At what point am I supposed to throw in the towel and abandon this project?

LowRider CNC Advice
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Not satire, to be clear. Inches away from either crying or punching my LR3, maybe even both at the same time.

This build has given me nothing but trouble since the board has been introduced into the mix. Fought through all of this, and had it working. Had it cutting, even. And now it’s borked again, and nothing makes sense why.

deep breath. Calming thoughts. GoosFrabaaa…

Okay, I was planning on building a full sized LR3 for the last 18 months or so. I had all my parts printed, my gantry was assembled, but no board or screen implemented. Went to go make a table, and apparently made a 7’ long instead of 8’ long. It wobbles from someone looking at it too hard. But you know what, that’s fine. The table can be remade later, as long as it can CUT, i’m good with it. Table is annoying but not the end of the world. I accept this as my fault.

Look through my pile of SKR boards for something similar enough to a SKR Pro v1.2 to use. SKR2? Sure. Attempt to re-write Marlin FW for different board. Didn’t finish, didn’t understand what I was doing wrong. Decide to use prebuilt FW on a pre-selected board. I know the SKR series, so SKR Pro it is! (What a mistake this was). Forget to order board to finish project.

18 months later, I catch flak from the better half about needing to finish projects instead of starting more. CNC needs to be finished and working.

Fine.

Time reference: 3 months ago.

I get the board (SKR Pro V1.2 with TFT35 screen), flash it via SD card, wire it in. The screen? Flashed with Firmware. Did not customize anything, used the firmware as it was given for BOTH of these silicon rat bastards. Screen works, but can’t connect to the board.

I attempt to re-flash the board? No flash. I try different SD cards, no flash. I try my dedicated “FW Updater” card for my non-klipperized 3d printers? STILL no flash. Ugh. I disconnect all the wiring, bring it back inside, connect it via USB into the PC, try to look at it with STM32Cube. No issues, takes the flash from direct injection juuuust fine.

Take it back outside, reconnect all the wiring, fight with the endstop locations because I plug them in wrong (there’s a forum post I made about it but it’s a Marlin min and max issue, I have been re-educated but i’m still counting this as a frustrating issue). Think it’s a faulty Z2 endstop on this board, because the stupid little light next to where that motor is plugged in isn’t doing anything when the endstop is triggered, when all of the other ones will toggle. Order new board.

Fight with flashing, not as hard this time but still irksome. Wire in the board. Power on. Screen doesn’t work. Attempt to reflash, nothing. Testing, screen is dead. Tried to apply power directly to it without using a USB connection, no joy. It’s dead, Jim. D-E-D, Dead. Order another screen. Flash and install. Hasn’t given me another issue (yet).

Fighting with board 2, Figure out the endstops i’ve wired are wrong. Reconnect in proper alignment. Finally make forum account and ask why (this is where I got educated). Go to home all axes? Z1 doesn’t move. Bends Z screw on Z2 side during uneven movement.

Diagnostics and process of elim says the motor is good, the driver is good, it’s only that specific port on Board 2 that doesn’t work. Multimeter testing confirms issue. Board 2 is working, but natural Z1 port is not an option. Didn’t want to redo the Firmware to move the motor over, mainly due to vietnam-level flashbacks of trying to recode for the SKR2. Nah, i’m good. Idea! First board I was trying to use may not have been actually dead, forum post (somewhere) said that the LED can be burnt out but the endstop will still trigger! Might as well test it, otherwise it’s another 60ish bones for another board. Board 1 works! Back from the grave it comes!

This is the part where things start going well. All axes and endstops work, machine moves! Need to square it before use, obviously. Take measurements on my stupid 4’x7’ table of corners. By the way, no way to change the movement speed of the steppers, nor is there a way to input a coordinate I want it to go to (Didn’t test terminal commands). I’m having to tap the screen many, many, many times to move from X0 Y0 to X1225 Y2140. Measurements are off by 40+ mm.
Ughhhhhhhhh.

