OneBox mod for Rat Rig V-Core 3 printer

Complete OneBox V-Core 3 mod files

Mod and all files fully compatible with both V-Core 3 and 3.1 upgrade.

Both STL and STEP files also included.

Update, It should be noted that Rat Rig have now followed this design with their 2.0 enclosure. Which is very similar to the OneBox mod, to the point that all parts are interchangeable.

Consequently the front belt tensioners and other parts from this design are compatible with the Rat Rigb V-Core 3 (and 3.1) 2.0 enclosure.

If you are using the OneBox with the V-core 3 hybrid upgrade kit use the front belt tensioners from the hybrid upgrade kit instead of these OneBox ones.

I have included front belt tensioners and also some optional lead screw guides that integrate with the belt tensioners. These leadscrew guides are much more professional looking than the Rat Rig ones. You can either use the normal bearings in them or the TPU wiggle woggles that will last forever and are totally silent in operation.

I have also included magnet holders for a front panel in this mod. To fit these require drilling of the front panel (Easier than making square or rectangular holes).

Updates

23/07/22 Added new leadscrew guide files.

28/08/22 Lead screw guides and caps updated to version 3. These offer more clearance on left hand side one for different Z probes.

There are so many advantages to the OneBox design:

1. Allows the use of the included easier to access front mounted belt tensioners.

2. Being able to move the belt tensioners off the print head allows you to use a lighter and more compact modern print head for faster printing such as the Microlight or Full Frontal Gantry Ultralight Print heads.

3. Cleaner better looking design. 

4. Much cheaper to enclose (less panels to cut).

5. Easier access to printer and tool head for servicing (no front extrusion going across the printer at the gantry height and getting in the way)

6. Much easier to seal enclosure, as there are air gaps between lid panels and lower panels.

7. More rigid frame when enclosed. The bolted on full height side panels and roof panel add rigidity. By comparison, the standard Rat Rig hinged lid adds nothing to rigidity of the printer frame.

8. I have also added a 3030 crossmember in front of the rear Z motor mount to stop this mount sagging. 

Coffee fund

If you decide to make a donation to my coffee fund (which keeps me up late at night doing more of this stuff) I would appreciate it. There is absolutely no obligation for you to do this. My PayPal account is [email protected]

Please remember to post feed back as it is always valuable to me for future iterations.

Many thanks.
Liam Venter
MFBS Design

Bill of materials for upgrading and existing V-Core 3 OpenFrame

• 4 x new corner posts. 750 long for a 300 x 300 (240mm longer than current ones which are 510 mm long.) On a 300 x 300 printer this will give you enough clearance for a flying umbilical cable to the tool head. I find this height perfect for a 300, for a 400 or 500 you may want to go more than 240 mm taller especially if you you are still using a flying umbilical cord. Remember you can still lift the roof panel off to get in and service the print head quickly and conveniently.
  

• 8 x T plates. (Available from Rat Rig or Aliexpress)
  

• 40 x 6mm x 12 mm cap screws (black oxide). Recommend that you order 50 of these as I have probably missed a couple and always useful to have a few extra for mounting things to the extrusions.
  

• 40 x 6mm T nuts. Recommend that you order 50 of these as I have probably missed a couple and always useful to have a few extra for mounting things to the extrusions.
  

• 2 x extra front idler plates (Available from Rat Rig or Funssor on Aliexpress).
  

• 2 x extra XY motor mounting plates (Available from Rat Rig or Funssor on Aliexpress).
  

• 8 x 3mm x 42 mm cap screws (black oxide) for XY motor mounting. May have to order longer and cut them shorter.
  

• 4 x 5 mm x 42 mm cap screws (black oxide) for rear idlers.

Instructions:

1. Remove the eight right angle plates from the top perimeter of your existing frame.
   

2. Remove your existing 440mm top front extrusion
   

3. Remove your four corner 3030 vertical extrusions.
   

4. Replace your four corner 3030 extrusions with the new taller corner vertical extrusions.
   

5. Re-install yoiur original 400 mm top front extrusion at the ttop of new front corner vertical extrusions using its original two corner mounting plates.
   

