Hello, I recently dipped my toe into CNC by purchasing a TEP milling machine. It cost me very little and although after stripping it down and building a z axis it would have been easier to start from scratch, it did give me a good basis.
The driver running the machine is a TB6560 3 axis driver - one of the cheapo chinese blue circuit board. I`ve had it running with both Mach3 and EMC2. Last week I managed to cut two nice little door signs with it and recently did an engraving.
During the last week I`ve stripped the machine to do some mods and in the last few days got it back together. However, I just can`t get my head around the fact that the movement is well out of sync! Just a simple example, say I draw two ovals concentric to one another, they will end up overlapping and even with little flats on them instead of nice curves!
The wierd thing is, I get the same results one both Mach3 and EMC2... so either I`ve got a setting wrong in the software on both or something is wrong with the TB6560 driver?
I`m sure it was working OK just last week and so after nearly a full day trying to correct it today, any thoughts or suggestions would be helpful...I`m totally out of ideas!
What you are encountering are missing steps. The Blue Tb6560 based cards are notorious for missing (dropping) steps. Search/find the thread on " how I fixed my tb6560 " for how to resolve this, pictures included.
The optical isolators, the 4 legged chip with PC817 writen on them are part of the problem. The solution is removing the step and direction optos and replacing them with wire jumpers, staples, what ever you can jumper with.
The design of the card is terrible and the optos, apart offering little protection, are causing a timing issue, hence the dropped steps.
There are a series of modifications to make the card work bettre and faster but simply removing the step and direction optos for each axis and jumpering in the proper manner should resolve you issue.