Have a simple part ready from something like Aluminum, with a couple pockets and a couple threaded holes, total cycle time of around 2-3 minutes. Show them the drawing, then the part in MC, and then make it, hopefully with a shower of chips hitting the side of the enclosure so it sounds like there is a machine gun in there. Of 20 kids, 15 will be oblivious. 5 will have their jaws on the floor. These 5 are the only ones you need to be worried about. MattW

John, your formula doesn't just get you "in the ballpark", it is right on. A little research reveals the following- " In 1907 the American Society of Mechanical Engineers (ASME) defined two series that used Seller's thread, numbering the sizes by gage numbers from 0 to 30. In the series the major diameter increased by 0.013 inch with each size from 0 to 10, and by 0.026 inch between gages above #10." (from http://www.sizes.com/tools/thread_history.htm ) And I had always thought the numbers were arbitrary. I find this kind of historical information interesting. Anyway, I believe current ANSI recommendation is to specify standard screw threads by decimal size and TPI, e.g., .190-32 for #10-32 and .250-20 for 1/4-20. The number system will probably die at the same time as the universal adoption of the Metric system. To address the original question, .122-40 looks like a misprint, and I would get clarification on what is desired. MattW

As a corollary to the highjacking of this thread- "You want it bad- you get it bad" one of my faves. MattW

There are probably much simpler ways to do this, but I think what you are looking for is code that looks like: G01 Z-.025 F20.; Z-.020; Z-.050; Z-.045; .... Z-5.000; This can be generated fairly easily in Excel using the autofill functionality, and then copied and pasted into your program. This would be the easiest way to do once, if this is going to be a regular occurence I would use other means. I just generated these values in about 3 minutes (had to check to see if it was as easy as I was hoping). I will send you a text file if I can- 385 lines! MattW

I am using a radiused slot mill, both in verify and and in reality. Verify shows the radiused bottom groove, the tool moves the right way, but the groove spirals the wrong way, and the ends aren't shown correctly, they are in the wrong place. I am just wondering if it is something I am doing or if it does this for everybody.

I have a part that needs a spiral groove on the outside, and I am using thread mill for the toolpath, which works great. However, verify shows a left hand thread being cut, although backplot shows right hand, and that is what is posted out. This confounded me for a while, until a made sure the right code was being put out. Anybody else had this happen? V9.1 MR0105, I have X but haven't installed it yet. MattW

Hey, I might actually be able to make a contribution to this thread.... On a Haas, set setting 33 (coordinate system) to "HAAS". This works just like Fanuc, but doesn't reset g52 when the program resets. I put the length of my offset gauge in my G52 Z value (-2.000 for the electronic guage), so now all tools are set to zero at the point I touch off (top of the vise, most times, in my case). I then put a z value in the g54, g55, etc to offset to where I want z zero to be on the part. This also works pretty good for operations where you are worried about running into the vise- just check the operation of concern to make sure the z value is less than the g54... value. I do my calculations on a spreadsheet- you get a better chance to verify that the numbers you are entering are correct. MattW Vertex Pharmaceuticals

This isn't as slick as I think it should be, but... 1) make a copy of the drawing 2) open the drawing 3) right click in a view, and open the part (should still be the original part) 4) do a 'save as...' new part name. You will get a warning about the part being referenced by other open files (your new drawing) and the references will be updated. This is what you want. DO NOT 'save as copy'. 5) Gabba gabba hey. This should do what you want. I am pretty sure there is a more elegant way, but I don't know what it is offhand. MattW

The California State Railway museum has the Lima locomotive works drawing collection, although you will have to do some homework to get what you want. If it is a Lima built locomotive you are after, this is probably the place to go. http://www.csrmf.org/doc.asp?id=270 I have a uninitiated background backburner project in this area, so keep me posted on your progress. MattW

Marc actually asked this question on my behalf (I am in the class he is teaching now), so I will thank you all myself. The requested tool doesn't appear to be off the shelf anywhere, but we may have a workaround- a 3/64 radius on the bottom of a 7/64 hole. I just sectioned a sample and it looks pretty good. MattW Vertex Pharmaceuticals

quote: Running two measuring systems in one shop is a receipe for large numbers of mistakes. At first, anyway, and it may well be a significant ongoing problem. On the other hand, it sounds like the decision has been taken away from you, and unless a big portion of your compensation is in the form of stock or profit sharing, The cost of these problems is coming out of the owner's pocket, not yours, and you probably don't need the headache of this battle. So state your case and then do as your told. You can then put on your resume that you are experienced in programming in both standard and metric units. I had a boss once who would frequently ask me to do things I had reservations about. I would relay my concerns and then say something like "but if you still want me to do this, I will". He would laugh and sometimes change his mind, and say something like "no vicious obedience". Sometimes vicious obedience is called for. MattW Vertex Pharmaceuticals

Make sure you are typing the axis letter from the alphabet keypad (?), not the axis keypad. This is the only CNC I have tried to run, but this feature strikes me as pretty cool. MattW Vertex Pharmaceuticals

I am using Mastercam direct out of solidworks 2004. I can't save the file in SW until I close MC. I can edit the file in SW, just not save. I get the following messages: "unknown error opening filepathSW file name ", click OK,and then "an unknown error occured while accessing filepathSW file name". After closing MC, the file saves fine. Since it is just me needing to do this, the workaround isn't too bad. MattW Vertex Pharmaceuticals

Beware of George, he asks trick questions. Standard Atmospheric Pressure is 29.92 "Hg. Standard Atmospheric conditions are 29.92"Hg, 59 degF, which is of interest when air density is of concern. For the purposes of Vacuum holddown, only local atmospheric pressure is of interest. When I said blank the pump to check for leakage, that is as simple as pinching the hose to the fixture like a garden hose, and the gauge should not move much (not at all would be good). I have a vacuum pump like this Gast unit at home for vacuum bagging composites, it should work well for vacuum holddown of non porous material. The downside is they are a bit noisy, but are small and portable and not expensive. Now if I could just learn to use MC effectively... MattW Vertex Pharmaceuticals

Hey, maybe I can help on this one... it doesn't involve MC... Standard atmospheric pressure is 14.7 psi, 29.92 in Hg at sea level. You will lose about 1 in Hg every 1000' of elevation. Pressure varies day to day, but not by much more than 1/2 in Hg. My quick and dirty conversion is 1 psi = 2 in Hg. You can get a decent vacuum pump for not a lot of money, 15 in is kind of low. Compare level with the pump blanked to determine how tight your seal is, it doesn't take much of a leak to spoil the vacuum. MattW Vertex Pharmaceuticals

OK, thanks all, I have some things to try. I have been making progress on this part, but there are going to be others like this (I can imagine an item with 1500+ bosses). I figured there had to be a better way than selecting them individually. MattW Vertex Pharmaceuticals

Thanks for the suggestions. I can't seem to access the FTP site, and the problem isn't immediately obvious to me. I could email it to someone that could post it. The bosses are in a 16 x 24 array, and part of the problem I am having is after making a tweak, it takes something like 15-20 minutes to regenerate the tooling paths. I need to build a mini part to experiment with. I feel fairly certain I am making this much harder than it needs to be. MattW Vertex Pharmaceuticals

I am just a beginner at Mastercam, so bear with me. I have a part with 384 bosses on it, brought in from Solidworks. the bosses are .080 dia and there is .078 between them at their closest. The best I have been able to do is to offset a line from the outer edges of the part and then pocket, selecting all 384 bosses individually. There has to be a better way, and I haven't fumbled my way there yet. Also, the toolpaths generated by this method spend a lot of time cutting nothing. Any suggestions? MattW