MP3DP v4 - Aza's build

Sharing notes/questions for my (likely slow) MP3DP v4 build, will periodically update as I make progress. Appreciate all the info people have been sharing, hoping my aggregated notes here helps others. This’ll be a lagged snapshot of what I’m frequently pushing to github.

MP3DP v4 (aka Repeat v2) — 3D Printed, CNC’d CoreXY 3D Printer

Tracking plan/tasks/actions in my build Log. Intending this doc to end up evolving into fleshed out structured notes.

See Official V1E MP3DP V4 Docs, they reference :

  • Repeat V2 forum thread containing design process/updates/feedback.
  • Fusion 360 hosted Design, export/download and print these parts for latest greatest design. Related forum post is here.
    • IF you open/import the model in Fusion 360 desktop app, you will be looking at a snapshot. The imported snapshot will not get updated if/when Ryan makes additional updates. So, you may need to reimport every so often if you’re wanting to absorb latest edits, and then make dimension/design changes for your build.
    • Created Python script, and topic showing How to Bulk Export parts to .STL files. Included a snapshot of exported .STLs in the /models subfolder.
      • As-is models will need orienting before splicing and printing.
  • Printable .STL files will be stable, but not latest.

 Note: Until full Official v4 docs are available, reading through v3 docs (albeit a different design) for general guidance will help. For example v3 printed parts docs has info that applies to v4 too.



Pics from

Pics / Gallery


Mostly Fun, and, maybe profit. Have an Ender 3 Max, great machine but has limited speed/quality/temps. Want something faster and capable of other printing other materials, not just higher temp ASA/ABS/PC, but TPU will be easier with direct drive instead of bowden. CoreXY frame/motion has misc benefits over my Cartesian Ender 3 design.

Super secret goal, arguably the most important one… is to inspire and lure the kids into 3D printing, a gateway to becoming a Maker…

Why others built one…

Low Cost (Parts, not labor…)


Quality / Speed / Reliablity

Ryan/V1E relies on these to run his business, so that says a lot.


Alternatives considered :

All that said, am biased toward building MP3DP v4 largely because of the V1E community support. To me, the V1E mindset is focused on getting great quality results for great value. This resonates with me more than paying a significant premium for something that pushes the limits, and may involve lots of maintenance. Creating, experimenting and extending is more fun than maintaining.


  • Default design is for 200mm x 200mm x200mm (not common).

    • Smaller builds like this are more rigid, so better-quality/faster.
  • Sizing related thoughts/considerations:

    • Dan200mm^3 is good all-purpose, but linear rails may be easier to source for 250mm^3
  • Calculate dimensions for your build using A) Math and/or B) Fusion 360 parameters:

    • A) MP3DP v4 dimensions math…

      TODO: Clarify

      Linear Rail X = Usable X + 100mm
      Linear Rail Y = Usable Y + 50mm
      Linear Rail Z = Usable Z + ~50mm (**)
      Extrusion Frame Length X = Usable X + 170mm
      Extrusion Frame Length Y = Usable Y + 145mm
      Extrusion Frame Length Z = Usable Z + ~145mm
      Linear Rail Cut list...
      Extrusion Cut list...
      3 x Extrusion Frame Length X
      8 x Extrusion Frame Length Y
      3 x Extrusion Frame Length Z
      Belt Cut List...
      e.g. Buy 5m for Usable 300mm^3
      3 x (Usable Z + 150mm ) +
      1 x (4 x (Usable X + 200mm)) + (4 x (Usable X + 50))

      (**) Z dimension is approximate, can vary depending on bed mounting thickness.

      References: Dan

    • B) Change dimensions Use Change model parameters


Read: Mp3dp v4 bom - #79 by azab2c




Solved the MP3DP v4 BOM Puzzle thanks to folks in this Topic. Using the following info:

V1E Shop Parts

Parts listed for purchase from V1E Shop. Alternative links provided incase parts out of stock, and/or you’re purchasing from other place(s).

