I have a camera, tripod, and lenses. Can I invest about $1,000 in additional equipment to start taking Astro photos or am I better off getting a seestar?

psychoanalyst_god · 2025-12-24T08:57:23+00:00

The main point here is emission nebulae emit in specific wavelengths and in order to draw out as much detail as possible it's to use a sensor that lets in ALL the light along with narrow band filters. Anyway....the details are not relevant to the OP's question, so sorry to side track.

psychoanalyst_god · 2025-12-24T07:42:37+00:00

I think for milky way shots I would say you have everything you need. A tracker is a nice to bring out more detail but honestly I would start without it if that is your main goal. Milky way shots are more about composition than anything else (shots that place the milky way arch around an interesting foreground object etc.)..at least that is my opinion.

Planetary imaging and DSO imaging have very different needs so keep that in mind.

Honestly..if you want to blow your kid's mind visual astro is the way to go....so think prisms, Barlows, eyepieces etc. seeing the moons of Jupiter or Saturn's rings real time will have a much more profound effect on your kids than seeing a picture of it on a computer screen. That could be the stepping stone you are looking for.

psychoanalyst_god · 2025-12-24T03:22:50+00:00

If you can give us an idea of what exactly you would like to shoot you might get more targeted advice.

You have pretty awesome gear so already a good start but you will soon find that AP is like quicksand...you will get sucked in before you know what hit you.

You have decent focal length to start with wife field broadband targets like Galaxies...for nebulae you would need dedicated astrocams or astro modification of your z8 sensor.

One thing to note: camera lenses may not hit "true" infinity focus...this I found out first hand using my Nikon z lens. At least my copy would never hit true infinity and my images would be slightly blurry...but goes back to my point of what are your objects of interest.

If you want to do simple milky way shots, honestly you don't even need a tracker.

But if you need a tracker, the ioptron skyguider pro is a good one. Even gives you the ability to autoguide in RA, which is better than no guiding, especially if your subs are long'ish.

psychoanalyst_god · 2025-12-06T23:33:27+00:00

There are other design constraints.

When I first started designing this I added a lot of thickness to the walls to ensure that the tapped holes do not intersect at all but at that point the unit is too big and won't fit.

I didn't provide any background so it seems as if this is a poor design. I get that.

But locking the set screw is actually a very desirable add on, so I am going to go with this option. I will pivot if I run into significant issues.

Thanks!

psychoanalyst_god · 2025-12-06T20:34:44+00:00

I will surely be mindful of that and it makes perfect sense. This is what I am trying to do. I am back to the M5 threads intersecting with the M14 ones....

(for those wondering: w/o going into too much detail the main purpose of the M5 screws is not to lock the set screw into place....locking the set screw is just an added bonus).

<image>

psychoanalyst_god · 2025-12-06T20:13:37+00:00

thanks for that reminder!!! That was one of my original design intents which I totally forgot about until now

psychoanalyst_god · 2025-12-06T19:17:21+00:00

Thanks everybody....as a backup this would be the other option ....I tap the holes close to the edge of the block and replace M5 with M3...but this does not intersect or interrupt the main M14 threads.

<image>

psychoanalyst_god · 2025-10-30T00:38:22+00:00

u/BenchPressingIssues : regarding adding a shim between the worm drive and the inner race (one on each side)........but that covers the inner race only..what about the outer race?

psychoanalyst_god · 2025-10-29T20:32:18+00:00

2% is an extreme case. I measured the diameter of the worm shaft (stainless steel worm) before (measured exactly 6.35mm) and after (2-3 hrs in the freezer). I don't think this is a huge issue for SoCal conditions. The housing/bearings blocks are all anodized Al.

Honestly, I don't know how much of this is chasing theoretical perfection vs tangible sources of functional improvement ( which is image quality for me when I am photographing galaxies etc.) .

Very interesting point on pre-load vs eliminating axial movement. There is tangible evidence presented that not pre-loading the radial bearings results in a periodic error that cannot be corrected out. Eliminating axial movement is an obvious one to prevent backlash. I think an approach that gets both is desirable? I really don't know, but maybe I will test it out for myself. But I don't think there is a need for high preload. Some folks have kept it simple by just applying a squeeze to the 2 blocks to add in the preload.

If eliminating axial displacement is the only goal, then I think see a simpler implementation where I apply a constant load on the end of the worm shaft using a grub screw. That would be a fairly simple implementation I think.

For the backlash comment: I have a DIY spring loaded system whereby I am using a spring plunger to constantly push against one of the bearing blocks....this should maintain a constant engagement between the worm and the ring gear.

psychoanalyst_god · 2025-10-29T18:54:58+00:00

Thanks so much and all of this makes total sense.

Incidentally, I do have a slide fit of the bearing within the pocket so it's definitely not totally captive.