6. Re-install your Y 3030 blinear rail support extrusions using four of your new T mounting plates.
   

7. Re-mount your original rear top X 3030 extrusion in its original position using two of your new T mounting plates
   

8. Cut one of your old corner vertical extrusion to 440 for the rear top extrusion and install this using its original two corner mounting plates.
   

9. Cut two of your old corner vertical extrusions to the same length as your existing Y extrusions (505mm for a V-Core 3) and install these at the new top Y side extrusions. Using their four original corner plates.
   

10. This leaves you one old corner extrusion spare. Cut this to the same length as your front bottom extrusion (440 mm long for a V-Core 3) and intalll this using two of your new T plates as a cross brace to support the front of a modified rear Z motor mount (see my modified Z motor mounts).

Front belt tensioner parts

1 x 5 mm x 36 mm pins (right front idler).

1 x 5 mm x 33 mm pin. (left front idler) I ground down a 36 mm one to save me needing to order different sizes). These pins are available from your local bearing supplier or Aliexpress. some of the Aliexpress pins may need sanding in an electric drill for a couple of minutes to make them a nice sliding fit in the idler bearings.

https://www.aliexpress.com/item/4000233682608.html

2 x 6mm x 35 mm cap screws (black oxide) for belt tensioners

2 x standard 6 mm zinc nut for belt tensioners.

8 x 6 mm nylock nuts (4 for retaining front idler stationary block and 4 for clamping XY rear motor plates.

2 x 6 mm 50 mm cap screws (black oxide) for clamping left front idler stationary block

2 x 6 mm 54 mm cap screws (black oxide) for clamping right front idler stationary block

Side and roof panels. 

I used 4 mm Dibond (Aluminium Composite material) for all my panels other than the front panel as it is very cheap and easy to cut by score and snap method and you can also cut any cut outs required easily with a hack saw blade.I bolted these in place with M6 T nuts and cap screws and placed a washer under the head of each cap screw to spread the load better.

Magnetically attached front panel

For the magnetically attached front panel I used 4.5 mm polycarbonate as that what was readily available locally.

On my full height front panel on my OpenFront '300' I recommend 4 magnet holders at the top and the bottom and six down each side. These each hold 3 magnets (1 or 2 proved not strong enough). For a larger panel I would use more magnet holders.

The receptacle holes in the polycarbonate are 7.75 mm in diameter and the magnetic holders are a tight friction fit in these.

Here is what you need for each magnetic catch:

1 x T-Nut. I use the 30-M6 sized ones from here https://www.aliexpress.com/item/32851320734.html

1 x Grub screw, socket cup, black oxide steel M6 x 8mm to hold T-Nut in place and improve magnetic performance. https://www.aliexpress.com/item/33029779249.html

3 x Magnets 6 mm dia x 3 mm per magnet holder. https://www.aliexpress.com/item/1005001991968667.html

Lighter more compact print heads
Being able to move the belt tensioners off the print head allows you to use a lighter and more compact modern print head for faster printing such as the fantastic Microlight print head. https://www.printables.com/model/595269-microlight-print-head-for-rat-rig-v-core-31

If you want to stick with the legacy EVA print head there are a range of upgrades available for this as well. Tensioner-less back plates are available for a range of upgraded fan options, Including 5015, 4028 and Pabst fans.

The full range of tensioner-less back plates are here: https://www.thingiverse.com/thing:5322790

For more of the mods on this printer please search "MFBS Gold Series" in thingiverse.

Update 27/03/2022

changed spacing of bottom mounting holes to provide more clearance for heads of cap head screws.

Acknowledgements

This upgrade is a derivative of the Rat Rig V-core 3, open frame printer which I believe owes much of it's design to Pawel Kucmus and the Jubilee printer.

Print Settings

Printer:

Rat Rig V-Core 3

Supports:

Yes

Resolution:

0.2 mm

Infill:

30% Gyroid infill, 3 perimeters

Category: 3D Printer Parts