QTY Description Comment Link
1 ** SKR Pro 1.2 Control Board 6 driver minimum (for 5 motion steppers + 1 direct drive extruder) ShopAmazon
6 TMC 2209 Buy 6 drivers if not supplied with Controller board Shop
5 Steppers, Nema17 76OZ/in, e.g. KL17H248-15-4A ShopAmazon
5 *** Pulleys 16T 10mm 10mm GT2 16 Tooth ShopAmazon
6 *** Idlers w/Teeth 20T 20T w/Teeth 5mm Bore ShopAmazon
8 *** Idlers Smooth 20T 20T Smooth 5mm Bore ShopAmazon
5m for 300m^3 **** Belt GT2 10mm No steel belt ShopAmazon
2 Omron Limit switch, endstop Use Omron or red rollers ShopAmazon
3 Springs For bed, silicon tube will work ShopAmazon
* Thread locker Optional for grubs screws ShopAmazon
* Lube Optional for idlers ShopAmazon
* PTFE Tube Optional Extruder to filament ShopAmazon
* Print Fan Optional fits hemera mount ShopAmazon
6 Stick on Stepper temp gauge Optional Shop
1 ESP-01s ESP3D headless Optional Wifi dongle for SKR Pro 1.2 Shop
6 3/8" wire sleeve Optional Shop
1 50mm PTFE liner Optional, need more if building bowden setup Shop

As an Amazon Associate Ryan earns from qualifying purchases.

** Personally, am using Octopus 1.1 instead of SKR 1.2 for my build, will have more Mod options, but will be more work to setup. SKR 1.2 and Rambo have better Community support.

*** Pulley/Idler break down :

  • 6 Pulleys 16T 10mm.
    • 6 = 6 x 1 per Stepper.
  • 6 Idlers w/Teeth 20T
    • 4 = 2 x 2 per Left/Right rear corner
    • 2 = 2 x 1 per XY Left/Right
  • 8 Idlers Smooth 20T
    • 6 = 3 x 2 per Z post
    • 2 = 2 x 1 per XY Left/Right

**** Belt Calculations, cut list :

  • 3 x (Usable Z + 150mm )
  • 1 x ( (4 x (Usable X + 200mm) ) + (4 x (Usable X + 50) ) )

Parts not listed on V1E Shop



QTY Description Comment Link
??? M3x8 - Linear rails all use M3x8
  - (x+100+(2 * (y+ 50) + 3 * (z + 50)) / 25
  - Excel… =(A1+100+2*(B1+50)+3*(C1+50))/25
  - e.g. 62 for 200mm^3
- One stepper mount marked with an “8”
??? M2.5x12 - Endstops
??? M3x10mm
~113 M3 or M5 Button head by 8+ mm - 4 x 25 Side/Back/Bottom Panels
- 13 Front lower Panel
- (M5’s will have less wiggle room)
- 8mm for 1/8" panels, 10mm for 5.5mm+ (e.g. 1/4")
- Measure/check length needed for panel thickness
Panel bolts
??? M5x30mm
??? M5 Slide in Nuts - Use slide-in nuts, rotating T-Nuts are horrible amzn



QTY Description Comment Link
1 X Linear rail MGN Usable X + 100mm MGN12H FilaAmazon (select correct dimensions)
2 Y Linear rails MGN Usable Y + 50mm MGN12H FilaAmazon (select correct dimensions)
3 Z Linear rails MGN Usable Z + ~50mm MGN12H FilaAmazon (select correct dimensions)


QTY Description Comment Link
1 Extruder or other tool Hemera,example, match voltage, 24V is good.
1 Power Supply Match voltage to your setup
e.g. MEANWELL LRS-350-24
1 Heated Bed Style and Size will vary ShopAmazon
1 BL Touch Probe
1 Pi 4 or at least 3+ Klipper/OctoPi controller Good luck!
1 Micro SD
1 Display BIGTREETECH TFT35 E3 V3.0.1 BIQUAmzn
1 Adaptor Board BigTreeTech EBB 36/42 Can Bus
- CAN Bus overview by Teaching Tech (YT)







Vibration Management




Extruder Options

E3D Hemera

BIQU H2 V2.0








Frame Assembly

Z Post Assembly


Squaring/Aligning rails


  • Dan recos routing wiring to Z Post M Steppers along the Bed Support Plate, use misc holes in the plate to secure wiring, including providing strain relief for heater bed wiring.


