Hadley dew shield and solar filter adapter combo

This model helps to adapt Hadley telescope better for use in cold climate and for observing the Sun.

Update 2026-03-12: added a Bahtinov mask (made using this generator)

Update 2026-04-14: added version 2 - lighter baffle, lid that fits around the adapter and sits firmly regardless of whether sleeve is used or not.

⚠⚠ NEVER POINT THE TELESCOPE AT THE SUN ⚠⚠
without protective measures: a good certified solar filter securely attached; a full-length light baffle tube. Direct sunlight should have NO WAY inside the telescope.
⚠⚠ Risk of severe damage to the eyes ⚠⚠ - and not just yours!

And DO NOT USE PLA for this model! PETG or other high-temp and UV-resistant materials should be used instead.

If you're planning solar observing - ATTACH THE SOLAR FILTER BEFORE TAKING THE SCOPE OUTSIDE. And when you're done observing - FIRST TAKE THE SCOPE INSIDE, and only then remove the solar filter.

I also recommend buying some eclipse goggles so that you don't stare directly into the Sun while aiming the scope. Another trick I discovered is to to pre-aim the scope by using it's own shadow. I also try not to look in the eyepiece right away, but attach my phone first and use it's screen for aiming and focusing.

Description

I had several problems that I tried to solve with this model:

• I live in a very cold climate and when observing in winter I often get my secondary covered in frost - a dew shield is supposed to help with that

• the solar filter adapter I have is too loose and there's a risk of it falling off the rods

• there's quite a big gap between solar filter and the tube, so there's a risk of some sunlight going in from the sides

This model is an attachment that goes on top of the telescope (above UTA) and is secured onto the extra length of the rods with 3 M4 nuts and 3 M4 12mm+ bolts.

The solar filter adapter part is inspired by this model and is meant to be used with off-the-shelve solar filters that are 155mm in diameter or more.

This attachment is meant to be a permanent addition, so I've made a separate model for a plug that covers the opening of the tube and prevents dust going inside the tube when the telescope is not in use.

Also, the inside of the attachment should be black. You can either print the whole thing black, paint the inside with a black paint (see original Hadley assembly instruction document on "blackening"), or you can print a provided sleeve in black and insert it into the main part.

Instructions

1. First, measure the length rods are sticking out of the telescope

1. Load the model into slicer, place on the solar adapter ring (upside down) and cut away extra length from the top, so that the model is slightly (1-2mm) higher than the previously measured length. Here I measured 132.2mm on the rods, and made the model 133mm tall.

   

   Print the main part using the settings you normally go with, or ones you used for other parts of Hadley.
   

2. If you need a sleeve - cut it too, but make it 1-1.5mm shorter than the main part. E.g. in my case I made it 132mm

   

   I advise printing the sleeve in vase mode with 0.4-0.5mm line width, so that it's not too thick.
   
   Sleeve should slide right into the main part, and I advise to add some glue so that it doesn't slip out.
   

3. Print the cover - this one should not be tricky, use your normal settings.
   

4. Assembly is pretty straightforward - insert the nuts into the corresponding slots, screw in the bolts, put the part onto the rods and tighten the bolts.
   

5. Rebalance the telescope - the attachment it quite heavy, so it's better to balance the scope again by moving the MTA upwards toward UTA.