How to Machine Undercuts

[JiXXeR750]

Just wondering if someone might be able to point me in the right direction on how to cut the flat surfaces on either inner side of this part ... Because they are bolt surfaces, they need to be as flat as possible...
We are using a HAAS VF3 with a 4th Axis Table, but I still can't seem to figure out a way to cut the flats, or what type of tool I might need to get this done effectively. (Be kind, I am new to this game)

Between that and the radius under on each end - I need a better idea on how to do that also.
(I am trying to get a pencil operation to make a pass, is that close ???)

Because of the length I assume you need special tooling to reach, and at present I only have a 150mm 12mm End Mill, but I can't rotate it and cut those surfaces neatly, so I must be doing something wrong ...

Any help would be greatly appreciated, thanks in advance,

Aaron.

[seth.madore]

What condition is the part arriving at before the 4th axis operations? Is this starting as billet, or has some machining been performed already? Is the goal to rotate around the 4th axis and finish the entire part, minus the holes?

[seth.madore]

Also, how many of these do you have to make; 1 or a thousand?

[engineguy]

@JiXXeR750 

This may be way off outfield for you but either you use your Mill as a Lathe by using the Rotary toolpath and setting a round shank square end Grooving Lathe tool in the spindle and using an M19 command (Can be inserted either manually or using Manual NC Passthrough) to hold the spindle in position.

So, rough it out first using 4 x 90 degree index moves using 3D Adaptive and then the Rotary to finish off. You will still have to setup on the Mill to drill the holes, more time used !!

OK, that`s the ugly way, nice, easy way is to do the job on a proper Multi Axis Lathe/Mill-Turn that will do the Rotary operation to get the odd shape, if you don`t have such a machine in your shop then looking at the job realistically the time it is going to take you to do that piece on your Mill, for me personally I would "sub" that job out, would probably be way cheaper than using up lots of your Shop hours on it.

Just my Humble Opinion, I have done this sort of thing in a mill many years ago, trying to be clever, then found that it was pretty dumb really, so sent that sort of thing out to a local Turning Specialist Shop, meantime the Mill was making money on other easy Mill work, pretty much a "win-win" situation 🙂 🙂 🙂

May well be not what you wanted to hear but you did ask !!! 🙂 🙂 🙂

[DarthBane55]

Another suggestion, if this is your part, change those radiuses to be flats and use a slitting saw (you will cut them from underneath, no 4th axis needed).  If you really only have an endmill, you can still cut these from the sides with your endmill (4th axis needed).

If this is a customer part, and they want it cheap, ask them for that modification.  Success for that request will depend on if they want it cheap or to look as good as possible.

Picture below of what I mean.

I am assuming this is turned or cast or something before you need to mill those clearance cuts, because you didn't mention that you need to machine the whole shape of the part.  So the flange face that goes all around the part that is flush to your cuts must be already present (no need to machine all around part, my assumption).

[JiXXeR750]

It is Billet 6061 Alloy ...
we think we have the previous actions sorted and looking nice, it is just the small little pieces to finish we are having trouble with.

[JiXXeR750]

WE need to make a few, just unsure about the numbers just yet, depends if it works I guess.

[JiXXeR750]

Yes Sir, we are trying to do everything in house as best we can ...

Sorry for the late reply man. I didn't realise that there were replies cause I didn't click the email option.

I really shouldn't be using a machine. hahaha

[JiXXeR750 · Accepted solution]

I have yet to start cutting these parts, I think we have a tool path that might get us close.

We didn't figure out that cut for the minute, we figure if we can get the main body done for now, we can turn it 90° and get the ends done easily enough.

Thanks heaps for you advice. Muchly appreciated.