Double insulating windows for the Core One

Edit: After doing this mod, I did some math and realized that it is really the width of the airgap that drives the effect of this mod. Therefore, the impact can be doubled or tripled by upping the gap from 1mm to e.g. 3mm or 5mm. I will rework the model for that, but if you want it now, you can simply thicken the spacer parts. Either stretch the rivets correspondingly, or simply replace them with M3 screws if stretched rivets don't work.

High chamber temperatures improve layer adhesion and suppress warping with materials such as ABS, ASA, and PC. To get better temperatures, you can either increase heat production or reduce heat loss. This project aims to do the latter.

I suspect that one of the primary sources of heat loss on the core is the large single-layer windows on the Core One. To help reduce that, I got some 1mm clear polycarbonate sheets and designed these double-walled windows that help insulate the chamber better. The upgrade is nearly invisible, but should help maintain better temperatures.

Features:

• Uses 1mm clear polycarbonate sheets off amazon, which are thin enough to be cut by hand.

• The hand-cut edges are covered by a spacer that hides imperfections and preserves the original look. 

• Insulation is provided by a 1mm air gap between the 1mm PC sheet and the original 2mm window panel.

• The spacer only covers areas that are already covered by the Core One frame. This mod maintains the full view of the original design.

• Using this design for the side panels might help hold a degree or two higher. For best results, you should also upgrade the top window. I don't have a design for that yet, but I will make one soon and link it here.

• Includes 3D printable rivets which are long enough to attach the whole 3-layer stack to the frame.

  • Note that these rivets are right at the limit of what can be feasibly printed with a 0.4mm nozzle. I have carefully dimensioned the thicknesses to yield two walls with a 0.4mm nozzle. Don't use a nozzle any larger than that.

  • I found that these rivets work quite well once in place, but they have a high risk of breaking while you push the pin in. The solution is to print a lot of spares and to simply keep trying until you get enough surving rivets in place.

Bill of materials:

• 1mm clear PC sheet with enough area to cut out two sheets of approximately 36 x 14 cm each.

  • I did not try with 1mm acrylic. Perhaps that also works, but it might have more of a tendency to crack during cutting. If you try with acryil, please let us know in the comments if it works.

  • I used this: https://www.amazon.it/dp/B01AC7WHOM

• Drill with a 4mm and 7mm drill bit. I used a wood drill.

• A sharp knife

• A good pair of scissors

Instructions:

1. Print all the parts in the window kit file. One plate contains all the parts for one window, as well as a cylinder set to print at minimum speed to avoid low layer times on the rivet tips. If you organize a plate yourself, then make sure to print something alongside the rivets that keeps the layer times long enough that they don't melt.

2. Lay out the PC sheet on a flat table

3. With the assembled spacer as a guide, use the knife to mark the outline of spacer into the PC sheet.

4. Use the scissors to cut along the marked line.
   

5. Place the spacer back onto the newly cut sheet and mark the location of the holes with one of the drill bits. Do not attempt to drill immediately, just mark the location of each hole with the tip. Avoid moving the sheet or the spacer before all holes have been marked.
   

6. Place the sheet somewhere you won't cut into your table and drill out the marked holes. Use a 4mm bit for the small holes and a 7mm bit for the large holes.

7. Clean the holes with either your knife or a deburring tool.

8. Prepare the rivets. I found that the outer part tended to fuse near the top, so it might be necessary to use a knife to split the tip of the rivet. If you don't do this, then it might be impossible to insert the inner pin without breaking it.

9. Remove the original window on the Core One. This can be done by pushing the rivets out from the inside of the chamber. The original nylon rivets are reusable, so be sure to save them, although we won't be using them here.

10. Make a 3-layer sandwich with your new 1mm sheet on the bottom, the printed spacer in the middle, and then the original window on top. Secure the stack by inserting the outer part of one of the printed rivets into one of the small holes.

11. You can now install the new window onto the printer. Start by anchoring the window with one of the top rivet holes. First insert the outer part of the rivet, and then hold the sandwich firmly down while you carefully sequre the rivet with the inner pin. Be careful to insert the pin completely straight and use even presure, or it will break. Expect several of the pins to break even with care. Don't worry, bush out any broken pins from the inside, and simply keep trying with spares until all the rivets are in place. Once seated, they should hold the whole window stack securely.

12. If you made it to this step you have successfully inserted all rivets and are now the proud owner of a Core One with double-insulated windows. Now, repeat with the second window.

Enjoy! The model files are included in STEP format in case you want to modify them for any reason.