Blood Drive - BLVProjects Ender 3 Conversion Mod - Direct Drive - For Mosquito Hotend w/ BMG-M Extruder by stormbringer91

Last crawled date: 3 years, 4 months ago

This mod is based on having converted your Ender-3 Pro to the linear rail conversion kit from BLV Projects
As well ownership ofSlice Engineering's Mosquito Hotend and the BMG-M from Bondtech
If you intend on doing this modification to your printer, PLEASE read through or you will damage your printer bed!!! With that at the forefront-
Design purpose:
To reduce imbalanced inertia from stepper motor weight in a direct drive configuration and to maximize printing stability and precision.
I wanted to be able to attach Bondtech's BMG-M, which was specially purposed to fit to Slice Engineering's Mosquito Hotend. After obtaining both, I could not find a way to mount them.
The vast majority of X-Axis plates will be too tall in height to allow direct mounting of the BMG-M to the Mosquito with the extruder facing front and the stepper motor mounted over the top of the X-Axis rail, as the nozzle won't be able to touch the build plate, since the Mosquito is a very compact hotend. The stock creality X-Axis plate will not work.
This is not an issue for the BLV X-Axis Carriage however!
I didn't attempt to design a duct. So I went looking for the best design that would also be compatible with my design.
Hangtight's ducts proved in my tests to be the best engineered & highest flow. After consulting with him, I have gained his permission to use his duct and include it as part of this design.
Special thanks to Hangtight.
I: Design Challenges & CAUTION:
Small form factor, there is 5mm of clearance between the tip of the Nozzle and the bottom of the BLV X-Axis Carriage with the Mosquito in its lowest mounted position. There's no way around this.
What this means is as the nozzle comes to the bed, the belt clips will hit the bed first.
The stock bed strain will also be in the way as the printhead approaches the back left of the bed, where the cables extend above the flat plane of the bed.
Finally, because of the reduced form factor of the Mosquito, the linear rails need to be lowered down to allow the Z-axis to come down far enough for the nozzle to touch the bed.
Since this needs to happen, the height between the Z-axis Linear Rails and the bed is CRITICAL. If the linear rails are mounted too low, the bed will slam against the sides of the linear rails. If the linear rails are mounted too high, the rail carriage blocks will partially come off the rail channels as the nozzle meets the heated bed platform.
II: Solutions
1) The brass belt clips that are attached to the underside of the BLV X-Axis Carriage are too long and need to be reduced.
Option A - Print my remixed belt clips. You need to be able to remove the existing belt clips, do not clip them off. It can be quite a pain to remove the brass clips, but you can accomplish it using some pliers or needle nose, a small flathead screwdriver and your brain. If you can't manage removing the belt clips you will need to buy another belt that isn't crimped, as you need all of the length from the belt provided in the BLV kit.
Option B - By clipping the brass belt clips down to 3-4mm maximum in height with a side cutter or pliers with a cutting edge. Please don't attempt to cut them down with the blue flush cutters included with the Ender 3, they far too cheap and brittle to cut brass.
2) An alternative bed strain must be printed to prevent the BLV-X Axis carriage belt clips from coming into contact with the stock bed strain and its cables. I've found two on thingiverse that are adequate, both links are provided at the bottom of this page.
3) The Z-Axis Linear Rails must be lowered down in order for the printer head to reach the print bed. This can be accomplished easily without any disassembly of your printer.
III: Hardware & Installation
Hardware:
(Button head screws are required where stated in order to fit)
Blood Drive to X axis plate:
(3) 3x8mm button head screws
(1) 3x12mm screw(can be longer)
Mosquito Hardware:
(2) 2.5x15mm button head screws
BLtouch Mount Hardware:
(2) 3x10 or 3x12mm button head screws (BLTouch Mount to Blood Drive)
(2) 3x8-10mm button head screws (BLTouch to BLTouch Mount)
(4) 3mm nuts; Two retaining the BLtouch to the mount itself, and two retaining the mount to the Blood Drive.
Hardware for 5015 Fan Duct with Duct Adapter Mount:
(2) 3x20mm screws for 5015 Fan
(2) 3x4mm screws (Duct adapter to Blood Drive)
(2) 3x12mm Screws (Fan Duct to Blood Drive)
(6) M3 Nuts (Two for Fan Duct, Four for Duct Adapter Mount)
Blood Drive Installation:
First off and most importantly, be careful of overtightening and stripping out the holes in the x-axis plate. These are steel screws going into aluminum and it's very easy to do so. Follow basic torquing rules and always tighten your screws in a staggered fashion.
Before installing, Push-fit all of the M3 nuts into place on the Blood Drive.
Insert the 2.5x15mm button head screws into the depressed cavities on the backside of the drive.
Be certain that there isn't any filament ooze/stringing or stuck supports in the way of the M2.5 screws going into the Mosquito. If the screws are not seated properly into the depressed cavities before pressing the drive onto the x-axis plate, your Mosquito will not sit flush against the Blood Drive and/or you will strip the Mosquito's threads.