GCODE configuration

Power down and/or resets will cause bed to crash down. So, “gcode needs to park the z axis at zmax”

MP3DP v4 V1E Community builds / builders

Some of the Community MP3DP Build Logs that helped me.

v4 builds

v3 builds

  • @ RootsMedia’s 310x310x280mm MP3DP Repeat, Take Two
    • Repeat v1 with sweet ACM/PolyCarb enclosure, complete with logo engraved panels.
      • 24v Mean Well
      • Textured PEI magnetic build plate

v2 builds


  // DONE - sort by print order
│     2 x Z Post.3mf    2.3hrs
      Z Post M.3mf      2.3hrs
      XY Left.3mf       2.3hrs
      XY Right.3mf      2.3hrs
      Left Stepper.3mf  2hrs
      Right Stepper.3mf 2hrs
      X Carrier.3mf 4.25
      Back Corner Left.3mf  1.75hr
      Back Corner Right.3mf 1.75hrs
      2 x Tension Block XY.3mf   1hr
      6 x Z Belt Holder.3mf  6 x 0.5hr, 3hrs


  // TODO
      Hemera Fan Shroud.3mf

  ├───Misc 2020 clips and parts
      2020 Corner Bracket.3mf
      cable tie Wire Hanger.3mf
      Power supply bracket.3mf
      Wire Clip 90 degree.3mf
      Wire Hanger TapeTrick.3mf

  ├───MP3DP V4.1
      Bed Washer.3mf
      filament Rev Bowden Holder.3mf
      Rail Aligner.3mf

  ├───SKR Pro
      SKR Pro Cover.3mf
      SKR Pro Wire tie.3mf

  └───TFT E3 V3
      TFT Holder.3mf

PARTS - Decisions and purchases


  • Probe : Have unused BL Touch
  • Frame: Have Black/Silver extrusion leftovers
  • Wifi: Have Pi (will Klipper/OctoPi)
  • Controller: Octopus v1.1
  • Drivers: 5+ TMC2209 (EBB 36 has TMC2209 onboard that can drive Nema 14 in BIQU H2S V2 REVO)
  • Display: Bigtreetech TFT E3 V3.0.1
  • Linear motion: Iverntech, chose because deliver fastest and best seller… Wasn’t reco’d by forum, so could be mistake, will find out…
  • Fasteners: Rummaged, purchased, delivery pending. Guaranteed to need more parts.
  • Power Supply: MEAN WELL LRS-
    350-24, enough/too-many Watts?
  • Extruder: BIQU H2S V2 REVO - Paying premium for REVO to reduce effort for kids/me to change nozzle.
  • Nozzle: REVO 0.6mm (for now)
  • CAN Bus controller: EBB 36
  • DIN Rail, bought wago 210-504 from local electrical supplier (Platt Electric Supply), cheaper/faster than online.



  • Heater Bed with Thermistor :
    • My current Ender 3 Max has 24v 310mm x 320mm, 4mm thick Carborundum Glass, 3mm Alu, 3mm Foam.
  • Wiring: Same as above.
  • Solid State Relay (SSR) if using 120vac bed heater.

