Bed Leveling - N2+ (My Experience & Solution)

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geekhands
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Bed Leveling - N2+ (My Experience & Solution)

Postby geekhands » Wed May 10, 2017 8:16 pm

I'll give you a bit of a the back story. I bought a brand new Raise3D N2+ back in February. Got a great first print off the device. Printed some more. Learned my bed was not 100% level from the factory. I first tried making adjustments using the hotend and the supplied feeler gauge. It was back breaking work. In the end it was impossible to use this method. I then read a ton of forum posts and tried everything from dial indicators to spring mods with thumb screws. 5 Positions to 9 Positions. You name it. I spent a solid month getting this device dialed in.

In the end it was the simplest solution that worked and continues to work for me to this day.
I treated the machine like the precision device it is. I sucked it up and bought an $80 Starrett 18" Steel Straight Edge.
I tightened all the bed nuts to their lowest position and backed off the two side supports. I then laid the straight edge on end across 3 positions front-to-back and 3 equal positions side-to-side...

The straight edge gives me a perfect visual indication of what areas require adjustments (up or down). The goal is to see no light from under the straight edge in every position.

No bed mods, No dial indicators, No Printing Band-Aids. This just works.

Here's a link to the one I bought (http://amzn.to/2q6FVuu). I hope this revelation helps others. I spent more than the $80 - probably twice that looking for solutions.

Any questions hit me up!

Now I love this printer and appreciate it's ease of use more and more each day!
Happy printing!

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walshlg
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby walshlg » Thu May 11, 2017 2:10 pm

Yes the straight edge and eyeballing is good but it is useless if the bed is flat but aligned tipped. I use the eyeball technique for aligning the dual heads as well.

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geekhands
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby geekhands » Fri May 12, 2017 1:00 am

Tipped in what way... wouldn't that mean a problem with the Z Axis?

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jmp
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby jmp » Fri May 12, 2017 1:06 am

geekhands wrote:Tipped in what way... wouldn't that mean a problem with the Z Axis?

Image the back 3 screws all being +1mm, the middle 3 screws 0mm, and the front 3 screws -1mm. You straight edge would say the plate is flat (which it would be) but your plate wouldn't be trammed in respect to your hot end (your prints would be smashed in the back and not touching in the front). This would not be a z axis issue.
RL Name: Jason Preuss Thingiverse: JMP Youtube:http://youtube.com/c/patterntoprint Website: http://www.patterntoprint.com

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geekhands
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby geekhands » Sun May 14, 2017 1:18 pm

I totally get what you're suggesting except it hasn't born out for me on this machine given the 13 adjustment screws.
The straight edge has been perfect for making precise tweaks in each position when starting with all screws/nuts tightened and the two support screws loosened not touching the under portion of the bed.

I place the straight edge across the bed in a lattice type shape across X and Y and tweak the positions to close the gap. Which are minor adjustments but significant enough to cause issues if left unchanged.

I then check the center and four corners for equal z. So far it's been working great.

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Gwen
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby Gwen » Mon Jul 03, 2017 7:48 pm

Have you checked the flatness of your bed at different temperatures afterwards? There are notable differences between a cold setting at 60 ° or 110 °. There is an ideal bed temperature that would allow for a valid setting.

I will try your technique and if I can not, I would ask for free physical assistance because this machine caused me enough worries and wasted time. If nothing is done, I would ask for compensation.

In any case, to say that the tray is factory set seems lying to me. Moreover the basic programs under IdeaMaker are parameterized with a raft and it is not for nothing.

This is my first and last Raise.

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Vicky@Raise3D
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby Vicky@Raise3D » Tue Jul 04, 2017 8:16 am

Actually, every machine in our factory has at least 3 time leveling and check.
The first one is during assembling.
The second one is during quality control process. We will print a full size test on this plate to make sure that the levelness of this build plate is at proper range.
The third one is before packaging. We will put the build plate with this machine onto this machine and use dial gauge to make a final check.

Which means every machine has its calibration data in our factory.

For Raft, the main purpose for adding Raft is not for compensate for the bed levelness, but for the first layer of model to get a better bottom surface, easier to peel off and better adhesion.

