Last night I achieved first light of sorts.
After fine tuning the polar alignment, using a broomstick as a crowbar for nudging the pier supports, I went on to tweak the collimation and finally I even did a bit of lunar imaging.
It wasn't smooth sailing though. The mount in this configuration is much more prone to vibrations and resonances. I was driving the RA axis with an Arduino Uno/DRV8825 and getting vibrations that were interfering with the imaging.
Once I changed from 1/16 micro stepping to 1/32 and adjusted the current draw, things were ok, but I will need to do some vibration dampening work.
I'm afraid, this it is the only way for me to space travel. I was born 50 years too soon, otherwise I would be lining up to get on Musk's Starship.
Quote:
Originally Posted by Joshua Bunn
Thanks fir the updates, Stefan. I'm enjoying following. Crisp capture of the moon!
Thanks Josh, it was a difficult capture as I was only able to correct the RA drift and the Moon drifts in both axes. I have ordered a cheap CNC shield that I will write some code for, and I will be able to make DEC corrections too. On the longer run, I will use a OnStep controller, just at the moment I don't feel like sorting out the multitude of versions that exist.
Quote:
Originally Posted by Andy01
Very impressive first light Stefan, I imagine the results will be spectacular once you've sorted out the remaining niggles.
Thanks Andy, the main niggles will be with the recoating of the primary mirror as my vacuum chamber can fit max 10" mirrors.
Looks really impressive Stefan. Despite your concern about remaining niggles, the Moon image looks terrific. I’m looking forward to seeing more images from it.
Looks really impressive Stefan. Despite your concern about remaining niggles, the Moon image looks terrific. I’m looking forward to seeing more images from it.
Rod
Thanks Rod,
I posted another image, from the same night, in the solar system section.
I also found a mistake in my Arduino code that was contributing to the drift in the tracking.
This this is Philip, with the binoculars. Thank you for help on the day and for showing me your scope.
As I said, looking very good indeed!
I expect you are well aware of this, but, just in case, you should set the current limit for the stepper motor on the driver.
A link showing this is here, about 3/4 down the page.
Have fun
Philip
Thanks Philip, yes I have been using the DRV8825 drives for a while on my DIY engraver, with the same CNC shield. With the small NEMA17 motors I set the current limit just a bit above 1A.
Quote:
Originally Posted by Joshua Bunn
Nice Stefan,
Is this a manual machine to CNC conversion?
Josh, this CNC shield is open source, and it is used for all sorts of DIY engravers and 3D printers. The firmware for CNC control is available from the GRBL website. I am writing my own firmware for the telescope control.
