I am prepping my AR152 achromat as a narrowband imaging rig. I am preparing to order a Sesto Sento 2 for her to wear, but wanted to check fitment before I did so. Here, I ran into a slight snag. Once having removed the fine focus knob, I do not see a means to remove the coarse knob.
When the fine knob is removed, a grub screw is exposed on the side of the coarse knob. Upon loosening that, I can detect no new freedom of movement in the coarse knob that would suggest that this is the proper course of action. Reasonable application of force yields no progress here.
I also see a pair of slots in the side of the coarse knob that seem tailored to fit a spanner type wrench. Applying such a wrench here would then seem to remove a threaded cap restraining the coarse knob. I don't know if I'm interpreting this arrangement correctly, and at any rate, do not have a spanner to fit.
I'd like to have some surety before proceeding. I am of some mechanical aptitude, but the answer is not obvious to me.
I am in the capable hands of this group. Have you any thoughts on this?