Need tool recommendation

[Bob W.]

I will be doing some mold machining in the near future and I need some tool recommendations. These are simple gate molds but they are fairly large compared to what I am used to. These are gate molds with drafted pockets dropping down 4.5" from the parting line and I will be removing 500 cubic inches of material. I can finish these with a 5/8" ball mill without the need to rest mill.

 

I had planned on roughing to 2" with a 1/2" MA Ford 135 series will and then go with longer tools for the deeper cuts. My mill is a Haas VM3 (12k spindle) and I have Volumill as well. I also plan on using shrink fit holders. I have had IMCO tools recommended but I don't have any experience with them.

 

I would like some insight on the best performing tools for roughing and finishing in this application. Any help would be appreciated.

 

These are aluminum molds.

 

Thanks,

Bob

[Chris Rizzo]

I've found an economical and well performing tool to be the Mitusbishi BXD in a shrinker. I've ran 1", 1.125" and 1.25" in a vf3. The haas machine rigidity seems to be very sensitive to doc with the longer lengths. Other folks have run the high feed ajx and like it. You get your tools from Western? I'm sure the mitsu rep would give you something to try. Let me know if you want his contact info.

 

I've tried some kenametal products and I prefer the mitsu from a price/performance/service standpoint.

 

oh I run the 138 fords. The 3 fluters. They work very well for everything and practically chatter-proof.

 

that's m2c. But 10 diff. people will recommend 10 different tools. :/

[Cad-Camr]

We run a 2" Mil-Tech Face Mill on a 4" Extended holder .125 DOC 350 IPM. The material disappears in a hurry.

[Colin Gilchrist]

Is this a repeat job Bob? How concerned are you about cycle time?

 

The reason I ask is that I do a lot of aluminum mold work here at Boeing, and I've found a style of cutter I really like for roughing and/or finishing.

 

I use a .750 diameter 3 flute endmill, .09 Corner radius, 1" LOC, Extended Carbide (solid, reduced diameter shank) with 4.5" Length Below Shoulder, 6" Overall length.

 

Even though it is a 6:1 Depth to Diameter ratio, this cutter is great for hogging. I usually do a Core Roughing style toolpath and get great results.

 

That is the reason I asked about how critical the cycle time is for you. You can't be super aggressive with a tool like this, but you can go really deep and still get decent material removal. You could potentially Rough and Semi-Finish the entire job with this single tool.

 

This is the kind of job I would program at low to moderate feeds/speeds and just let run unattended all night.

[Bob W.]

I will be doing a fair number of these and I would like to minimize the cycle times but it isn't critical. I don't believe the roughing will take that long but I don't have that much experience with larger parts. I expect the finishing to take a fair amount of time and I do plan to load up both machines and let them run lights out until finished.

 

Did you get my earlier email Colin?

[gcode]

Get a Mitsubishi AJX 2" shell mill and whatever

lenght extended arbor is requires to get to the bottom of the cavity.

On long arbors I run it at 1100 RPM 84 ipm .04 to .05 depth of cut with a high speed area roughing at 45% stepover and ramp of 1 degree.

Your biggest problem will be getting the chips out of he way.

I've run these paramters on a 12" long arbor

on a 50 taper machine in mild steels with excellent result.

The Mitusbishi catalog has excellent feeds and

speed charts for these tools.

It may take some trial and error to find the sweet spot for your Haas, but once you do

it will be nothing but beautiful bright blue chips bouncing off the glass.

[Colin Gilchrist]

Hi Bob,

 

I did get your email, I'll be sending you a response shortly.

 

Thanks,

[gcode]

quote:

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These are aluminum molds.

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missed that... even AJX cutters can't get blue cips out of aluminum..

[Chris Rizzo]

Your right about roughing not being a big time saving opportunity. I've been programming about 20 aluminum molds a bit smaller than yours (10x15x2.5). 1" big-tool roughing takes about 20 min. Rest roughing with a .500 about 45 min, rest again with a .3125 around 2hrs, and finishing with a .250 ball around 10-15 hrs. From a time saving standpoint, the best tooling investment for my customer could arguably be a faster spindle.

[Bob W.]

quote:

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From a time saving standpoint, the best tooling investment for my customer could arguably be a faster spindle.

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Since the finisher will be sticking out 4.5" I have been told to back off the rpms to reduce chatter. Any thoughts on this? I will be finishing with a 1/2" ball mill. Would you finish to 2" with a short ball mill, then go back with a longer ball mill at lower rpms? I plan to get the roughing really close to keep the finishing chip load to a minimum.

[Jayson Kramer]

Colin, sounds like you are talking about the Hanita 3flt with there re-leafed shanks . I like those allot and you can still cut fast in alum.