Haas Chatter

[Milland]

We actually discontinued that model. The aluminum components were 7075 but we had a lot of trouble sourcing the material. We were able to substitute with 7050, but that source dried up quickly. That was 3 years ago. Material sourcing issues are even worse now.

This confuses me - I've never had issues getting 7xxx material, although I haven't ordered much lately. But even before the pandemic you were?

Was it just getting pricing you considered acceptable given your market, or was there more to it than that?

 

[Houdini]

We make 7075 injection molds and it is a harder material to source, especially in those thicknesses, and especially if you dont want cut plate.
We almost never get our 7075 local, mostly out of state, and its only 7075 we have this with.
Also depends on what you mean by sourcing, because I want it inner state.
I make a few small parts from 7075 bar stock that I have to source from the other side of the country, and this is pre pandemic.
So its not all easy to source, and probably costs almost as much as the Durabar if not more.

 

[Houdini]

We actually discontinued that model. The aluminum components were 7075 but we had a lot of trouble sourcing the material. We were able to substitute with 7050, but that source dried up quickly. That was 3 years ago. Material sourcing issues are even worse now.

If you're looking for a lighter dual station vise, our Delta IV vises are coming out in dual station versions very soon. We've already begun shipping them but haven't officially launched them yet.

A 4x9 dual station features all steel construction and weighs in at under 30 lbs. So about 1/3 the weight, 1/3 the cost, same quality (hardened body, ground four sides) and some nifty new features like snap-on jaws.

Ill have to check these out, Thanks!

 

[Houdini]

Also as a reference for others, before I bought this machine I had the Haas Sales Rep contact Haas
on the table weight limit (250lbs), Because I had already bought 3 vises (315lbs)
I wanted to find out if the weight limit was just because of the fast rapids, or it was an actual table limit for the
rails and ball screws/motors etc.
Haas replied that the table limit was because of the rapids, that I could run more weight on the table (500lbs) but would need to turn on the
option to "reduce rapids to 50%".
There by turning this thing into a less capable VF2SS, which is the same price almost exactly, I wish I would have just bought the VF2SS,
but we have really limited power here and I am trying to maximize number of spindles.
This thing is only rated at 17 amps while the VF2SS is rated at 70 amps.OUCH!

 

[Houdini]

Images arent the greatest, image with chatter artifacts from DM2 (right) no chatter artifacts from a MiniMill (left)
all the same setup, tools, vise type, .........
Second image you can see it doesnt show the artifacts on arcs.
I believe the issue is in the X and is amplified when the Y is driven also, in a angular linear move, elongating the effect to say.

 

[G00 Proto]

Images arent the greatest, image with chatter artifacts from DM2 (right) no chatter artifacts from a MiniMill (left)
all the same setup, tools, vise type, .........
Second image you can see it doesnt show the artifacts on arcs.
I believe the issue is in the X and is amplified when the Y is driven also, in a angular linear move, elongating the effect to say.
View attachment 340017View attachment 340018

That is exactly the “chatter” we have seen. It can be improved, but not eliminated by tuning the servos and friction settings. This is by no means the worst I’ve seen.


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[Houdini]

This is as clean as I have gotten it,until they come fix it, its only 1" depth,
So on this I used a ER32 Super RIGID holder runout measured .0001",
with a 60° helix 3 flute @ 10k rpm 35 IPM just to try to minimize it.

 

[Milland]

I think post #14 called it. Ball bar, tuning, threats of sugar in the gas tank of the tech's car if it's not fixed before they leave.

Or get some Brothers in. Have test parts made before you sign anything.

 

[Wick Craft]

This is as clean as I have gotten it,until they come fix it, its only 1" depth,
So on this I used a ER32 Super RIGID holder runout measured .0001",
with a 60° helix 3 flute @ 10k rpm 35 IPM just to try to minimize it.

Way too slow FPT for a finish pass, IMO. For that high of helix EM, you need at least 0.002-0.004 FPT on a final pass to get a good finish. Have you played with bumping your feedrate? As a baseline I'd be running this @ 70-100 ipm @10K for 6061 or 7075.

 

[G00 Proto]

Way too slow FPT for a finish pass, IMO. For that high of helix EM, you need at least 0.002-0.004 FPT on a final pass to get a good finish. Have you played with bumping your feedrate? As a baseline I'd be running this @ 70-100 ipm @10K for 6061 or 7075.

Except for one problem… you can see the same “chatter” on the edge break as well.

This is certainly a kinematics issue. Run the same part on two machines with the same code. Don’t let the tech leave until the DM or DT finish looks as good as the Minimill or VF.


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[Houdini]

Way too slow FPT for a finish pass, IMO. For that high of helix EM, you need at least 0.002-0.004 FPT on a final pass to get a good finish. Have you played with bumping your feedrate? As a baseline I'd be running this @ 70-100 ipm @10K for 6061 or 7075.

Like I have said before, it doesn't matter what the cutting params are, tools, or holders are.
it leave these marks even with a 1.5" index mill at 10krpm and 150-300 IPM,
or a chamfer tool breaking an edge for .015"
All these same tools, programs and jaws, ran in 2 other smaller lighter machines don't have this issue.
Its the machine not the setup.
And a .001 IPT finish pass on 6061 will cut good and not chatter on sub 2X length, and its usage here was to minimize the effect.

 

[Garwood]

I had a totally knackered early 80's Mori VMC with chowdered thrust bearings, badly tuned servos and a 4500 max spindle. Finishes were way better than that. That looks like shit.

 

[CarbideBob]

Notable is on part number two the rads look better than the flats or the frequency very different.

 

[DMF_TomB]

you have any machines not giving you chatter marks ? ...its not always servo oscillation
.
dull cutters, or not made for material cut and not optimum feeds and speeds and coolant have a effect.
some use sharp new cutter before finish cut thats hasn't been roughing for best finish, and tool life
can be shorter with more abrasive metals
.
try new sharp inserts on a mill try facing or low depth of cut. some materials prefer certain higher
sfpm rpm and certain ipt feed and really need coolant for less bue "built up edge" longer life
.
and tool runout can leave runout lines requiring adjusted feeds and speeds to compensate

 

[Dan from Oakland]

My vote is for a linear guide. Might be wrong, but we have seen the same pattern on a mill where the vertical turcite on the Y axis was done. Looks like the saddle is doing a crab walk. Bolt a long bar on the table with some indicators and try to rotate the table and check for slop. Or put an indicator on a straight edge perpendicular to an axis and see if you get any movement at either end when changing direction. I hope its is servo tuning- easier to fix.

 

[Houdini]

Anyone interested, Haas sent out the 3rd tech, area supervisor.
they gathered info sent to Haas and then he came out.
Haas said the surface finish looked acceptable HAHAHA
but he adjusted gain parameters until the marks minimized.
Haas said it is a issue because of the low helix ballscrews,
so in essence the things a piece of junk buyers beware!
Anyone want to buy a DM2? HAHA

 

[Milland]

If you get a chance, please post "before and after" pics - it would be interesting to see the current finish.

 

[Houdini]

before Right, After Left

 

[Milland]

View attachment 341790

before Right, After Left

It's better, but if that was a new-ish sharp cutter on a finishing pass, that's still disappointing.

What were the S/F and cutter diameter/flutes for the two runs?

 

[Houdini]

YG-1 1/2 x 1.25 8500RPM 40IPM LOC .8 WOC .01
you have to remember that none of that matters though, it is the servo drives creating this, not the feeds and speeds.