LowRider 3 — Aza's IDEX upgrade (2 Routers!)

Plan / Design > Intro

Who doesn’t want an automatic tool changer? That’s something I always wanted, but I still can’t rationalize the time/material cost of pursuing a full on automated solution.

However, @jamiek’s innovative LR3 IDEX build topic, now that seems like a neat achievable upgrade with decent enough ROI to be worth trying out. Also, his design allows cutting multiple identical/mirrored parts at the same time. So, here we go…

Jamie’s already figured out the details, written up and shared LowRider Dual-Carriage How-to (IDEX). So, am hoping this upgrade will go quick and smooth… LOL

Currently figuring out parts, have a router and filament already.

Parts > Hardware BOM

Specialty Parts

You can buy most of the Specialty Parts and hardware here, V1 Shop

QTY Description Comment Link
1 Steppers, Nema17 20mm+ shaft length ShopAmazon
1 Stepper wire extenders ShopAmazon
1 Pulleys 16T 10mm 10mm GT2 16 Tooth ShopAmazon
2 Idlers Smooth 20T 20T Smooth 5mm Bore ShopAmazon
2M Belt GT2 10mm See Calculator, no steel belt ShopAmazon
1 Endstops ShopAmazon
8 608-2RS Bearings ShopAmazon
* Thread locker Optional for grubs screws ShopAmazon
* Lube Optional for idlers and linear rails ShopAmazon
* Vac Hose Optional any 1.5" OD Vacuum hose should work Amazon

As an Amazon Associate, Ryan earn’s from qualifying purchases.


This is what is needed for upgrading LR3 to IDEX. You will need more or less depending on what craziness you’re embarking on.

QTY Description US Equivalent
8 M8 x 40mm 5/16" x 1.5"
8 M8 Nylock nuts 5/16" Nylock
10 M5 x 30mm Machine Screws
10 M5 Nylock None
4 M3 x 10mm Machine Screws
2 M2.5 x 12mm Machine Screws
2 Female spade crimp connectors
2 *Solid State Relay (SSR)

*Overspec reputable SSRs to easily handle expected Router ampage. Don’t want them running hot and close to the ampage limit.

Also reading through LR3 Core Assembly and watching my Core assembly video to recall parts and assembly.

Curious if anyone else has done this already? Been wanting to try upgrading my LR3 to an LR3 IDEX ever since following Jamie’s build, guessing he’s inspired others too?

Edit: Will try to keep this post updated, but at some point Discourse will lock and prevent additional changes. So, from then onwards, latest details can be found at https://github.com/aaronse/v1engineering-mods/tree/main/lowrider3/idex.


Awesome! :heart: :heart:

It occurs to me that SSRs might not be needed if you are willing to manually turn off one router and turn on the other. Powering the routers is a tiny fraction of the hassle of switching tool bits so you still get pretty much all the benefit of the dual-tool setup. Or maybe start without them and add it if you get tired of manually switching power.

In my case I was looking for 100% unattended setup, meaning primarily it had to be outside in a spot where fire is not a problem, and also to run unattended the SSRs for powering the tools were mandatory.

I’ll be watching this closely!


Parts > Hardware Ordered from V1E

@vicious1, how’s your experimental / new hardware counter/sorter/bagging system working out? I’d buy an IDEX hardware kit from you if that’s an option (order #23237) :slight_smile:

Order summary

60x60 Trucker Cap × 1
Black $21.75
60x60 Red Line Laser 5V × 2 $6.50
60x60 Tiny Touch Plate × 1
Kit $8.49
60x60 Stick On Temp Gauge × 2 $6.50
60x60 Small Screwdriver Set × 1
Black $2.99
60x60 Small Screwdriver Set × 1
Red $2.99
60x60 Bearings 608-2RS × 8
Standard $3.60
60x60 LowRider V3 Alternate LeadScrews × 1 $14.99
60x60 Limit Switch, Endstop × 1 $1.59
60x60 GT2 10mm Belt × 2 $4.98
60x60 20T Idler GT2 10mm × 2 $4.80
60x60 Pulley 16 Tooth GT2 10mm × 1 $2.80
60x60 Nema 17 84OZ/in Steppers × 1 $11.50

Subtotal $93.48

Shipping $16.20
Taxes $0.00

Total $109.68 USD

1 Like

Gotcha covered.


Ok, watching with interest.


Woo hoo. Watching this one with interest, Jamie’s IDEX getting a 2nd build… This is going to be great to see play out.


I bet there is a ton of footage coming that is getting run through some custom software…

Parts > Print Core > Attempt #1

Done bunch of small-medium prints on my MP3DP v4, have printed test cubes, large rectangles and temp towers to calibrate. Even so, I probably should’ve tuned more before kicking off this print, but what the heck… This’ll be the first yuge print on my MP3DP, added custom Fan Duct for the occasion.

No idea whether these are good/bad settings. Initial layers are laid. We’ll see what happens…

Edit: Changes while printing (layer ~26 of ~550) :

  • Dialed back speed to 80% after noticing 100mm/s infill was causing printer to shake too much and result in blobby mess. Doesn’t help that I forgot to take printer off a low profile lazy susan before printing :man_facepalming:
  • Dialed back extrusion to 97% after noticing nozzle seemed to be too low and carving through material previously laid. Vaguely recall calibration test cube wall thickness was a few percent too thick, so this makes sense.

