Messages

11

Show"N"Tell ( What you have made with your CNC machine.) / Re: Help/Advice

« on: July 10, 2013, 06:20:09 AM »

The Screen Set should make no difference at all when machining I use a different Screen Set to the standard 1024 that comes with Mach and as for measuring the tool after the roughing cut the machine auto measures the tool so that it start in the correct place and at the correct depth so I have no need to use paper / feeler gauge etc. and my finishing cuts are normally around 0.0200 mm (0.0007873992 inch) and on the few occasions a little more.
Thanks for your input.
Alan

12

Show"N"Tell ( What you have made with your CNC machine.) / Re: Help/Advice

« on: July 09, 2013, 04:13:14 PM »

Thanks guys I know that it is not in the software it is something on this machine it is just finding it, I might well strip down the "Z" axis and remove the 5 axis head unit and fit the spindle motor direct onto the "Z" axis and see if that does make any difference not sure why it would but it is something to try and if all else fails I shall totally rebuild the gantry again but in a slightly different way.
Again thanks for everyone's response.
Alan

13

Show"N"Tell ( What you have made with your CNC machine.) / Re: Help/Advice

« on: July 09, 2013, 12:12:29 PM »

Brett
here is what you asked me to machine it is just under 1/2 inch deep and it has come out without any lines or marks anywhere so what does that tell you about the problem??
Alan

14

Show"N"Tell ( What you have made with your CNC machine.) / Re: Help/Advice

« on: July 09, 2013, 11:51:19 AM »

Am using Raster finish tool path, the grooves always seem to be in or around the same area no matter what angle I machine parts from, the parts in the pictures are machined at an angle of 90 degrees, at the moment I am machining what Brett has asked me to do which is machine a pocket into the same shape (Oval) using the same tool, I am in agreement with you on Aspire that is for sure not the problem the problem does lie within the machine somewhere but do not know where else to look at the moment hopefully when I finish machining this part Brett might have some idea.
Thanks
Alan

15

Show"N"Tell ( What you have made with your CNC machine.) / Re: Help/Advice

« on: July 09, 2013, 10:36:47 AM »

Have just started machining will post a picture once it is finished
Alan

16

Show"N"Tell ( What you have made with your CNC machine.) / Re: Help/Advice

« on: July 09, 2013, 08:56:25 AM »

Hi Brett
machine does move exactly the distance programmed i.e.if I ask the machine to move 1" inch it moves 1" inch and that is the same for the "X","Y" an"Z" axis , am a bit busy at the moment but will then machine up as you have requested, do you want me to use a ball nose or end mill cutter?
Alan

17

Show"N"Tell ( What you have made with your CNC machine.) / Re: Help/Advice

« on: July 09, 2013, 08:25:41 AM »

Thanks for your response Dave as I was just about to write the same thing, if you were to put a dial gauge you could move all the axis and spindle especially if I were to use a prybar I am afraid that the only thing that I would use the prybar for is to smash the machine (joking) as for reinforcing the machine at the points you have marked (Craig) I was already looking at doing this, but the gantry is very solid and believe me I have pushed very hard at where the connections are but I will reinforce it anyway just to make sure.
Thanks for the input all ideas and advice taken on board it is very much appreciated.
Alan

18

Show"N"Tell ( What you have made with your CNC machine.) / Re: Help/Advice

« on: July 09, 2013, 03:58:16 AM »

Thanks
for all the response much appreciated, Gerry why do you say that the machine does not look rigid?? the frame of this machine weighs around 1/2 ton and is as solid as it could be and the sides and the gantry etc. are also very solid! just a bit curious about that, the tool path is a 3 axis was I can see now a bit confusing saying that it was a 5 axis machine, I do a roughing tool path and then a finish path and the finish path cuts at a depth of 0.5 mm (0.01968498 inch) the tool is new so there is no damage to that as for feed rates etc. I have been down to 75 mm (3 inch) per minute makes no difference as for step over have not been quite as low as 5% been down to 8% but will try going lower and see what happens, you make a comment about flex where might this flex be? I can run this machine at some 8 meters (26 feet) a minute and there is no flex/movement anywhere that I can see at that sort of speed not that I ever have or would try and machine anything anywhere near those sort of speeds what I am saying is that if I am not getting any flex/movement at those speeds then at the speeds that I use which for large areas of roughing I might at times go up to 1500 mm (59 inches) per minute and finish speed of 700 mm (27 inches) per minute then I certainly should not be getting any flex etc. anywhere, the gantry and all axis move as smoothly as can be no juddering or jumping around it never loses steps, so can you give me some idea as to where I should look for flex? the spindle motor again there is no vibration or run out it does not lack power (4 Kw - 5 HP) in fact it is way over the top for my needs really, anyway if all else fails I will do as you say and put it over on the Vectric site.
Thanks to everyone.
Alan

19

Show"N"Tell ( What you have made with your CNC machine.) / Re: Help/Advice

« on: July 08, 2013, 05:27:03 PM »

Hi Brett
I have done as you asked checked backlash etc. found no problems there and again done as you suggested machined  a piece of wood (Oak) then sprayed it back and then re-machined taking off just 0.0200mm (0.0007873992 inch) and you can see the problem with the lines are just top and bottom not sure if that tells you anything that might help?? and because it is a 5 axis machine I did also check that the tool was running vertical etc.
Thanks
Alan

20

Show"N"Tell ( What you have made with your CNC machine.) / Re: Help/Advice

« on: July 08, 2013, 03:43:31 PM »

Software used is Vectric Aspire4
Thanks