Reprap Forum - Mechanics Discuss any sort of mechanical stuff here: positioning systems, gears, extruding methods, etc. https://reprap.org/forum/list.php?14 Sat, 05 Sep 2026 20:29:04 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?14,896823,896823#msg-896823 TR8X4 Lead screw tension nut (5 replies) https://reprap.org/forum/read.php?14,896823,896823#msg-896823
I have a homemade cartesian FDM printer and I finally ditched the c-beam carriage wheel assembly for a linear rail assembly. The rails and carriage are working fine. During the update a moved from an 8X8 lead screw to a 8X4 lead screw. I took it for granted that a tension nut or some kind of locking nut would be easily available for the 8X4 lead screw. I can not find one. Do these exist? This entire DIY 3D printer project has been fun but there are surprises all over the place. I have a lot of height/homing problems for Z because the coupling nut is two springy for the lead screw. I need to add a bracket to support the lead screw and a tension or locknut to remove the Z height variability.

looking forward to some insight or suggestions.

Robert]]> roptics Mechanics Tue, 20 May 2025 21:54:43 -0400 https://reprap.org/forum/read.php?14,896794,896794#msg-896794 is it possible to use a piece of flex plastic and use it as a extruder (no replies) https://reprap.org/forum/read.php?14,896794,896794#msg-896794 Vorroriw Mechanics Sat, 26 Apr 2025 10:58:11 -0400 https://reprap.org/forum/read.php?14,896780,896780#msg-896780 is it possible to replace a stepper moter with a dc moter you found in a cheap toy car (8 replies) https://reprap.org/forum/read.php?14,896780,896780#msg-896780 Vorroriw Mechanics Sat, 26 Apr 2025 10:38:39 -0400 https://reprap.org/forum/read.php?14,895948,895948#msg-895948 Anybody know anyhing about this motion system? (5 replies) https://reprap.org/forum/read.php?14,895948,895948#msg-895948 Fantastika Mechanics Sat, 27 Dec 2025 07:42:32 -0500 https://reprap.org/forum/read.php?14,895875,895875#msg-895875 High(ish) temp cheap all-metal mgn linear rail (no replies) https://reprap.org/forum/read.php?14,895875,895875#msg-895875
Long story short, I am thinking about buildng my own printer with heated chamber and I was quite logically looking into linear rails that could operate at higher temps when I saw these Aliexpress HT rails.
I then searched a bit further and saw some other at least similar looking ones KB3D HT rails. Has anyone already had any experience with such cheapo all-metal high(er) temp claiming linear rails ? Or opinion ? Or maybe has anyone tested those at some higher temps (>70°C). Thanks ;)]]> mikeymike Mechanics Sat, 05 Oct 2024 23:53:12 -0400 https://reprap.org/forum/read.php?14,895861,895861#msg-895861 What causes a stepper motor to shut off mid print? (2 replies) https://reprap.org/forum/read.php?14,895861,895861#msg-895861
EDIT: I thought this wasn’t very coherent, so I have modified it a little.

I have 2x Kingroon KP3s 3.0's. Intermittently (possibly during a travel move), the bed motor just switches off but the printer carries on printing (I can move the bed freely by hand, so the motor isn't locked). The board is a modified version of the MKS Robin Nano 1.2 with integrated TMC2225 stepper drivers.

I have tried reducing speeds and acceleration, also Increasing the voltage, but it hasn’t helped.

As per the title, what is causing the steppers to shut down? Is it possible that the TMC2225 drivers are shutting down? Or is it more likely the stepper motors themselves?

Any help greatly appreciated!

