Sure, that sounds ideal. My reason for suggesting we pause the video stream too was to make it obvious to other clients (e.g. if you’re running an experiment from a notebook) that something has happened. Also, I’m not sure there is currently a nice mechanism in the interface for a global status message for the microscope - though I think that would be a helpful thing to have if @jc2450 has a sensible way to implement it.
Yeah adding a modal that blanks out the entire display should be easy enough.
I do worry though like you said about cases where people are using notebooks or something instead of the JS client.
I have motors sitting here powered up and moving about a sample for hours. They are barely warm. I think the timeout may be more of a sticking plaster to cover a problem that is actually about motors.
These little steppers surely should not get hot. If they are I think it best to sort that out as a hardware issue. For the problems @jlauer and @Bogdan have seen, are they just bad batches of motors, or are they driven at the wrong voltage, or are they labeled incorrectly?
They heat up when not moving. When moving there’s actually less power going through them as it’s getting turned on/off averaging about 50% current. When not moving it’s at 100% current.
Moving or not moving, these ones here stay barely warm. Hot enough to burn you sounds as though there is something wrong. I want to do some current monitoring to see what power they are taking.,
I have a step-down converter with a current and voltage display. I have connected this to power the motors only. At 5V with all three motors energised it is 0.57A, so about 2.8W for the three.
Interestingly when x or y motors move it drops to 0.55A, but when z moves it drops all the way to 042A. I shall clearly need to check whether this is a difference in the motor or a difference in the stiffness of the z-axis.
Hi,
Was a solution ever found to the problem of the motors overheating? I’ve built mine with the recommend 5v motors in the build guide and like the first poster, they get blistering hot. Is there a trick to prevent this? I don’t want to have to disable them because the big selling point for me was having it automated for tile images, but it is not possible to operate it for much longer than 30 min without it over heating.
Thanks in advance,
Robert
If you have the 5v version of the motors and run them at 5v they should not get hot. These are very low cost and it appears that one consequence of that is that some batches take too much current and get very hot.
On my setup none of the motors gets hot, but they do perform very differently. One seems to have twice the resting current if the other two, even though the running current is the same.
I think the only real solution to hot motors is unfortunately trying some different items of the same type, but a different batch. Unless anyone has a better suggestion? Or a way that this could be a problem with the H-bridge, not the motor?
It’s just one Darlington pair per motor coil, not even an H bridge! I’d be surprised if the driver was at fault, though it’s easy enough to check by swapping channels, if your motors differ. Re: lower current while moving, there are 8 possible states, alternating between 1/4 and 2/4 coils being energised - I think the reason for lower current while it moves is to do with the impedance of the motor changing when it stops?
I suspect this could be sorted out with current control (rather than simple on/off voltage control) but that would take fancier drive electronics, which usually requires bigger, bipolar motors…