This is a long thread about my latest, fairly small project, which some of you might have seen already elsewhere, but I thought I will show it here also. I will start with a bit of a history...
My machine is nowhere near as nice or heavy as many others have built, but I don't feel I have to be ashamed of it, I built it completely on my own, cut and drilled, threaded almost every bit of it by myself, so all in all, I am pretty proud of it. Especially since I am an "office rat" engineer since the last 30-ish years. At work I never have to use any other machine than a computer, and even that only through the keyboard. Never the less, I miss my first 15 years of working life, not only because I was MUCH younger, but also because I do like to use my hands and brains in many ways, so at home and as a hobby, I take every opportunity to get my hands "dirty", do some practical engineering and so on...
So, to cut the story short, I built this CNC, driven of course with CNC drive products, initially only with a UC300USB and Mach3, but since several years with UCCNC plus UC300ETH. OK, to be honest, really initially I used parallel port and Mach3, but that was a hundred years ago... and I quickly realized that it was not the future. This is how my CNC looked like just a few weeks ago.
I built this a few years ago, and use it mainly for plastics and PCB, but also mill some aluminium on it, so for my needs the machine is definitely good enough. From the start I kept track of the weight, but as time went by, the machine got heavier and heavier after all the modifications I constantly made. I knew it was heavier than 100kg, but not more exactly. The other day I managed to check it more precisely by placing two ordinary bathroom scales under it, just for fun. One showed 60kg, the other showed 67kg, so now I know that the total weight was 127kg, which explains why it was more and more difficult to move it around. I noticed this "problem" some months ago when I moved to another, much larger room in my house. This was the way I had to do it:
I had to lower the round black feet on all four corners to lift the machine, remove the wooden blocks the machine normally was resting on, raising the black plastic feet to lower the machine on the four castors, move it to the new place, lift it again, place the wooden blocks under it and lower the machine on those. It was a complicated, back breaking operation, which actually put me off from doing any improvements and modifications. So I decided to do something about it.
What I did was I ordered four linear actuators, installed castors on them and installed on the four profiles acting as CNC feet. This is a short video about that activity
[youtube]https://youtu.be/4sUEEOjzpeg[/youtube]
Each linear actuator can lift 152kg, so I knew I had good margin. The only thing I am not that happy about is that they extend to three different lengths, only two are the same, but in this application that is not critical, all extend by about 50mm which was what I needed.
I made a simple, but over-engineered, control box with some relays, a switch and three LEDs to control the actuators.
Even that part is documented in a video.
[youtube]https://youtu.be/aB5bX-nn4K4[/youtube]
The control box itself is of course been engraved on my CNC. I am not extremely proud about the looks of it, but this wast the first time I made this sort of engravment, so maybe the results are excusable.
This project is finished. Now it is easy to move my machine around, just flipping a switch and that lifts the machine with the wooden blocks permanently attached under it's feet. No more crawling on floor for a simple move. Yesterday I swapped out the PSU to a more powerful one and released the last part of my video series about it.
[youtube]https://youtu.be/p-EtlIY0Zb8[/youtube]
The new PSU was necessary because the current use was too high for the 7A PSU I initially chose to use. I was not sure about how much current is needed, and was a bit naive, thought that since my CNC is far below of the maximum load, I would need far less than the maximum current, but that seems to be the case only for "normal" operation, which is starting from zero load, i.e. when the linear actuators are fully up and the castors are dangling. From there I could drive the actuators to full extension, but if I stopped before, I could not restart. When the CNC was resting on the castors I could not restart to push the CNC further up, because the load to start from that position was just too much for the 7A PSU so the PSU just stalled, no movement. In that situation I had to lower the machine completely and restart from there. This I though was not very safe. Imagine if my toe gets caught under one of the CNC feet and there is no way to change direction, meaning I have to lower the CNC fully on my toe before lifting it up again... not good for my future... so I changed to the 82A 12V PSU I have and with that it can be stopped, restarted or instantly swap direction any time I want to.
Anyway, I am now ready, it works well and no regrets, would do it again if I had to. Yes, it is over-engineered, but it was fun and I really like this solution to a fairly simple problem. It's really cool in my opinion and hope it inspired a few people, so thumbs up for me.
Edit: I don't understand why the YouTube links are not working in this thread. Strange...
