2014. június 30., hétfő

Hackaday.io

Just a quick note, because I don't really have to much time to advance my projects, it is World Championship time.
I started to publish my things to an other place also. To the hackaday.io.
Here are my things. It is in early stage:
http://hackaday.io/projects/hacker/6962

2014. június 19., csütörtök

CNC Improvement 1. - project kickoff

I bought my CNC router. There are usable things starting to come out from it. At the same time I feel the problems of it. I found many things online to improve it and I have additional ones in my head, what I want to resolve.



The planed changes
Fan exchange
The current one is noisy. I know, when the machine runs it can't be heard, but when it is in standby it's noisy. It bothers me. Acquired one with magnetic bearing.
PSU exchange
I found an article online. The integrated PSU is quite weak. Therefore they exchanged it to a switching one:
http://lab.whitequark.org/notes/2014-05-29/cnc3020t-switch-mode-power-supply-conversion/
On the other side this solution is dangerous. The mains supply left freely touchable what is totally unacceptable. The PSUs are going to a separated enclosure and will be connected to the control box with a similar connector like the steppers.
Spindle control
It looks like the controller would be able to control the rotational speed of the spindle motor from software. This is not connected. The current solution contains a manual switch and a potentiometer, what is a joke. I hope that the surgery can be done based on this:
http://lab.whitequark.org/notes/2014-02-12/cnc3020t-emc2-configuration-and-hidden-features/
Axis end switches
Based on the previous, it is possible to that all of the axises got an endswitch. If I'm not wrong, besides  cables, connectors a microswitches nothing needed.
PCB probe
If I make PCB on the router the leveling of the workpiece is crucial. Why? Because the planed 100um milling depth not tolerate to much error. This can be handled with a probe:
http://www.autoleveller.co.uk/cnc-probe-guide/
If I'm right the controller has input for it, just need to be try it out and maybe create one what suits to my needs.
I've a further question need to be answered about the last three points above. Will it fits into the parallel port pins? Instead of the machine in the article I've a 4-axis machine what needs more pins.
Spindle
I'm not satisfied with the performance of the spindle drive. The engine rated to 230W and I already experienced sticking while working deep in wood. It maybe caused by the insufficient power sourcing, but maybe this engine is just not powerful enough.
In preparation to the engine exchange I ordered a 600W PSU because the price difference was acceptable. If I need to exchange the engine I can use a maximum 400W one. Unfortunately the motors more powerful than this has a bigger diameter. The motor holder was milled from one piece together with every moving parts of the Z-axis (extruded linear bearing + ballnut). I want to avoid the change of the whole Z-axis because it lead me to build a bigger/stronger machine.
Tachometer
During the work it would be nice to see the rotational speed of the spindle. I was thinking to pick one of my frequency counters and use it. The question is what would be the sensor. Most probably I'll create some kind of optical encoder, just I've no idea where and how can I lock it.

This is all for now. Be continued...

2014. június 12., csütörtök

UV Lightbox 16. - Woodwork continues

After the struggling of the past period, I continue some of my abandoned projects like the UV lightbox.
Thanks to the CNC router here are the holes on the backplane:


Ready for lacking:


After the first layer: