5ax Trunnion table - on and off machine - pitfalls???

[Newbeeee™]

Hi all,

We need another rotary table. We currently have 2x 8 inch matched heights and 1x 5c which any of them can go (dowelled) on any machine onto our grid tables.

Load any program and go - all datums in programs via G10 and it works really well.

We need another, and I'm wondering if we ought to put a toe into the 5ax world...

 

So assuming I know absolutely nothing about this, what's the pitfalls?

We would only be looking for 3+2 positioning - which would save the need for additonal ops or fixtures. So think simple prismatics rather than fancy pants simultaneous!

If we went for something like a nikken 5ax 130 http://www.nikken-wo...-table/5AX130/3 and put it on a sub plate which could go on and off the machine, I'm asuming it's a stronger configuration being a trunnion.

I appreciate that this would only be able to go on the 1x machine (because of the additional cable/drive configuration over our other machines).

So to run any existing 4th axis progs with this configuration, we'd have to mod the prog to lock the tilt axis (C?) to horizontal (or would that be 90?), and use the rotary (would that be A like our others)? This I'm happy with...

 

My main concern I suppose, is comments I've read where people say you can't get repeatability when you pull tables off and back on machines.

If we just used only 1x dowel on the 5ax table centre line at the 'front' , I'm asuming the 5ax table could go back onthe bed and the (rotating) face could be clocked back into zero to get perfect alignment (mallet tapping the sub-plate round), and then the thing clamped to the bed of the machine???

Centre heigth wouldn't change.

If we had a G5# datum per face/index, this could always be 'tweaked' at the 1st part stage to get any small miss-alignments out?

So what am I missing?

 

For programming, we currently have 5ax curve/drill and know absolutely nothing about this either so more learning curve, but I'm not too worried about this as I know a forum where everyone is sooooooooooooo helpfull

TIA for any comments

 

[Rotary Ninja]

While I can't comment on a trunnion, or give you any insight into the use and setup of one, I can say that if you have dowels to locate everything I don't see why you can't get repeatability taking it on and off the machine. I save my Y and Z offsets for my rotary which is pinned and I take it on and off and reuse these offsets all the time. And I am always within a thou or so. I make gauge cuts anyway, so final adjustments are made during machining.

 

If you machine parts at weird angles that require complex fixtures a 5 axis would certainly save you some time in programming, designing, and machining. Because sometimes it takes me longer to design and machine a fixture than it does to machine the part. So 5 axis capability will soon pay for itself in savings in these areas. It just depends on the type of work you want to do. But also consider that even on simple parts, a 5 axis can eliminate setups. Parts you have to do a setup just to drill a hole at some weird angle are now nothing more than a couple clicks of the mouse and a few keystrokes away from having that feature added to the main program to be run in one setup. So think about the parts you currently run. Go look at your fixtures you have made in the past. Is there a lot of complex tooling components sitting there with dust on them?

 

You also have to weigh in the fact that you will be able to take on new projects. Jobs you normally wouldn't quote now become an easy part to make money on. I've seen this first hand. A shop has a hit and miss workload then after they acquire a 5-axis the type of work flowing through the shop changes and becomes more steady. 3 axis machines start doing prep work for the 5 axis. Your programmers and machinists may have to learn new skills. But in my opinion learning is never a bad thing no matter what the cost.

[Guest]

To me, the real question is "why not". Fewer constraints, fewer setups, better relationships between features.