Broaching a Keyway in an HMC

[Seabeast]

Hello from Dunedin, New Zealand

 

I've just signed up, hoping someone can lend a hand with programming.

 

I'm using X7, the machine is a Horizontal Machining Centre and the job is broaching internal keyways in small shaft couplings.

 

OK, I've got it running using M19 spindle orientation and have programmed it using Surface Rough Plunge toolpath with a 0.02mm step over. I've made a couple of keyways. My problem is the bore dia is quite small so I can only set a retract vector after each plunge pass of 1.5mm (Y axis) otherwise the arbor of the broaching tool will strike the opposite side of the bore on the first couple of passes. The Keyway is about 5mm deep which means after the broaching tool has cut the keyway more than 1.5mm deep it is starting to reverse out of the bore while still being engaged in the keyway. Carbide inserts don't like this obviously.

 

My question is does anyone know how to set a retract vector in the plunge cycle which will retract to the same point after each pass instead of being essentially incremental. ie I'd like to retract to the same Y position after each pass to ensure the carbide insert is fully out of the keyway before reversing out.

 

Or, is there another toolpath I should be using ?

 

Any help appreciated!

 

Seabeast

[Zoffen]

I made a broaching macro that takes care of everything. Even errors if the parameters are imposible. I would look down this road if you do them alot!

[crazy^millman]

I would make a chain that is the motion you want. Do a control toolpath set to 3D and then use the multipass to control me step overs and everything should be good to go.

 

HTH

[Mr. M]

I do the same as Zack and use a macro for it

[Matthew Hajicek - Singularity]

I'd do a 3D contour if it's only a few, or the macro if it's many.

[Hertz]

I had this issue before. I was cutting on a lathe though but what I did was create multiple finish passes with retracting to a point rather then a distance. I needed it to retract to an absolute position but like yours, it was retracting incremental. You could probably do the same thing on a mill.

[Seabeast]

Hi Guys thanks for your help, the 3D contour is the answer right now and I'll be looking at a macro once we start doing a few.

 

Cheers!

[Zoffen]

ya i used to use 3D contour untill i made a macro. Way easier now!