Fastener BOM break down:


Fastener and mount parts:

  • 4 M2.5 x 12mm Bolts

    • 4 = 2 x 2 Endstops
  • 40 ??? M3 x 8mm Bolts (8mm for extrusion, maybe 10mm for wood/plastic panels with inserts)

    • 6 = 6 x 1 per Z Belt Holder
    • 20 = 5 x 4 per Y and Z Linear Rails (~100mm spacing)
    • 4 = 2 x 2 per Tension Block
    • 10 = 5 x 2 per Motor Block
  • 44 M5 x 10mm Bolts

    • 12 = 6 x 2 per Right Angle Corners (Z Mid extrusion)
    • 32 = 4 x 4 corner brackets x 2 nuts per Z Corner extrusion
  • ??? M5 x 30mm Bolts Pan Head (reco Philips)

    • v3 required 29
  • ??? M5 x Nylock Nuts

    • v3 required 29
  • 30 M3 Sliding T Nuts amzn

    • 6 = 6 x 1 per Z Belt Holder
    • 20 = 5 x 4 per Y and Z Linear Rails (~100mm spacing)
    • ?? = X Linear Rails?
    • 4 = 2 x 2 per Tension Block
  • 44 M5 Slide in Nuts amzn

    • 12 = 3 x 2 corner brackets x 2 nuts per Z Mid extrusion
    • 32 = 4 x 4 corner brackets x 2 nuts per Z Corner extrusion
  • 20 ??? Corner Bracket Right Angle

    • 6 = 3 x 2 per Z Mid extrusion
      14 = 7 x 2 per Z Corner extrusion
  • Order M5 slide in nuts

  • ??? M3 12mm Button Flange for 1/4" (6.35mm) external panels.

  • TODO:

    • Stepper?
    • Board Mount?
    • Fans?
    • Hot end?
    • Cable mounts/brackets?
    • PSU?
    • Panel design
      • For builds without bottom panel helping square X and Y extrusion, consider adding slotted holes (dimensioned for 2020 Corner brackets) for where bottom Y Axis extrusion meets back X extrusion.
      • Review all panels, ensure sufficient number of perimeter holes to securely fasten panel. Perimeter bolts should be no more than 100mm apart, ideally much closer.
      • Ensure side panel perimeter holes line up with sheet metal slotted holes.
      • Doc M5 x 10mm if 2mm panel
      • Doc M3 x 10mm if 2mm panel
    • Doors?
    • LID?
  • Model changes

    • Added top|bottom Z Belt Holders to rear, so holes can be projected onto sketch for interior rear panel.


  • Usable_Depth = 250mm
  • Usable_Height = 250mm
  • Usable_Width = 250mm


  • 4x Frame Z corner uprights, Front|Rear Left|Right 395mm

    • Actually cut 500mm and 600mm for uprights, added 100mm below for all uprights to accomodate wiring, also added 100mm for rear upright to accomodate lid.
  • 4x Frame Y Top|Bottom Left|Right 395mm

  • 3x Frame Z Mid Left|Rear|Right 355mm

  • 3x Frame X Front|Rear Top|Bottom 420mm

  • 1x MGN12 X Rail 350mm

  • 2x MGN12 Y Rail 300mm

  • 3x MGN12 Z Rail 300mm


Assimilated Voron Parts

Voron Trident GNU License
Voron Trident Manual



1 Like

Ugh. After feeling smug about using Teaching Tech’s Calibration Tool to tune your settings; Do remember to uncheck “Remove All Holes”, before you print ~8hrs worth of parts :man_facepalming:

Bummer, I wonder why that setting even exists. That can not be a common need.

1 Like


1 Like

Thanks for all the info!!!

1 Like

Wrote Fusion API Python script to query parameters and parts. Was curious how easy/hard querying bounding box for geometry dimensions would be. Wasn’t too bad, however…

Currently, most of the extrusion frame dimensions change if you edit User parameters, this is great. Unfortunately, the linear rail and a couple of mid extrusion frames are not updated correctly. Not a big deal, can easily workaround by using the 200mm^3 as a baseline, then just add to each dimension as needed for your build. Easy!


