Hi folks,
I'm setting up a RASA 11V2 and wondering what autofcusers are working for you. Thanks in advance for your input.
Dave
I'm setting up a RASA 11V2 and wondering what autofcusers are working for you. Thanks in advance for your input.
Dave
Focuser for RASA 11V2
Hi Dave, I have the V1 RASA11 and a ZWO EAF. There are about 100 motor steps covering the CFZ in seeing of 2.0 arcsecs (5% focus tolerance, NCFZ formula). If NCFZ is new to you, you can google New Critical Focus Zone for the formula... I find the EAF works great, even though there is some backlash when switching directions (about 85 counts). I prefer to focus consistently inward to conclude a focus run to avoid that, but there are other options (like just adding a pre-offset count if you are switching directions).
CS Doug S
https://app.astrobin.com/u/dmsummers
CS Doug S
https://app.astrobin.com/u/dmsummers
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Thanks Doug. So it looks like for the EAF you need to replace/ add on to the stock RASA focuser , a feathertouch somehow? Is that what you did?
yes, you need to remove the stock outer knob and then connect (via set screws) a spring like bushing to the focuser drawtube (tel side), and to the EAF motor shaft. There's a bracket to hold the motor as well. The procedure for this was straightforward enough (and there's instructional material that can be found on the web or in the EAF document).
I have the Pegasus FocusCube Zero (for SCT) on my RASA 11 v2. Works really well. Very similar to the EAF (I have one on another rig). As above, there is a bit of backlash with the USFS. I use NINA and have "overshoot" set in the autofocus settings.
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I have the Rasa 11 V2 and use the Celestron focus motor, works fine !
CS,
Miguel
CS,
Miguel
Thanks again everyone for your input on this. I finally decided to go with a Starlight Instruments feathertouch to which I connected an Optec FTX20 stepper (image attached). It’s working great so far. 👍️
Dave
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