Rockmover

Also, here is part 2 of my video series...I had thought I was doing well....

Ok, Im definitively stuck now and can use some help! I have all the optics installed in the LowSpec. I believe I have the guide scope correctly installed and focused. Basically I set up a halogen lamp, poked a hole in a box, and initially used that for a starting point. At first i put a white sticker in place of the "slit" and focused on that. However, when I focused the guide camera, the slit was not focused at all. So (and maybe incorrectly) I focused the guide camera on the slit and then adjusted the telescope focus. But this doesn't seem right to me? As you can see in the image below with the barcode, the slit seems focused, as does the label in the image. Does this mean the image is properly focused at the slit? Next, if I use an artificial star, (5 stars all uncovered) I get a huge amount of ghosting, and cant seem to focus on the whole image. If I focus on one star, then another is unfocused.... Moving on to the main camera, If I put the artificial star in the slit, I cant find any spectrum pattern at all (and I have tried focusing everywhere). If I just throw a really bright light in front of the scope, I do see the slit and some bands (last image)? Is this the spectrum, or just junk? Is this haw I should find focus of the main camera??? I have no idea where to go next....so thanks very much in advance!

Yes, this is all making MUCH more sense now. I am going to quickly 3D print a square holder (same size as the grating) with a spot for the guide mirror. Then I can just put that in and align the collimater position. This is a really fun project, and I know its evolving, but I'm surprised no one has made a nice YouTube video as a guide for building and setting this thing up. Hopefully, if my unit is successful I can make that (PART 2) for others so they don't have the struggles I am having.

That is the OVIO guide platform. Everything makes sense now, I now just need to wait for the OVIO slit ring to arrive from JEULIN....or make one as you did.

I found the "missing" 15 degrees. And I now it makes sense that the surface is polished and the light is all reflected back except what passes through the slit.

So is the light "reflected" off the slit, or how does it bounce back to the pickup mirror? It seems it would all just pass though? I am still waiting to get my slit ring from France (it's set to be delivered next Monday). Perhaps once I get it, it will make more sense. Or is the surrounding slit surface a mirror and its that light that is bounced back to the guide mirror?

OMG, I had assumed (incorrectly) that like a off axis guider, light is picked off the incoming light and reflected into the guide lens. This is clearly not the case, and I had the mirror holder in 180 degrees backwards! A picture is worth a thousand words. To be honest if this image was in the manual it would have helped me a lot!! Step 17 shows it, I just 100% had my head wrapped around a normal off axis guider setup.

Ahh...so the slit has to be in place for it to work correctly? I just set a piece of paper in there, focused on a flashlight across the room to get a rough focus on where the slit will be, and then moved the scope a little to then focus that same light source on the guide camera. Seems this is a flawed approach?

LMAO.... So why is it at 30 degrees, and not 45? is it not a right angle or is there some optics stuff there I don't understand?

Guide mirror centered and at 45 degrees.

Yes...that what I have been asking about! "Last night I tried aligning the guide camera....."

LOL! But yes, I have it done and am throwing it in CURA now.

Surly not my design, Paul Gerlach gets all the credit!! I'm just a newbee in spectrometry and stumbled across this project a couple weeks ago! Bought the optics and started printing! In no way do I want to take away any of Pauls hard work, but I am certainly more than happy to help make this project better for others to enjoy !!!

Thank you! I thought I was missing something, and it was driving me crazy! I am going to just redraw this part with the correct dimensions this morning and reprint it since I have that little mirror here. Seems like kind of a significant mistake though, I am surprised no one else has caught it.

Last night I tried aligning the guide camera, but the angle was way off and I couldn't adjust the pick-off mirror enough. Eventually I cracked the slider trying to get it aliened. I re-printed another piece, but looking at the part in CAD the pick-off angle is 30 degrees. Shouldn't this be 45? Why 30? I am going to re-draw this at 45, unless I am missing something? Surely if it is supposed to be 45 other users must be having this same problem to?

Thanks Louise, and now the movement makes sense. Ie the collimation len should focus the light on the grating (I actually didn't realize that). The idea of temporary using a mirror in place of the grating is also a great idea. That allows everything to be approximately positioned before installing the sensitive grating, and allows a first time user the ability to get a feel for the adjustments before installation of that.

Paul has fantastic instructions on the assembly, but I don't see anything on setting/adjusting the mirrors. Unless I am missing a second manual somewhere? Maybe I'm overthinking things and it will become obvious once I start using it. I was planning on using the laser beam to adjust the main reflecting mirror, and then the angle of the diffraction grating. Is that also how the front/back tilt is set (ie the vertical)? Also, do I just start with the collimating lens in the middle? If so why have a slot for it and not make it fixed? What does the position of that do?

Also, here is my unit assembled, without the optics. Looks good so far for $35 of PLA, $10 for the micrometer, $30 for the illuminator, and about $15 of bolts and hardware.

I just printed a LOWSPEC Spectrometer, and am installing the optics now. However, I have NO idea how to go about focusing the mirrors and calibrating it. I am very new to spectrometry and have only played with a SA-100 so far. I have made a video on the 3D printing aspect (below). I intend to do two more to help others out, but I would prefer to not give bad advice so any help would be so appreciated. I assume first is to set it up on a scope and get the pick-off mirror aligned and the guide camera focused and positioned correctly (with a star focused on the OVIO slit ring). I have an artificial star (the pinhole flashlight model) thing I used years ago for collimation I was going to use. Next I was planning on maybe shining a laser down the scope to rough align the mirrors. But from there I'm lost. Clearly the main reflection mirror is next and should point to the collimation optics. But where should the collimator lens be positioned (back, middle, front of the slot)? How does this effect the image? Then how to align the reflective grating? There is a set screw to adjust the vertical plane (on the front of the base inside, and on the rear on the outside of the case). Again, I am new, and maybe I am missing a manual someone already wrote on this? If not I am happy to do so for the next users because this seems like an awesome, and fun, project! Thanks!!!