  • Usable_Depth = 200mm
  • Usable_Height = 200mm
  • Usable_Width = 200mm


  • Frame X
    • Frame X Back Bottom 370mm
    • Frame X Back Top 370mm
    • Frame X Front Bottom 370mm
  • Frame Y
    • Frame Y Rail Bottom Left 345mm
    • Frame Y Rail Bottom Right 345mm
    • Frame Y Rail Top Left 345mm
    • Frame Y Rail Top Right 345mm
  • Frame Z
    • Frame Z Back Left 345mm
    • Frame Z Back Right 345mm
    • Frame Z Front Left 345mm
    • Frame Z Front Right 345mm
    • Frame Z Mid Left 305mm
    • Frame Z Mid Right 305mm
  • 1x MGN12 X Rail 300mm
  • 2x MGN12 Y Rail 250mm
  • 3x MGN12 Z Rail 250mm

(manually formatted a bit for easier reading)

Edit: Striked out wrong info in my original post. You can update model dimensions, there’s just some extra steps involving editing multiple files. See MP3DP v4 - V1 Engineering Documentation for details.


This is awesome. Would you mind to run it for 310 x 310mm print bed size?


  • Usable_Depth = 310mm
  • Usable_Height = 400mm
  • Usable_Width = 310mm


Short: Sure thing… Add 110mm to the X and Y values above. Add 200mm to the Z values above.


Sure thing… Problem is that the model doesn’t update correctly, and the script is merely reporting whatever the Geometry dimensions are… Looks like Linear rails, Mid Frame extrusion and Back bottom frame do not update correctly, at least for the current MP3DP v4 snapshot I’m looking at.

Not a big deal, not something we need fixed. We can just add to the values for the baseline 200mm^3 numbers.

e.g. if Usable Z 200mm has Frame Z Front Right 345mm then a Usable Z 400mm would have Frame Z Front Right 545mm

That help?

Edit: Striked out wrong info in my original post. Removed link to the video as well. You can update model dimensions, there’s just some extra steps involved to edit multiple files. See MP3DP v4 - V1 Engineering Documentation for details.

1 Like

Yes, that does help. Thanks.

If you update the parts, then update the assembly model, it works.

@DougJoseph because the MGN rails work out best for 25mm increments, I’d either go with 300mm for t he X and Y, or else bump it to 325. (If you’re cutting the MGN rail anyway, I suppose that you could still do 310, it will just be a bit weird for the hole spacing.)


The X dimension has to be in 25mm increments, or the X rails will not fit on the side blocks.

1 Like

Good to know, although I’m not sure what it means to update the parts!

OK, doing 325 instead of 310 should not be a problem. I guess it would mean the platform for the 310x310 print bed would have extra space on all sides.

Do you have a drawing for the z plate that connects to the Z motors?

I have updated the instructions, showing exactly how to make one that fits whatever bed you plan on using. Most beds have holes in different locations.



Thanks for taking time to update the docs, wasn’t expecting you’d have time for those.

I striked out the wrong info in my earlier posts. Didn’t realize we need to edit dimensions within the “Parameters” file, that’s great to know. I was wondering why I couldn’t edit dimensions within Favorite User parameters from within the MP3DP v4 file.

The big red arrows on MP3DP v4 - V1 Engineering Documentation help :slight_smile: Cheers!

Edit: I should have read Repeat v2 Topic more closely…


It just takes soooo long to do. I love that something is finally done though. I got all my MP3DP parts cut out today so maybe I will have some more time for that before Rmmrf, we’ll see I still have the rest of the build and hopefully a LR3 to finish and pack up.


the purpose of this post in this thread is to ask for some clarity on the baseplate holder hopefully as an informational addition to the information above for those of us interested in correctly sizing a 3d print heated bed to be put on a somewhat custom plate inside the MP3DP. What material should the plate be made of and is there a recommended size or size overage for the desired effective print area?

@vicious1, your useable print plate area is 200x200 for xy, what size heated plate did you put in there? 210x210, 235x235? your baseplate design instructions are well done.

@DougJoseph you asked for a 310x310 heated bed plate. Are you planning for 300x300 useable print area?

@supraguy building a 250x250, what size plate did you use?

azab2c (we are only allowed to mention 3 users in a post?) are you going stock on your build in this thread? And thank you for the time spent to link everything into one place! Your BOM list is very helpful as are the links to the other builds.

Yes, that’s the plan.

1 Like