DWO/ TCPC upgrade on 4th Axis Haas VF2 and VF4SS

[dodgin]

and yes i'm well aware of the fact that its a haas, still makes it easier and faster to program different things.

It has its place but I've had Haas DWO "easier and faster" bite me in the ass on more than one occasion.

 

[empower]

It has its place but I've had Haas DWO "easier and faster" bite me in the ass on more than one occasion.

how so?

 

[dodgin]

how so?

We've seen it enough times to know which parts can and can't go on the UMCs anymore, but there have been instances of those machines using DWO not being able to hold tight true position tolerances on complex parts. Yes, we limit repositioning as much as possible when we need to. Yes, we routinely recalibrate the DWO. Of course I'm sure any issues there are with repeatability drop by some exponential value when you're less an entire axis. Either way, yeah, I've had jobs programmed and done and almost running on a DWO machine where I had to go back and reprogram off of a tooling ball with separate hard pick-ups because the machine couldn't hack it.

 

[empower]

We've seen it enough times to know which parts can and can't go on the UMCs anymore, but there have been instances of those machines using DWO not being able to hold tight true position tolerances on complex parts. Yes, we limit repositioning as much as possible when we need to. Yes, we routinely recalibrate the DWO. Of course I'm sure any issues there are with repeatability drop by some exponential value when you're less an entire axis. Either way, yeah, I've had jobs programmed and done and almost running on a DWO machine where I had to go back and reprogram off of a tooling ball with separate hard pick-ups because the machine couldn't hack it.

UMC is very different, i completely agree, they're total trash. on 4 axis stuff in VF series, DWO/TCPC works pretty well. the issues you're having are primarily due to shitty machine construction/geometry, and amplified by a control thats not capable of compensating for shit design.

 

[dcrace]

I have a couple of macro programs that I use here on our VF-4 with a rotary that you can use G254/G255 for DWO positioning only. It will not work for any simultaneous toolpaths. Fairly easy to setup if you are interested, send me a PM and I can send the programs and some brief instructions.

We are a production shop that uses 4th axis alot. Currently using the 4th axis's programed as indexers with many many offsets.

Looking to upgrade our machines to have DWO to just make life alot easier for ourselves programming/ setup etc

What have peoples experience been with making the change over/ things to ask/ horror stories to avoid?

Programing side we use Fusion 360, which I do have some experience using in 5th Axis machines in other shops. Machines are 2018 VF4SS with HRT210 and 2021 VF2 with HRT210SS (with NGC of course)
I understand we need some settings enabled/ measured (MZRP I think Haas calls it).

Just looking for peoples experience with making the change over and how it went for them. There seems tobe a lot online with 5th axis with DWO but next to nothing with 4th axis.

I have a couple of macro programs that I use here on our VF-4 with a rotary that you can use G254/G255 for DWO positioning only. It will not work for any simultaneous toolpaths. Fairly easy to setup if you are interested, send me a PM and I can send the programs and some brief instructions.

 

[MunsterCanada]

this has nothing to do with right or wrong. neither way is 'right' or 'wrong'. if you dont have DWO/TCPC, you HAVE to model everything perfectly in CAD/CAM when programming, and it has to PERFECTLY represent whats actually in the machine. having DWO/TCPC lets you program any part without having to do any of that, just place your work offset anywhere on the stock you're machining. regardless of how you look at it, having it is much better than not. can you do without it? absolutely! but its akin to walking to work instead of driving your car. and yes i'm well aware of the fact that its a haas, still makes it easier and faster to program different things.

You hit the nail on the head there.

One of the main issues I left out is that the last guy I replaced for what ever reason didn't model things correctly. So to go back into every file for every product we have and remodel everything then reprogram off of center is a pretty huge task.

This seemed like the quickest and most reliable way forward for workflow and also backdating everything that has been programed before.

@empower did you make the change yourself? Or im guessing you already run a 5th Axis?

 

[MunsterCanada]

We've seen it enough times to know which parts can and can't go on the UMCs anymore, but there have been instances of those machines using DWO not being able to hold tight true position tolerances on complex parts. Yes, we limit repositioning as much as possible when we need to. Yes, we routinely recalibrate the DWO. Of course I'm sure any issues there are with repeatability drop by some exponential value when you're less an entire axis. Either way, yeah, I've had jobs programmed and done and almost running on a DWO machine where I had to go back and reprogram off of a tooling ball with separate hard pick-ups because the machine couldn't hack it.

Thats fair enough.
What kinda true position tolerance are we talking about with yourself?

 

[empower]

You hit the nail on the head there.

One of the main issues I left out is that the last guy I replaced for what ever reason didn't model things correctly. So to go back into every file for every product we have and remodel everything then reprogram off of center is a pretty huge task.

This seemed like the quickest and most reliable way forward for workflow and also backdating everything that has been programed before.

@empower did you make the change yourself? Or im guessing you already run a 5th Axis?

well, i dont run hass crap, havent for a few years thank god! but yeah the machines i run all have TCPC albeit under different names, i wouldnt work any other way simply because its way more work than necessary.