Mo]]> mlewiseverley Mechanics Tue, 15 Oct 2024 06:31:29 -0400 https://reprap.org/forum/read.php?14,894942,894942#msg-894942 Bed thickness for 200x200mm recommendations? (1 reply) https://reprap.org/forum/read.php?14,894942,894942#msg-894942 sparky.summer Mechanics Fri, 07 Jun 2024 16:01:17 -0400 https://reprap.org/forum/read.php?14,894924,894924#msg-894924 Experiences with Tungsten Carbide Nozzles (1 reply) https://reprap.org/forum/read.php?14,894924,894924#msg-894924
I’m curious about your experiences with tungsten carbide nozzles for 3D printing with abrasive filaments. I've read about several potential downsides, such as their higher cost compared to hardened steel nozzles, their brittleness which can lead to chipping or cracking, and their lower thermal conductivity which might impact print quality with temperature-sensitive materials. Additionally, their availability and compatibility might be limited. There's also the concern about filament leakage as the nozzle doesn't have a good thermal expansion to form a tight seal. Have any of you faced these issues? What problems have you encountered, and are there any solutions or best practices you’ve found to mitigate these downsides? Your insights would be greatly appreciated!]]> gaurangsk Mechanics Sun, 02 Jun 2024 11:08:20 -0400 https://reprap.org/forum/read.php?14,894905,894905#msg-894905 Hot/Cold swap Nozzle idea (2 replies) https://reprap.org/forum/read.php?14,894905,894905#msg-894905
The first one and the one I animated uses a metal clip that slots into a groove in the nozzle and heatbreak. The nozzle itself would have no threads and would be prevented from being pushed out by the clip itself.

The second iteration that I may eventually draw up and animate would swap the clip for a spring loaded button. Same idea where you would have a metal blocker keeping the nozzle in but it would be as easy as pushing a button.

This is an animation of my first draft.

The very unfinished rough draft is here Github Repository incase I actually end up working on it.


I'm open for ideas and suggestions. My main goal however is to get the idea out there before someone patents it.]]> SomeRandomGodDamnFurry Mechanics Fri, 07 Jun 2024 15:59:39 -0400 https://reprap.org/forum/read.php?14,894526,894526#msg-894526 Overconstrained dual belt XY Gantry - how to align motors? (no replies) https://reprap.org/forum/read.php?14,894526,894526#msg-894526
I am in the design phase of a large format 3D printer. Its moving gantry uses a mirrored double layer H-bot kinematic with a Nema23 bipolar 1.8° stepper motor in each corner.
Each stepper has its own Trinamic 5160 with a custom driver board on a custom mainboard. Firmware is Klipper, the belts are Gates GT 3mm belts with a width of 15mm.
This results in a total of 8 motors, 4 for each H-bot layer. It may look like total overpower but I design for speed and accelleration to keep print times viable despite the size.

Now I am wondering how I should align the motors considering their step angle. Initially I thought about ensuring all 8 motors resting in a full step. But then I have read somewhere that if you have a dual belt system you can align the second belt system in a half step position to minimize VFAs. Considering that there are many other alignment combinations.

What you you think about that - any advice or experiences? Does stepper motor step angle alignment matter in the first place?

Best regards,
Demo]]> Demolux_D1 Mechanics Fri, 15 Mar 2024 15:32:09 -0400 https://reprap.org/forum/read.php?14,894506,894506#msg-894506 Positioning the z-axis endstop (6 replies) https://reprap.org/forum/read.php?14,894506,894506#msg-894506


The X and Y axis were easy, but I am not sure about where to put the Z axis.
Ideally it should be near the origin of the Z axis, where the heated bed is closer to the extruder. However, I don't think the endstop should be precisely at the right position where the heated be is less than a milimiter away from the extrusion (it would be really hard to fine tune that). But if I put it further away, it becomes a physical limitation so the heated bed will never get into position. If I put too near, there is the risk of crashing the extruder into the bed.
Please can someone clarify how this z axis endstop should be positioned in relation to the distance between the bed and the extruder? By the way, my z axis uses a pair of lead screws to move up and down.
]]> nnnooo Mechanics Tue, 19 Mar 2024 07:21:11 -0400 https://reprap.org/forum/read.php?14,894444,894444#msg-894444 Oversize bearing balls for rails and ball screws? (1 reply) https://reprap.org/forum/read.php?14,894444,894444#msg-894444
My particular need is for SFU1204 ball screws on my CNC, which use 3/32" balls. Last time I had one get worn I just bought a whole new ball screw since they don't cost much, but it's a shame to throw out an almost-perfectly-good piece of equipment. I had intended to make an adjustable split-nut using the spare nut from the old one, but was unsuccessful. I suppose I could try again, but if anyone knows a source for oversize bearing balls in reasonable quantity, I'd like to try that first.]]> dekutree64 Mechanics Fri, 23 Aug 2024 19:09:53 -0400 https://reprap.org/forum/read.php?14,894303,894303#msg-894303 Mini Pellet Extruder (3 replies) https://reprap.org/forum/read.php?14,894303,894303#msg-894303
I purchased components recently to build a mini pellet extruder. I'm thinking it should work for melting and extruding powder which is the plan.

