Hi guys,
We are having problems with the spindle taper bell mouthing (lower contact point wears away) on our Haas VR-11. This causes the tool holders to stick in the spindle. A major job that we do on this machine is machining two parts complete from 7050-T7451 aluminum plate, 5.25” x 12.5” x 15.50”. Volume on these parts is about 40 per month. To rough out these parts we are using the following:
Cutter: Onsrud AMC704164, .750” dia., .060” radius, 2.50” stick out
Tool Holder: Parlec C40-75MC3 Milling Chuck. We also regularly evaluate and replace our retention knobs.
Cutting Parameters: Mastercam Opti-Rough Tool Path, Minimum Tool Path Radius (center of cutter) .125”, Step Down 1.27423”, Step Over .120”, Spindle Speed 7500 RPM, Feed Rate 300 IPM. Per a HAAS Application Engineer, we have recently (05-09-2013) modified our tool path to only climb cut which increases the time in this tool path by about 20-25%.
We’ve modified our VR-11 with a programmable air blast to keep the chips away from the machining area and from the tool probe when checking tools. We primarily run these parts at night, unattended, and we are expecting to generally run about 12 hours at night.
We experimented with our cutting parameters and adjusted them so we are always in the green on the load meter (90-100%). We are experiencing tool life of 2500 to 3000 pounds of chips with a good spindle taper. The machine absolutely sounds great when it is in the roughing tool path.
After running these parts for several years roughing with a 1.25” Iscar insert cutter, we switched to the Opti-Rough tool path to decrease machine time and lower tool costs. However, the spindle tapers are wearing out. We replaced the spindle when we started the process in October, 2012. We again replaced it in February, 2013, and then a third spindle in June, 2013. We are generally running only about 60 days before we start showing significant wear.
Haas’s response to our problem: “The spindle taper is worn out. You must be abusing your machine.” We fail to see how running the machine well within the parameters the machine is designed for is abusing the machine. Everybody, to a person, that has seen the machine cutting with the Opti-Rough Tool path has been impressed with the smoothness and performance. If we were abusing the machine, we would not be able to generate 2500 to 3000 pounds of chips with one cutter. In addition, Haas will not give us suggestions on where we should run the machine for the spindle taper to last, say a year. We’ve moved most of the roughing off this machine and the roughing we are doing is now at a 50% spindle load. We are still having problems and showing spindle taper wear.
We believe that Haas has a significant spindle taper problem and is not addressing it. As more Haas machines start using the Opti-Rough and similar tool paths, be aware that you might have to start replacing Haas spindles due to this taper wear problem. Is anybody else having issues with Haas spindle tapers? Suggestions? Thw problem we are having is, if a single tool can create 3000 lbs, of chips, how can I believe HAAS when they tell us we are abusing the machine. Especially if the load never goes over 50% now. I just need some help from somebody, or at least I am trying to pass on a warning to others that HAAS is not even coming close to keeping up with current maching practices. Thanks guys!!