishing pass fed in the opposite direction of the previous pass. That sometimes removes the burr from the previous pass and leaves only a small burr from the final pass.