Messages

41

General Mach Discussion / Re: Now I am into a new pickle!

« on: October 20, 2011, 12:17:54 PM »

I had a thought here. Maybe looks are deceiving and it's straight across cutting and just hard to tell and measure while in motion, but the z depth is definitely wrong. BUT..thinking about numbers, I wonder if because i am in radius settings, it doubles the cut depth?  Correct me if I'm wrong, but Here's what I am thinking.  I want .0625. It is currently something like .045 even though it says .025.  I have 3 passes, the third pass supposedly to be .125.  Now, if it is cutting .045, in two passes that is .09 If I take point .0125 and double that I have .025 added to .09 is .115. That is almost double what it is supposed to be, and since the .045 I measure is with a ruler, and in motion, it could be slightly more than that taking the total depth to double what it should be.  Now radius is half the diameter of a circle. So the machine is thinking 2 times for diameter two times for depth?  Am I way off here, or am I on to something ?

42

General Mach Discussion / Now I am into a new pickle!

« on: October 20, 2011, 11:53:31 AM »

Darn if it isn't one issue after another!  I thought the 4 axis was set up right now having taken the steps to switch to using radius for control and entering the radius of the rod. That made a major improvement to the performance of the machine. When I did the test cut, it was amazing, but the test cut went too deep. I thought nothing of it, as the hole in that test rod was just a hair too big to begin with. Well now I am cutting a piece of aluminum rod. The hole in the rod is perfect. I drilled it, and then I stuck it between centers and cleaned up the rod on my metal lathe so it is perfectly parallel with the hole. The 4 axis and tail stock in my mill is lined up perfect. The rod is situated dead straight in all directions.  I have 3 passes around the rod set up. First pass is .025, then .05 and ends at .0625.  The Z on the screen says I am at .025.  I am not at .025, not even close! I have to bet that I am about .045 ..a pretty good guess as I used a ruler on a side wall that is cut. But..to make things worse...The pocket area is 2 inches long, it is making cut .045 on one side, but the cut tapers toward the tail stock where I'd say it is about .015 deep.  You'd think the whole table is tilted, but it is not.  By switching to A axis radius control, the Z has gone nuts somehow. Did I miss a step somewhere setting this up?  I'm going to let it run through it's full first rotation before stopping the machine so I can recheck all the physical setup like re verify the rod is parrallel with hole and the head and tail stock on the mill is aligned, but I since I have already done that, I don't think that's the issue at all.  I notice a couple spots where the bit did not fully raise too, just grazed the surface running from one pocket to another. It's driving me bonkers.

43

General Mach Discussion / Re: controlling my speeds

« on: October 19, 2011, 04:48:38 PM »

WOW>>>HAHAHAHA!!!  You guys rock! Hood...you were absolutely correct about the speed was too fast. I about jumped out of my shorts when it took off after making the suggestions of the second kind sir!  I cut this design, it took 2 hrs 40 minutes.  Now I recut, took 4 min 48 seconds! Plastic dust was launching. I was about to do a manual over ride and slow it down but thought heck..let her go and away she went. She cut that baby out super sonic speed. It did break off a few pieces, but I actually don't think the speed was the issue, the rod was an extra one where the inside hole I accidentally bored a touch too big, so the depth of the hole ended up going all the way through the rod and that's why the center of the A disappeared and part of the inside of the M broke off.  I will slow it down next time, but not hardly by much.  I got the boxes on the top of the two letters perfect too.

This was the suggestion to try in the visual mill and it worked out.

Can you try setting the Co-ordinate output in the post to non-modal and see if this makes any difference?. To edit the post processor, select Set Post Options (2nd button on setup tab), Click edit next to current post processor. This opens up the post processor generator.
On the General tab, clear the check box for Co-ordinate under Modal Output. Save and close the post processor.
Now post process your toolpath.
Setting the co-ordinate to non-modal, outputs X Z and A co-ordinate motions for every line of code.

