Haas servo bar 300 not pushing correct length

[Scott Wayne]

Hey everyone. I’ve been searching for answers for this and haven’t found anyone with my exact problem, or any answers that work.

We have a Haas ST 30y and a Servo bar 300 at work. We set it up once and ran 150 good parts. I broke it down for the next job and now I’m getting incorrect push lengths. I set it up per the manuals instructions, Q6, Q4, Q2, etc. fill in 3100, 3101, 3102 etc. What’s weird is that the first push is correct at 2”, only varies by a couple thou. Any push after that will be 1.84 - 1.85”. The part length is .840, I’m using a 1/16 part off tool and I add .05” for facing, so #3100 is .952. #3101 is 2” and 3102 is 2”. We couldn’t figure it out so we fudged the 3100 number to make each push the correct length and we ended up crashing a $600 drill because it pushed out way too much after loading the next bar.

Something else I’ve noticed is the #3110 value “current bar length” is very inconsistent. On a 48” bar I was getting 45.87-45.89”. On a 36” bar I’m getting 33.715 - 33.957”. So both bars it’s about 2.2” off what it actually measures. Is all of this due to a faulty sensor? Please help because Haas is completely useless! Thank you!

 

[Mr. Atoz]

We had a similar problem and fixed it by slowing down the push rate.

 

[Scott Wayne]

Right now it looks like ours is set to 100,000 in the parameters. What did you set yours too?

 

[Mr. Atoz]

Oh wow, it has been years. I will have to check. Which setting number is it? Is your barfeeder well lined up with the lathe?

 

[Scott Wayne]

On the classic Haas controls it’s under parameters, then system, and “push rate” is 323.

I had to go back and level the bar feeder a little bit better because the setup guys didn’t do a great job, the push bar would rub the spindle liner at the end of its reach, but it’s good to go now.

 

[bigjon61]

I tried reasoning with a friend who went from running a mill in our shop to a lathe in another shop. Same thing, crashed a $600 drill because it pushed too much stock out. BUH BUH BUH. Use the parting tool to stop off of and you won't have any problems over feeding. It is a fail safe insurance you won't crash.

 

[curtis r]

What size and type of material? We had that problem pushing 1 1/4" brass. It would slide from momentum. We also slowed down our pusher also but I don't remember what the number is that we set it to. You can always program in a push back to verify the length.

Have you used a 1' bar to check your end of bar parameter?

 

[70olds]

I tried reasoning with a friend who went from running a mill in our shop to a lathe in another shop. Same thing, crashed a $600 drill because it pushed too much stock out. BUH BUH BUH. Use the parting tool to stop off of and you won't have any problems over feeding. It is a fail safe insurance you won't crash.

Same here. On our first lathe we got an LNS servo feeder and they swore up and down it would repeat within .005 or .010" whatever it was. Crashed the first drill in short order. As coolant and the like get into the tube, unless you push slow as hell, the bar can slide out further than the pushers goes. Just bring the turret in front of where it should be by an extra .010" OR set up the pusher (if you have the option) to push to force instead of a specific distance. There is still a window it will stay in, but inside the window it looks for feedback. Then you can never over-feed.

To the OP
If you are seeing it come out short sometimes, perhaps you already have a setting like that in there that is active and your bars are slightly bent this time, something could be hanging up, misalignment, spindle liner is too big, etc. You fudging the numbers made it too long when it worked "correctly".

The barfeeder is probably trying to push the proper length by the numbers it just cant get there.

"Something else I’ve noticed is the #3110 value “current bar length” is very inconsistent. On a 48” bar I was getting 45.87-45.89”. On a 36” bar I’m getting 33.715 - 33.957”. So both bars it’s about 2.2” off what it actually measures. Is all of this due to a faulty sensor? Please help because Haas is completely useless! Thank you!"
Can't speak for HAAS but LNS barfeeds have a usable length value that shows. The missing 2.2 may be in there as a minimum chucking allowance, so the feeder knows if it doesn't have the part length plus that value to just get another bar or at least stop running that one so you don't risk trying to run a part while holding on to .5" of the bar stock.

 

[Mr. Atoz]

On the classic Haas controls it’s under parameters, then system, and “push rate” is 323.

I had to go back and level the bar feeder a little bit better because the setup guys didn’t do a great job, the push bar would rub the spindle liner at the end of its reach, but it’s good to go now.

That in itself may help.

 

[Ox]

I tried reasoning with a friend who went from running a mill in our shop to a lathe in another shop. Same thing, crashed a $600 drill because it pushed too much stock out. BUH BUH BUH. Use the parting tool to stop off of and you won't have any problems over feeding. It is a fail safe insurance you won't crash.

Does the Haas feeder have remnant retract?


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Think Snow Eh!
Ox

 

[Mr. Atoz]

Does the Haas feeder have remnant retract?


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Think Snow Eh!
Ox

What is that?

 

[Ox]

Does it pull the bar end back and dispose of it on the loader, or does it shove it out into the chip conveyor?


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Think Snow Eh!
Ox

 

[Mr. Atoz]

Clear.

 

[Fancuku]

Worked at an all Haas shop briefly and they had the problem with the bar pushing too far sometimes when loading a new bar. What fixed the isse was spray painting the first couple of inches of the bar in a dark color (black or blue). The material was too shiny and the laser that measures the bar would mis measure it.

 

[bigjon61]

Worked at an all Haas shop briefly and they had the problem with the bar pushing too far sometimes when loading a new bar. What fixed the isse was spray painting the first couple of inches of the bar in a dark color (black or blue). The material was too shiny and the laser that measures the bar would mis measure it.

Wow. I just don't understand what the problem with bumping the parting tool is. The tool is already there. The machine is going to do nothing until the bar feeder sends a finished signal to the lathe. The only time you lose is the time it takes to rapid to your safe index location and index to the next tool. The trade off is reliable feed out lengths and no crashed tooling, as well as peace of mind.

 

[bigjon61]

Does it pull the bar end back and dispose of it on the loader, or does it shove it out into the chip conveyor?


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Think Snow Eh!
Ox

No idea but it doesn't matter. The remnant ends up in the scrap bucket either way.

 

[Ox]

OK, s'plain how that works, as I have never ran a Haas lathe.

How does the remnant git in the bucket.
Does the feeder push the remnant out prior to retracting?

If so, that is a good idea, but my LNS's don't doo that, but they are older than any Haas feeder, so ....

???

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Think Snow Eh!
Ox

 

[curtis r]

Ox, the next bar pushes out the remnant into the chip conveyor when going to it's initial push length.

 

[Ox]

OK then, how does Big Jon's posts about loading a new bar to a stop work then?


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Think Snow Eh!
Ox

 

[curtis r]

OK then, how does Big Jon's posts about loading a new bar to a stop work then?


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Think Snow Eh!
Ox

Can't comment on what he does because I don't have to do that.