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Gwen
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby Gwen » Tue Jul 04, 2017 12:04 pm

So why so many people complain about the problem, on my machine there was a default of 0.05 in X and 0.08 in Y? What happens between the factory release and the delivery to the customer? My dealer confirmed that there was a real problem on your machine! But maybe you can give me your typical IdeaMaker settings for PLA and ABS without raft and buidltak but only with Dimafix for example!?

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Gwen
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby Gwen » Tue Jul 04, 2017 12:50 pm

During the different phases that you describe to me, have you seen variations in planesite between a plateau at 20 ° and a plateau heated to 110 ° for example?

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Gwen
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby Gwen » Wed Jul 05, 2017 10:57 am

There is an ideal bed temperature that would allow for a valid setting ?

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walshlg
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby walshlg » Wed Jul 05, 2017 12:04 pm

I leave mine set at printing temperature (80C for PETG) on a cleaned bed, doors closed - no hairspray, doors closed for 30 min before leveling

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Gwen
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby Gwen » Wed Jul 05, 2017 6:32 pm

thanks for your answer walshlg, i'll try like that.

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Gwen
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby Gwen » Wed Jul 05, 2017 9:13 pm

Thanks for your lake of reponse Vicky !

Andy Cohen
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby Andy Cohen » Sat Jul 08, 2017 5:05 pm

geekhands wrote:I'll give you a bit of a the back story. I bought a brand new Raise3D N2+ back in February. Got a great first print off the device. Printed some more. Learned my bed was not 100% level from the factory. I first tried making adjustments using the hotend and the supplied feeler gauge. It was back breaking work. In the end it was impossible to use this method. I then read a ton of forum posts and tried everything from dial indicators to spring mods with thumb screws. 5 Positions to 9 Positions. You name it. I spent a solid month getting this device dialed in.

In the end it was the simplest solution that worked and continues to work for me to this day.
I treated the machine like the precision device it is. I sucked it up and bought an $80 Starrett 18" Steel Straight Edge.
I tightened all the bed nuts to their lowest position and backed off the two side supports. I then laid the straight edge on end across 3 positions front-to-back and 3 equal positions side-to-side...

The straight edge gives me a perfect visual indication of what areas require adjustments (up or down). The goal is to see no light from under the straight edge in every position.

No bed mods, No dial indicators, No Printing Band-Aids. This just works.

Here's a link to the one I bought (http://amzn.to/2q6FVuu). I hope this revelation helps others. I spent more than the $80 - probably twice that looking for solutions.

Any questions hit me up!

Now I love this printer and appreciate it's ease of use more and more each day!
Happy printing!

Revelation?
After simply replacing FOUR screws and adding springs I can manual level the bed on the very rare occasions I need to. Some of us actually use this machine for low qty production and the need to swap bed plates out is essential. Each time you change plates there are differences in the plate height. Using the thumbscrew to change the height to the limit switch is not what I would call an acceptable solution. Doing that way is tedious and takes multiple trials. Leveling the bed conventionally with thumbscrews underneath the bed can be done on the fly! When you know what you are doing you can level the bed during the drawing of the skirts in the 1st layer. It takes SECONDS. Seems to me your approach is more work then simply changing 4 screws out and adding 4 springs and thumb nuts. "Just works"? Sure, until you change plates, the plate surface or some other aspect of the extruder.
Those of us who have been 3D printing long enough already know that a fixed factory "leveled" bed is based on a lack of use case experience... IOWs it's BONEHEADED!!!

resteele
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby resteele » Sat Sep 16, 2017 1:29 am

