Microlight print head for Rat Rig V-Core 3/3.1 printers

Microlight 3.2

Very light and rigid print head for a V-Core 3 printer.

The top plate and front plate are now printed as a single item. There are several other small detail changes.

The integrated top/front plate offers several advantages to the design including making an already extemely rigid design, even more rigid, and reducing the printed part count to just four parts, including the part cooling duct and integrated mount.

Please also note, there are many remixes of the Microlight on the internet, which I fully encourage, and is the reason that I also published the STEP files on Printables. However sometime in December last year I corrected a small error in the belt offsets and would encourage anyone using the Microlight or a derivative to adopt this latest version.

The Microlight 3.2 print head is the simplest and lightest print head for Rat Rig V-Core 3 printers.

It is compatible with all Rapido hot ends including the Rapido Ace and all models of V-Core 3 and 3.1 hybrid printers.

I have now also added a DAFT (Dual Anchor Front-Top) Mount version of the Top plate-face plate for those who are using DAFT Mount heat sinks. I highly recommend DAFT mounts on all print heads. For the DAFT mounts please go to this link.

https://www.printables.com/model/1427211-microlight-32-v-core-3-daft-mount-option-print-hea

Key features

• Very light.
• Supremely rigid.
• Very simple.
• Much faster and easier to work on and service.
• Very low part and screw count.
• Designed for far superior CPAP cooliing.
• Designed for use with BeaconH, low profile sensor.
• The top plate includes a support/rest for the rear of the Orbiter extruder to better stabilise it.
• The top plate includes an optional slot for a 2.5 mm zip tie to clamp the Orbiter extruder to the rest. I find using it provides a very slight improvement in recommended input shaper results.
• Mature design.

What hasn't changed between 3.1 and 3.2? With the release of the Microlight 3.2 the earlier 3.1 version has been deprecated. The only part that is compatible between 3.1 and 3.2 is CPAP pipe. All other printed parts must be changed when upgrading to 3.2.

 Important instructions: 

1. Recommend printing the top plate in either high temperature resistant PET-CF, or ABS, PPA-CF or ePAHT-CF. If you use ePAHT-CF or PPA-CF, heat treat all ePAHT-CF parts at 150C for 2 hours in a kitchen oven post printing, which makes the parts MUCH more rigid and also ensures they do not suffer from pressure/temp creep over time. No other PAHT-CF nylons that I have tested yet, is recommended for any parts of the Microlight. I printed everything for mine in ePAHT-CF except for the duct, and front plate which I printed in ABS. 
2. The Microlight must be used with frame mounted belt tensioners. When you remove the belts for servicing, leave the ferrules in the belt loops and remove them from the carriage just by undoing the vertical screws. If you haven't already upgraded to front mounted belt tensioners, CNC'd ones are available on Aliexpress or use the excellent ones from my OneBox design. 
3. When buying CPAP pipe please opt for the larger standard 19mm size rather than the smaller 15mm size. The 19mm pipe flows a LOT more air.
4. All parts other than the integrated bottom/plate duct and CPAP pipe, print without supports. I use tree supports when printing both of these which works great. The CPAP pipe prints easier than you might expect, vertically in the orientation it is mounted to the Microlight with a brim and tree supports. 
5. The belt ferrules all need to be exactly 9.5 mm long. 
6. Make sure the CPAP pipe flange fits flush against the the part cooling duct inlet. 
7. Use 1 x zip tie to fasten CPAP pipe to back plate zip tie support. 
8. Heat sink and part cooling fan wires go thru the right hand side cable management tab,, the tap on the right hand side is a spare for any future upgrades. 
9. To mount your CPAP fan you may want to use my SwitchBlade design. 
10. Anything with a 4 mm hole in it gets a threaded insert. 
11. After printing, drill out the four hot end mounting holes in the top plate with a 2.5mm drill. 
12. After printing, drill out the two holes in the top of the front plate, the central hole in the CPAP pipe and the 4 holes in the top of the duct with a 4 mm drill. These are the holes that the brass inserts go into. 
13. There are four non load bearing screws in the Microlight that screw directly into plastic. 2 on the side of the top plate that the X stop mounts to. 2 on the side of the front plate and 2 that the optional ADXL board mounts on to. 2 in the bottom of the duct that the Beacon mounts to. These can either be tapped with a 3 mm x 0.7 tap or self taped with the mounting screws. These are all moddelled at 2.25mm diameter which is a good size for a 3 mm tap tool in plastic. If you are going to self tap these with the screws drill these holes out to 2.5mm first. 
14. Drill out all of other holes in the top plate, front plate, duct and rear plate with a 3 mm drill bit.

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

BOM 

1 x 3010 part cooling fan. Has more pressure than a 4010 fan. 

4 x 3 mm x 46 mm top to bottom plate clamping srews 

1 x 3mm x 6 mm CPAP pipe mounting cap screw 

2 x 3 mm x 16mm Orbiter mounting cap screws 

2 x 3mm x 8mm X stop mounting cap screws 

4 x 3mm x 6mm MGN carriage mounting cap screws (If these bottom out grind shorter to 5 mm) 

2 x 3mm x 16 mm cap screws to mount 3010 heat sink fan. 

1 x Beacon Rev H, Low profile sensor. 
 

Attribution: All key design elements, including the integration of the function of what have traditionally been discrete parts into multifunctional single parts is original work. Every component is the result of original design and CAD work.

Updates:
17/01/25 The top plate and front plate are now printed as one part. 18/01/25 Corrected error in heat insert hole size in top plate. 18/01/25 Changed shape of PTFE tube hole in face plate.

29/1/25
Uploaded missing Orbiter motor rest that I forgot to upload before.

21/5/25
Added DAFT Mount version of the Topplate-face plate for those who are using DAFT Mount heat sinks.

31/5/25
Have made holes around the heads of the cap screws in the top plate slightly smaller.

15/8/25 
Have made the belt fasterners more robust.