Askar FMA180 / TPO Ultrawide 180 - MOUNT / DEWSHIELD / BAHTINOV by gobo333

Last crawled date: 3 years ago

UPDATE 03/23/21 -
Much prefer BahtMask_1 for performance, followed by BahtMask_3, and then 2.
UPDATE 03/22/21 -
Added 2 variations of the Bahtinov Mask for testing fun (Baht2 & Baht3). Different line widths and angles. These come with segmented collar for easier fit on dew shield.
Updated the Baht1 file to have segments for easier use.
Will update with a Baht performance recommendation after testing in the field.
Updated and added DewShield_2 with segmented collar.
ORIGINAL POST:
Trying to set up an ultra-portable widefield rig for travel using the very compact Askar FMA180 (also rebadged as the TPO Ultrawide 180).
I needed a support ring for the telescope that allowed the entire assembly to rotate for framing, so I didn't bother with a clamp, but settled on a snug slip fit. Note, this is for use with a smaller format ASI Pro cooled camera in the ZWO mount they make.
The dew shield included is short so I have created an extension that also slips on, and is reversible for storage and transportation. Note that I have removed the focus set screw to allow the dew shield to be installed backwards. I found it is tiny and the focuser holds its position fine without it.
Finally, without autofocus I need a Bahtinov mask. This has a fine pattern and is designed to fit over the extended dew shield.
Please see notes on finishing below...