Raise3D N2 Plus Dual Extruder Review and Recommendations

First impression: This is a huge printer, built on a very solid frame, heavy duty mechanical construction and parts, nicely implemented touch panel control, and plenty of connection options. Many reasons to expect long term reliability with heavy duty use.
As you may expect early in the development of any complex new product, shortcomings may be discovered and improvements may be suggested or even required. Notable examples include the heavy weight of the dual extruder mechanism leading to print quality anomalies in high print speeds (addressed nicely by an upgraded extruder offered by Bondtech) and the reported problems caused by high temperatures within the enclosed chamber, leading to Raise3D recommendation to leave the top cover off when printing with certain material such as PLA. (My simple recommendation for the temperature problem is add a temperature controlled exhaust fan in the top cover to vent air when the interior is too warm, maintaining the optimum ambient temperature at all times. I plan to do this on mine, as well as insulate the heat blocks on the extruder nozzles for improved nozzle temperature control.)
The most serious problem I have encountered (immediately) is that the heated bed in my brand-new printer is badly NOT level, with variance of as much as 0.4mm over several areas of the bed plate (acceptable variance would be on the order of about 0.01mm or less). Raise3D suggests a procedure to re-level the bed. Since my career as a computer engineer involved considerable experience making very fine and critical adjustments like this, you’d think “no problem”, right? HA, think again!
There are very serious problems with Raise3D leveling procedure. Probably most critical is the recommendation to (try?) to level the heated bed with the glass/buildtak print plate on top of the bed. This is misguided, because (in my case) the badly adjusted heat bed is NOT flat, but too high in some areas and too low in others. The flat glass/buildtak print plate simply rests on the high areas of the bed plate and bridges over the low areas, making the low area impossible to measure or even detect. (You might think this is good, but actually this condition will simply result in uneven heating or even warping of the glass/buildtak print plate.) Conclusion: the bed must be leveled as well as flat for optimum print performance, and must be adjusted without the glass/buildtak print surface installed.
One more comment re: flatness of the heated bed: It has been noted that simply installing clamps on the edge of the glass/buildtak plate can warp the plate. A superior approach is to lay a thin silicon heat transfer sheet on the heated bed under the glass/buildtak plate, the plate will stick to the silicon sheet and clamps not needed. Result, better and more even heat transfer but plate is still removable.
Now, to the design of the heated bed mounting and leveling process itself. There are 13 adjustment areas. Each area consists of 3 critical adjustment points (two support pins pushing up on the bed (locating the vertical position of that portion of the bed) and one screw pulling the bed down against the two pins. If either pin is too high or too low the bed will be warped when the screw is tightened. If the screw is too tight the bed will be warped between the two pins. This adds up to a total of 39 (13 X 3) critical adjustments, any one or any group of 3 having potential to impact the total. Not impossible, but certainly very difficult.
I am currently working on the adjustment procedure using a dial indicator mounted to the extruder assembly, making the actual measurement of the bed plate flatness much easier. Depending on my success (or lack of success) I am seriously considering replacing the bed plate attachment screws with 13 45mm long screws, going through 13 20mm long bed plate compression springs (as used in most other bed plate mounting systems with 3 screws), and not using the 26 adjustable support location pins at all. The springs will support the bed plate vertically, and the 13 screws will now provide the adjustable vertical positioning previously accomplished by the pins. I expect this will result in a much easier adjustment process, with only 13 critical adjustments rather than 39.

I have plenty of experience with two other (smaller) 3D printers, and still have high hopes for this one. Will post again after I get it set up to my satisfaction.

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Gwen
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby Gwen » Tue Sep 26, 2017 5:59 pm

I fully agree with your thinking resteele. I could see it myself, you can pull on a point of the plate and it will no longer be in contact with the glass, therefore necessarily a bad distribution of the heater. 3 points are normally enough to define a plan like on the Ultimaker, so why 13 points? Would the tray be deformed too much with the temperature? If this is the case, you will have to study a new plate!

resteele
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby resteele » Wed Sep 27, 2017 2:31 am

Here's an update to my problem: (Note: Raise3D support has responded already and a replacement is in the way for my warped bed, which caused this problem.)

My problem is very similar to KeS, posted with pictures on Fri Sep 01. My brand new machine bed was NOT level, nor was it even flat, with a bow downward of half a millimeter in the center of the heated bed. With the flat build plate on top of the bed it SEEMED flat, but the level of the build plate would change depending on where I placed the clips to hold the build plate in place. So I took the build plate off the bed and checked the level of the bed without the build plate in place. I found VERY LARGE deviations (as much as .025", almost a full mm) all over the bed surface. With a straight edge across the bed (front to back, left to right, and diagonally) there was a gap of around .6mm all around the center, and the bed was clearly warped downward in the middle. I used a dial indicator attached to the extruder mount to verify these measurements.

As I reviewed the recommended bed leveling procedure, I noted the recommendation to have the build plate installed on the bed during the adjustment. This CANNOT be correct, because the build plate will simply bridge over any low spots in the bed, making the low spot impossible to even measure or detect, let alone correctly adjust. I suspect that whoever "factory adjusted" my bed did NOT understand this issue.

