looks great :)
Printable View
looks great :)
That is definitely a great success. The cut looks very nice. Chamfer also needs a finishing pass. Same like normal side milling. I am almost sure you did not do that? So no real reason of disappointment. 0.05mm or 0.1mm will do the job next time. Also workpiece needs to be tightened to bed very strong.
You are correct, I did not do it. Lesson learned again. Thanks Boyan!Quote:
Originally Posted by Boyan Silyavski
Hi guys!
I have an issue with my machine.
Please look at the pictures.
Outside dimension should be nominally 50.00mm and inside 30.00mm.
Same toolpaths with finishing pass.
I use Fusion360 for cam. Mach3 for controller. Probably messed up settings/offsets somewhere?
https://uploads.tapatalk-cdn.com/201...69e56519eb.jpg https://uploads.tapatalk-cdn.com/201...84e136302a.jpg https://uploads.tapatalk-cdn.com/201...2cc7fdf15e.jpg
What cutter are you using, and how accurate do you believe it is?
I normally use single-flute cutters, and my experience is that they tend to cut as if they are slightly smaller than their marked size. For example, I get pretty accurate results from my nominal 6mm cutter if I specify it as 5.7mm in my CAM software.
I spent a lot of time chasing this kind of inaccuracy and whatever tests I did, the machine seemed to be pretty good. However, when I cut a simple test square and measured it, the size was always wrong. Now, I do a quick test with every new cutter to work out its "real" diameter. The problem is that you cannot just measure single-flute cutters. Maybe they are just cheap cutters and no-one else seems to have this problem, but this is the only way I can get accurate, consistent, results.
Looking again at your measurements, though, I'm not sure that this is the case here. If, for example, the cutter were cutting 0.3mm undersize, the internal dimension would also be wrong (29.7mm). Similarly, a scaling error would also see errors in the internal dimension. Maybe it's something silly like using an offset in the CAM settings for the external cut? Or did you forget the finishing cut? Sorry if this sounds rude, but sometimes the answer is a small error that you have made and you only find it when you show it in public! That is something that you might find if you examine the gcode.
I use 2 flute 6mm cutter from sorotec.de.
Inside measurement is spot on. Thats the reason I can not blame the cutter diameter? Or am I missing something?
I think this kind of problem has been there from the start. But now I recalibrated all my axis with Mitutoyo digital indicator and all is repetable within .005mm (i dont claim the machine to be that accurate) First axis calibration was with digital caliper which accuracy cant be trusted below 0.02mm. So now I see this strange variation.This part X and Y measurements with caliper dont vary more than 0.02mm.
I've just made an edit that you might not have seen. Yes, it does look like an offset problem in the CAM settings for the exterior cut. Can you go back to your F360 operations and double-check?
For Compensation Type I use In Computer.
Attachment 23593
I will try other options today - will try changing tool offsets in Mach3.
Although I have been using my machine for a year now, I am quite clueless about G-code :( If I need something to change I always go back to CAM and repost...
For faster/better workflow I should compensate in Mach3 I guess.
For roughing passes I leave 0,5mm stock which is default by F360.
Im not good at this stuff, but just a thought..
Do you get the same error in the rough cut?
Skickat från min SM-G955F via Tapatalk
I will measure in the evening. I use adaptive cuts for roughing out - little circular cuts with 2,4mm load. But I guess I should be able to measure 0,3mm. Will try.