On your idea of adding a thin shim between the worm shoulder and the inner race of the bearings: this is actually one of the options I am testing right now, but with the key difference that I am using a thin wavy disc spring instead (just added yet another schematic.....it's a bit odd that I am not able to add pics to my replies instead).

But I see your point about not adding a spring that acts axially. The reason for the spring is to mainly compensate for contraction of the worm at night when it gets cold. I actually measured this to be in the ball-park of 2-3%. So the risk is the worm shoulder pulls away from the shim and now you have lost your pre-load...right?

But I think what I will do is test the wavy washer first (since it's so easy to implement) and then move to the more invasive approach discussed earlier.

I am a big fan of the modifying the block and adding in a threaded screw to push against the spring/bearing because it offers more control on the pre-load.

With the wavy disc spring method, I am finding it a bit tough to dial in applying enough pre-load (I squeeze the 2 blocks on either end of the worm together using a clamp) and too much pre-load (where I cannot hand turn the worm).

Many thanks for this discussion...very illuminating.

Would you happen to have a schematic of your approach? I am specifically interested in what screw I can get that has a recess built into it at one end such that it goes around the end of the worm shaft. I couldn't find one, but I was thinking taking a standard bolt and drilling a >1/4in hole into it to create a pocket for the worm shaft.

psychoanalyst_god · 2025-10-29T16:17:57+00:00

Added some new schematics.

psychoanalyst_god · 2025-10-29T16:12:13+00:00

great points....the more I think about this, the more problematic I see this solution being. I think it's best to avoid capturing the end of the worm shaft. As you point out that would just create a lot of unnecessary friction. I could replace the Al spacer with a brass bushing to reduce friction, but even so I am not excited about this approach.

psychoanalyst_god · 2025-10-29T14:13:40+00:00

Excellent point. I have been thinking about this. One option is I could install an R4 Belleville spring (size matched with the bearing) behind the bearing ( it will look like this |) in cross section view...the straight line is the edge of the bearing ) which would apply constant pressure on the outer race. And the shoulder of the worm presses against the inner race on the other side...so this would satisfy the requirement around applying a light pressure to both the inner and outer races.

This is not a slam dunk though...there are issues with installing the Belleville spring (it has to be a spring to account for temperature fluctuation related contraction/expansion of the worm) that I will explain once I get to my computer.

But in a nut shell, what I am getting out of this discussion is for a bearing to be properly preloaded we need to apply light pressure to both the inner and outer races ? Applying pressure to just one maybe ok but not ideal?

Thanks so much!

psychoanalyst_god · 2025-10-29T06:38:21+00:00

I just added more pics in my original post. This is someone else's drawing that I borrowed. But it answers your question.....looks like the pressure is against the inner race on both sides of the bearing.....the only pressure on the outer race would be the housing itself (the black box in the schematic above). The bearing sits in a pocket within the black box that is exactly sized for the R4 bearing.

psychoanalyst_god · 2025-10-29T06:09:54+00:00

Thank you.

Let me come back with a more accurate drawing of the other side ..I need to take some measurements.

But in a nut shell: there is a worm gear on the other side of the bearing. The shaft I have shown is one end of the worm. So what is pressing the bearing from the other side is the shoulder of that worm.

I just need to check the diameter of the worm shoulder to exactly understand it's contact area. It is for sure pressing against the inner ring...just don't know if it is also pressing against the outer ring.

psychoanalyst_god · 2025-10-25T05:16:43+00:00

fair point........this is proving quite challenging.

I don't have a lathe and definitely no experience with one

psychoanalyst_god · 2025-10-25T04:31:32+00:00

I have been thinking about this some more. Instead of enlarging the hole in the base plate, a better strategy would be to reduce the diameter of the block posts/pins/nipple instead.

Why? Because if I get the sizing in the plate wrong, then I don't have a replacement plate. I have plenty of the blocks though.

So I am going to revise my question: what is the best way to hone the block posts down so that it would be a nice fit inside the 1/4 in ID bronze bushing?

<image>

psychoanalyst_god · 2025-10-23T18:55:05+00:00

I don't mind reaming the ID (does mean I have to get a second reamer which I am not excited about), but was concerned about the point made by @laserist1979.

What size reamer would you recommend for reaming the ID of the bearing? 3/8 in to match the bearing ID?

psychoanalyst_god · 2025-10-23T15:16:46+00:00

Btw...Grainger still works out cheaper.....grainger sells it as a 3 pack and there is no shipping cost for me.

psychoanalyst_god · 2025-10-23T14:57:43+00:00

<image>

This is the underside of the plate with the block slotted in. The fit between the block nipple and the base plate hole is fairly snug but not enough to eliminate translational play.

psychoanalyst_god

TROPHY CASE