You did a max flow rate test? 120mm/s with what diameter nozzle?

I think I max out at 55mm/s with a 0.5.

In terms of settings, I usually do the infill the fastest/or 120 width and a touch slower on the outer walls.


That’s a really good idea, so no, I forgot/skipped that. Did kind of test max extrusion speed when calibrating steps by feeding 100mm.

After checking dimension/skew accuracy I skipped a few tests, and jumped straight to the “suck it and see” test… 0.6mm noz, 0.32mm layers. Reduce speed a few layers in down to walls ~64mm/s, infill ~80mm/s, while rocking on a lazy Susan, vibration dampened with microfiber rags.

Everything’s going great, no problems…

Part cooling duct too high?

Edit: Done. ~9hrs 47mins. Hopefully dimensions are ok…


This test really opened my eyes. CNC kitchen has a blob test that you weigh…I want to try that one. Teaching techs is more quick and dirty, run it until your extruder skips or doesn’t flow smooth, then back off a bit. That got me to right where E3D said it should be (even though that info does seem to be sort of buried). I have not tried the H2 yet.


Parts > Print Core > Attempt #1 FAILED - Too tall

Checked Print dimensions (relative to the print bed’s XYZ orientation). XY are great, but Z height is ~5mm too tall :man_facepalming:.


  • Print Bed to highest point is expected to be 175mm (see dimensions in Fusion 360 sketch below). But my print actually measures 180mm.
  • Core width is expected to be 180mm. My print actually measures ~184.5mm across.

Didn’t calibrate Z axis as well as I thought. For my penance, have spent time measuring edges/diagonals of significant features touching the print bed :

Tempted to add calibration marks, slice and print first 2mm to verify dimensions/skew. Will use to compare against my existing LR3 Core. Reason being the existing Core was printed ~yr ago on different printer, I should verify new calibrated Core will match before doing another full print. I potentially might end up intentionally mis-dimensioning the new Core to match the old one.

Will recalibrate Z then kicking off Attempt #2

What your steps are off a tiny bit? That doesn’t seem right. Should be a whole number.

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Well, it could be out a bit on an MP3DP with belted Z… I have had pretty good luck with my belts personally.

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Parts > Print Core > Attempt #2 Success

Completely my fault, I calibrated Z using a pathetically small 20mm cube. The irony is that after calibrating again my Z rotation/esteps are back to 32. Related Klipper config edits.

Checked Z height this time by homing XYZ, Z-tilting, then moving Z axis to largest distance possible that could still be accurately measured from the bed. Ended up using the Attempt #1 Core and some other objects as measuring sticks…

2mm thin core slice from new printer matches 1yr old Core from diff printer close enough. Kicked off Attempt #2

Update: Attempt #2 in-progress. Consider Stick On Temp Gauge on Steppers mounted to PLA. Back when I first saw Stick On Temp Gauges, I laughed and thought they were a bit gimmicky. Today’s different, while observing a long running print, the stickers gave me useful information to not overly enclose and smother the printer. The nice and quieter snuggly towel wrapped printer quickly started to heat up with steppers getting to a point that would be an issue for PLA mounts. So, although am using PETG, have unwrapped and left the front open until if/when am using higher temp materials (ASA?).

Update: Attempt #2 done. Looks great. More importantly, dimensions and layer adhesion are great.


Now you have a core for destructive testing…


Put a router in it and tighten the mount as tight as you can. Bet it splits in half LOL

Plan / Design > Router Power and Control

Short: Bought NOYITO 4-Channel Relay Module, 5V trigger, Optocoupler Isolation, Load DC 30V AC 250V 30A to control power to Routers (and maybe other stuff) via Controller board’s Fan pins.

Enabling gcode to control power to each Router individually would be nice. @srcnet shared link to Enclosed High-Power Power Relay for Arduino, Raspberry Pi, PIC or WiFi, Relay Shield, looks neat, I hadn’t looked at before. Dug around the forum and found several folks seem to like and recommend this solution for easy and relatively safely controlling power to Mains powered devices. Dug around for product info:

Until now, have been turning Router on and off manually, guessing most people do, it’s easy. Originally had lofty goals of adding a relay, and PID speed control. But as usual, got distracted and ended up prioritizing other stuff… Despite this track record, instead of doing the quick safe option mentioned above, am going to try a 4-channel 5V triggered 30A rated Relay Module hooked up to my Octopus’s Fan ports. 4-channels instead of just 2, because might end-up achieving lofty goals of hooking up Vac, cooling, lights, lasers, etc… Have to make an enclosure at this point, so may as well include space for futures.

  • Was considering SSR, but they seem too reliable and pricey for things that needs relatively infrequent on/off switching?
  • Saw AMZN’s best selling HiLetgo OptoCoupler Relay Module is rated at 10A, which was too close to the Router’s 7A for me.



In general, “Horizontal Scaling” designs are great, but this…

Parts > Unboxing

@vicious1, thank you kindly for the “IDEX Kit #1” bag and other goodies, including the JackPot collectors edition pcb, nice! :slight_smile: