Category Archives: Projects

Craft, Hardware, or Software projects I’ve done

Building a solar filter for the Vaonis Vespera smart telescope

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After my success with a Dual Band filter holder, I spent $38 on a sheet of BAADAR AstroSolar Safety Film (from ScopeStuff in Round Rock TX) and used some 3M VHB double sided tape (cut in very thin strips) to attach it to the 3D printed filter holder.  The filter holder is really designed for screwing in a 2″ (50.8mm) astro filter, so it didn’t have as much surface area on the “ring” as I would have liked, but it worked reasonably well, especially as I then sandwiched the outside film within the larger outside ring when I snapped them together.    [I cut one bit of film a little too short, so it didn’t go under the ring, you can see it in the bottom left in the photo below.] I put a ring of UV cured resin around the outside of the filter film just as added insurance it won’t pull up in the wind or something.

I was very tempted to use superglue on the ring before dropping it down onto the filter film (instead of small pieces of VHB double sided tape).  I didn’t do that because I was worried it might not stick to the film, and I was also worried about CA glue offgassing when the filter was used in the sun.   After I made this filter, I tested gluing the resin print to some cutoff film, and it appeared to work great. If I need to make another filter (or make one that looks a little smoother around the edges) I will try using CA glue instead, and make sure I put the whole filter out in the sun for a day before using it on my telescope to make sure the CA glue won’t offgas onto the lens.

However, even though the edges of the filter film look a little wrinkly, almost the entire surface of the optical path was very flat (but not overly tensioned) and the images through the solar filter look as good as any of my other smart telescopes produce, so I think functionally it worked great.

Sun stats: 0;0;0;0.003048, exposure: 300µs , gain: 0dB

I used a 4.6 Kohm 1/8 watt resistor with the leads circled and soldered inside the filter holder to indicate to the Vespera that it had a solar filter installed, and it was detected correctly as soon as I plugged in into the telescope.

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DIY Dual Band Filter holder for the Vaonis Vespera Smart Telescope

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I purchased a used Vaonis Vespera smart telescope, but if I wanted to buy the “official” (and proprietary) Dual Band filter to use for imaging emission nebula, it would cost $400 USD!

This especially smarts, as I already own a 2″ SVBony SV220 dual band filter that I use on my main telescope.  Luckily for me, aureliend2000 has posted a 3D model on Thingiverse that allows you to create your own ‘Vespera compatible’ filter by screwing in any standard 2″ optical filter.

[And if you put a 24k Ohm resistor in the right spot, the Vespera automatically detects that a  “Dual” band filter is installed, setting the gain of the camera appropriately.]

Here is a video showing the full process of how I made mine:

Here is a 48min exposure of the Rosette Nebula (from Bortle 7.5) without the Dual Band filter:

NGC2237_44 (290 exp)

And for comparison, here is a  48 min exposure WITH the SvBony SV220 dual band filter:

NGC2237_44 (287 exp)

 

And here is a 57 minute exposure of the Owl Nebula using the SV220 dual band filter:

M97 (342 exp)

Considering I already had the SV220 filter, a 3D printer, and a 24k Ohm resistor “in stock” I’m very pleased with the ability to use a dual band on the Vespera without spending (any more) money.  I’m so happy with the result that I’ve ordered a sheet of solar film and plan on making my own Solar Filter so I can use the Vespera to image the sun.   [Yes, my Zwo Seestar S50 came with a solar filter and a built in light pollution / DB filter….but the optics, tracking, and software of the Vespera are all just slightly nicer, and since I got it used the cost wasn’t outrageous.]

Telescope dolly alignment jigs to repeatedly return to polar alignment

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I want my telescope to be polar aligned when using it. To do this, I need to have the base accurately pointing exactly towards the north pole (in the Azimuth direction) and the Altitude of the wedge the same as my latitude. [This essentially means that I need the tripod base to be exactly level.]

Getting the tripod level is easy, as I have 3 leveling bolts built into the ends of my home built rolling dolly and a bubble level on the telescope wedge.  However, to get the AZ orientation correct, I need to reliably place at least 2 of the alignment bolts in the exact same spots on my patio every time I wheel the telescope outside to use it.

To make this easy, I built these alignment jigs. They consist of a square piece of 2×4 (3.5″ by 3.5″) which rest inside a white square of gaffers tape. The square gaffers tape lets me put these wood base blocks at the exact same point each night. But, I really need to align the 3 leveling bolts, not just the wood blocks. So I designed and printed two 3D printed jigs. One to align the anti vibration puck to the center of the wood spacer block, and one to align the bolt to the center of the anti-vibration puck. The combination of jigs allows me to place the three leveling bolts (and hence, the dolly, and tripod) at the exact same location every night.

You can watch the video below to see how this works in practice.

Google Pixel 5A – Colorful Snow screen flashing problem – Resolved by re-flowing solder on motherboard

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My wife’s Google Pixel 5A phone developed a problem where the screen would “flash” between a colorful snow pattern and was it was supposed to be showing. It started out slowly, with intermittent flashes, but quickly got worse where the screen was barely ever showing what it was supposed to. [It also does not accept touch input events when “flashing” the colored snow pattern..]

I was able to retrieve the data off of the phone by heating the entire phone up, but this was a temporary fix as the problem returns as soon as the phone cools down.

I was able to fix the problem (hopefully permanently) by completely disassembling the phone, extracting the motherboard, and hitting it with 5 minutes of heat from a 300 deg c hot air rework station. (I aimed the hot air at the video connector, and then at the covered set of chips right above the video connector (opposite from the battery connector), as I figured that was the most likely location for the video graphics chips. I still don’t know which EXACT component had the problem, but allowing the solder joints in that general area to re-flow appears to have fixed the problem, as when I re-assembled the phone it is working perfectly at room temperature.