 

[MunsterCanada]

Maybe more transparency needed from OP but he starts by saying he's in a production shop and is looking at jobs that maybe go from rapid prototype to long production or whatever.

I see absolutely no value in a quick and dirty setup if this is the case. If you're running a shitload of parts just make sure your setup is on center of rotation every time and program accordingly.

Plus we're talking about DWO on a Haas, which is reason enough for me to double-down on saying do it the right way the first time and be done with it.

One of the other issues is that within Fusion 360 if you have more then say 3 or 4 setups with a bunch of tool paths it will reorder toolpaths in a super weird way. Often trying todo toolpaths before the required roughing toolpaths.

The programs workflow is really set up for using some kind of DWO for reordering toolpaths.

 

[empower]

One of the other issues is that within Fusion 360 if you have more then say 3 or 4 setups with a bunch of tool paths it will reorder toolpaths in a super weird way. Often trying todo toolpaths before the required roughing toolpaths.

The programs workflow is really set up for using some kind of DWO for reordering toolpaths.

huh? watchu talkin about willis? i've never seen it do anything like that.

 

[MunsterCanada]

Yeah its something you have to be careful of. I think its something todo with having 3 instances of each tool path (I program a single part and say in the setup that its 3 offsets. one for each of the three parts.)
Some of the setups are purely for dedurring at weird angles or finishing certain features that the other setups dont relate to toolpathwise.
But Fusion cant tell that certain toolpaths need to happen last of setups themselves last. It will just lump them all together when it reoders toolpaths to minimize tool changes.
(it looks at the each tool for each setup and in what order, if they are the same it will lump it together.)

Seems to only happen if you have more then a single part with multiple offsets on something 3+ axis in some form.

But im posting 100+ toolpaths at once (its also doing these 3 time over for the three parts on the 4th) So it could also be too confusing with all the setups required for indexing as well.

Long story short when posting in fusion not using DWO and its on a 4th or 5th axis with alot of setups, double check your toolpath order it posts!!!!

 

[mhajicek]

i'm not denying that, lol. literally said that the purpose of it is so you dont HAVE to program off the center of rotation. well aware that you can do that, and i've done so many many times. but it can be a bit of a pain to always do that, sometimes you just need to throw something quick on a vise/fixture, probe it and go.

Well, no. If you have your fixturing modelled, as you should anyway, and know where the CoR is, as you have to in order to do dynamic offsets, programming off CoR saves you even having to probe the stock. CoR is faster and easier; just load the stock and go.

 

[D Nelson]

Maybe this pic will help understand picking up a feature of a part on a 4 th axis in a haas using dynamic work offsets. Without it you would have lots of troubles because the forgings vary in size. It puts your next cuts off center
Don

 

[friesen]

Kind of late to the party, but see Drace suggestion. Look on forums for macro, I’ve been doing this on 4th for indexing for some years now, it really works nice. The short version of how it works is math based off a stored center point in a macro that you set, then calculates a G53 offset. The G53 might smoke some minds, but it works well, and always resets when program is finished.

Advantages are as stated above, you pick a rotation center on the part and never have to remodel the part in cad/cam.

It’s free for any version, but as stated, it’s not for simultaneous movement.

 

[Rapidmotioncnc]

Can you pm me the macro your using?

 

[gkoenig]

I know that part, I guess I was just used to using a 3 jaw for 99% of my 4 axis work and a self centering vise for the other bits and locating them on center.
I wasn't thinking about using a platter that can hold multiple vises and whatnot where your part is out in space.
I can see that now.

Couple of instances where DWO/G54.2 are exceptionally handy on a 4th axis:

1- I do a lot of multi-part fixtures on my 4th axis. Fabricating these off the centerline is a terrible idea for longevity because all of that work is basically locked-down to the configuration it was originally made in, and on the machine it was built on. Sure, I could measure stuff and massage the CAM to rejigger it all after the fact, but using G54.2 makes the pallet entirely independent of the machine configuration.

2- Even if I am just working off of a centering vise, DWO gives me the ability to directly probe my workpiece for far better process control and overall accuracy on subsequent operations. Not so important when I have wiggle room from raw stock on Op1, but if I need to do an Op2/Op3, it is extremely beneficial to have direct datums instead of relying on anything else.

The real problem with programming off centerline is that you aren't programming the part, you are programming the machine. All your work is generally getting dedicated to the kinematics and kinematic variations for one spindle, and how intimate your knowledge of that one machine and set of fixtures is defines the overall accuracy of the parts you make. Haas DWO, G54.2/G68.2, Cycle 19, Cycle 800... all of these technologies let you program the part directly, regardless of the machine it is going on (or, more relevantly) whatever the current kinematic state of your machine is.

Some of the most talented, brilliant machining hacks I've ever seen are the elaborate measures old curmudgeon programmers did to work around programming from centerlines. Centerline programming is the main reason 5 axis machinists from 20 years ago aged like US presidents do over their terms in office. As much respect for all of those brilliant hacks - they need to go the way of the dodo and people need to let modern controls mange all this trig for them.