(NOTE: This .6mm air gap between the heated bed and the build plate will also severely impair heating of the build plate, causing colder spots over the air space and hotter spots over the contact points. Not conducive to quality printing!)

I am concerned that this gross maladjustment was either caused by or would cause permanent bending or warp damage of the heated bed, so I removed the bed from the printer and again checked the bed (out of the printer) with the straightedge. There was a warp of over .4 mm (down in the center) over one diagonal and somewhat less downward warp over the other diagonal. (kind of like a twisted bowl shape overall).

With the bed removed and my dial indicator set up I decided to reset the 26 adjustable level locating pins (which support the bed) to a flat plane level with the extruder travel plane. With the dial indicator this was fairly simple and easy, but I found I had to move some pins as much as .022". I expected to refine the adjustment of each pin after the bed was reinstalled, to account for any thickness variations in the heater plate or to counteract bending stresses resulting from the observed warp in the bed.

As expected, when the (warped) bed was reinstalled on the initially flat plane of the locating pins it still measured low in the center by about 008" (.2mm) I then spent a couple of hours slowly and methodically adjusting each point, observing the effects on adjacent points as well. I finally got most of the bed consistent within +/- .002", but some of the worst variations are BETWEEN adjustment points. I have a hunch this problem is due to the warp in the bed, which further adjustment will not resolve.

I expect the replacement bed to arrive tomorrow, and will update this report further when I get it installed and properly adjusted.

In answer to Gwen, re: "why 13 points?", this is a very large, thin plate, subject to bending or flexing between widely separated support points. The 13 point support provides closer together support points to minimize this flex or bend. Makes better support with the trade-off of more difficult adjustment. I am happy with that, as long as the adjustment procedure is understood and properly described. I have not yet seen a description I believe or trust yet, so hopefully I will be able to suggest a better one when I am done with mine.

Three point support would be feasible, however I think that would require a much thicker, heavier and braced (to eliminate flex) bed, which would in turn require more space and more power to heat and longer to achieve temperature or cool down. At the moment I'm thinking I can make the current system work very well (if my replacement bed is flat as expected).

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Gwen
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby Gwen » Wed Sep 27, 2017 12:26 pm

Hello, resteele. I personally received a new set several days ago since I encountered the same problem as you. My old plateau was completely deformed, it was a real basin. However, the setting remains tedious despite a correct tray, I saw that the set to 80-90 °. Raise refuses to admit it but the setting of the plateau remains the biggest problem of the N2. They claim that it is factory set but I do not believe it, where then there is a big problem in their chain of manufacture in China. Hopefully this will be your only problem on this machine, the list is very long for me.

resteele
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby resteele » Fri Sep 29, 2017 4:06 am

As previously noted in this thread, My N2+ arrived with a warped heated bed, which was badly out of adjustment. In working out this problem, I have developed what I feel is a significantly improved technique to adjust the level of the heated bed.

I know Raise3D advertises “factory adjusted” level beds, but the factory adjustment on mine was quite bad. They do suggest a procedure for user leveling of the bed, which does not work for me at all.

Because this bed is mounted at 13 points (actually 39 points, with 3 adjustments for each of 13 bolts) the adjustment process is much more complex and difficult than the 3-point compression spring mounting used on most smaller 3D printer beds. There are 13 bolts whose function is to pull the bed down against 13 pairs of vertically adjustable support pins whose function is to establish the flat plane parallel to the plane of travel of the extruder nozzle and support the bed upward on this plane. To move any one of the 13 points up you must loosen the nut on the bolt, adjust both associated level pins upward (tighter) maintaining the correct flat plane between the 2 pins, then retightening the nut on the pulldown bolt, all this while measuring the vertical position of the bed at that point.

There are 4 potential critical errors in this adjustment. The pair of locating pins could be too high or too low relative to the flat plane, or one of the pins could be higher or lower than the other, warping the bed at that point, or the nut on the bolt could be too loose allowing the bed to float above the 2 pins, or too tight warping the bed downward between the 2 pins.

