RatRig V-Core 4 Panel Latching Clamps

Panel warping during enclosed prints is an annoyance with RatRig V-Core 4 printers causing corners of the top panel and top part of the front panel to lift up opening gaps in the chamber and allowing heat to escape (along with VOCs/etc). I have tried to battle this problem ever since I got my V-Core 4. Initially I had strong rubber elastic bands holding the corners of the panels by the bolt heads which works fine, but bands often tear up or fly away if I am not careful when taking them off to open the printer. Then I went with a corner clamp design emulating the job elastic bands did, that did the job but since they were not permanently attached to the printer, often I'd drop them behind it while putting on/off, plus it felt a bit too much involving, making me go back to elastic bands and their original problems.

I was unbuckling a chest with some instruments in the garage the other day and I thought why not create similar style latch as on that chest for the panels - one that will be neat and permanently attached to the printer, yet easy to use and not turning the task of putting the panels on and off in a “procedure”. Couple of iterations later, this is what I came up with and it seems to address all problems noted above. 

In order to keep the profile of the latches low, I switched the stock socket head screws panels with low profile head ones, these are easily available on Amazon and AliExpress.

My printer uses 6mm panels on all sides, but the back where I have a 3mm panel. Early days of V-Core4 it was unclear if thicker panel can be used at the back and from V-Core3 experience where that panel can't be thicker than 4mm, I went with 3mm just to be safe. I had the panels cut months before RatRig shipped the printer. Long story short - since many folks would have either 3 or 6mm, I created variants for both, including a ‘hybrid’ variant for those like me who got thinner rear panel. The hybrid was mandated by the requirement to be able to rotate top panel in either direction (avoid having to match longer to shorter latches. Hybrid uses 6mm panel hooks all around. 

Each latch consists of 4 components - base, lever, hook and buckle. Buckles attach to the front and rear panels while base bolts to the top one. Depending on the panel thickness 16mm (6mm panels) or 12mm M6 flathead bolts are required. Buckle, lever and hook are held together by an M3x30mm socket head cap screw (base to lever) and M3x20 countersunk screw (lever to hook). Lever and base take a heatset, RatRig style (M3x4.65x4), refer to the pictures for details. I recommend adding a bit of Loctite to the tip of the bolts as they should not be tight for the mechanism to move freely.

When printing these - make sure part orientation is as per STLs to ensure long lasting part. Lever and base need supports in the overhang areas - I added couple of pics on how they should look like sliced.

Buckles are panel thickness and location specific (RL - rear left when facing the front of the printer, etc). Hooks are panel thickness specific - 6mm ones would be the hybrid as well.

As far as material to print these from - I used ABS as it provides a bit of flex which is required for proper operation of the hooks. I'd say avoid CF filaments at least for the hook, as CF tend to creep and may not work as well after a while. These are all on the outside of the printer, so perhaps even PLA might be fine. I decided to add ‘accent’ by printing the levers in green to match the RatRig color scheme.