RatRig V-Core 3: How to Get a Square Frame

[@j.abella6892]

Thank you for this. I was struggling to get my mesh better and had the low D corner. I was trying to raise all the other corners using the frame jacks since I couldn't lower the D corner. I undid those adjustments and started by lowering all corners back and ended up with a bow in the middle. I then used your comments about the linear rail across the top and just loosened all the bolts and tried to tighten them all consistantly by hand in a smooth row and I ended up with a .142 variance on my V-Core 3 - 500mm. Thank you, Thank you.

[@Streamlines]

Oh...I have a bow too...

[@warmesuppe]

I was being laughed at for using a precision machinist square in another discord group, and I was laughing at them for not. Squaring is really important for good results.

[@isaactavares1767]

Finally, someone explains how and why the V-Core 3 should be built. In fact, I started build one almost one year ago. It took me several weeks to do it because I had very very little spare time to do so, aggravated by the fact that I know almost zero bout 3d printers. It was building and learning at the same time. And one thing I never understood was the frame assembly sequence, because as you clearly appoint in the video, the fundamental is getting the horizontal top quadrilateral squared and it’s plan perpendicular to the 3 columns/z linear guides which forcedly should be parallel to each other. Know I know where the change in building instructions in V3.1 came from 😉 and why you are so considered by the RatRig staff and community. Another subject you addressed and I never seen anyone do so, is the screws tightening torque. I know we are not building a turbo fan to propel a commercial airliner, nor a oil pipeline or a F1 car engine, but come on, this is a device where we talk about tens of microns. So it’s kinda strange that this matter is so overlooked. I mean, we need that the linear rails don’t move relative to the extrusion where they’re attached to, but we need to accommodate for the different thermal expansion they have in relation to the extrusion (steel vs aluminium), and I believe an eyeometer is not the best tool to achieve an adequate torque to cope with this antagonist needs. I never thought that the guides whit all the screws placed and tightened to the extrusion could lead to a behavior like a bimetallic strip in a thermostatic switch. Know I understand why the bowing in the gantry is different at room temperature or 70 ºC. In short, much congratulations for this video lesson.

[@Thomas0]

great explanation, I definetly learned something today and will bookmark this for my next (re)build. Thanks for your efforts Marc

[@uncletio8418]

It works, it freakin works. Thank you, exactly what i needed.

[@HMAlotaibi77]

Amazing video. Very detailed and helpful. Thank you for all your great work

[@nf4553]

Amazing! This just solved all my first layer problems! Thank you so much for taking the time to explain the details.

[@SUB13333]

So many great tips! I'm so lucky i didn't complete the build yet to implement these beforehand!

[@alfmikaelconstantinou3798]

Thanks a lot for this advice. Bought the tool you mentioned, so we'll see. :)

[@HelgeKeck]

i learned a lot, thank you

[@chriss2295]

Orthogonal 3d printer is one of the most satisfying and frustrating procedures. Not necessary unless it's necessary. :)

[@TheFotoGuys]

Great explanation, it helped me a lot to get my printer into square. :D

[@DanMcGee3271]

Nicely done ... the correction for the gantry was (in my mind) counter-intuitive and I'd have done a great deal of head scratching coming to that conclusion on my own by reviewing bed mesh results alone. I also like the simple terms you provided in relating what's really important to pay attention to when building the frame (which extrusions really matter).

[@PieterStefan]

That is very useful. Thank you.

[@SUB13333]

reached to 0.2 deviation on my 500mm bed. thanks a lot ! :) ( also with some kapton tape at certain areas ) . but I couldnt figure out that I should lower B to side to increase the distance at C. Thanks!

[@MrLzender]

Where did you place the kapton tape?

[@MitkuSan]

0:14 That jumpscare sound got me.

[@titobeuille3009]

Very well explained, many thanks!

[@MDFP]

Awesome bud!

[@unholymass]

really great and i got one of those engineering sqares with the din 875/1 norm but how you exactly clamp them? and from where measuring cause i end either way with a bend it seems if i put on another extrusion or on my tabletop but i'm sure i am doing something wrong here.

[@MDFP]

I agree with less screws on the rails…

[@somedud1140]

10:00 You mentioned DIN875/1 right square, but you have quite big one, how big should it be?

[@jc84com]

Fantastic video, very informative.

[@DesignEntity]

The opposite does not seem to be working. If I try to raise D by elevating A, then D does not move but A does.

[@jay1st1st]

excellent and simple, nice !

[@TommiHonkonen]

i mighta have to take out some bolts on the x axis rail at 21:50 innit the deviation more than 0.2, the scale is not on, the high is just about 0.2 and low is clearly below flat plane. you are looking at like 0.3 or so. i did a mesh just to check, mine is 0.4 or worse on a 500, bowed af but might try to fix that by letting some bolt go on the a axis.

[@ragwafire]

You are a godsend

[@PennStateUSAF]

What is the method to understand what physical points "A,B,C,D" corresponds to the virtual bed mesh? For example how do I determine what point is physical point "A" when looking at the bed mesh?

[@markleaf1970]

When you look at the heightmap generated in RatOS, the position x=0,y=0 is A, and position x=300,y=300 (or whatever size printer you have, this is for 300mm) is C. So basically the origin 0,0 is at the bottom left corner which is A. After homing in the dashboard of RatOS you can move the print head to any location to know where it is physically as well if you are still having trouble.

[@scottwillis5434]

I appreciate the video, very helpful! 7:50 isn't the change in Z height (1 - cos(phi)) * 500 mm? The layers would be skewed relative to each other, by sin(phi) * layer thickness for each layer, by sin(phi) * 500mm maximum. This would be quite subtle. That's if all the Z axes had identical, parallel tilts; otherwise that turns into a mix of the center of the build plate shifting sideways, rotating and tilting.

[@D4mations]

Absolutely amazing!! Could you do a voron 2.4 r2????

[@AgentHubcap]

Awesome video! Is lowering B the same as raising A? I don't have any wiggle room on my B extrusion.

[@3dprintersawhiteboard401]

Yes, depending on the state of the frame, it can make sense to use the other corner in the opposite direction.

[@satoshipokemon8411]

Thank you

[@Peet6644]

since all important corners are on the top, so building the printer upside down on a flat surface should get you a better / faster result.

[@3dprintersawhiteboard401]

I agree and suggest that myself in the video (and also build myself this way). Still, a later frame adjustment can also get you a long way.

[@HelgeKeck]

nice

[@morbus5726]

0:15 ouch

[@BigDan1190]

Would you consider recording a video of you building a square frame from the ground up? I'm having a lot of difficulty with mine and i want it to be perfect lol

[@3dprintersawhiteboard401]

I want to do a few other videos first I think. If I need to build a new RR frame (I usually do mods on my frames) I will consider it again.

[@andrewkoval9451]

can you do a video on how to fix low D

[@3dprintersawhiteboard401]

The very same principle applies. Low mesh in D -> gantry on D is too high in relation to gantry in A -> up gantry in A. I assume you might be the same person who asked in discord. If so, you need to up that thing a whole millimeter. For that, please open all screws holding that extrusion.