It's branded as Funssor and similar to this one branded as a Polished3D
[www.amazon.com]

The difference is the "barrel/heat sink" should be brass with the version I purchased and it was about 15$ cheaper. I mostly bought it for the screw. I can make or have made a different barrel pretty easily.

I'm interested in developing a new series of filaments. I looked at the cost of Filament extrusion machines and found one called the FilaStruder that appears solid and at a good price. Others that seem appropriate for what I want to do at first are from about 2,000-12,000$.

The primary reason I'm interested in developing a little mini screw extruder is to test/prove the concept of the material(s) I want to develop at as cheaply as possible.

Should essentially replicate filament production skipping the actual filament.

Has anyone here any experience with these parts or know of any examples of they're use in D.I.Y. setups?

Any links to working projects or information on how to set them up/build out the extruder assembly would be appreciated.

[www.robotdigg.com]

The link above shows a schematic for a Mahor extruder.
I think these parts available in a couple types under different brands may be leftovers/abandoned from production run parts for the v1, 2, or 3 Mahor. I looked at the version of the Mahor that's currently being sold v4 and it appears the barrel is significantly different.

Anyway if anyone would like to offer suggestions, information and such I'm open to that and looking for whatever help I can get in developing this project.

Thank You]]> brianmh13 Mechanics Sat, 26 Apr 2025 12:55:04 -0400 https://reprap.org/forum/read.php?14,893859,893859#msg-893859 Choosing stepper non captive leadscrew motor (no replies) https://reprap.org/forum/read.php?14,893859,893859#msg-893859
I need to choose non captive leadscrew motor, however I do not know how to properly do it.

I tested several online calculators like these below:
https://www.daycounter.com/Calculators/Lead-Screw-Force-Torque-Calculator.phtml
https://www.vcalc.com/wiki/vCollections/Leadscrew-Torque-lift

I need motor of Nema 17 or Nema 23 size with a push pull operation, the force will be ~15Kg
Leadscrew will be (as big diameter as possible) Tr11x2mm


I plan to use chinese cycle controller like HF020, photo below:


]]> smilem Mechanics Sun, 26 Nov 2023 17:39:05 -0500 https://reprap.org/forum/read.php?14,893476,893476#msg-893476 Heated Beds (10 replies) https://reprap.org/forum/read.php?14,893476,893476#msg-893476 Mr Kroll Mechanics Tue, 03 Oct 2023 07:37:40 -0400 https://reprap.org/forum/read.php?14,893006,893006#msg-893006 Z-Axis thread rod pitch ? (9 replies) https://reprap.org/forum/read.php?14,893006,893006#msg-893006 I have a lathe, I have thread gauges and I cut my own threads on a lathe.

Yet I can’t understand what I am seeing referenced about these Z- axis threads

My machine, GeeeTech I 3 C Pro has the factory installed rods.

20 revolutions moves 25mm. So that is a 1.25mm thread pitch
8mm on the major diameter

Yet I keep seeing z-Axis lead screw sold as 8mm pitch

Is that correct 8mm ? So one revolution moves the gantry 8mm vertically ?
Seems very inaccurate . Surely not ?

Can anyone explain

Thank you]]> NeilP Mechanics Thu, 22 Jun 2023 14:02:55 -0400 https://reprap.org/forum/read.php?14,891411,891411#msg-891411 Dual Wire Gantry ? (4 replies) https://reprap.org/forum/read.php?14,891411,891411#msg-891411
[attachment 119976 240px-DW-G_X-axis.jpg]

There would need to be simple modifications so the belt isn't twisted other than that it seems good.

Simply does it work and is it any good? The printer would have a 200x200mm build plate.

Atb. Aamcle

[reprap.org])]]> aamcle Mechanics Tue, 20 Dec 2022 16:16:42 -0500 https://reprap.org/forum/read.php?14,891228,891228#msg-891228 Building a CoreXY : machined or printed parts ? (37 replies) https://reprap.org/forum/read.php?14,891228,891228#msg-891228 The author warns against using CNC machined parts (vs ABS printed ones). Good news : I have conventional machine tools (used, industrial), no CNCs.

I've been searching why.
I found some answers, but none makes sense to me.

