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Showing results for tags '5% or 20%'.
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I am helping a customer with parts like this. Has 40 taper machines and thinking 20% step over with a 125% depth of cut is going to be too much for their machines. They are Mori-Seiki machines, but still it is 40 taper so I am leaning towards the 5% step over which means I can go upwards of 700 sfm and up to .004 per tooth. Using a 5 flute endmill I would be at 3560 rpm and 57 imp taking a 1" x 6" x 4" section of Material in about 14 minutes. If I get aggressive and go up in the my step over to 20% at my 125% step down I need to slow down to .0035 per tooth and 450 sfm. That is 2292 rpms and 32 ipm and would cut the same area in 7 minutes. The HSM Adviser is pointing to better tool life using the more aggressive step over and I would agree with that, but on these 40 taper machines I am just worried they will hold up for the next 4 years pushing them to hard. It is a 4 year contract for my customer so trying to weigh the balance of time and wear and tear on his old equipment. My customer wanted me to program everything with cobalt and 3 imp and think I have lost my every loving mind going in this direction. Has his cobalt endmills on stand by when the Carbide Endmills fail. Needs to be able to produce the parts in a timely fashion and I am very confident in the HST toolpaths, but going back and forth between my crazy push it to the limits and get it done mode to a more conservative get it done, but be easy on the machines. Anyone who has worked with me knows I go not problem burning up tools to get the job done. Customer will be happy just getting the parts made and if they took 20 hours a piece to machine he would be happy. Problem is I see now way to produce 80 parts a month if you old school it. Need to HST these parts and would be able to hit his desired 80 parts a month capacity. Take an average amount of hours a month on a 30 day month and get to 720 hours and divide it by 80 part you have 9 hours per part to machine them. Thinking one spindle is going to do all the work is where is wants to be. I am thinking one HMC to do a majority of the work and 3 VMC's to od other operations be would be able to his his mark if we HST these parts. Going to Cobalt 3 ipm way is not going to make it happen. Question do I push 40 taper 10 and 15 year old machines with 20% step over or do I take it easy and go to 5% step over? Cobalt is not an option for me and I know some old school folks on here will be right here with this part telling me I am crazy, but seen these toolpaths in action and one customer I talked to this week on a part they use to do before HST toolpaths was taking 5 hours to rough after HST toolpaths were getting them roughed in 2 hours. Not 6AL-4v, but the principle is still the same. I am open to other suggestion or comments about this.
