simond
Western Thunderer
Way back in 2016 I obtained a second-hand K40 laser, and went through loads of shenanigans sorting it out. The story is here if anyone’s suffering from insomnia - https://www.rmweb.co.uk/forums/topic/110058-co2-laser-the-learning-curve/
I replaced the dreadful Chinese controller and firmware with a V1 Smoothieboard, which was a learning curve in itself, and amongst other things, built my loco shed and some other bits and pieces.
I tried last week to laser some Trotec floors for the N4 coal wagon project that Magmouse & I are “enjoying” and they didnt fit. Not even close…
Now, there’s a thing about CNC machine tools, they’re absolutely fantastic at doing the same thing over and over again. Indeed, that’s probably their main raison d’etre. Predictable. Reliable. So when none of the above is true, they really aren’t much use at all. Chocolate teapot, well, not even.
The grid above comprises a set of 50mm squares with 10mm lines on two axes. In theory. They’re not square, they’re not equal, etc.
So, the old machine was stripped, fiddled with and finally rebuilt.
that’s better.
whilst I cleaned and adjusted everything, I didn’t find “the problem”, but one of the symptoms was that the Y axis was “lumpy”, it wasn’t smooth.
After dismantling, cleaning and re-mantling, it is now, and my suspicion is that a very small piece of swarf or paper of a dust ball had somehow got to rest on the drive belt. The Y axis drive is a stepper motor mounted on the lower right of the machine. It has a toothed belt pulley directly on the motor, and an extension that runs across to the left side, where there is another toothed belt. These belts run over a pair of idler pulleys at the top of the machine, and keep the carriage parallel. This means that the toothed surface of the belt is horizontal, and given there’s a fairly strong breeze from the extract, I could imagine something just landing in the wrong place.
To add complexity and frustration to the exercise, I discovered that it wasn’t cutting properly. The cooling ring for the tube output mirror had broken off. I had resigned myself to splashing out on a new tube (£80 on Ali Express, £200 on Amazon, £400 + from UK Retailers) but some googling suggested simply gluing it back on. So far, so good. 5-minute Epoxy. Had to stand there holding it for about 8 minutes to be sure it wasn’t going to move when I let go, it’s one way to give yourself pins & needles.
I am considering building a multifunction machine to carry a laser, perhaps both CO2 and Diode, a riveting head, needle cutter and a milling spindle. If I do, it will have leadscrew drives! (And it will be a great deal more accessible for servicing than this thing is!)
best
Simon
I replaced the dreadful Chinese controller and firmware with a V1 Smoothieboard, which was a learning curve in itself, and amongst other things, built my loco shed and some other bits and pieces.
I tried last week to laser some Trotec floors for the N4 coal wagon project that Magmouse & I are “enjoying” and they didnt fit. Not even close…
Now, there’s a thing about CNC machine tools, they’re absolutely fantastic at doing the same thing over and over again. Indeed, that’s probably their main raison d’etre. Predictable. Reliable. So when none of the above is true, they really aren’t much use at all. Chocolate teapot, well, not even.
The grid above comprises a set of 50mm squares with 10mm lines on two axes. In theory. They’re not square, they’re not equal, etc.
So, the old machine was stripped, fiddled with and finally rebuilt.
that’s better.
whilst I cleaned and adjusted everything, I didn’t find “the problem”, but one of the symptoms was that the Y axis was “lumpy”, it wasn’t smooth.
After dismantling, cleaning and re-mantling, it is now, and my suspicion is that a very small piece of swarf or paper of a dust ball had somehow got to rest on the drive belt. The Y axis drive is a stepper motor mounted on the lower right of the machine. It has a toothed belt pulley directly on the motor, and an extension that runs across to the left side, where there is another toothed belt. These belts run over a pair of idler pulleys at the top of the machine, and keep the carriage parallel. This means that the toothed surface of the belt is horizontal, and given there’s a fairly strong breeze from the extract, I could imagine something just landing in the wrong place.
To add complexity and frustration to the exercise, I discovered that it wasn’t cutting properly. The cooling ring for the tube output mirror had broken off. I had resigned myself to splashing out on a new tube (£80 on Ali Express, £200 on Amazon, £400 + from UK Retailers) but some googling suggested simply gluing it back on. So far, so good. 5-minute Epoxy. Had to stand there holding it for about 8 minutes to be sure it wasn’t going to move when I let go, it’s one way to give yourself pins & needles.
I am considering building a multifunction machine to carry a laser, perhaps both CO2 and Diode, a riveting head, needle cutter and a milling spindle. If I do, it will have leadscrew drives! (And it will be a great deal more accessible for servicing than this thing is!)
best
Simon
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