Not sure if HSM would be a solution to the parts we run here. I've been to mmsonline.com and some other sites to get a feel for the basic concept. So let me see if I have this right - HSM is a process of CNC machining designed for specific applications where conventional "big cut" machining would not work well. For example, parts that require a very high degree of accuracy and surface finish, intricate parts with thin walls and floors, or very hard materials. Using very light axial and radial depths of cuts and uniform tool loading, you get longer tool life and low cutter deflection. But how do I know if HSM is right for us? Let em fill you in a bit on the story so far. From '95 to '04 we had a senior design engineer who kept his parts simple and machine-friendly. Good thing because for a while we didn't even have a true CNC center, we had a 2-axis EzTrak and that was it. In '99 we got a Fadal VMC3016. We ran all our parts fairly conventionally. Majority of them are 6061 or 7075 AL, with the occasional stainless, brass, or engineering plastic. Since he left, our new senior engineer has had a lust for either small, complicated, or small AND complicated designs. Right now I'd say we machine Ultem 1000 and AL6061 in about equal amounts. A lot of the plastic parts especially have small features and tight tolerances. We question the necessity of some of this complicated stuff... Our production numbers are also changing. Used to be a lot of prototype and small-time batches, less than 10 items. But now we're getting into runs of 100-400. Also have some tight deadlines and budget restraints. So a good way of machining this stuff accurately and quickly would be great. I'd like to try re-running the toolpaths on some of these parts we've made during some downtime, but I have no idea where to begin. I'm a student, fairly new to this stuff, and our senior engineer has 40 years experience but is fairly old school about doing things. So where do I start on appropriate feeds, speeds, and depths of cut? I'm used to just running handbook values, bout 400sfm for Aluminum, cut depth of say 30% the tool dia, 50% stepovers. What are typical changes to these for HSM? And why in every demo video I've seen is there only air blast, no coolant at all? Then again I'm not sure we're really capable of HSM. Our Fadal, spindle only gets up to 7500RPM and the travel rate either maxes out at 200 or 500IPM. But I think we can do better than where we're at, I've never seen any tool run past 5000RPM or 60ipm.

Ah, I see. Thanks a lot guys.

Hmm, thats kinda cool. Might have to try that.

And what exactly does wear comp do?

I just have always left it on Computer, measure my tools before I load them, and run my test piece. Then depending if the dimensions come out a little over or under from cutter deflection I might fudge the cutter dia in Mastercam to make things come out right.

Whoa! Wasn't expecting anyone from the area to reply. Will do Walter, thanks!

7.62mm? I have the opposite problem. I'd love to find some work around here at a shop, get some more experience. But I have looked and don't see openings.

No, I'm not asking for a post. As I was saying in my other thread, been trying to update this old EzTrak post from v6 to v9. Got it ALMOST where I want it. But! Right now the block numbers I'm getting are N102 N104 N106 N108 etc And I'd like them to be N001 N002 N003 N004 etc It can't be THAT hard to change in the post, can it?? But looking at this post file for the first time, its kinda daunting! And yea I tried the v9 EzTrak post on the CD but its outputting stuff totally different from what our machine takes.

My first +1! Hooray!

Not sure what you mean...can you elaborate a bit?

I use wireframe to define toolpaths as the norm rather than the exception, and I learned MasterCAM simultaneously on 6, 8, and 9. Lot of parts I get are more or less prismatic. If I get a dxf, not much choice but to just set the depths, select a few chains, and bam there are my toolpaths. If I get a parasolid or what have you and have some trimmed surfaces and edge geometry, its a lot quicker to again just select some chains than to mess around with drive and check surfaces. If there's some geometry that has a flowing, 3d surface, then obviously surfacing is the way to go

Hmm, seems this whole thread may be un-necessary. Didn't realize there was an "update post" feature under NC UTILS.

Don't know that there is one for 9. I don't recall seeing one. To be honest I haven't contacted out reseller about it yet either. Was just wondering if there was an easy way of doing it. The senior machinist I work with, he's been machining for 40 some years. He isn't all that computer-oriented I don't think, and kinda set in his ways. According to him we have to use 6 to post to the EZ-TRAK. I'm certain this isn't the case, we just don't have the post for v9. Doesn't have to be anything special. The thing just needs some X,Y points to work with.

