Messages

71

General Mach Discussion / Re: Abnormality (Exact stop vs constant velocity)

« on: July 19, 2007, 06:11:55 AM »

looks great Ashby, I'm impressed. I took a sneeky peek inside my unit then closed it up fast. waaaay too complicated for me.
Cheers George

72

General Mach Discussion / Re: Near crash

« on: July 19, 2007, 06:00:17 AM »

Thanks for that Jim. This programe was written automatically by lazycam. I did a dry run on the screen and thought yip that looks like the right shape. When I ran it in anger the tool moved in the correct sequence most of the time ie( lift, rapid, drop ) no problems but one time it went (rapid,lift,drop) and I dont know why. It was quite a complicated shape (lots of blended curves)  with hundreds of lines of programe and I did have to up the connection tolerance to get the pocket to work. Do you think this is where the error has come from?
cheers George

73

General Mach Discussion / Near crash

« on: July 18, 2007, 02:46:15 PM »

Dear All

I am new to cnc and still on a steep learning curve. Today I produced a pocket with island using Autocad 14, loaded it in to  Lazycam pro 2.08 then ran it with Mach 2.065. All was well until near the end the cutter did a rapid speed through  the workpiece. Thankfully I was using a soft plastic so no harm was done.

N1050   G0
N1055   X225.7769  Y35.6699
N1060   Z10.1
N1065   G1 Z-1.000 F50

It looks to me as though Z10.1 needed to be before the G0 command. The programme did several repositionings prior to this without incident.

 Am I doing (or not doing) something stupid?. Is this a common error I need to be aware of.?

Any help would be greatly appreciated as my underpants can only take so much trauma

Cheers George

74

General Mach Discussion / Re: Abnormality (Exact stop vs constant velocity)

« on: July 18, 2007, 05:14:22 AM »

Hi TP
The tapping head I have got is a Tapmatic SPD5 which doesn't have a clutch and has a gear ratio of 1:1 ie same feed out as in. I know what you are saying as the catalogue shows that alot of the clutch models have a ratio of 1:1.75 and withdraw at just under twice the speed. It was the Tapmatic instruction manual that recommended the use of G85 or G01
for control. I have found the G01 method works however I am new to the world of cnc and not very good at manual programming.I can't afford an expensive CAM package. Thats why Lazycam seemed like an answer to my prayers.

Cheers George

75

General Mach Discussion / Re: Abnormality (Exact stop vs constant velocity)

« on: July 17, 2007, 05:21:13 PM »

Hi Bob
yes that works on my system when I follow Williams suggestions, but it doesn't work at the drilling phase G81 (not that it matters for drilling) and the partmaster programe uses G01 for the tapping portion. I wonder if it has something to do with the canned cycles?

Has anyone else noticed the same?

76

General Mach Discussion / Re: Abnormality (Exact stop vs constant velocity)

« on: July 17, 2007, 11:47:48 AM »

Hi William,
Tried that but no change. as soon as the programe reaches either G81 or G85 it still knocks off cv mode.
The programe was created using lazycam as two drilling operation then manually editing the second from G81 to G85.
Will this have an effect?

Any thoughts anybody!!!!

77

General Mach Discussion / Re: Abnormality (Exact stop vs constant velocity)

« on: July 17, 2007, 04:17:02 AM »

Thanks William
I'll give that ago today and let you know how I get on.
Cheers George

78

General Mach Discussion / Abnormality (Exact stop vs constant velocity)

« on: July 16, 2007, 02:44:18 PM »

Dear All

I have just purchased a tapping head which has a geared ratio of 1:1 (ie same feed going in as withdrawing). Tha manual recommends programming using G85. This works to a point except it chatters on the way out. The trouble shooting guide says the problem may be due to the fact process not using constant velocity mode. I have altered the general config file to cv mode but during the process it always reverts back to exact stop.

Does anyone have any ideas on what is controlling it?

79

G-Code, CAD, and CAM discussions / Tapping using G85

« on: July 12, 2007, 04:52:01 AM »

Dear All
I am new to the cnc world and am still finding my feet. I have just puchased a Tapmatic tapping head SPD5 which has a geared ratio of 1:1 . Want to use tapping head rather than rigid tapping as I want to reduce wear and tear on machine
as it is a small benchtop model (wabeco 1210). As the feed for this unit needs to be the same going in as out the instruction manual recommends programming with G85. When using lazycam I have treated the drawing as 2 drilling operations then I manually edited the second drilling operation from G81 to G85. This works to a point. Except there is a small amount of chatter on the way out. The trouble shooting guide says this problem may be due to the fact process not using constant velocity mode. I have altered the general config file to constant velocity mode but during the process it always reverts to exact stop. (the backlash is not enabled and cv less than angle is not enabled) I have tried the program by modifiying the program to use two G01 lines and this works but this method is a pain when there is a few holes . I liked the sound of LAZY cam for a reason. My two questions are A) Is there an easier way of using the tapping head via lazycam that I don't know about?   B) Any ideas on what is controlling the constant velocity mode?
Cheers George