1 - machining from STLs does not work because tolerancing and shrinking are taken into account at design time. BS. Parts just have to be redesigned and retoleranced, no big deal : F360 files are open sourced.
2 - the gantry has to be flexible because it self adjusts, and auto trams and un-skews. Sounds even more BS : a machine tool, if it is rigid enough, is first leveled, then trammed, it does not have to be readjusted each and every time it is powered on.
3 - high frequency resonance is difficult to dampen (as far as I know, it is the opposite)
4 - I stopped googling...

My lathe and my milling machine were leveled then trammed. They can move a bit, because of the concrete (200mm, reinforced). But a 3D printer is not 1 or 2 tons !!!

So what ?

I can understand the weight argument for moving parts. It is a killer argument. But the other parts ?

Not being a professional, I will not pretend I always get +-0.01mm. More within +-0.02 to 0.03.
What would you recommand ? Machining everything, or just the static parts, or printing everything as it was designed for ? (CADing is not a problem)]]> yet-another-average-joe Mechanics Thu, 18 May 2023 14:11:27 -0400 https://reprap.org/forum/read.php?14,890913,890913#msg-890913 estrusore non modifica step (1 reply) https://reprap.org/forum/read.php?14,890913,890913#msg-890913 grazie buona giornata ho provato a farlo senza hotend sempre lo stesso faccio estrudere 10mm me estrude 50mm]]> Claus59 Mechanics Tue, 01 Nov 2022 11:39:02 -0400 https://reprap.org/forum/read.php?14,890901,890901#msg-890901 Belt driven Z axis (7 replies) https://reprap.org/forum/read.php?14,890901,890901#msg-890901
The Voron printers 2.4 and Switch Wire use belts to lift the X axis or motion carage.
However some of the things I have read suggested there would not be enough resolution (Z steps per mm) unless a large pulley is included.

Assuming a normal 1.9° stepper that's 200 steps per rotation if you set up microsteping for example 32 microsteps 200x32 micro steps.

I haven't measured a pulley but if I assume a 30mm circumference then the resolution should be

...........................30/(200×32) mm ~ 0.005mm

Surly that's good enough, 0.1mm is the thinnest layer I would ever attempt.

Is this correct or have I misunderstood something?

Atb aamcle]]> aamcle Mechanics Mon, 31 Oct 2022 09:52:42 -0400 https://reprap.org/forum/read.php?14,890892,890892#msg-890892 motore estrusore (1 reply) https://reprap.org/forum/read.php?14,890892,890892#msg-890892 Claus59 Mechanics Mon, 31 Oct 2022 03:13:18 -0400 https://reprap.org/forum/read.php?14,890873,890873#msg-890873 Test Rods and Bearings? (2 replies) https://reprap.org/forum/read.php?14,890873,890873#msg-890873
The hotend has been upgraded and all other appropriate upgrades done except the bed platform.

Is there some reasonable way to check to see if any of the mechanical bits should be replaced?

I have the feeling that the poor old thing might be nearly beyond its economic life.


Atb. Aamcle]]> aamcle Mechanics Thu, 27 Oct 2022 09:23:11 -0400 https://reprap.org/forum/read.php?14,890839,890839#msg-890839 stepper motor not rotating smoothly (no replies) https://reprap.org/forum/read.php?14,890839,890839#msg-890839
I have both X and Y axis 3D printer stepper motors rotating in a weird way, when I rotate em by my fingers I feel they turn like 90 to 120 degree (a bit more than a quarter turn) smoothly without reisistance, then a little resistance after that requireing more force, which makes both heat bed and the extruder move the same way , a bit free/smooth , then resistance, like if something is braking...

I was inspecting X and Y axis belts thought they were loose, because of 3D printing issues (attached) to find that its the stepper motors are behind this.

are these damaged stepper motors ?]]> Negus Mechanics Fri, 21 Oct 2022 18:44:49 -0400 https://reprap.org/forum/read.php?14,890439,890439#msg-890439 Closed-loop belt differential actuator (1 reply) https://reprap.org/forum/read.php?14,890439,890439#msg-890439
Assumptions:
  • Static plate with two motors with timing pulleys ( A, B ) and two idlers;
  • Moving plate with two idlers;
  • Closed-loop belt;
  • Moving plate is constrained in single axis.

[attachment 119722 DifferentialClosedBeltActuator__Linear.png]

This system has several modes of operation based on the difference of rotational speeds of motors.

