Boss 5 chatter????????

[MrHorsepower]

OK I finally got my machine to talk to the computer and ran some parts. I can't seem to get a good finish at all! I have tried new (sharp) cutters many differant feeds and speeds no luck at all. Where do I look next. Thanks to everyone who has helped this newbie during this process.

[machintek]

Remember that this steps in .001 inches. In a straight line or circle. Have you tried conventional milling and a good cutting fluid?

George

[MrHorsepower]

I don't know what you mean by "conventional" milling. I am using a good flood coolant. I think the head is out of tram, I'm sure of it actually. how do I fix that shim the ram?

[machintek]

There were two different BOSS 5 types. One was a rigid ram and the other had a fully articulated head like the series 1 STD.
The rigid ram had an eccentric on one head mounting nut to the ram. This allowed adjustment left and right, but there is no provision for tilting the head forward or backward. Which way is it out of tram? Did you sweep the table with a dial indicator?
Do you have the maintenance manual?
If the end mill motion is such that it is trying to crawl along the part, it is called climb milling. If the motion of the cutter along the piece is such that the cutter flutes are being fed into the part, it is conventional milling. If you do not know this, it indicates that you do not have any formal training in the machinist trade. I advise you to get some education or watch a machinist and ask questions. I advise you to do this so you do not get hurt. Shake hands with some machinists and you will see what I mean. Quite a few are missing fingers.

George

[One of Many]

Originally Posted by MrHorsepower I don't know what you mean by "conventional" milling. I am using a good flood coolant. I think the head is out of tram, I'm sure of it actually. how do I fix that shim the ram?

It may help if you describe the exact operation you are doing. As in cutter info, depth of cut, RPM, feed rate and even part shape or attributes that might add to this condition.

The most common chatter troubles that I have seen trainees fight is when taking a pass the full width of the cutter path it is capable of. What they fail to realise is that the cutter is trying to climb around inside its own cut radius at a compound frequency induced by the number of flutes over the RPM and chip load. Amazingly I see this time and again with a longer than needed cutter and only cutting .100 depth at the end.

There is quite a learning curve to making the most efficient removal of material with only half the cutter diameter or less. Using step over and deeper depths of cut to control cutter pressure to reduce the chances of it or the part ringing.

There are benefits and limtations where climb or conventional cutting can be an option. Multiply this with cutters of different spiral and cut direction so the impossible to produce part, can become a lower risk challenge.

To Climb or not to Climb

DC