44

General Mach Discussion / Re: controlling my speeds

« on: October 19, 2011, 03:00:09 PM »

ok, thanks. I have something to try first and if it doesn't work out I can do that. I want to get these perfect as I can so the customer can get the legal rights to it.  The visual mill guy gave me something new to try, some kinda edit in my posting process that might fix it. I have about an hour or so left on the current part in the machine. Then I'm going to do the mach edits and load in the new software edits and see what happens. Hopefully it will cut much faster this time too. The visual mill says it should take 7 minutes, but the real time it has been taking is 2 hrs 41 minutes. Be sweet if I could even just do one in an hour, then I could be profitable! I have a lot of money tied up in this machine. Good news is I paid cash. It's been a real struggle the least few months, but I feel much better every day using it. I actually drew this logo using the mouse and visual software, posted all the stuff, 100% accomplished it by myself this time! Every bug I encounter and fix teaches me a whole lot..I learn best by my mistakes.  Heck..you see the tape on this rod..yea, I learned that fast, no tape and the rod can slip in the bushings and get trashed out by the bit. DAMHIKT..lol!

45

General Mach Discussion / Re: controlling my speeds

« on: October 19, 2011, 02:12:19 PM »

Sounds awesome, thank you. I am cutting right now, when finished I'll give that a try!

do you think that will fix this other problem maybe?  This pic is for the Texas AM logo. I have a guy working on licensing and I am making his samples.  In Visual Mill 6, I created this and in Simulation mode it works perfect. Each letter has a box on it, so like the A has 3 boxes, one on top and 2 on the bottom, that's just how they font their letters.  I cut this out and the T is flawless. The A and the M are perfect but not on top. If you look close at the pic you can see the box on the top of the A. It should be flat across the top, but it is V shaped. The boxes on the bottom legs of the A are perfect. The M is doing the same thing. The 2 top boxes on the M is v shaped and the leg boxes at the bottom are perfectly square. It's bizarre.  I sent my program to Visual mill and they say it's perfect, got to be some other issue.  Right now, I am able to still make these samples, but what I have to do after it is cut is jog the bit with my mouse into the top square and carefully buzz across the top of each box to clean and square it up. It's not easy, but it works, and it sucks having to do it.

46

General Mach Discussion / Re: controlling my speeds

« on: October 19, 2011, 01:06:25 PM »

Interesting. How do you sync to the A part diameter?

47

General Mach Discussion / Re: controlling my speeds

« on: October 19, 2011, 10:40:25 AM »

I am cutting plastic rod. I figured out the PWM issue. Right on the very last page, troubleshooting in my mill manual. I needed to change motor control. It was 500 and 15%, I needed to change it to 500 and 0%. Since then, no more PWM error.  Things seem to be working much better now.  I did not change any of my programming speeds. The tiny bit is cutting great at those speeds. I actually think it can handle more, but when I bump my speeds, the rotary table speed does not increase. I think it's just a slow table, does like 1000 degrees per minute..seems to me though that is faster than what it is doing. No doubt i'll get that worked out. Right now I have to figure out what's going on with my software. I'm cutting like a letter A and an M and both letters have a box at each corner. The boxes at the bottom of each letter is cutting out spot on perfect. The boxes at the top of each letter are cutting out perfect except for across the top of each box is not flat it is V shaped. It's strange. I had to do a manual clean up jog across the top of the two letters to clean them up.

48

General Mach Discussion / Re: controlling my speeds

« on: October 18, 2011, 12:59:57 PM »

oh..also, is this the reason that the PWM error kicks on..I am asking the machine to move too fast?

49

General Mach Discussion / Re: controlling my speeds

« on: October 18, 2011, 12:58:26 PM »

ok..what kind of speeds would you choose?

50

General Mach Discussion / Re: controlling my speeds

« on: October 18, 2011, 10:35:51 AM »

The x does not fly away, it just flies across the piece super fast. It is doing the correct cut path, just at sonic speed, the A is slow. When they work together, there's no problem, it's just when the x moves in a straight line without needing a that the speed jumps way up. The code does set the radius of the piece being cut. Everything is actually cutting perfect, it's just when that x axis has the opportunity to do a cut without combining with a then she speeds way up.  When combined with A it's way slower than i'd like. I need to find the happy medium.

Maybe this will help.  Here is my motor tuning settings

Steps        Velocity            Accel

x 10160     31.158            31.158

Y 10160     100.02           12

z  10160      129.42          50.5

a  400           1000        1000


My software Settings from Visual Mill 6 for cutting 3 letters on a tube, 4 axis pocket

Bit is 0.024

Plunge 25 in/min
Approach 25
Engage 22
cut 17
retract 25
depart 26

Total cut depth is .07
 Finish Rough depth is .056 and finish depth is .014
Rough depth cuts are .0224    <but that's what it's supposed to be.  The machine is cutting right now and each layer is not .0224, it's cutting layers at .0117 for whatever reason I don't know.