1. If A and B have the same angular speed (same RPM if pulleys have same number of teeth), then moving plate position is not changed, belt just runs through the loop. This is a useless mode.

2. If one pulley is spinning, while the other is blocked - this is a simple block and tackle mechanism, so the moving plate will travel for a half of pulley circumference.

3. If pulleys are spinning in the same direction, but with the small difference in angular speeds - the amount of belt passed through the each side will be slightly different and the moving plate will move the half of this difference.
For example, the GT2 40 teeth pulley on motor A will move 80mm of the belt, while the same pulley on motor B will spin faster and move 82mm of the belt (one tooth more). This will take 2mm of belt from one side and push it to another, and this will cause the moving plate to change its position for 1mm. The system acts as a reducer - the movement of 82mm of belt is transformed to 1mm.

4. Last mode is when the pulleys spinning in opposite directions - this will cause the loop halves to change their lengths faster that for 2nd mode, but limited with the sum of angular speeds of both pulleys.

Result:
In such configuration this linear actuator can provide reduction rates (from pulley surface speed to moving plate speed) from 1 to "infinity".



Also it can be reworked to the rotational joint with the same properties:

[attachment 119723 DifferentialClosedBeltActuator__Rotational.png]


Pulleys can be arranged for fixed reduction rates and be driven with a single motor with the same RPM, but with different amount of teeth (eg 40 and 41).

I did a version with coaxial pulleys with moving idlers in the perpendicular plane to join two stacking halves of the drive, but it is a hell to create a drawing for it. I'll try if it will gather some interest.]]> grytole Mechanics Mon, 05 Sep 2022 05:26:12 -0400 https://reprap.org/forum/read.php?14,889612,889612#msg-889612 Quality Parts (8 replies) https://reprap.org/forum/read.php?14,889612,889612#msg-889612
I have an Anet A8, and have been having trouble finding consistent quality components.

I really don't want this post to become a venue to "bash component suppliers or components" If you don't have something positive to contribute, Please don't post.

I recently replaced the linear bearings with Ingus polymer bushings. I absolutely loved them. They were quiet and ultra smooth. They were supposed to be self lubricating. I found that they tended to run less and less smoothly with time/use. Silicon spray would lube them for a print or two, and then they would be dried out again.(running rougher/ noisier) I then tried a product called Super Lube (absolutely awesome stuff) Super lube would keep the printer running smoothly for a week at a time, with heavy use. It just seems to me that the polymer bushings get very loose fairly quickly, causing print artifacts. Link to Super Lube - [www.amazon.com]

I have now replaced the bushings with standard Chinese 8 x 15 x 25 mm linear bearings. Out of the box when I slide them onto the shafts, they seem to grind. I very carefully worked super lube into the new bearings, and installed them. They are quite noisy, and loose. They slide in a very inconsistent manner. Has any one found a quality supplier for bearings/bushings? If so, what brand and size? where were they purchased? What did you notice about the operating characteristics/performance?

Does any one have any results for other components that they would like to share?]]> Mr Kroll Mechanics Sun, 09 Apr 2023 14:16:52 -0400 https://reprap.org/forum/read.php?14,888824,888824#msg-888824 Is this ringing? - What is causing this lines? (1 reply) https://reprap.org/forum/read.php?14,888824,888824#msg-888824 As you can see in the pictures below there is both horizontal and vertical lines appearing on all of the axis
Notice that horizontal lines only occurs below and above of the letters
I don’t think it is ringing because there is no artifact of ringing around letters so no echo
I have tuned x-y steps ( didn’t tuned z yet ) as well as e steps
Acceleration has been tuned to reduce the ringing ( and if you ask me it worked )
My jerk is set to 10 I have reduced it to 1 and that vertical lines doubled than I set it to 20 now I have shaper edges but still same lines same places

Like I said I have changed mb drivers and marlin so this is probably a mechanical issue
Or maybe slicer settings?

What could be the reason of this
And how can I solve this

A note
This issue been appearing way before I have changed parts this is why I think it is mechanical]]> AfroPsycho Mechanics Tue, 29 Mar 2022 12:28:33 -0400 https://reprap.org/forum/read.php?14,887928,887928#msg-887928 Reducing weight on Cartesian printer X and Y axis (9 replies) https://reprap.org/forum/read.php?14,887928,887928#msg-887928
If the bed weight is generally more than the hotend how much impact does reducing the weight of the hotend have? How much of an impact does bed weight have on ringing or is that more of an issue related to the actual hot end swinging around and not the print surface.

