Boring tools

[edinthecloudsParticipant @edintheclouds]

Hi,

I've have a new boring tool kit as the link. **LINK**

The boring tools look as if they are ground ready to go. I'm trying to bore out a 3 inch hole on the mill table, using the boring tool in the horizonal position, with point of the brazed carbide tool facing the surface to be bored, the trailing edge of the carbide tool seems to be rubbing on the cut surface.

My question is do I need to grind a relief angle to clear the work surface, or is the setup wrong?

As it's a new kit I didn't want to rush in and start grinding the trailing edge without asking first.

Many thanks

Les

[edinthecloudsParticipant @edintheclouds]

Trailing edge rubbing on work piece

[Martin WParticipant @martinw]

Les

If the body of the the toolholder is vertical and the tool is held at right angle to this axis i.e. cutting tool horizontal, then the cutting tool leads relief side to the cut. The wrong way round!! This question has been asked before and it was something I found out the hard way. The only way to get round it without regrinding the tool is to run the mill in reverse. The problem with this is that things want to unscrew, so tighten everything up well and take very gentle cuts.

Martin

Edit:  This links to the thread

Edited By Martin W on 28/02/2016 17:55:33

[edinthecloudsParticipant @edintheclouds]

Thank you Martin for the link to the thread.

I did run the mill in reverse as it seemed to solve the problem but it unscrewed the head, so I gave up on that idea.

Les

[John ReeseParticipant @johnreese12848]

The boring bars that came with the kit are meant only to be used parallel to the shank of the boring head. Tools used in the cross hole require a totally different geometry. I usually use square tool bits in the cross hole, either HSS or crbide, depending on what I am cutting.

the

[edinthecloudsParticipant @edintheclouds]

Thanks John, it didn't make sense to me at first.

You've confirmed what I was thinking.

Les

[Douglas JohnstonParticipant @douglasjohnston98463]

If I bought one I would prefer to pay the RRP of £55 rather than the bargain price of £70!

Doug

[JonParticipant @jon]

Paid £40 for mine but 17 years ago then add on the fitment about £30. All the holes are at 90 degrees or horizontal on the ends used daily.

**LINK** £76.45 here or £122 with carbide cutters.

Those Chinese carbide cutters are good value for money but need grinding and reprofiling, come in cast or for steel.
As they come theyre not sharp just dressed to shape.
If finish still rough try another speed and feel for the cut, I often draw out to leave a finishing cut and keep the side tensioned up on dovetail. Will show any inadequacies in mill flexing.

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