Question 4th axis, another thought

I had another bright moment of reinventing the wheel. Instead of using the 4th axis in the conventional way, well, rotating, I thought of using it as a tilting table. That is: I attach a piece of stock, rotate it to the angle I need, and then run a XYZ conventional toolpath. After this is done I rotate the stock say 45º-60º-90º-180º, whatever, and run another conventional xyz toolpath.

Something in principle like this but smaller!



My problem is that I'd need some accurate and effective way to attach the stock to the triangular chuck so that rotation is symmetrical, that is, the attachment device must be aligned with the chuck axis and have symmetrical action. I thought of a triangular prismatic block with two jaws able to move simultaneously to keep axis symmetrical.

Any suggestions?

Obviously I have to do all the thinking in this damned outfit!

No ideas yet, anyone?

Ahhh, there's more like it! Now the issue is making those clamp jaws acting at the same time so that alignment is symmetrical!

MMorao wrote: Obviously I have to do all the thinking in this damned outfit!

No ideas yet, anyone?

No ideas but I feel the same way on another forum I am the leading poster on

I am still unclear as to your requirements. This is my fault MeshCAM only does indexing so the only use I could get out of my rotary table and tailstock is quantised rotation in the way you describe, not lathe like continual rotation required to mill a table leg or something.

What about a precision milling tilting vise?

Doug

Hi Doug,

My requirements are clear, see the photos I want a way to rotate the piece to certain fixed positions for machining at specified angles, no big deal. I don't want to buy yet another gizmo as I am certain the current 4th axis will be able to do this.

Look at the photo on my third post, you can see the PCB is stuck between two fixed "clamps". These clamps work only with a certain part thickness, 1.5mm or so. Now the idea is to get rid of these clamps and use something proper that will open and close with the same movement along it's axis, and I think the answer is something like this Claw Clamp:



You can see that the movement is symmetrical rotating on the small hinge bolt, which is what I want. I'm going to buy a couple of these things to work out how I can associate this with some plate that can be grabbed by the chuck. Or else I can mill a prototype of my own, or why did I buy the damned thing?

Is it clearer now? I'm sorry you can't do proper rotating work with your machine, it can really be fantastic!

Will a precision tiltable milling vise not work for you? There are a variety available here:

http://www.chronos.ltd.uk/acatalog/milling_vices_jaws.html



"something proper that will open and close with the same movement along its axis"

Like a vise?

Doug

Doug, Mmorao wants the system ON the 4th axis, and what you show do not have both jaws moving, they need to close from each side, so when they touch that point is on the centre line.
He has a great idea, using the 4th as a table, but the clamps need to be set up on the 4th, so that both jaws close to keep item on the centre line regardless of its thickness

Mmorao, will give it some though as I could definately use the set up, I have only recently purchased the 4th axis, not yet set it up.

Alan

AlanUK wrote: Doug, Mmorao wants the system ON the 4th axis, they need to close from each side, so when they touch that point is on the centre line.

That's perfectly clear now, thanks. What MMorao needs is a self-centring clamping system, a bit like this but perhaps lighter duty:

http://www.directindustry.com/prod/roehm/product-15881-1799087.html

Hi everyone! I'm sorry, I have been rather busy lately and couldn't keep up but thank you all for the input I have some parts on order for an idea I had, I'll see if that works.

Doug, that little gizmo in this latest post is what I want, but they don't even advertise the price which is normally bad news.

I found this among others in Grabcad which should also work on the same principle. The problem for me ATM would be cutting both progressive and retrograde* threads both male and female, but nothing impossible. There are another couple of ideas in Thingiverse.


* This is probably not the right terminology but bear with me