If ringing is also an issue due to the weight of the bed are their designs that are aiming toward reducing bed weight? Like lightweight heatbed/print-surface/plate.
With the amount of mass on the bed I don't think I could decrease it's weight to be less than a modest hotend/extruder combo. But the bed could be driven by a bigger stepper, would a large stepper and a tight belt overcome any ringing that could be presented by the weight of the bed?


Would the alternative be to just use a core XY or delta design instead and deal with weight in one area.]]> valsk Mechanics Wed, 23 Feb 2022 14:14:08 -0500 https://reprap.org/forum/read.php?14,887196,887196#msg-887196 CoreXY Design Alternative (16 replies) https://reprap.org/forum/read.php?14,887196,887196#msg-887196
I'm by no means an expert in understanding the various tradeoffs involved in the design, so I'm assuming I'm missing something, but it seems like a much simpler design is possible. You can see what I've come up with so far here (link). The design is still far from complete, and the stuff that is "complete" is still pretty rough around the edges (e.g., I may cut the number of motors in half and drive both sides of the cross-bar with a single motor, but the mass of the cross-bars may prevent that from being an option). But the basic idea is there, which is to have the gantry connected to two cross-bars instead of just one with motors connected directly to the cross-bars with belts.

Ultimately, my question is twofold:
  1. Why are there no large volume 3D printers?
  2. What am I missing? Why is something similar to my design (or at least something that avoids the complexity involved with the belts) not being used already? Certainly, I'm not the first to think of it. So I must be missing a design decision that precluded its use, but I'm not sure what it is.
]]> tlewis3348 Mechanics Sun, 14 Aug 2022 10:18:00 -0400 https://reprap.org/forum/read.php?14,887179,887179#msg-887179 Markforged vs. Stratasys Kinematics (no replies) https://reprap.org/forum/read.php?14,887179,887179#msg-887179
MarkForged:

[user-images.githubusercontent.com]


Stratasys:

[ibb.co]

[ibb.co]

[ibb.co]


Which one is more effective design as far as both maintaining precision on long 24 hour prints and maintaining precision with minimal binding.

Markforged works well only because the built volume is 320mm x 150mm and it’s a Bowden design, so the distance on the X is short, and even then they advise to check the belt tension every 800 hours.

If we used MF design on a something like 350x 250 mm with direct drive, then compared it to the Stratasys kinematics it does becomes less effective, the question is by how much.

Is Stratasys more efficient? Sure it has longer belts and more idlers, so in theory each idler would increase the level of backlash, but to me binding is as important as back lash so with Markforged we are more prone to binding but maybe less backlash.

Would either of the two designs work better if the axis with extruder motor was the longest one in a 350x250 design?

Then we have the issue of synchronization on X,Y motors, Would Stratasys benefit from using an axis motor on the extruder axis so in this case we have the Y axis with it's own motor on in and not stationery in the corner, so we eliminate the issue of synchronization?

With Markforged having the X aid the Y with syncro in moving up and down is integral to maintain less binding. What about Stratasys, I’m straggling to understand if having the Y stationery and also is synchronization is necessary in aiding the X to move up and down vs. Markfoged design?

Cheers.]]> lightyears101 Mechanics Tue, 23 Nov 2021 18:40:14 -0500 https://reprap.org/forum/read.php?14,887165,887165#msg-887165 Scraping flexible magnetic sheet flat? (no replies) https://reprap.org/forum/read.php?14,887165,887165#msg-887165
I am aware of scraping as a technique for making metal flat.

The top of the soft magnetic sheet is really my reference surface.

It occurs to me that scraping might be a reasonable technique for making the top of the magnetic sheet flat, similar to what can be done with cast iron on big machines.

I could mount a dial indicator to the carriage and drive it around the bed or mount a probe and use Bed Mesh Visualizer, and scrape off the high spots, until it's all flat.

If you have used any technique to attempt to make the top of a flexible magnetic sheet a flat reference surface, I'd be interested in hearing your results. Thanks!]]> mcdanlj Mechanics Tue, 23 Nov 2021 08:29:06 -0500