Take a break, re-print a new electronics case that has space for a rPi. Install CNCjs so I can control it with the laptop instead of the touchscreen. Remove and re-wire the entire thing. Re-test, works just like before, no issues whew. Endstop connectors are a little loose. Apply hot glue to all connectors to prevent accidental disconnect.

Use the wrong method for figuring out which side to shorten (Tried to use Trig, thought I needed to shorten the ArcCos… you know what, just trust me, every time I did my calculations I was essentially doing it backwards, and making it further away from square. I need to draw photos to show what I did wrong). End up completely redoing attachment points for the belts, Y2 side rail clips, all of it other than rebuilding a table or rebuilding a gantry. Machine is now like 2mm off. Good enough for a 4’x7’ working area for now.

Attach Dewalt 611 to LR Base. Ready to start doing real stuff, yeah! Dewalt attached. Attempt to attach shop-vac hose from Ridgid shop vac. Hose too fat. Not 1.75 inch, larger. Scour forums for correct size of hose to purchase (Because why would it be on the build instructions?). Find correct size. Buy 10ft hose. (This was not a long enough hose, btw.) Return to house, run hose through the hose hangers on the gantry. Power on, attempt to home? Z can’t raise up. Able to assist the gantry by applying upward force, like everything is too heavy for the Z motors.
Increase amperage from 0.6 (default) to 1.0A, knowing that maximum is 1.2A RMS for these steppers. Steppers now move! Feel smart, attempt movement tests with vacuum hose attached.

Nope. Just… nope. Hose wasn’t long enough, didn’t give the gantry enough of it to hold onto, hose and wires for X snag on everything instead of falling back into the hose hangers. Don’t know WHY I expected this to work like a cable chain, but it obviously didn’t. To hell with it, we’ll redo Dust collection later. Let’s just get these strut plates cut so it’ll have the rigidity it needs. Check the electronics box that I printed, designed for a 1/4 inch strut plate. Sure, that sounds fine, but I have no 1/4 inch material. Did you know that the large box stores don’t carry 4’x8’ sheets of 1/4" MDF anymore? The only thing that was thin enough to work for the strut plates was 1/8" plywood. Nooooooope. Not enough rigidity and for sure not for that price. Leave disappointed. Strut plates are still not cut to this day.

That brings us to today!
Machine is running, but if I’m going to use it, need to surface my spoilboard. Largest surfacing bit I have is 1". 25.4mm diameter but 50% stepover on the surfacing, over 2100x1200 area at 3000mm/min it’s gonna take a while. Start the cuts. Let it run for an hour or so, maybe get 1/4 of the way done. Garage looks like a Cheech and Chong movie, but with sawdust instead of smoke. Dust collection is no longer an optional item. Stop the cuts, start sucking up the dust with shop-vac, clean the garage up.

Look at the LR3? Tilted. Z1 at 1/4 up from bottom, Z2 at top of travel. Attempt to home machine to fix Z imbalance. Z2 moves down from top of travel, standard homing procedure. Z1… not so much. Z1 moves down, like what the machine would do if it were trying to home after clicking the endstop… but doesn’t move back upwards. Motor is not jammed, able to be freely rotated when power not applied to motor.

Oh! Is the endstop constantly triggered? That’d make sense, if it’s trying to move away from the triggered endstop. Nope. It’s not that, endstop passes M119 open and triggered tests. No issues.

I’m mad at a lot of things, and i’m not excluded from that list. But this… This makes me wish I hadn’t disassembled my xCarve, since the only issue THAT had was that the Z wobbled when attempting to cut. Which would have been FAR easier to fix than dealing with all of this.

Lastly? Marlin sucks on CNC. IF I continue this project, i’m gonna try going to a FluidNC ESP32 board…combo…thing. I’m so mad I can’t even remember it properly.

This post took 6 passes to remove the profanity, because it was laced harder than [Removed by Editor].

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Oh man - I’m so sorry you had this experience. It must be driving you crazy.

I’m tired just from reading your experience. Wow - you really persisted.

I’m afraid I’m not an expert, but I can certainly sympathize. I would simply offer that the guys on this forum are awesome and I’m sure there are several that can help you with some troubleshooting ideas.