Building a Telescope Tripod dolly (Meade LX-200 12″)

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I built my own Tripod Dolly with casters & Leveling bolts (out of 2×4’s and plywood) for my Meade LX-200 12″ with Giant Field Tripod (the one with the 3″ diameter legs).

I was originally thinking it would be just so I could play around with the telescope (move it in and out of the garage) and get a feel for things until I decided what commercial dolly / truck / cart to buy, but I’ve been so happy with the results that I think I’ll just use it permanently.

Tripod Dolly built from 2x4s and plywood

 

I’ve got a short 5 minute intro video here (which links to a full 40 minute how to build step by step video if you decide to follow along and build your own):

Also of potential interest to people with the Meade Giant Field Tripod is that I modeled the tip of the tripod legs and designed a 3D printed bracket for holding the tripod tips securely in place on the 2×4’s…[Of course, you could just drill a 1″ hole at a 55 degree angle, but if you’ve got a 3D printer everything needs a custom bracket….]

You can find the 3D model & OpenSCAD design file on Thingiverse here: https://www.thingiverse.com/thing:6826864

 

Google Pixel 5A screen flashing “colored snow” – Recovering the photos.

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Pixel 5a phone showing the USB Preferences screenGoogle pixel 5a showing the "colored snow" pattern

My wife’s Google Pixel 5a phone suddenly developed a hardware fault that presents as a “colored snow” screen flashing over the entire phone display. While the “colored snow” pattern is on the screen, the phone does not respond to touch events.

However, when the colored snow pattern is NOT showing, the phone display goes back to showing what it should be showing, and it will accept touch events.

The difficulty is that the speed of flashing is very fast (on the order of 0.5 seconds) so it is difficult to read the screen and push buttons or UI areas effectively to do anything.

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Is your camera image sensor dirty, and if so, how do you clean it?

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Do you have dust and foreign particles on your camera’s image sensor?  If you have an interchangeable lens camera body, you probably do. But in many cases, a few random specks of dust won’t be detectable in normal photography.

However, if you have visible spots showing up in your images, you know it’s time to clean your camera image sensor. For example, in this closeup of the N2A Goodyear Blimp, if you look closely at the end of the black hand drawn arrows, you can see the results of dust on the image sensor of my second-hand A6300 camera. [Obviously, all dust is the fault of the first owner, and I can keep claiming that until after I clean it.]

Photo of the goodyear blimp, with small dust spots evident in the photo.

Now that you know there are at least a few pieces of dust/debris on your image sensor, you can characterize just how bad the problem is by shooting a “flat” image.  Point your camera towards a clear patch of sky, put the lens in manual focus mode and defocus it, and take a photo that is just slightly over exposed. [Note that to take a true astrophotography flat you need to do more than this, but for the photos below I didn’t bother. You risk having cloud shapes show up in your flat image by not having a tight white cloth over the lens….but since we are just looking for dirt it’s not critical that your flat not have gradients in it.]

defocused image showing dust and debris on the sensor

If you have a lot of debris on the sensor, it will be easily visible directly in the image. In the image above, you can see I even have some type of fiber or thread (middle right). This is an example of a sensor that definitely needs cleaning.   But you can also digitally enhance these images to highlight the debris more, which is useful in cases where the amount isn’t as bad.  Just import it into a photo editing tool, and use the “auto adjust input levels” feature to get something like this:

digitally enhanced image showing lots of debris on an imaging sensor

With digital enhancement this looks super bad, but as you can see from the image of the Goodyear Blimp above, even this level of dust and dirt doesn’t mean you can’t take a mostly usable photo with the camera.

 

How to clean your image sensor

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Bearing Replacement on an iOptron Cube E 8500 Alt/Az Telescope mount

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I had to replace one of the Alt bearings in my Cube E mount (it was “grinding” and causing star trails at 1-5 second exposure times due to vibration).  I made a video of the procedure here:

https://www.youtube….h?v=TrKLkgV_WYM

 

The iOptron Cube E 8500 that I have uses 2 sizes of bearings:

 

1x   6804z bearing (20x32x7mm) for the Alt axle closest to the telescope.

3x  6803z bearings (17x26x5mm) for the ALT axle nearest the “lock” handscrew
and for both the top and bottom of the AZ axis in the bottom.

I purchased and used this NSK brand bearing.

You’ll also want a 14mm or 9/16th box end wrench to remove the AZ axis bolt head if you need to access the bottom.

Before/After results (click to enlarge):

Aftermarket Glowforge Hinge bracket installation

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I’ve had issues with the front handle and rear hinges separating from the glass lid of two different Glowforge units.  After repairing one side of the rear hinge that was separating I decided to try out an aftermarket hinge bracket designed to get a better connection between the glass lid and the two hinges.

I paid $160 with shipping to an eBay seller for item number 175473691329 “New GLOWFORGE Aftermarket LID Hinge Repair Bracket, All Metal Construction” which has a U-shaped channel to surround the rear edge of the glass lid.  It was a bolt on (and silicon sealant glue) procedure, and the hardest part was unsticking the double sided adhesive used to hold the glowforge lid ribbon cable in place.  [I ended up using dental floss to saw through the sealant behind the cable….when I replaced it I just used electrical tape to hold the cable in place.] I also had to spend some quality time removing the epoxy that I had used to initially repair it for a few months.

The procedure went smoothly, and the lid appears to be working (and sticking) well, although only time will tell for sure how much better this bracket is compared to the original one.