In our fairly small shop, we have two NC machines. One is a nice Fadal 3016 that we program with 9.1 sp2. The other, which we use for secondary stuff or small projects that students such as myself work on, is a Bridgeport 2-axis EZ-TRAK. Can only hold 256 lines, can't be run DNC. We program it with v6. v6 though is a pain in the rear, especially if you don't use it for a while and have to come back from the v9 interface. So I'm wondering, how feasible is it to use the EZ-TRAK post in v9? Would I have to just make a whole new post? Might be a nice challenge...since I've never written one.

Ok. So I've been plugging away at MasterCAM for a few months now, ran a few projects, but there's a few things that I just haven't been exposed to yet. So here goes! 1) What is a chook?? 2) What are levels?

Yea I was about to say. Use a chamfer mill or something, hit all the contours, no more than .005-.010 and it knocks em all off. Personally I haven't used it on Nylon, but it works for every other material we've used.

Where in CO are you, Putt?

Do you have a solid model or print of this that we could see to better grasp what kind of feature youre referring to?

I'd probably program for the slowest and set them all for that. Then you have each machine running the same feeds and speeds, same tools on same material, so you should have very good repeatability in results.

"Any chance of convincing them to use a machinable plastic..like Delrin?" Oh I wish. But what they're doing is taking off-the-shelf syringes and modifying them into this thing. Our customer has the part listed as a "one-time use throwaway" type deal. So we need lots of them and on the cheap.

Heh, "only" a thousand parts. We do almost exclusively small batches. Large piece of hardware that gets put in a locker and blasted into space. Ran some contraption a while ago, 75 of em (each with 6 parts) and that was a lot! 4-axis, not a bad idea I guess. That ties up our only CNC though, for quite some time (maybe 30 sec of milling but then gotta take it out and put a new one in and start the program again each time). Don't think that's an option, got some parts that need surfacing and many tool operations. I had been running it on a Bridgeport tracker (2 axis).

Hmm, I'll have to try some of this. Can't use coolant because the end use is as a sample container for a cell culture for space flight. They want to keep these as clean as possible and not have to spend loads of time swabbing them out. Still kinda leaning towards the punch idea. Running these with the .063 EM I was using about 260rpm and 1.5ipm. Faster spindle speed and the damn thing would melt more and make a nastier burr. Faster feeds and it cracks/shatters. For 1000 of these think it would be easier to make a press that punches out the slot (slot by the way has radius ends) on say 10 at a time in one swift movement. Rather than having to take the thing, put it in a collet, mill one side, flip it 180 degrees, mill the other side, and take it out.

Has anyone had good experience working with PP? Some part I have to make is a modified syringe, bout half inch diameter with ~.063 walls. The hard part is milling a thru slot about a quarter inch long by .063 wide, perpendicular to the axis of the syringe. And it has to be machined dry. Tried using a .063 endmill, low speed with the feed up. Fast speeds made the thing melt and gum up. In any event, it always comes out with a nasty burr and about .010 undersize, probably to the material being so soft. Requires considerable time with an exacto knife and gauge pins to clean it out and bring it to spec. First they wanted a prototype, then a batch of 85, and now they want 600-1000!!! So I need a better way to run these things. Either machined so it comes out cleanly on one pass or something else. I'm thinking of maybe making a punch tool. Anyone have some experience working with this stuff?

What kind of data are you looking for exactly? What unusual size is it?

If you're going to be doing simple 2 or 2.5 D stuff, it might be easier just to import the DXF and work from there. But, if you want to do it off a solid model, when you import the object (in whatever format...IGES or ACIS or whatnot) make sure you import all the line geometry. Then you get the object in and bam, all your geometry is there and at the right depths. Another good thing to do with SolidWorks, if you've noticed it uses a different geometry system than MasterCAM. The Y and Z axes are switched, so when you go to import things you have to flip it around and all this crap. But you can make a reference geometry system in SW and export it using that system instead of the default one. Then when you get it in MCAM its oriented the way you want it.