My suggestion would be to carefully move the machine and take a quick video of each incorrect movement, take some close-ups of the control board and wiring, and take some stills of the various issues. If you post that, I’m sure people here will start to point out areas where you might try making a change to correct the issues. Posting images is pretty easy, but I think you might need a place to host videos to link.

I’m pretty sure the expertise exists in this forum to get you up and running. I’m betting each of your problems have been conquered by people here.

I’ll watch and chime in when I can contribute.

Edit - and I started on an SKR board but the Jackpot is potentially the best decision I’ve made recently. I think you’d have a completely different control board experience with a Jackpot. (Or other FluidNC based board.)

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That was a painful read, but it had to be more painful to experience. Sorry man. I gave up Marlin on the CNC for klipper. It isn’t perfect, but all this reconfiguring is much easier. The initial setup takes a little longer though. I have cooked a few boards and had one motor stop moving because of a bad wire connection. On the MPCNC, the z axis would only go down because one wire was broken. If the same thing happened on your LR, one z side would go up as it should, but the other one with the bad wire would go down. It is likely a pin pulled loose. good luck! sounds like you are seriously in the home stretch.

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Greetings, @Zearkos .

I’m super bummed out that you’ve had such a rough experience with your LR3 build journey.

One thing you’ve just started with on this journey is to leverage the forum.
We have a really great community here to support each other and help get builds working, troubleshoot, coach, teach and when necessary commiserate or just plain cuss.

As I read through each of your issues listed above, I think about the help and guidance that we might have been able to offer to you and how we might have helped you along.

If you’d like to try and let the community help you, let’s take a deep breath, regroup, and as a community let’s see how we can help you get that thing up and running reliably.

I gaurantee you that there’s no problem you’ve encountered, no defective hardware, no mistake made, no frustration felt that a bunch of us in this forum haven’t screwed up worse, broken more thouroughly, or flat lost our sh1t over.

We can help you if you want it, bring it on.

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^ THIS!

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I thank all of you for your kind words, and the sympathy for the struggle up to this point. Now that i’ve slept on it, i’m not as overwhelmed as I was before, and can possibly make some half decent decisions.

I’m going to keep going, but not half-cocked or without a plan.

@dgkeith237 The Jackpot board was what I was thinking of going with! I couldn’t remember the name. Either that or i’m thinking i’ll pick @orob brain on the Klipper use.

@orob Physically, the wires did not look broken, and the pin housing was hot-glued onto the board, but I will check for continuity on the motor’s windings. Could I pick your brain on the Klipper setup for the MPCNC? Specifically how you bypassed klipper wanting an extruder?

@MakerJim I thank you for the welcoming attitude towards the challenge. My main issue is that the problems I’ve been experiencing aren’t specifically difficult. I understand what needs to be done to solve each individual issue, but I was also trying not to use the “Fire the parts cannon” mentality that usually pervades my build projects like this. I’ll reach out and explain the problems I have, and my expected resolution, but mainly it’s just tedious to constantly run into roadblocks when I JUST WANT TO CUT THINGS (and possibly be able to make the hobby pay for itself.)

I’ll let you all know how it goes. Thanks for letting me vent by writing out the chronicles of this build.

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You simply remove references to the extruder. Add a couple manual zero macros and set up a custom .pp file in estlcam for it. There is more room for macro tuning, but I think the mpcnc is up to about 10 hours of cut time with klipper doing pockets and carves, so it isn’t just a thought exercise.

I put an skr on the LR4 I just built with klipper and I can get you the printer.cfg file for it. It also uses a btt LCD, but not the touch screen. I have a 3.5" rpi-connected touch screen on the mpcnc. Microcenter carries them for like $20 and it works ok. The 8" touch is where it’s at.

I’m using RPI 3a or 3b/b+ or zero2w (with pi4 expander connector). Klipper was installed with kiauh utility on a lite image with no gui. Printer.cfg file came from the btt example file for the skr pro and was customized for my board connections. I fought the extruder failure on startup until all references to it were removed. Once it went away. It just works.

