2 Attachment(s)
Re: Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet
Thanks Chaz. Sometimes the right job needs the right equipment to get the consistency and overall quality. These units are also now made in the correct material for the job, so anodising is now a realistic option should that path be looked at again.
Jogara should be given a lot of credit to be frank. He has done pretty darn well considering nearly everything has been stacked against him. 10 out of 10 for bravery and perseverance.
This the next lot being machined.
Attachment 24564Attachment 24565
Re: Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet
Quote:
Originally Posted by
JOGARA
Been a few months. Thought I would update this car crash of a thread with a little something.
As some of you have seen already, I farmed out the work. Glad to say that it has gone really well and has actually save a lot of my time and was totaly worth it.
@JOGARA, a big thank you from downunder where I have thoroughly enjoyed following your thread, and have learnt loads from it.
Cheers,
Andy
Re: Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet
Usually these things are die cast but I guess volumes are low?
Anyway beautiful work spluppit ! Can’t beat shiny fresh cut aluminium.
Re: Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet
Any ideas on how to square the gantry?
I need to do some pretty accurate circles in a week or so. Just cut a 22mm hole for a carbon rod and the circle is oval...
Re: Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet
Sure that’s not due to backlash?
Other than improving the backlash situation, the only answer to that is backlash compensation in the control software.
To square the gantry the best I found was to drill 2 holes for precision dowels in the y axis and butt a precision square up against it. I then run a dial indicator along the edge in X axis, and then loosen the gantry bolts and smack it with a mallet until it’s as square as I can get it. You won’t get it perfect as the gantry isn’t completely flat.
Re: Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet
Quote:
Originally Posted by
Zeeflyboy
Sure that’s not due to backlash?
Other than improving the backlash situation, the only answer to that is backlash compensation in the control software.
To square the gantry the best I found was to drill 2 holes for precision dowels in the y axis and butt a precision square up against it. I then run a dial indicator along the edge in X axis, and then loosen the gantry bolts and smack it with a mallet until it’s as square as I can get it. You won’t get it perfect as the gantry isn’t completely flat.
Could well be backlash.
I just measured it again and my 22mm diameter is 0.04 under in the Y and 0.14 under in the X.
It is pretty close but next week I need to do a 190mm diameter hole and close fit a bearing in it.
Yes I am using a caliper... Need a bore gauge.
It is not as off as I thought but if I can get it close as possible, would be less nervous about the big part.
Re: Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet
What Zee said although also indicate along the Y also to make sure you have the square square.
That’s a big bore and a tight tolerance for a machine like that. Good luck.
Re: Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet
Quote:
Originally Posted by
JOGARA
Could well be backlash.
I just measured it again and my 22mm diameter is 0.04 under in the Y and 0.14 under in the X.
It is pretty close but next week I need to do a 190mm diameter hole and close fit a bearing in it.
Yes I am using a caliper... Need a bore gauge.
It is not as off as I thought but if I can get it close as possible, would be less nervous about the big part.
You can't measure a bore with calipers and believe that 0.04mm measurement or even the 0.14mm for that matter..!! . . . Only a bore gauge can do that with any accuracy.
Also, it's not just the gantry squareness you need to worry about, the spindle tram and parallelism of the rails all come into play and I know for sure that these machines are not good enough in either of those areas to machine a bore that size to any decent accuracy.
Re: Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet
Hmm
Built a new enclosure for the machine. This meant I disconnected the PC and moved it for a sort time while I built everything.
Put it all back together and now the CNC stutters. :joker:
https://www.youtube.com/watch?v=3GlH5yDGhRc
[edit]
It looks like turning the backlash toggle off stops this...
The machine earlier did lose a load of steps though and fked up my part -_-
[edit 2]
Now getting that "Is the Xpod inserted OK? it has ceased to respond..." error again god dam it
Re: Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet
Surely if you are looking at a bearing fit , then bore micrometers are what is needed.