Once the rough machining is finished, it’s time to finishing.
As the model ends just in the Dm plate, the tool must go down exactly the radius distance of the spherical tool. So I’ve programmed some paths to draw the contour and remove 5mm of DM. In that way, the tool will do the finishing path much more easily without hit the DM. In a finishing machining, it’s better not force the tool.
The spherical tool has a similar length problem, but I have enough distance to not touch the model with all the structure, just less than 1mm, without doubts, this model is reaching to the cnc limits…
Once the finishing is done, it’s time to check measures, and it’s in that moment when something is wrong. With a naked eye, the model is perfect, but the last part of the model has a deviation of 2mm in Y axis… for this kind of work, this mistake is big enough for make the model not valid. What happened??
After a big research, I think that the electronic had the problem, as it’s not the best driver, it’s possible it has loose steps. maybe a few each time, but enough for accumulate them and after 3 hours of machining, in Y axis the error is big enough. This is a big problem, because when we join both moulds, they will have a displacement of 4mm.
It’s clear that the only way to solve this, is to putty all the model again, giving at least 2mm of thickness, and do the finishing programm again.
After some tests, i’m pretty sure that the electronics was the problem, as it was broken two drivers. Definitely, cheap things are expensive. Now, i will not use anymore the TB6560 driver. So I’ve bought the driveer 2M542, much more strong. One month later, I already had it mounted and running.
Start again, put the part in the correct place, and this time I’ve modified the program. Every 300mm, I’ve add some paths to send the tool to the origin, and make a pause. So I will check the alignment and the correct position, so if it’s not good, I can correct without keep machining wrong.
3 Hours later, happily the model was well done, the dimensions are correct, so it seems this electronic is great and works great.
There is only one thing to machining, the positioning holes, and ready
Once the machihing is finished, and as the DM plate will be part of the model, I’ve had to putty the canal along the perimeter, and sand ir very well.
What’s now? sand all the model, polish until mirror surface to get the molds. But this will be other story, I hope to talk about it later!