As this is a depressed fit design, the blood drive should be able to fit flush, directly onto the X-axis plate. If it does not, check to see where you might need to cut away or sand any plastic so that it can slide all the way into place, flush to the plate. If you don't do this, you will be relying on the screws pressure/force to smoosh down any plastic deposits, which the aluminum threads are unlikely to handle. If you have bleeding edges, it will tilt the mosquito so the hotend is not perpendicular to the build plate.
Position the Mosquito with the attached BMG-M into mounting position.
Screw in the 2.5x15mm screws one at a time, starting with the left(facing front) screw first, finger tight, then the right screw.
Then you may place your stepper motor in (wiggle it up and down to fit into the extruder gear) and tighten the stepper motor to the extruder.
AGAIN, you don't need to tighten this stuff very hard. Don't overtighten, or it will bind up the stepper motor gears with the BMG-M gears. You can spin the extruder gear to feel if it is binding.
Follow pictures for the rest.
Bed Strain & Z-Linear Rail adjustments:
After you have printed everything you will need and are ready to install the bed strain and blood drive, now is a good time to adjust the Z-rails.
To slide down the linear rails, use the MGN-12 jig alignment tools you should have from installing the rails previously, placing one on the top and bottom.
Center your X-axis carriage in the middle spot on the Z-linear rails where no screws are holding the linear rail to the aluminum extrusions.
Slowly Loosen each screw on opposing sides of the linear rail one at a time(do one rail at a time), being sure to not lose the t-nut inside the aluminum extrusion. When you have all of them loose enough, slide the linear rail so there is roughly 33.5mm of space between the top of the z-linear rails and the bottom of the top aluminum extrusion. Now tighten them back up in the same fashion.
Now when you adjust your bed springs, the bed should be no more than 2mm below the bottom of the z-linear rails.
Depending on your setup, you will have full 250mm of Z-space.
If you have Dual-Z with a single stepper and tensioning pulley or Z-braces, that will reduce the Z-height to about 235-240mm.
Printing:
The tolerances in this design are very tight, so be sure to have calibrated your printer.
As printing this object can be a challenge, I will provide a Cura only 3mf file with support blocks built in for the key areas.
Don't let the supports connect from the extruder mounted side to the Stepper motor mounted side. You will have a very difficult time removing supports if you do.
Minimum of 0.16 Layer Height is recommended. 0.12 for best Fitment
I'd also recommend at least 1.8mm thick walls, and 100% infill will give you the strongest part and yet again, better resistance to heat distortion.
The smaller the nozzle, the better the accuracy, and the better the fitment. I use 0.25 Nozzles for anything I want to print with very high accuracy. You can use up to 0.4mm.
My wire strain needs supports to print the concaved recess for countersunk screws.
The fan duct doesn't need supports.
The fan duct can be printed in PLA Pro/Plus if you like but recognize the ducts will deform if your leave your hotend on and/or parked near the heated bed on without the fan spinning.
With that said, you can actually anneal the ducts themselves naturally by printing with the fan spinning at 50%=>, as the radiant heat from the hotend and bed will reach the ducts and exceed the glass transition point, while the fan will keep the plastic cool enough to not melt and deform. PLA Pro can actually obtain a higher glass transition point of 90C, compared to PETG's 75C. I've had success doing this myself.
The belt clips are very small, might be possible with 0.4mm nozzle, but 0.25 will work better.
Firmware adjustments:
BLTouch Offsets:
X-40.2 ; Y-3.72
Firmware Y-Axis Offset:
Y-15.5 (This may be different depending where your y-end stop and rail is at, so just park the print head at the front of the bed and figure out how much you need to add or subtract to the offset)
Printable Surface Area:
X Axis: 230MM
Y Axis: 235MM
Z Axis(no dual z belt/tensioning kit): 250
Z Axis(w/ dual z belt/tensioning kit): 235-240
This modification is not plug and play!
However, I suspect that if you are interested in doing this mod and have already assembled your BLV conversion, you have the tinkering skills to accomplish this modification as well.
If you have found my work to be helpful in acheiving your goals, please consider throwing me a tip if you are able to. I've spent hundreds of hours on this design, improving it, and providing documentation for installation. You can use the tip designer button or click here. Thanks!
Thanks for checking out my design!
And please post your makes.
Why?: I received the Ender-3 Pro as a Christmas gift last year, having expressed interest in 3D Printing before. I became quite interested quickly. Then became the issue of owning a Mosquito and BMG-M with no way to mount it. I have set out to make this machine my own and to maximize its potential. I've learned a lot! It's been a journey.
Height Reduced 90 Degree bed cable Strain : https://www.thingiverse.com/thing:4104141
Alternative Height reduced extended bed cable strain (pay no mind to "drilling a hole" in the summary): https://www.thingiverse.com/thing:4497591
Bed Cable Clip for 4040 Extrusion: https://www.thingiverse.com/thing:3360288
Motherboard Case by ADKS : https://www.thingiverse.com/thing:4622318
Silicone Sock Mold - https://www.thingiverse.com/thing:3793665
Bonus Points Round:
I also designed a dual-z belt tensioning style mod that's purposed for parts from common dual-z kits available for purchase out there.
It incorporates ProperPrinting's Z-brace mod to work with the kit I already bought. This is probably one of the biggest upgrades you can do to your printer.
You can check it out here : https://www.thingiverse.com/thing:4668292