The pp file for estlcam was required to send G1 / GX instead of G01 and G0X. It initially choked on that and then the arcs were backwards… Use relative arc motion.

The LR4 is currently with a friend. I can get the config files for it, but not right away.

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The best advice I can ever provide to people struggling with electronics for these builds is to purchase your board from the V1 shop. The boards are tested and come pre-loaded with the correct firmware for the machines.

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LOL, I’m a cheap bastard, and hate to spend any more than is absolutely necessary. So I have had to learn patience when doing this and other projects (well that, and using Microsoft products…)

If you choose to continue with Marlin, I can help as much as possible. GRBL, Klipper, Jackpot/FluidCNC - you are better to rely on the others who have posted so far.

The trick, I think, will be to start at the very beginning, and verify simple things, such as having you tell us exactly which firmware versions are currently loaded into the SKR Pro v1.2 and the TFT35 boards. Then we can have you do some simple movements from the screen, and then look at the homing issues. But one step at a time.

It may seem like we are traveling roads that you have already been down, but sometimes we may have been down the road, but missed noticing the important road sign because we were rushing/distracted/tired/frustrated etc.

In any event, the community can and will get you going here, whichever path you choose to take.

.

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Yeah, I am cheap, and I am persistent, but in your post, I think i would have quit and bought a jackpot by now.

Configuring marlin on its own is a process. I am very talented and have never tried. Others do it very well. With the jackpot, EVERY Change is just a file change, even stepper amperage. Ryan does not charge alot for it, and it comes with nice 2209 drivers.

Then if you still have issues, we can all assist very easily.

It does not state where you are at, but if you order from the link, it will come out of California.

As stated, there are many BRILLIANT minds on here, and you can possibly get help to rectify that skr board, but at this time, it may just be easier to get the jackpot. Ask you wife, I am sure she would say your time is worth more than 65 bucks.

Oh no!, I just saw Sold Out in the store. If you want one, ping Ryan and see when they will be back in stock!

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Im cheap and stubborn. If i have something that will do the job, I’ll take the 6 months to make it work if only once just to check the box. I’m not buying another board when I have one that will work. I’m going to make it work the way I want it to work even if it isn’t an approved setup. Google is my friend.

Having said that, I’ll help you get yours working if that is what you want. Throwing more parts at the problem is always one answer, but I have found that you can often fix what you have with some time.

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The option to have the store email you when they are back in stock is a better option. It is reliable and when new stock comes in, it is almost never selling out in a short period of time.

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Oh no! I got to the end of the thread and there’s no conclusion to the story. @Zearkos did you get it working?

I went the SKR Pro route recently and I should not have. (I think it should be stricken from the docs.) The endstop circuit having a known design flaw is particularly bad. I have had the Z endstops get shoved out of alignment soo many times. I was going a little nuts, checking wiring and everything that could be related, but at last found an old thread about it on this forum.

Oh and FWIW, I’ve put Klipper on my LR4 and it’s been a kinda crappy experience. It’s flawless on all my printers but it’s not designed for the CNC workflow/scenario/hardware no matter how many macros you write. Just as one example: you must enter a positive Z max height in the config or it’ll complain about moving out of bounds after you’ve set zero to the stock surface and try to move the gantry up (e.g to put on the dust shoe). The issue with having a positive Z value is the firmware will happily move the gantry up even after homing Z (pushing the gantry up through the endstops and stalling the motors or breaking plastic).

I’m going to try grblHAL and already I can see things like gSender have nice features that would be impossible or a lot of work to implement in Klipper, like the “frame” feature that moves the toolhead in a box over where the cutting would happen.

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Interesting that your z has been an issue with klipper. I’ve put it on 3 cnc systems and never had that particular issue. One was an mpcnc and the other 2 are LR4s. Would my config file be of any help?

Start your own thread and Ill post it if you want.

The lr4 homes to max. You need to tell it that is the max and what the max z is, so when you zero, it only shifts the zero position, but doesn’t change the max. Macros make it work, but it has to be the right macro code. Happy to help if you want to try again.