[twocik]

Not sure where Tormach is with the device, but need to find something very soon. I'm getting to the point where time is money flipping my parts 4 times, then probing them, etc.. This is the only way it can be done without a trunnion unfortunately or a right angle spindle attachment, but the trunnion would probably be more sturdy.

Curious why the trunnion tables aren't centered and kind of offset when rotating. How do you program for this without stopping, probing, etc.. for each turn ?

Is there some sort of offset you can add to each program ? Kind of in the dark on this, anyone that can shed some light would be great !!

[Magnum164]

Can you define the trunnion table? Not sure I am thinking of the same thing.

[MichaelHenry]

Perhaps twocik is thinking of this blog post from Tormach:

New Adventures with 4th Axis PCNCs « Milling Around

Looks pretty handy for certain types of jobs.

Mike

[Magnum164]

Ah ok, I have noticed since then they have added the tilting motorized rotary. Perhaps they are getting closer.

[twocik]

Yes that's the one... Here's just one of the parts I'm making and it's taking about 45 mins - 1 hour to complete a nest of 4 - 7.

[Magnum164]

Yes that's the one... Here's just one of the parts I'm making and it's taking about 45 mins - 1 hour to complete a nest of 4 - 7.

Guess I am confused on how the trunnion can make that go faster. I am making similar parts (granted one at a time). But that is almost straight profile cuts minus the holes on the edge. Unless you are saying rotating on the side you can drill the side holes in all parts at once? I was thinking that Tormach setup was for more complicated surface machining.

[twocik]

No sorry, I mean with less setup time. Yes pretty much straight cuts, but flipping the parts 5 times can be a bit time consuming. I'm sure you can use this for more complex type parts, but this is what I need.

Each side is spot drilled, tap drilled, screw fit drilled, tapped and then slit. With the help of a fixture I could machine 3 (L,TOP,R) of the sides, not to mention being able to cut without an angle plate/sine bar for other parts.. I guess a power draw bar could also speed things up...

[R.DesJardin]

Have you considered have lets say four parts mounted one for each operation. then when the mill cycle completes you get one finished part and then move each part over one spot and add a new piece of stock and start again. So you would be doing four ops at once, one on each part. Hope I explained to be understandable.

[David Bord]

Have you thought of making a custom fixture plate that you could grip with a 4 jaw chuck on a 4th axis that would allow you to rotate the parts and get the rigidity you need?

That or machining directly on bar stock mounted in the 4 jaw chuck? Do 3 sides having the part oriented along the Y axis.

(thinking out loud here)

David

[Magnum164]

I wanted a Roland before I found the Tormach and realized the Tormach could open a lot more doors.

that being said, Check out this video at about 2:30. This is what I wanted to do with the 770 and the reason I bought the 4th axis kit and end kit. Just have not had time to try it out yet.

Not sure if this is what you were thinking of.

‪Producing a Prototype with a Roland MDX Milling Machine‬‏ - YouTube

[rowbare]

Have you considered have lets say four parts mounted one for each operation. then when the mill cycle completes you get one finished part and then move each part over one spot and add a new piece of stock and start again. So you would be doing four ops at once, one on each part. Hope I explained to be understandable.

This is a really good idea. Depending on your production needs, you could extend it a bit, by building a tombstone to mount on your 4th axis (with outboard support) and do this 4x per run... This way you would have 16x in process and get 4 finished per run.

bob

[Spinnetti]

Have you thought of making a custom fixture plate that you could grip with a 4 jaw chuck on a 4th axis that would allow you to rotate the parts and get the rigidity you need?

That or machining directly on bar stock mounted in the 4 jaw chuck? Do 3 sides having the part oriented along the Y axis.

(thinking out loud here)

David

I was thinking both of those things too... I've found that many of us, once we discover CNC think more cnc is the solution to everything.. there's lots of ops that are better done on a simple fixture mechanically constrained rather than programming stuff. Can also have some simpler/cheaper "2nd ops" machines coupled with fixtures where you can quickly plop on the part, drill a hole or make a cut then pop it out and do the next one... Think out of the box! - Lots of ways to do it....

[David Bord]

Not sure if you have it, but this is one area where the ATC really helps. Especially if you do a setup mentioned earlier that uses a different opp at each fixture.

I do like the idea of a tomb stone as well. You could probably set it up where it had 4 or more equal sides and bolted direct to the 4th axis. with a few parts per side.

David

[twocik]

Actually I don't own a 4th axis yet and was waiting for the Tormach Trunnion. At the moment I'm cutting them in nests of 4's and have made fixtures to hold them when machining multiple sides.

I thought of just machining them one by one using bar stock and a 4th axis, but that would be much longer machine time then what I'm getting now. I was also thinking of using the fixture I have for the drill, tap, slitting mops in a 4th axis, just wasn't sure how i could mount this without losing any accuracy. That Roland flat mounting bar stock device would work perfect... Here's how the pieces are coming off the mill before I start the back facing and side drill, Tap, and slitting mops.






.

[David Bord]

Man that finish looks beautiful! What kind of tooling are you using. Are you running 2 vises to double your work per tool change?

David

[twocik]

Thank you David. It took me a little bit to find the sweet spot on this one, but yes the finish comes out next to perfect. As for tooling I use a lot of different brands / tools to make this part(s). I have been really impressed with Accupro 1/2" 2FL ZRN coated EMs and believe it or not the cheap $12 rougher HSS rougher EMs from Enco I've had laying around for years.

I spiral rough those pieces with a HSS 4FL 1/2" rougher leaving .015" - .02" wall and finish them at full depth with the Accupro 1/2" 2FL Accupro. I have a Accupro 3FL laying around just haven't had time to try it out yet. Which I'm sure will leave a much better finish, but I'm very happy with what I've achieved so far. I have a thread here showing different speeds & feeds to get the same results, let me see if I can find it.


No I'm waiting to see if 2 MGT vise's or something else would give me better results. The Shars vise I have well is just ok, but not worth what I got it for. Live and learn, you get what you pay for. There's about .001" - .002" pickup on ever piece I clamp in that vise. It's a real POS if you know what I mean, not to mention the company doesn't sell replacement jaws. I'll leave it at that for now, but nothing beats a good old dead blow hammer



.

[David Bord]

Cool, thanks..

Yeah I hear you on the Shars vise. I have the exact same one and found the same as you how it would flex about .002 once I tightened it up.

I waited for a 20% off coupon from Enco and purchased 2 Kurt 675 vises. Free shipping as well! $350 each... The Kurt vise, using the stock jaws doesnt move but maybe .0005 when cranking on it.

David