Hi
I have built another focuser using a nema 17. my previous uln2003 has been great but the backlash can be troublesome and the weight of various items is putting it under strain. however one thing about the little motor is its very quiet! the nema17 however omg it will wake the dead let alone my neighbours!
it is quieter if I run 1/8th step and also different if its in slow mode but still not silent
is this just the way they are?
do the tmc driver boards make them quieter?
many thanks
Dave
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Hi Dave
Yes they do run a bit louder, but most of the current is set too high.
You can always put one of these so there is a cushion between the stepper motor and the telescope
Goin to 1/8 is a bad idea. The torque is significantly reduced about 30% for each reduction in stepmode. So at 1/8th is a lot less than at full.
And at 1/8 you have to run with coil power on, else every time you move the stepper motor, you motor can lose up to 7 steps when coil power is turned off after a move. That means you will run into the position of the focuser keeps changing, and maxstep will quickly invalidate, Its noticed over several nights, where best focus is say 5127, then a few nights later it has moved by 50 points, and keeps moving every night till a month later is off by 1000+ steps.
Better to do the maths again and goto a Planetary Geared stepper motor. That way the motor runs at full steps, get maximum torque and no slippage. Only downside it the weight which makes things a little more difficult to balance. And they are a bit quieter.
TMCxxxx
My advice is dont bother. They are difficult to configure and get going, even more so with Stall guard, I just do not have the patience to set those up.
The mount slewing is around the same as the noise from the stepper motor, from memory the older cg5 mount was pretty noisy. And if you are imaging, then the focuser is not winding itself in and out all the time because autofocus is by small amounts during an imaging run (NINA) . So the duration of the noise of the stepper is much less, and its not winding itself to 0 and maxstep all the time.
Regards
Robert
Plse forgive the thought train jumping around, I'm deep in the rabbit hole trying to rewrite all parts of code for the focuser, and that keeps breaking my train of thought.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hi
I have built another focuser using a nema 17. my previous uln2003 has been great but the backlash can be troublesome and the weight of various items is putting it under strain. however one thing about the little motor is its very quiet! the nema17 however omg it will wake the dead let alone my neighbours!
it is quieter if I run 1/8th step and also different if its in slow mode but still not silent
is this just the way they are?
do the tmc driver boards make them quieter?
many thanks
Dave
Hi Dave
Yes they do run a bit louder, but most of the current is set too high.
You can always put one of these so there is a cushion between the stepper motor and the telescope
Goin to 1/8 is a bad idea. The torque is significantly reduced about 30% for each reduction in stepmode. So at 1/8th is a lot less than at full.
And at 1/8 you have to run with coil power on, else every time you move the stepper motor, you motor can lose up to 7 steps when coil power is turned off after a move. That means you will run into the position of the focuser keeps changing, and maxstep will quickly invalidate, Its noticed over several nights, where best focus is say 5127, then a few nights later it has moved by 50 points, and keeps moving every night till a month later is off by 1000+ steps.
Better to do the maths again and goto a Planetary Geared stepper motor. That way the motor runs at full steps, get maximum torque and no slippage. Only downside it the weight which makes things a little more difficult to balance. And they are a bit quieter.
TMCxxxx
My advice is dont bother. They are difficult to configure and get going, even more so with Stall guard, I just do not have the patience to set those up.
The mount slewing is around the same as the noise from the stepper motor, from memory the older cg5 mount was pretty noisy. And if you are imaging, then the focuser is not winding itself in and out all the time because autofocus is by small amounts during an imaging run (NINA) . So the duration of the noise of the stepper is much less, and its not winding itself to 0 and maxstep all the time.
Regards
Robert
Plse forgive the thought train jumping around, I'm deep in the rabbit hole trying to rewrite all parts of code for the focuser, and that keeps breaking my train of thought.
Ok Bob I do have a PG27 to try so I will give that a go and see how it is.
keep up the good work :)
try these, I use them on a lot of different projects
https://www.aliexpress.com/item/32811401993.html
well!
I got this working!
and its totally silent!
awesome!
picture of controller