LR3 Kits Advice

Hey, quick question:
The assembly docs make reference to “rear” but I don’t see where that is defined. I may have missed it.

Is “rear” referring to the long Y side that has the Y rail? Or the long Y side opposite of that? Or the short X side having the wiring brackets nearest it?

Opposite side of the tool. Can you tell me where this is so I can try to clarify it.

X is left to right, Y is front to back, Z is up and down.

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I guess when I wrote this, I did not expect the LR to ever be someone’s first CNC. We have definitely changed that over the last couple years.

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On the docs page here: LowRider CNC V3 - V1 Engineering Documentation

…there are 11 mentions of “rear” (by my browser’s find tool count). It may seem obvious to some what is considered rear, but I think it would help if it was defined at the start (a type of “conventions used in this documentation” kind of thing).

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Clowns to the left of me, Jokers to the right, Here I am stuck in the middle with you…

That’s the first thing that came to mind when I read the above. But the more I thought about it, I asked myself, how did I know the X Axis was L-R, and Y is F-B and Z meant up and down? And you may ask yourself, “Well, how did I get here?” - enough with the songs, in all seriousness:

Did I read it somewhere? Did I just become familiar with CNC thru work and absorb the knowledge? Did I guess it by luck? Was it intuitive?

And then what Ryan said really hit me “I guess when I wrote this, I did not expect the LR to ever be someone’s first CNC. We have definitely changed that over the last couple years.”

Yes you certainly have, and there is a whole new audience out there, that probably doesn’t know the difference between their ABC’s and their XYZ’s.

And yet they are able to build an MPCNC or a LR. This is a lot like software, constant change. Either you get the code documented for another programmer to understand the logic, or documented for an end user, but never both!

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The station I listen to plays this at least once a day!

I did dig around and I have this explained on the software page, but for most I suspect they will not look at that until after they build the machine. I do need some sort of diagram.

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We have a coordinates page too. But a big concept like that could use repeating.

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Re: LR3 control box for SKR Pro 1.2 + TFT35 E3

Hey, has anyone already modified the “blank cad model” for SKR Pro 1.2 + TFT35 E3?
If not I could give it a go.

UPDATE: Um, I just realized I typed the wrong board name. I had mistakenly typed SKR 2, which I have in a lot of my printers. I revised the post to SKR Pro 1.2!

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Yeah, I agree.

I just realised my entire concept of how this thing moves has been wrong for the past two years, and I should have double checked before I framed a wall in my woodshop.

I assumed user was standing facing the long edge and park (0,0) was therefore front left, with gantry moving left to right.

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FWIW, mine is the same way. The original decision was a bit arbitrary and I am sure just as many people would be confused if it was swapped. But they don’t ever complain, or realize there is a difference. But now it would be extra work to support both directions.

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I’m pretty sure it was pictures of your build plus Teaching Tech videos that made me think that was ‘default’

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Funny, I assumed that the TT videos were set up so that the camera position was viewing things from the front, same as he sets up his 3D printers, origin towards the camera, left of frame.

He sits/stands behind his printers, too.

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Correct. His camera is set up where ‘you’ would be standing in that pic I shared in the other thread.

And he states that his origin is top left from camera position, which would put it on the ‘back’ or top of the Y axis

FWIW, this is my first CNC build and I have found it quite easy to follow so far. I started the sub assemblies yesterday as other parts are finishing printing and it’s been pretty straight forward. Though, I’ve read the docs 2 or three times end to end before I tried assembling anything to get a feel for the flow.

I forked the docs and submitted a PR today to update some typos and grammer. I’ve been writing down some notes of things that can be updated that hopefully will help others moving forward as I am building this and will submit a PR for review to update the docs after I’m finished building.

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Add 3dp housings for screen and board?

Another thought: Maybe adding endstops as an add-on option to the kit would be helpful? I completely forgot about them in my excitement to order.

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lol same, that and touchplate, which i still dont know how to use, but the endstops were easy enough to pick up on amazon next day for cheap.

Appreciate the info in this thread. Especially this…

Ordered LR3 kit, SKR, plus endstops and wiring that comes with dupont connectors. My crimper overly crushes through the 24AWG that arrived, making a weak easy to break connection. Have some 22AWG laying around, so will try crimping that instead.

If the crimps feel unreliable after giving them some test tugs, backup plan is to spoil my LR3’s endstops with soldered, heatshrink wrapped 22AWG, similar to what @vicious1 recommended earlier. Hopefully 22AWG will fit the prints, about to find out…

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I gave up trying to crimp them myself, as soon as i tried pulling the plugs out, they’d give up… ive crimped different connectors for years with no issue, but jst type just defeat me…

So now, i use 2S 3pin balance charge cables from amazon (or any radio control model shop), they’re the right connectors (jst-xh 2.5mm iirc) and pre-wired, so a quick solder to some longer cable and some heatshrink and no faffing with those flippin crimps!!

Heres an example JST XH2.5 3Pole Balance Connector Extension Wire for 2S 7.4V Lipo Battery 711331893499 | eBay

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Based on the pic, guessing builds with SKR boards should make ~2’ ( ~600mm) wiring lengths for Z Stop & Z Stop M, wired endstops? ( 2 * Pi * ZStopLength * 2.25 )