The ability to accurately measure the position of any point on the bed relative to the plane of the extruder nozzle is critical. With the 3-point compression spring mount this was fairly easy using a feeler gauge. With repeated measurement necessary at least at 26 points on the N2+ I find mounting a dial indicator securely to the extruder mount greatly simplifies and speeds up the measurement process and improves accuracy as well. Accuracy is not critical here at all, only repeatability is required to identify relative differences at various points on the bed, so inexpensive units starting around $15 on amazon will do fine. I have 3D printed a secure mount to attach my dial indicator in place of the fans on the extruder mount. https://www.amazon.com/Indicator-Resolu ... +indicator

Having been very frustrated by the difficult triple adjustment at each of the 13 bolts, I decided to eliminate the most difficult one with a simple modification. I removed the bed from the machine by lowering the bed, detaching the electrical connections to the heater, and removing the 13 nylon insert nuts from the bed attachment bolts. With the bed out of the machine, I removed the 13 attachment bolts, saving the 13 nuts and lock washers for reuse. I purchased the following parts on Amazon:

M3x45mm 304 Stainless Steel Flat Head Hex Socket Screws https://www.amazon.com/gp/product/B01N5 ... UTF8&psc=1

M-jump Heated Bed Compression Spring 7.5mm For 3D Printer Extruder DIY Accessories (20 pack) https://www.amazon.com/gp/product/B0744 ... UTF8&psc=1

M3 Carbon steel Knurled Thumb Nuts https://www.amazon.com/gp/product/B01HS ... UTF8&psc=1
And a package of #6 flat steel washers.

I replaced the 13 20mm long flat head screws with 13 45mm long flat head screws, reusing the 13 lock washers and nuts. I noted that the lock washer on the center screw had cut into the small fiber washer under it, so I added one of the #6 flat washers on the fiber washer and the lock washer on that. I used a 7/32” deep socket or nut driver to tighten all the nuts securely, since we don’t want these screws to turn after reassembly.

Before reinstalling the bed plate on its support, I used my dial indicator attached the extruder mount to check and adjust the level of each of the 26 adjustable support pins to a flat plane parallel to the travel plane of the extruder mount. I then adjusted the 4 pairs of pins at the mid point of the 4 sides (left, right, front and rear) about .002” higher, to start with the bed slightly higher than all the other pins. We will then start our leveling at these 4 locations, then easily bring all the other locations up to match these 4 locations.

I then set the bed plate back on its support, with the 13 longer screws extending through and below the support frame. Now I installed one of the springs, followed by a #6 flat washer, followed by a knurled thumb nut on each screw. Note that these springs will now function to pull the bed DOWN against the adjustable supports, and will provide a relatively constant pressure downward regardless of the level of the support pins. More importantly, it will no longer be required to loosen this thumb nut in order to adjust the level of the support pins, as it will be effectively “self adjusting”. At this point, leave ALL of the thumbscrews close but NOT compressing the springs, because you don’t want to pull the bed down to an adjustment pin that is set too low (nearly all of them at this point).

Now comes the actual adjustment. Start with the 4 outside mid point thumbscrews and tighten them to compress the springs about 3 or 4 mm, seating the bed firmly on the pre adjusted pins there. Move the dial indicator directly over each of the 8 pins (2 beside each screw) and adjust each pin as required to exactly match the measured level of the other 7. Set the dial indicator dial to exactly 0 at this level.
Now follow a pattern to adjust each of the other attachments. I started with the center, followed by the square outside the center, followed by the outside corners. At each point set the dial indicator over one of the adjustable support pins, tighten the knurled nob to pull the bed down, while observing the dial indicator and moving the adjustable pin up to locate the bed at the proper level so the bed is not pulled too low. Check both pins next to this screw, and adjust each as required. Do this for each screw in the bed.

After the first pass, check all points again. It is expected that changing the level at any point may affect the level at other previously adjusted points. Repeat until satisfied that all points on the bed are properly in level. Optimally, variations should be less than .001”.

I have done this for my already warped and partially straightened bed, and found the process much easier, faster, and more effective than without the compression springs. I have not quite reached what I consider optimum level, but I’m way closer than before.

compression mod1.jpg
compression spring mod.jpg

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walshlg
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Re: Bed Leveling - N2+ (My Experience & Solution)

Postby walshlg » Sun Oct 01, 2017 8:42 pm

excellent work. My only suggestion is to make the spring in the center stronger (2x higher spring constant) since it is trying to push up against all the screws around the outer edge pulling down.


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